2543 lines
70 KiB
Diff
2543 lines
70 KiB
Diff
commit fe512819010f71694384621b34ec32f8be678bbb
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Author: Michael S. Tsirkin <mst@redhat.com>
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Date: Thu Jan 14 06:17:27 2010 +0000
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vhost_net: a kernel-level virtio server
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What it is: vhost net is a character device that can be used to reduce
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the number of system calls involved in virtio networking.
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Existing virtio net code is used in the guest without modification.
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There's similarity with vringfd, with some differences and reduced scope
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- uses eventfd for signalling
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- structures can be moved around in memory at any time (good for
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migration, bug work-arounds in userspace)
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- write logging is supported (good for migration)
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- support memory table and not just an offset (needed for kvm)
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common virtio related code has been put in a separate file vhost.c and
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can be made into a separate module if/when more backends appear. I used
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Rusty's lguest.c as the source for developing this part : this supplied
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me with witty comments I wouldn't be able to write myself.
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What it is not: vhost net is not a bus, and not a generic new system
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call. No assumptions are made on how guest performs hypercalls.
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Userspace hypervisors are supported as well as kvm.
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How it works: Basically, we connect virtio frontend (configured by
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userspace) to a backend. The backend could be a network device, or a tap
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device. Backend is also configured by userspace, including vlan/mac
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etc.
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Status: This works for me, and I haven't see any crashes.
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Compared to userspace, people reported improved latency (as I save up to
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4 system calls per packet), as well as better bandwidth and CPU
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utilization.
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Features that I plan to look at in the future:
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- mergeable buffers
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- zero copy
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- scalability tuning: figure out the best threading model to use
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Note on RCU usage (this is also documented in vhost.h, near
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private_pointer which is the value protected by this variant of RCU):
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what is happening is that the rcu_dereference() is being used in a
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workqueue item. The role of rcu_read_lock() is taken on by the start of
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execution of the workqueue item, of rcu_read_unlock() by the end of
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execution of the workqueue item, and of synchronize_rcu() by
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flush_workqueue()/flush_work(). In the future we might need to apply
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some gcc attribute or sparse annotation to the function passed to
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INIT_WORK(). Paul's ack below is for this RCU usage.
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(Includes fixes by Alan Cox <alan@linux.intel.com>,
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David L Stevens <dlstevens@us.ibm.com>,
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Chris Wright <chrisw@redhat.com>)
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Acked-by: Rusty Russell <rusty@rustcorp.com.au>
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Acked-by: Arnd Bergmann <arnd@arndb.de>
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Acked-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
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Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Signed-off-by: David S. Miller <davem@davemloft.net>
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(cherry picked from commit 3a4d5c94e959359ece6d6b55045c3f046677f55c)
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commit 7b6a72cf7f96d5c75ce91e826372c6d488ac1e18
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Author: Michael S. Tsirkin <mst@redhat.com>
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Date: Thu Jan 14 06:17:18 2010 +0000
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mm: export use_mm/unuse_mm to modules
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vhost net module wants to do copy to/from user from a kernel thread,
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which needs use_mm. Export it to modules.
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Acked-by: Andrea Arcangeli <aarcange@redhat.com>
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Acked-by: Andrew Morton <akpm@linux-foundation.org>
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Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Signed-off-by: David S. Miller <davem@davemloft.net>
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(cherry picked from commit 5da779c34ccff5e1e617892b6c8bd8260fb1f04c)
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commit 24f4237bf319b27e7c28544425e2cd52abe9332c
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Author: Michael S. Tsirkin <mst@redhat.com>
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Date: Thu Jan 14 06:17:09 2010 +0000
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tun: export underlying socket
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Tun device looks similar to a packet socket
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in that both pass complete frames from/to userspace.
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This patch fills in enough fields in the socket underlying tun driver
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to support sendmsg/recvmsg operations, and message flags
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MSG_TRUNC and MSG_DONTWAIT, and exports access to this socket
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to modules. Regular read/write behaviour is unchanged.
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This way, code using raw sockets to inject packets
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into a physical device, can support injecting
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packets into host network stack almost without modification.
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First user of this interface will be vhost virtualization
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accelerator.
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Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
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Acked-by: David S. Miller <davem@davemloft.net>
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Signed-off-by: David S. Miller <davem@davemloft.net>
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(cherry picked from commit 05c2828c72c4eabf62376adfe27bd24797621f62)
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diff --git a/MAINTAINERS b/MAINTAINERS
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index 3f59162..0b4c8be 100644
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--- a/MAINTAINERS
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+++ b/MAINTAINERS
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@@ -5795,6 +5795,15 @@ S: Maintained
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F: Documentation/filesystems/vfat.txt
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F: fs/fat/
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+VIRTIO HOST (VHOST)
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+M: "Michael S. Tsirkin" <mst@redhat.com>
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+L: kvm@vger.kernel.org
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+L: virtualization@lists.osdl.org
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+L: netdev@vger.kernel.org
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+S: Maintained
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+F: drivers/vhost/
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+F: include/linux/vhost.h
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+
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VIA RHINE NETWORK DRIVER
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M: Roger Luethi <rl@hellgate.ch>
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S: Maintained
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diff --git a/arch/ia64/kvm/Kconfig b/arch/ia64/kvm/Kconfig
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index ef3e7be..01c7579 100644
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--- a/arch/ia64/kvm/Kconfig
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+++ b/arch/ia64/kvm/Kconfig
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@@ -47,6 +47,7 @@ config KVM_INTEL
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Provides support for KVM on Itanium 2 processors equipped with the VT
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extensions.
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+source drivers/vhost/Kconfig
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source drivers/virtio/Kconfig
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endif # VIRTUALIZATION
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diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig
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index 07703f7..e28841f 100644
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--- a/arch/powerpc/kvm/Kconfig
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+++ b/arch/powerpc/kvm/Kconfig
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@@ -75,6 +75,7 @@ config KVM_E500
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If unsure, say N.
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+source drivers/vhost/Kconfig
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source drivers/virtio/Kconfig
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endif # VIRTUALIZATION
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diff --git a/arch/s390/kvm/Kconfig b/arch/s390/kvm/Kconfig
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index 6ee55ae..a725158 100644
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--- a/arch/s390/kvm/Kconfig
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+++ b/arch/s390/kvm/Kconfig
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@@ -35,6 +35,7 @@ config KVM
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# OK, it's a little counter-intuitive to do this, but it puts it neatly under
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# the virtualization menu.
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+source drivers/vhost/Kconfig
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source drivers/virtio/Kconfig
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endif # VIRTUALIZATION
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diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
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index 4cd4983..3c4d010 100644
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--- a/arch/x86/kvm/Kconfig
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+++ b/arch/x86/kvm/Kconfig
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@@ -65,6 +65,7 @@ config KVM_AMD
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# OK, it's a little counter-intuitive to do this, but it puts it neatly under
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# the virtualization menu.
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+source drivers/vhost/Kconfig
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source drivers/lguest/Kconfig
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source drivers/virtio/Kconfig
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diff --git a/drivers/Makefile b/drivers/Makefile
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index 6ee53c7..81e3659 100644
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--- a/drivers/Makefile
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+++ b/drivers/Makefile
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@@ -106,6 +106,7 @@ obj-$(CONFIG_HID) += hid/
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obj-$(CONFIG_PPC_PS3) += ps3/
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obj-$(CONFIG_OF) += of/
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obj-$(CONFIG_SSB) += ssb/
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+obj-$(CONFIG_VHOST_NET) += vhost/
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obj-$(CONFIG_VLYNQ) += vlynq/
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obj-$(CONFIG_STAGING) += staging/
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obj-y += platform/
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diff --git a/drivers/net/tun.c b/drivers/net/tun.c
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index 2834a01..5adb3d1 100644
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--- a/drivers/net/tun.c
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+++ b/drivers/net/tun.c
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@@ -144,6 +144,7 @@ static int tun_attach(struct tun_struct *tun, struct file *file)
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err = 0;
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tfile->tun = tun;
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tun->tfile = tfile;
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+ tun->socket.file = file;
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dev_hold(tun->dev);
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sock_hold(tun->socket.sk);
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atomic_inc(&tfile->count);
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@@ -158,6 +159,7 @@ static void __tun_detach(struct tun_struct *tun)
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/* Detach from net device */
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netif_tx_lock_bh(tun->dev);
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tun->tfile = NULL;
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+ tun->socket.file = NULL;
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netif_tx_unlock_bh(tun->dev);
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/* Drop read queue */
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@@ -387,7 +389,8 @@ static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
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/* Notify and wake up reader process */
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if (tun->flags & TUN_FASYNC)
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kill_fasync(&tun->fasync, SIGIO, POLL_IN);
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- wake_up_interruptible(&tun->socket.wait);
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+ wake_up_interruptible_poll(&tun->socket.wait, POLLIN |
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+ POLLRDNORM | POLLRDBAND);
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return NETDEV_TX_OK;
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drop:
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@@ -743,7 +746,7 @@ static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
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len = min_t(int, skb->len, len);
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skb_copy_datagram_const_iovec(skb, 0, iv, total, len);
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- total += len;
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+ total += skb->len;
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tun->dev->stats.tx_packets++;
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tun->dev->stats.tx_bytes += len;
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@@ -751,34 +754,23 @@ static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
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return total;
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}
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-static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
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- unsigned long count, loff_t pos)
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+static ssize_t tun_do_read(struct tun_struct *tun,
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+ struct kiocb *iocb, const struct iovec *iv,
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+ ssize_t len, int noblock)
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{
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- struct file *file = iocb->ki_filp;
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- struct tun_file *tfile = file->private_data;
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- struct tun_struct *tun = __tun_get(tfile);
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DECLARE_WAITQUEUE(wait, current);
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struct sk_buff *skb;
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- ssize_t len, ret = 0;
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-
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- if (!tun)
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- return -EBADFD;
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+ ssize_t ret = 0;
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DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
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- len = iov_length(iv, count);
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- if (len < 0) {
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- ret = -EINVAL;
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- goto out;
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- }
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-
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add_wait_queue(&tun->socket.wait, &wait);
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while (len) {
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current->state = TASK_INTERRUPTIBLE;
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/* Read frames from the queue */
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if (!(skb=skb_dequeue(&tun->socket.sk->sk_receive_queue))) {
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- if (file->f_flags & O_NONBLOCK) {
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+ if (noblock) {
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ret = -EAGAIN;
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break;
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}
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@@ -805,6 +797,27 @@ static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
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current->state = TASK_RUNNING;
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remove_wait_queue(&tun->socket.wait, &wait);
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+ return ret;
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+}
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+
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+static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
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+ unsigned long count, loff_t pos)
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+{
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+ struct file *file = iocb->ki_filp;
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+ struct tun_file *tfile = file->private_data;
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+ struct tun_struct *tun = __tun_get(tfile);
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+ ssize_t len, ret;
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+
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+ if (!tun)
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+ return -EBADFD;
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+ len = iov_length(iv, count);
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+ if (len < 0) {
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+ ret = -EINVAL;
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+ goto out;
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+ }
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+
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+ ret = tun_do_read(tun, iocb, iv, len, file->f_flags & O_NONBLOCK);
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+ ret = min_t(ssize_t, ret, len);
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out:
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tun_put(tun);
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return ret;
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@@ -847,7 +860,8 @@ static void tun_sock_write_space(struct sock *sk)
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return;
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if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
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- wake_up_interruptible_sync(sk->sk_sleep);
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+ wake_up_interruptible_sync_poll(sk->sk_sleep, POLLOUT |
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+ POLLWRNORM | POLLWRBAND);
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tun = tun_sk(sk)->tun;
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kill_fasync(&tun->fasync, SIGIO, POLL_OUT);
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@@ -858,6 +872,37 @@ static void tun_sock_destruct(struct sock *sk)
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free_netdev(tun_sk(sk)->tun->dev);
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}
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+static int tun_sendmsg(struct kiocb *iocb, struct socket *sock,
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+ struct msghdr *m, size_t total_len)
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+{
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+ struct tun_struct *tun = container_of(sock, struct tun_struct, socket);
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+ return tun_get_user(tun, m->msg_iov, total_len,
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+ m->msg_flags & MSG_DONTWAIT);
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+}
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+
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+static int tun_recvmsg(struct kiocb *iocb, struct socket *sock,
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+ struct msghdr *m, size_t total_len,
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+ int flags)
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+{
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+ struct tun_struct *tun = container_of(sock, struct tun_struct, socket);
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+ int ret;
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+ if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))
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+ return -EINVAL;
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+ ret = tun_do_read(tun, iocb, m->msg_iov, total_len,
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+ flags & MSG_DONTWAIT);
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+ if (ret > total_len) {
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+ m->msg_flags |= MSG_TRUNC;
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+ ret = flags & MSG_TRUNC ? ret : total_len;
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+ }
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+ return ret;
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+}
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+
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+/* Ops structure to mimic raw sockets with tun */
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+static const struct proto_ops tun_socket_ops = {
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+ .sendmsg = tun_sendmsg,
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+ .recvmsg = tun_recvmsg,
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+};
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+
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static struct proto tun_proto = {
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.name = "tun",
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.owner = THIS_MODULE,
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@@ -986,6 +1031,7 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
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goto err_free_dev;
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init_waitqueue_head(&tun->socket.wait);
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+ tun->socket.ops = &tun_socket_ops;
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sock_init_data(&tun->socket, sk);
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sk->sk_write_space = tun_sock_write_space;
|
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sk->sk_sndbuf = INT_MAX;
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@@ -1525,6 +1571,23 @@ static void tun_cleanup(void)
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rtnl_link_unregister(&tun_link_ops);
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}
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|
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+/* Get an underlying socket object from tun file. Returns error unless file is
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+ * attached to a device. The returned object works like a packet socket, it
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+ * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
|
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+ * holding a reference to the file for as long as the socket is in use. */
|
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+struct socket *tun_get_socket(struct file *file)
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+{
|
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+ struct tun_struct *tun;
|
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+ if (file->f_op != &tun_fops)
|
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+ return ERR_PTR(-EINVAL);
|
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+ tun = tun_get(file);
|
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+ if (!tun)
|
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+ return ERR_PTR(-EBADFD);
|
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+ tun_put(tun);
|
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+ return &tun->socket;
|
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+}
|
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+EXPORT_SYMBOL_GPL(tun_get_socket);
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+
|
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module_init(tun_init);
|
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module_exit(tun_cleanup);
|
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MODULE_DESCRIPTION(DRV_DESCRIPTION);
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|
diff --git a/drivers/vhost/Kconfig b/drivers/vhost/Kconfig
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new file mode 100644
|
|
index 0000000..9f409f4
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--- /dev/null
|
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+++ b/drivers/vhost/Kconfig
|
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@@ -0,0 +1,11 @@
|
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+config VHOST_NET
|
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+ tristate "Host kernel accelerator for virtio net (EXPERIMENTAL)"
|
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+ depends on NET && EVENTFD && EXPERIMENTAL
|
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+ ---help---
|
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+ This kernel module can be loaded in host kernel to accelerate
|
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+ guest networking with virtio_net. Not to be confused with virtio_net
|
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+ module itself which needs to be loaded in guest kernel.
|
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+
|
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+ To compile this driver as a module, choose M here: the module will
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+ be called vhost_net.
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+
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diff --git a/drivers/vhost/Makefile b/drivers/vhost/Makefile
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new file mode 100644
|
|
index 0000000..72dd020
|
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--- /dev/null
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+++ b/drivers/vhost/Makefile
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@@ -0,0 +1,2 @@
|
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+obj-$(CONFIG_VHOST_NET) += vhost_net.o
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+vhost_net-y := vhost.o net.o
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diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
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new file mode 100644
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index 0000000..4c89283
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--- /dev/null
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+++ b/drivers/vhost/net.c
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@@ -0,0 +1,661 @@
|
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+/* Copyright (C) 2009 Red Hat, Inc.
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+ * Author: Michael S. Tsirkin <mst@redhat.com>
|
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+ *
|
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+ * This work is licensed under the terms of the GNU GPL, version 2.
|
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+ *
|
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+ * virtio-net server in host kernel.
|
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+ */
|
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+
|
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+#include <linux/compat.h>
|
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+#include <linux/eventfd.h>
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+#include <linux/vhost.h>
|
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+#include <linux/virtio_net.h>
|
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+#include <linux/mmu_context.h>
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+#include <linux/miscdevice.h>
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+#include <linux/module.h>
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+#include <linux/mutex.h>
|
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+#include <linux/workqueue.h>
|
|
+#include <linux/rcupdate.h>
|
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+#include <linux/file.h>
|
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+
|
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+#include <linux/net.h>
|
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+#include <linux/if_packet.h>
|
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+#include <linux/if_arp.h>
|
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+#include <linux/if_tun.h>
|
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+
|
|
+#include <net/sock.h>
|
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+
|
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+#include "vhost.h"
|
|
+
|
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+/* Max number of bytes transferred before requeueing the job.
|
|
+ * Using this limit prevents one virtqueue from starving others. */
|
|
+#define VHOST_NET_WEIGHT 0x80000
|
|
+
|
|
+enum {
|
|
+ VHOST_NET_VQ_RX = 0,
|
|
+ VHOST_NET_VQ_TX = 1,
|
|
+ VHOST_NET_VQ_MAX = 2,
|
|
+};
|
|
+
|
|
+enum vhost_net_poll_state {
|
|
+ VHOST_NET_POLL_DISABLED = 0,
|
|
+ VHOST_NET_POLL_STARTED = 1,
|
|
+ VHOST_NET_POLL_STOPPED = 2,
|
|
+};
|
|
+
|
|
+struct vhost_net {
|
|
+ struct vhost_dev dev;
|
|
+ struct vhost_virtqueue vqs[VHOST_NET_VQ_MAX];
|
|
+ struct vhost_poll poll[VHOST_NET_VQ_MAX];
|
|
+ /* Tells us whether we are polling a socket for TX.
|
|
+ * We only do this when socket buffer fills up.
|
|
+ * Protected by tx vq lock. */
|
|
+ enum vhost_net_poll_state tx_poll_state;
|
|
+};
|
|
+
|
|
+/* Pop first len bytes from iovec. Return number of segments used. */
|
|
+static int move_iovec_hdr(struct iovec *from, struct iovec *to,
|
|
+ size_t len, int iov_count)
|
|
+{
|
|
+ int seg = 0;
|
|
+ size_t size;
|
|
+ while (len && seg < iov_count) {
|
|
+ size = min(from->iov_len, len);
|
|
+ to->iov_base = from->iov_base;
|
|
+ to->iov_len = size;
|
|
+ from->iov_len -= size;
|
|
+ from->iov_base += size;
|
|
+ len -= size;
|
|
+ ++from;
|
|
+ ++to;
|
|
+ ++seg;
|
|
+ }
|
|
+ return seg;
|
|
+}
|
|
+
|
|
+/* Caller must have TX VQ lock */
|
|
+static void tx_poll_stop(struct vhost_net *net)
|
|
+{
|
|
+ if (likely(net->tx_poll_state != VHOST_NET_POLL_STARTED))
|
|
+ return;
|
|
+ vhost_poll_stop(net->poll + VHOST_NET_VQ_TX);
|
|
+ net->tx_poll_state = VHOST_NET_POLL_STOPPED;
|
|
+}
|
|
+
|
|
+/* Caller must have TX VQ lock */
|
|
+static void tx_poll_start(struct vhost_net *net, struct socket *sock)
|
|
+{
|
|
+ if (unlikely(net->tx_poll_state != VHOST_NET_POLL_STOPPED))
|
|
+ return;
|
|
+ vhost_poll_start(net->poll + VHOST_NET_VQ_TX, sock->file);
|
|
+ net->tx_poll_state = VHOST_NET_POLL_STARTED;
|
|
+}
|
|
+
|
|
+/* Expects to be always run from workqueue - which acts as
|
|
+ * read-size critical section for our kind of RCU. */
|
|
+static void handle_tx(struct vhost_net *net)
|
|
+{
|
|
+ struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_TX];
|
|
+ unsigned head, out, in, s;
|
|
+ struct msghdr msg = {
|
|
+ .msg_name = NULL,
|
|
+ .msg_namelen = 0,
|
|
+ .msg_control = NULL,
|
|
+ .msg_controllen = 0,
|
|
+ .msg_iov = vq->iov,
|
|
+ .msg_flags = MSG_DONTWAIT,
|
|
+ };
|
|
+ size_t len, total_len = 0;
|
|
+ int err, wmem;
|
|
+ size_t hdr_size;
|
|
+ struct socket *sock = rcu_dereference(vq->private_data);
|
|
+ if (!sock)
|
|
+ return;
|
|
+
|
|
+ wmem = atomic_read(&sock->sk->sk_wmem_alloc);
|
|
+ if (wmem >= sock->sk->sk_sndbuf)
|
|
+ return;
|
|
+
|
|
+ use_mm(net->dev.mm);
|
|
+ mutex_lock(&vq->mutex);
|
|
+ vhost_disable_notify(vq);
|
|
+
|
|
+ if (wmem < sock->sk->sk_sndbuf * 2)
|
|
+ tx_poll_stop(net);
|
|
+ hdr_size = vq->hdr_size;
|
|
+
|
|
+ for (;;) {
|
|
+ head = vhost_get_vq_desc(&net->dev, vq, vq->iov,
|
|
+ ARRAY_SIZE(vq->iov),
|
|
+ &out, &in,
|
|
+ NULL, NULL);
|
|
+ /* Nothing new? Wait for eventfd to tell us they refilled. */
|
|
+ if (head == vq->num) {
|
|
+ wmem = atomic_read(&sock->sk->sk_wmem_alloc);
|
|
+ if (wmem >= sock->sk->sk_sndbuf * 3 / 4) {
|
|
+ tx_poll_start(net, sock);
|
|
+ set_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
|
|
+ break;
|
|
+ }
|
|
+ if (unlikely(vhost_enable_notify(vq))) {
|
|
+ vhost_disable_notify(vq);
|
|
+ continue;
|
|
+ }
|
|
+ break;
|
|
+ }
|
|
+ if (in) {
|
|
+ vq_err(vq, "Unexpected descriptor format for TX: "
|
|
+ "out %d, int %d\n", out, in);
|
|
+ break;
|
|
+ }
|
|
+ /* Skip header. TODO: support TSO. */
|
|
+ s = move_iovec_hdr(vq->iov, vq->hdr, hdr_size, out);
|
|
+ msg.msg_iovlen = out;
|
|
+ len = iov_length(vq->iov, out);
|
|
+ /* Sanity check */
|
|
+ if (!len) {
|
|
+ vq_err(vq, "Unexpected header len for TX: "
|
|
+ "%zd expected %zd\n",
|
|
+ iov_length(vq->hdr, s), hdr_size);
|
|
+ break;
|
|
+ }
|
|
+ /* TODO: Check specific error and bomb out unless ENOBUFS? */
|
|
+ err = sock->ops->sendmsg(NULL, sock, &msg, len);
|
|
+ if (unlikely(err < 0)) {
|
|
+ vhost_discard_vq_desc(vq);
|
|
+ tx_poll_start(net, sock);
|
|
+ break;
|
|
+ }
|
|
+ if (err != len)
|
|
+ pr_err("Truncated TX packet: "
|
|
+ " len %d != %zd\n", err, len);
|
|
+ vhost_add_used_and_signal(&net->dev, vq, head, 0);
|
|
+ total_len += len;
|
|
+ if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
|
|
+ vhost_poll_queue(&vq->poll);
|
|
+ break;
|
|
+ }
|
|
+ }
|
|
+
|
|
+ mutex_unlock(&vq->mutex);
|
|
+ unuse_mm(net->dev.mm);
|
|
+}
|
|
+
|
|
+/* Expects to be always run from workqueue - which acts as
|
|
+ * read-size critical section for our kind of RCU. */
|
|
+static void handle_rx(struct vhost_net *net)
|
|
+{
|
|
+ struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_RX];
|
|
+ unsigned head, out, in, log, s;
|
|
+ struct vhost_log *vq_log;
|
|
+ struct msghdr msg = {
|
|
+ .msg_name = NULL,
|
|
+ .msg_namelen = 0,
|
|
+ .msg_control = NULL, /* FIXME: get and handle RX aux data. */
|
|
+ .msg_controllen = 0,
|
|
+ .msg_iov = vq->iov,
|
|
+ .msg_flags = MSG_DONTWAIT,
|
|
+ };
|
|
+
|
|
+ struct virtio_net_hdr hdr = {
|
|
+ .flags = 0,
|
|
+ .gso_type = VIRTIO_NET_HDR_GSO_NONE
|
|
+ };
|
|
+
|
|
+ size_t len, total_len = 0;
|
|
+ int err;
|
|
+ size_t hdr_size;
|
|
+ struct socket *sock = rcu_dereference(vq->private_data);
|
|
+ if (!sock || skb_queue_empty(&sock->sk->sk_receive_queue))
|
|
+ return;
|
|
+
|
|
+ use_mm(net->dev.mm);
|
|
+ mutex_lock(&vq->mutex);
|
|
+ vhost_disable_notify(vq);
|
|
+ hdr_size = vq->hdr_size;
|
|
+
|
|
+ vq_log = unlikely(vhost_has_feature(&net->dev, VHOST_F_LOG_ALL)) ?
|
|
+ vq->log : NULL;
|
|
+
|
|
+ for (;;) {
|
|
+ head = vhost_get_vq_desc(&net->dev, vq, vq->iov,
|
|
+ ARRAY_SIZE(vq->iov),
|
|
+ &out, &in,
|
|
+ vq_log, &log);
|
|
+ /* OK, now we need to know about added descriptors. */
|
|
+ if (head == vq->num) {
|
|
+ if (unlikely(vhost_enable_notify(vq))) {
|
|
+ /* They have slipped one in as we were
|
|
+ * doing that: check again. */
|
|
+ vhost_disable_notify(vq);
|
|
+ continue;
|
|
+ }
|
|
+ /* Nothing new? Wait for eventfd to tell us
|
|
+ * they refilled. */
|
|
+ break;
|
|
+ }
|
|
+ /* We don't need to be notified again. */
|
|
+ if (out) {
|
|
+ vq_err(vq, "Unexpected descriptor format for RX: "
|
|
+ "out %d, int %d\n",
|
|
+ out, in);
|
|
+ break;
|
|
+ }
|
|
+ /* Skip header. TODO: support TSO/mergeable rx buffers. */
|
|
+ s = move_iovec_hdr(vq->iov, vq->hdr, hdr_size, in);
|
|
+ msg.msg_iovlen = in;
|
|
+ len = iov_length(vq->iov, in);
|
|
+ /* Sanity check */
|
|
+ if (!len) {
|
|
+ vq_err(vq, "Unexpected header len for RX: "
|
|
+ "%zd expected %zd\n",
|
|
+ iov_length(vq->hdr, s), hdr_size);
|
|
+ break;
|
|
+ }
|
|
+ err = sock->ops->recvmsg(NULL, sock, &msg,
|
|
+ len, MSG_DONTWAIT | MSG_TRUNC);
|
|
+ /* TODO: Check specific error and bomb out unless EAGAIN? */
|
|
+ if (err < 0) {
|
|
+ vhost_discard_vq_desc(vq);
|
|
+ break;
|
|
+ }
|
|
+ /* TODO: Should check and handle checksum. */
|
|
+ if (err > len) {
|
|
+ pr_err("Discarded truncated rx packet: "
|
|
+ " len %d > %zd\n", err, len);
|
|
+ vhost_discard_vq_desc(vq);
|
|
+ continue;
|
|
+ }
|
|
+ len = err;
|
|
+ err = memcpy_toiovec(vq->hdr, (unsigned char *)&hdr, hdr_size);
|
|
+ if (err) {
|
|
+ vq_err(vq, "Unable to write vnet_hdr at addr %p: %d\n",
|
|
+ vq->iov->iov_base, err);
|
|
+ break;
|
|
+ }
|
|
+ len += hdr_size;
|
|
+ vhost_add_used_and_signal(&net->dev, vq, head, len);
|
|
+ if (unlikely(vq_log))
|
|
+ vhost_log_write(vq, vq_log, log, len);
|
|
+ total_len += len;
|
|
+ if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
|
|
+ vhost_poll_queue(&vq->poll);
|
|
+ break;
|
|
+ }
|
|
+ }
|
|
+
|
|
+ mutex_unlock(&vq->mutex);
|
|
+ unuse_mm(net->dev.mm);
|
|
+}
|
|
+
|
|
+static void handle_tx_kick(struct work_struct *work)
|
|
+{
|
|
+ struct vhost_virtqueue *vq;
|
|
+ struct vhost_net *net;
|
|
+ vq = container_of(work, struct vhost_virtqueue, poll.work);
|
|
+ net = container_of(vq->dev, struct vhost_net, dev);
|
|
+ handle_tx(net);
|
|
+}
|
|
+
|
|
+static void handle_rx_kick(struct work_struct *work)
|
|
+{
|
|
+ struct vhost_virtqueue *vq;
|
|
+ struct vhost_net *net;
|
|
+ vq = container_of(work, struct vhost_virtqueue, poll.work);
|
|
+ net = container_of(vq->dev, struct vhost_net, dev);
|
|
+ handle_rx(net);
|
|
+}
|
|
+
|
|
+static void handle_tx_net(struct work_struct *work)
|
|
+{
|
|
+ struct vhost_net *net;
|
|
+ net = container_of(work, struct vhost_net, poll[VHOST_NET_VQ_TX].work);
|
|
+ handle_tx(net);
|
|
+}
|
|
+
|
|
+static void handle_rx_net(struct work_struct *work)
|
|
+{
|
|
+ struct vhost_net *net;
|
|
+ net = container_of(work, struct vhost_net, poll[VHOST_NET_VQ_RX].work);
|
|
+ handle_rx(net);
|
|
+}
|
|
+
|
|
+static int vhost_net_open(struct inode *inode, struct file *f)
|
|
+{
|
|
+ struct vhost_net *n = kmalloc(sizeof *n, GFP_KERNEL);
|
|
+ int r;
|
|
+ if (!n)
|
|
+ return -ENOMEM;
|
|
+ n->vqs[VHOST_NET_VQ_TX].handle_kick = handle_tx_kick;
|
|
+ n->vqs[VHOST_NET_VQ_RX].handle_kick = handle_rx_kick;
|
|
+ r = vhost_dev_init(&n->dev, n->vqs, VHOST_NET_VQ_MAX);
|
|
+ if (r < 0) {
|
|
+ kfree(n);
|
|
+ return r;
|
|
+ }
|
|
+
|
|
+ vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, POLLOUT);
|
|
+ vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, POLLIN);
|
|
+ n->tx_poll_state = VHOST_NET_POLL_DISABLED;
|
|
+
|
|
+ f->private_data = n;
|
|
+
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+static void vhost_net_disable_vq(struct vhost_net *n,
|
|
+ struct vhost_virtqueue *vq)
|
|
+{
|
|
+ if (!vq->private_data)
|
|
+ return;
|
|
+ if (vq == n->vqs + VHOST_NET_VQ_TX) {
|
|
+ tx_poll_stop(n);
|
|
+ n->tx_poll_state = VHOST_NET_POLL_DISABLED;
|
|
+ } else
|
|
+ vhost_poll_stop(n->poll + VHOST_NET_VQ_RX);
|
|
+}
|
|
+
|
|
+static void vhost_net_enable_vq(struct vhost_net *n,
|
|
+ struct vhost_virtqueue *vq)
|
|
+{
|
|
+ struct socket *sock = vq->private_data;
|
|
+ if (!sock)
|
|
+ return;
|
|
+ if (vq == n->vqs + VHOST_NET_VQ_TX) {
|
|
+ n->tx_poll_state = VHOST_NET_POLL_STOPPED;
|
|
+ tx_poll_start(n, sock);
|
|
+ } else
|
|
+ vhost_poll_start(n->poll + VHOST_NET_VQ_RX, sock->file);
|
|
+}
|
|
+
|
|
+static struct socket *vhost_net_stop_vq(struct vhost_net *n,
|
|
+ struct vhost_virtqueue *vq)
|
|
+{
|
|
+ struct socket *sock;
|
|
+
|
|
+ mutex_lock(&vq->mutex);
|
|
+ sock = vq->private_data;
|
|
+ vhost_net_disable_vq(n, vq);
|
|
+ rcu_assign_pointer(vq->private_data, NULL);
|
|
+ mutex_unlock(&vq->mutex);
|
|
+ return sock;
|
|
+}
|
|
+
|
|
+static void vhost_net_stop(struct vhost_net *n, struct socket **tx_sock,
|
|
+ struct socket **rx_sock)
|
|
+{
|
|
+ *tx_sock = vhost_net_stop_vq(n, n->vqs + VHOST_NET_VQ_TX);
|
|
+ *rx_sock = vhost_net_stop_vq(n, n->vqs + VHOST_NET_VQ_RX);
|
|
+}
|
|
+
|
|
+static void vhost_net_flush_vq(struct vhost_net *n, int index)
|
|
+{
|
|
+ vhost_poll_flush(n->poll + index);
|
|
+ vhost_poll_flush(&n->dev.vqs[index].poll);
|
|
+}
|
|
+
|
|
+static void vhost_net_flush(struct vhost_net *n)
|
|
+{
|
|
+ vhost_net_flush_vq(n, VHOST_NET_VQ_TX);
|
|
+ vhost_net_flush_vq(n, VHOST_NET_VQ_RX);
|
|
+}
|
|
+
|
|
+static int vhost_net_release(struct inode *inode, struct file *f)
|
|
+{
|
|
+ struct vhost_net *n = f->private_data;
|
|
+ struct socket *tx_sock;
|
|
+ struct socket *rx_sock;
|
|
+
|
|
+ vhost_net_stop(n, &tx_sock, &rx_sock);
|
|
+ vhost_net_flush(n);
|
|
+ vhost_dev_cleanup(&n->dev);
|
|
+ if (tx_sock)
|
|
+ fput(tx_sock->file);
|
|
+ if (rx_sock)
|
|
+ fput(rx_sock->file);
|
|
+ /* We do an extra flush before freeing memory,
|
|
+ * since jobs can re-queue themselves. */
|
|
+ vhost_net_flush(n);
|
|
+ kfree(n);
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+static struct socket *get_raw_socket(int fd)
|
|
+{
|
|
+ struct {
|
|
+ struct sockaddr_ll sa;
|
|
+ char buf[MAX_ADDR_LEN];
|
|
+ } uaddr;
|
|
+ int uaddr_len = sizeof uaddr, r;
|
|
+ struct socket *sock = sockfd_lookup(fd, &r);
|
|
+ if (!sock)
|
|
+ return ERR_PTR(-ENOTSOCK);
|
|
+
|
|
+ /* Parameter checking */
|
|
+ if (sock->sk->sk_type != SOCK_RAW) {
|
|
+ r = -ESOCKTNOSUPPORT;
|
|
+ goto err;
|
|
+ }
|
|
+
|
|
+ r = sock->ops->getname(sock, (struct sockaddr *)&uaddr.sa,
|
|
+ &uaddr_len, 0);
|
|
+ if (r)
|
|
+ goto err;
|
|
+
|
|
+ if (uaddr.sa.sll_family != AF_PACKET) {
|
|
+ r = -EPFNOSUPPORT;
|
|
+ goto err;
|
|
+ }
|
|
+ return sock;
|
|
+err:
|
|
+ fput(sock->file);
|
|
+ return ERR_PTR(r);
|
|
+}
|
|
+
|
|
+static struct socket *get_tun_socket(int fd)
|
|
+{
|
|
+ struct file *file = fget(fd);
|
|
+ struct socket *sock;
|
|
+ if (!file)
|
|
+ return ERR_PTR(-EBADF);
|
|
+ sock = tun_get_socket(file);
|
|
+ if (IS_ERR(sock))
|
|
+ fput(file);
|
|
+ return sock;
|
|
+}
|
|
+
|
|
+static struct socket *get_socket(int fd)
|
|
+{
|
|
+ struct socket *sock;
|
|
+ /* special case to disable backend */
|
|
+ if (fd == -1)
|
|
+ return NULL;
|
|
+ sock = get_raw_socket(fd);
|
|
+ if (!IS_ERR(sock))
|
|
+ return sock;
|
|
+ sock = get_tun_socket(fd);
|
|
+ if (!IS_ERR(sock))
|
|
+ return sock;
|
|
+ return ERR_PTR(-ENOTSOCK);
|
|
+}
|
|
+
|
|
+static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
|
|
+{
|
|
+ struct socket *sock, *oldsock;
|
|
+ struct vhost_virtqueue *vq;
|
|
+ int r;
|
|
+
|
|
+ mutex_lock(&n->dev.mutex);
|
|
+ r = vhost_dev_check_owner(&n->dev);
|
|
+ if (r)
|
|
+ goto err;
|
|
+
|
|
+ if (index >= VHOST_NET_VQ_MAX) {
|
|
+ r = -ENOBUFS;
|
|
+ goto err;
|
|
+ }
|
|
+ vq = n->vqs + index;
|
|
+ mutex_lock(&vq->mutex);
|
|
+
|
|
+ /* Verify that ring has been setup correctly. */
|
|
+ if (!vhost_vq_access_ok(vq)) {
|
|
+ r = -EFAULT;
|
|
+ goto err;
|
|
+ }
|
|
+ sock = get_socket(fd);
|
|
+ if (IS_ERR(sock)) {
|
|
+ r = PTR_ERR(sock);
|
|
+ goto err;
|
|
+ }
|
|
+
|
|
+ /* start polling new socket */
|
|
+ oldsock = vq->private_data;
|
|
+ if (sock == oldsock)
|
|
+ goto done;
|
|
+
|
|
+ vhost_net_disable_vq(n, vq);
|
|
+ rcu_assign_pointer(vq->private_data, sock);
|
|
+ vhost_net_enable_vq(n, vq);
|
|
+ mutex_unlock(&vq->mutex);
|
|
+done:
|
|
+ if (oldsock) {
|
|
+ vhost_net_flush_vq(n, index);
|
|
+ fput(oldsock->file);
|
|
+ }
|
|
+err:
|
|
+ mutex_unlock(&n->dev.mutex);
|
|
+ return r;
|
|
+}
|
|
+
|
|
+static long vhost_net_reset_owner(struct vhost_net *n)
|
|
+{
|
|
+ struct socket *tx_sock = NULL;
|
|
+ struct socket *rx_sock = NULL;
|
|
+ long err;
|
|
+ mutex_lock(&n->dev.mutex);
|
|
+ err = vhost_dev_check_owner(&n->dev);
|
|
+ if (err)
|
|
+ goto done;
|
|
+ vhost_net_stop(n, &tx_sock, &rx_sock);
|
|
+ vhost_net_flush(n);
|
|
+ err = vhost_dev_reset_owner(&n->dev);
|
|
+done:
|
|
+ mutex_unlock(&n->dev.mutex);
|
|
+ if (tx_sock)
|
|
+ fput(tx_sock->file);
|
|
+ if (rx_sock)
|
|
+ fput(rx_sock->file);
|
|
+ return err;
|
|
+}
|
|
+
|
|
+static int vhost_net_set_features(struct vhost_net *n, u64 features)
|
|
+{
|
|
+ size_t hdr_size = features & (1 << VHOST_NET_F_VIRTIO_NET_HDR) ?
|
|
+ sizeof(struct virtio_net_hdr) : 0;
|
|
+ int i;
|
|
+ mutex_lock(&n->dev.mutex);
|
|
+ if ((features & (1 << VHOST_F_LOG_ALL)) &&
|
|
+ !vhost_log_access_ok(&n->dev)) {
|
|
+ mutex_unlock(&n->dev.mutex);
|
|
+ return -EFAULT;
|
|
+ }
|
|
+ n->dev.acked_features = features;
|
|
+ smp_wmb();
|
|
+ for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
|
|
+ mutex_lock(&n->vqs[i].mutex);
|
|
+ n->vqs[i].hdr_size = hdr_size;
|
|
+ mutex_unlock(&n->vqs[i].mutex);
|
|
+ }
|
|
+ vhost_net_flush(n);
|
|
+ mutex_unlock(&n->dev.mutex);
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+static long vhost_net_ioctl(struct file *f, unsigned int ioctl,
|
|
+ unsigned long arg)
|
|
+{
|
|
+ struct vhost_net *n = f->private_data;
|
|
+ void __user *argp = (void __user *)arg;
|
|
+ u64 __user *featurep = argp;
|
|
+ struct vhost_vring_file backend;
|
|
+ u64 features;
|
|
+ int r;
|
|
+ switch (ioctl) {
|
|
+ case VHOST_NET_SET_BACKEND:
|
|
+ r = copy_from_user(&backend, argp, sizeof backend);
|
|
+ if (r < 0)
|
|
+ return r;
|
|
+ return vhost_net_set_backend(n, backend.index, backend.fd);
|
|
+ case VHOST_GET_FEATURES:
|
|
+ features = VHOST_FEATURES;
|
|
+ return copy_to_user(featurep, &features, sizeof features);
|
|
+ case VHOST_SET_FEATURES:
|
|
+ r = copy_from_user(&features, featurep, sizeof features);
|
|
+ if (r < 0)
|
|
+ return r;
|
|
+ if (features & ~VHOST_FEATURES)
|
|
+ return -EOPNOTSUPP;
|
|
+ return vhost_net_set_features(n, features);
|
|
+ case VHOST_RESET_OWNER:
|
|
+ return vhost_net_reset_owner(n);
|
|
+ default:
|
|
+ mutex_lock(&n->dev.mutex);
|
|
+ r = vhost_dev_ioctl(&n->dev, ioctl, arg);
|
|
+ vhost_net_flush(n);
|
|
+ mutex_unlock(&n->dev.mutex);
|
|
+ return r;
|
|
+ }
|
|
+}
|
|
+
|
|
+#ifdef CONFIG_COMPAT
|
|
+static long vhost_net_compat_ioctl(struct file *f, unsigned int ioctl,
|
|
+ unsigned long arg)
|
|
+{
|
|
+ return vhost_net_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
|
|
+}
|
|
+#endif
|
|
+
|
|
+const static struct file_operations vhost_net_fops = {
|
|
+ .owner = THIS_MODULE,
|
|
+ .release = vhost_net_release,
|
|
+ .unlocked_ioctl = vhost_net_ioctl,
|
|
+#ifdef CONFIG_COMPAT
|
|
+ .compat_ioctl = vhost_net_compat_ioctl,
|
|
+#endif
|
|
+ .open = vhost_net_open,
|
|
+};
|
|
+
|
|
+static struct miscdevice vhost_net_misc = {
|
|
+ VHOST_NET_MINOR,
|
|
+ "vhost-net",
|
|
+ &vhost_net_fops,
|
|
+};
|
|
+
|
|
+int vhost_net_init(void)
|
|
+{
|
|
+ int r = vhost_init();
|
|
+ if (r)
|
|
+ goto err_init;
|
|
+ r = misc_register(&vhost_net_misc);
|
|
+ if (r)
|
|
+ goto err_reg;
|
|
+ return 0;
|
|
+err_reg:
|
|
+ vhost_cleanup();
|
|
+err_init:
|
|
+ return r;
|
|
+
|
|
+}
|
|
+module_init(vhost_net_init);
|
|
+
|
|
+void vhost_net_exit(void)
|
|
+{
|
|
+ misc_deregister(&vhost_net_misc);
|
|
+ vhost_cleanup();
|
|
+}
|
|
+module_exit(vhost_net_exit);
|
|
+
|
|
+MODULE_VERSION("0.0.1");
|
|
+MODULE_LICENSE("GPL v2");
|
|
+MODULE_AUTHOR("Michael S. Tsirkin");
|
|
+MODULE_DESCRIPTION("Host kernel accelerator for virtio net");
|
|
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
|
|
new file mode 100644
|
|
index 0000000..c8c25db
|
|
--- /dev/null
|
|
+++ b/drivers/vhost/vhost.c
|
|
@@ -0,0 +1,1098 @@
|
|
+/* Copyright (C) 2009 Red Hat, Inc.
|
|
+ * Copyright (C) 2006 Rusty Russell IBM Corporation
|
|
+ *
|
|
+ * Author: Michael S. Tsirkin <mst@redhat.com>
|
|
+ *
|
|
+ * Inspiration, some code, and most witty comments come from
|
|
+ * Documentation/lguest/lguest.c, by Rusty Russell
|
|
+ *
|
|
+ * This work is licensed under the terms of the GNU GPL, version 2.
|
|
+ *
|
|
+ * Generic code for virtio server in host kernel.
|
|
+ */
|
|
+
|
|
+#include <linux/eventfd.h>
|
|
+#include <linux/vhost.h>
|
|
+#include <linux/virtio_net.h>
|
|
+#include <linux/mm.h>
|
|
+#include <linux/miscdevice.h>
|
|
+#include <linux/mutex.h>
|
|
+#include <linux/workqueue.h>
|
|
+#include <linux/rcupdate.h>
|
|
+#include <linux/poll.h>
|
|
+#include <linux/file.h>
|
|
+#include <linux/highmem.h>
|
|
+
|
|
+#include <linux/net.h>
|
|
+#include <linux/if_packet.h>
|
|
+#include <linux/if_arp.h>
|
|
+
|
|
+#include <net/sock.h>
|
|
+
|
|
+#include "vhost.h"
|
|
+
|
|
+enum {
|
|
+ VHOST_MEMORY_MAX_NREGIONS = 64,
|
|
+ VHOST_MEMORY_F_LOG = 0x1,
|
|
+};
|
|
+
|
|
+static struct workqueue_struct *vhost_workqueue;
|
|
+
|
|
+static void vhost_poll_func(struct file *file, wait_queue_head_t *wqh,
|
|
+ poll_table *pt)
|
|
+{
|
|
+ struct vhost_poll *poll;
|
|
+ poll = container_of(pt, struct vhost_poll, table);
|
|
+
|
|
+ poll->wqh = wqh;
|
|
+ add_wait_queue(wqh, &poll->wait);
|
|
+}
|
|
+
|
|
+static int vhost_poll_wakeup(wait_queue_t *wait, unsigned mode, int sync,
|
|
+ void *key)
|
|
+{
|
|
+ struct vhost_poll *poll;
|
|
+ poll = container_of(wait, struct vhost_poll, wait);
|
|
+ if (!((unsigned long)key & poll->mask))
|
|
+ return 0;
|
|
+
|
|
+ queue_work(vhost_workqueue, &poll->work);
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+/* Init poll structure */
|
|
+void vhost_poll_init(struct vhost_poll *poll, work_func_t func,
|
|
+ unsigned long mask)
|
|
+{
|
|
+ INIT_WORK(&poll->work, func);
|
|
+ init_waitqueue_func_entry(&poll->wait, vhost_poll_wakeup);
|
|
+ init_poll_funcptr(&poll->table, vhost_poll_func);
|
|
+ poll->mask = mask;
|
|
+}
|
|
+
|
|
+/* Start polling a file. We add ourselves to file's wait queue. The caller must
|
|
+ * keep a reference to a file until after vhost_poll_stop is called. */
|
|
+void vhost_poll_start(struct vhost_poll *poll, struct file *file)
|
|
+{
|
|
+ unsigned long mask;
|
|
+ mask = file->f_op->poll(file, &poll->table);
|
|
+ if (mask)
|
|
+ vhost_poll_wakeup(&poll->wait, 0, 0, (void *)mask);
|
|
+}
|
|
+
|
|
+/* Stop polling a file. After this function returns, it becomes safe to drop the
|
|
+ * file reference. You must also flush afterwards. */
|
|
+void vhost_poll_stop(struct vhost_poll *poll)
|
|
+{
|
|
+ remove_wait_queue(poll->wqh, &poll->wait);
|
|
+}
|
|
+
|
|
+/* Flush any work that has been scheduled. When calling this, don't hold any
|
|
+ * locks that are also used by the callback. */
|
|
+void vhost_poll_flush(struct vhost_poll *poll)
|
|
+{
|
|
+ flush_work(&poll->work);
|
|
+}
|
|
+
|
|
+void vhost_poll_queue(struct vhost_poll *poll)
|
|
+{
|
|
+ queue_work(vhost_workqueue, &poll->work);
|
|
+}
|
|
+
|
|
+static void vhost_vq_reset(struct vhost_dev *dev,
|
|
+ struct vhost_virtqueue *vq)
|
|
+{
|
|
+ vq->num = 1;
|
|
+ vq->desc = NULL;
|
|
+ vq->avail = NULL;
|
|
+ vq->used = NULL;
|
|
+ vq->last_avail_idx = 0;
|
|
+ vq->avail_idx = 0;
|
|
+ vq->last_used_idx = 0;
|
|
+ vq->used_flags = 0;
|
|
+ vq->used_flags = 0;
|
|
+ vq->log_used = false;
|
|
+ vq->log_addr = -1ull;
|
|
+ vq->hdr_size = 0;
|
|
+ vq->private_data = NULL;
|
|
+ vq->log_base = NULL;
|
|
+ vq->error_ctx = NULL;
|
|
+ vq->error = NULL;
|
|
+ vq->kick = NULL;
|
|
+ vq->call_ctx = NULL;
|
|
+ vq->call = NULL;
|
|
+}
|
|
+
|
|
+long vhost_dev_init(struct vhost_dev *dev,
|
|
+ struct vhost_virtqueue *vqs, int nvqs)
|
|
+{
|
|
+ int i;
|
|
+ dev->vqs = vqs;
|
|
+ dev->nvqs = nvqs;
|
|
+ mutex_init(&dev->mutex);
|
|
+ dev->log_ctx = NULL;
|
|
+ dev->log_file = NULL;
|
|
+ dev->memory = NULL;
|
|
+ dev->mm = NULL;
|
|
+
|
|
+ for (i = 0; i < dev->nvqs; ++i) {
|
|
+ dev->vqs[i].dev = dev;
|
|
+ mutex_init(&dev->vqs[i].mutex);
|
|
+ vhost_vq_reset(dev, dev->vqs + i);
|
|
+ if (dev->vqs[i].handle_kick)
|
|
+ vhost_poll_init(&dev->vqs[i].poll,
|
|
+ dev->vqs[i].handle_kick,
|
|
+ POLLIN);
|
|
+ }
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+/* Caller should have device mutex */
|
|
+long vhost_dev_check_owner(struct vhost_dev *dev)
|
|
+{
|
|
+ /* Are you the owner? If not, I don't think you mean to do that */
|
|
+ return dev->mm == current->mm ? 0 : -EPERM;
|
|
+}
|
|
+
|
|
+/* Caller should have device mutex */
|
|
+static long vhost_dev_set_owner(struct vhost_dev *dev)
|
|
+{
|
|
+ /* Is there an owner already? */
|
|
+ if (dev->mm)
|
|
+ return -EBUSY;
|
|
+ /* No owner, become one */
|
|
+ dev->mm = get_task_mm(current);
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+/* Caller should have device mutex */
|
|
+long vhost_dev_reset_owner(struct vhost_dev *dev)
|
|
+{
|
|
+ struct vhost_memory *memory;
|
|
+
|
|
+ /* Restore memory to default empty mapping. */
|
|
+ memory = kmalloc(offsetof(struct vhost_memory, regions), GFP_KERNEL);
|
|
+ if (!memory)
|
|
+ return -ENOMEM;
|
|
+
|
|
+ vhost_dev_cleanup(dev);
|
|
+
|
|
+ memory->nregions = 0;
|
|
+ dev->memory = memory;
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+/* Caller should have device mutex */
|
|
+void vhost_dev_cleanup(struct vhost_dev *dev)
|
|
+{
|
|
+ int i;
|
|
+ for (i = 0; i < dev->nvqs; ++i) {
|
|
+ if (dev->vqs[i].kick && dev->vqs[i].handle_kick) {
|
|
+ vhost_poll_stop(&dev->vqs[i].poll);
|
|
+ vhost_poll_flush(&dev->vqs[i].poll);
|
|
+ }
|
|
+ if (dev->vqs[i].error_ctx)
|
|
+ eventfd_ctx_put(dev->vqs[i].error_ctx);
|
|
+ if (dev->vqs[i].error)
|
|
+ fput(dev->vqs[i].error);
|
|
+ if (dev->vqs[i].kick)
|
|
+ fput(dev->vqs[i].kick);
|
|
+ if (dev->vqs[i].call_ctx)
|
|
+ eventfd_ctx_put(dev->vqs[i].call_ctx);
|
|
+ if (dev->vqs[i].call)
|
|
+ fput(dev->vqs[i].call);
|
|
+ vhost_vq_reset(dev, dev->vqs + i);
|
|
+ }
|
|
+ if (dev->log_ctx)
|
|
+ eventfd_ctx_put(dev->log_ctx);
|
|
+ dev->log_ctx = NULL;
|
|
+ if (dev->log_file)
|
|
+ fput(dev->log_file);
|
|
+ dev->log_file = NULL;
|
|
+ /* No one will access memory at this point */
|
|
+ kfree(dev->memory);
|
|
+ dev->memory = NULL;
|
|
+ if (dev->mm)
|
|
+ mmput(dev->mm);
|
|
+ dev->mm = NULL;
|
|
+}
|
|
+
|
|
+static int log_access_ok(void __user *log_base, u64 addr, unsigned long sz)
|
|
+{
|
|
+ u64 a = addr / VHOST_PAGE_SIZE / 8;
|
|
+ /* Make sure 64 bit math will not overflow. */
|
|
+ if (a > ULONG_MAX - (unsigned long)log_base ||
|
|
+ a + (unsigned long)log_base > ULONG_MAX)
|
|
+ return -EFAULT;
|
|
+
|
|
+ return access_ok(VERIFY_WRITE, log_base + a,
|
|
+ (sz + VHOST_PAGE_SIZE * 8 - 1) / VHOST_PAGE_SIZE / 8);
|
|
+}
|
|
+
|
|
+/* Caller should have vq mutex and device mutex. */
|
|
+static int vq_memory_access_ok(void __user *log_base, struct vhost_memory *mem,
|
|
+ int log_all)
|
|
+{
|
|
+ int i;
|
|
+ for (i = 0; i < mem->nregions; ++i) {
|
|
+ struct vhost_memory_region *m = mem->regions + i;
|
|
+ unsigned long a = m->userspace_addr;
|
|
+ if (m->memory_size > ULONG_MAX)
|
|
+ return 0;
|
|
+ else if (!access_ok(VERIFY_WRITE, (void __user *)a,
|
|
+ m->memory_size))
|
|
+ return 0;
|
|
+ else if (log_all && !log_access_ok(log_base,
|
|
+ m->guest_phys_addr,
|
|
+ m->memory_size))
|
|
+ return 0;
|
|
+ }
|
|
+ return 1;
|
|
+}
|
|
+
|
|
+/* Can we switch to this memory table? */
|
|
+/* Caller should have device mutex but not vq mutex */
|
|
+static int memory_access_ok(struct vhost_dev *d, struct vhost_memory *mem,
|
|
+ int log_all)
|
|
+{
|
|
+ int i;
|
|
+ for (i = 0; i < d->nvqs; ++i) {
|
|
+ int ok;
|
|
+ mutex_lock(&d->vqs[i].mutex);
|
|
+ /* If ring is inactive, will check when it's enabled. */
|
|
+ if (d->vqs[i].private_data)
|
|
+ ok = vq_memory_access_ok(d->vqs[i].log_base, mem,
|
|
+ log_all);
|
|
+ else
|
|
+ ok = 1;
|
|
+ mutex_unlock(&d->vqs[i].mutex);
|
|
+ if (!ok)
|
|
+ return 0;
|
|
+ }
|
|
+ return 1;
|
|
+}
|
|
+
|
|
+static int vq_access_ok(unsigned int num,
|
|
+ struct vring_desc __user *desc,
|
|
+ struct vring_avail __user *avail,
|
|
+ struct vring_used __user *used)
|
|
+{
|
|
+ return access_ok(VERIFY_READ, desc, num * sizeof *desc) &&
|
|
+ access_ok(VERIFY_READ, avail,
|
|
+ sizeof *avail + num * sizeof *avail->ring) &&
|
|
+ access_ok(VERIFY_WRITE, used,
|
|
+ sizeof *used + num * sizeof *used->ring);
|
|
+}
|
|
+
|
|
+/* Can we log writes? */
|
|
+/* Caller should have device mutex but not vq mutex */
|
|
+int vhost_log_access_ok(struct vhost_dev *dev)
|
|
+{
|
|
+ return memory_access_ok(dev, dev->memory, 1);
|
|
+}
|
|
+
|
|
+/* Verify access for write logging. */
|
|
+/* Caller should have vq mutex and device mutex */
|
|
+static int vq_log_access_ok(struct vhost_virtqueue *vq, void __user *log_base)
|
|
+{
|
|
+ return vq_memory_access_ok(log_base, vq->dev->memory,
|
|
+ vhost_has_feature(vq->dev, VHOST_F_LOG_ALL)) &&
|
|
+ (!vq->log_used || log_access_ok(log_base, vq->log_addr,
|
|
+ sizeof *vq->used +
|
|
+ vq->num * sizeof *vq->used->ring));
|
|
+}
|
|
+
|
|
+/* Can we start vq? */
|
|
+/* Caller should have vq mutex and device mutex */
|
|
+int vhost_vq_access_ok(struct vhost_virtqueue *vq)
|
|
+{
|
|
+ return vq_access_ok(vq->num, vq->desc, vq->avail, vq->used) &&
|
|
+ vq_log_access_ok(vq, vq->log_base);
|
|
+}
|
|
+
|
|
+static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m)
|
|
+{
|
|
+ struct vhost_memory mem, *newmem, *oldmem;
|
|
+ unsigned long size = offsetof(struct vhost_memory, regions);
|
|
+ long r;
|
|
+ r = copy_from_user(&mem, m, size);
|
|
+ if (r)
|
|
+ return r;
|
|
+ if (mem.padding)
|
|
+ return -EOPNOTSUPP;
|
|
+ if (mem.nregions > VHOST_MEMORY_MAX_NREGIONS)
|
|
+ return -E2BIG;
|
|
+ newmem = kmalloc(size + mem.nregions * sizeof *m->regions, GFP_KERNEL);
|
|
+ if (!newmem)
|
|
+ return -ENOMEM;
|
|
+
|
|
+ memcpy(newmem, &mem, size);
|
|
+ r = copy_from_user(newmem->regions, m->regions,
|
|
+ mem.nregions * sizeof *m->regions);
|
|
+ if (r) {
|
|
+ kfree(newmem);
|
|
+ return r;
|
|
+ }
|
|
+
|
|
+ if (!memory_access_ok(d, newmem, vhost_has_feature(d, VHOST_F_LOG_ALL)))
|
|
+ return -EFAULT;
|
|
+ oldmem = d->memory;
|
|
+ rcu_assign_pointer(d->memory, newmem);
|
|
+ synchronize_rcu();
|
|
+ kfree(oldmem);
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+static int init_used(struct vhost_virtqueue *vq,
|
|
+ struct vring_used __user *used)
|
|
+{
|
|
+ int r = put_user(vq->used_flags, &used->flags);
|
|
+ if (r)
|
|
+ return r;
|
|
+ return get_user(vq->last_used_idx, &used->idx);
|
|
+}
|
|
+
|
|
+static long vhost_set_vring(struct vhost_dev *d, int ioctl, void __user *argp)
|
|
+{
|
|
+ struct file *eventfp, *filep = NULL,
|
|
+ *pollstart = NULL, *pollstop = NULL;
|
|
+ struct eventfd_ctx *ctx = NULL;
|
|
+ u32 __user *idxp = argp;
|
|
+ struct vhost_virtqueue *vq;
|
|
+ struct vhost_vring_state s;
|
|
+ struct vhost_vring_file f;
|
|
+ struct vhost_vring_addr a;
|
|
+ u32 idx;
|
|
+ long r;
|
|
+
|
|
+ r = get_user(idx, idxp);
|
|
+ if (r < 0)
|
|
+ return r;
|
|
+ if (idx > d->nvqs)
|
|
+ return -ENOBUFS;
|
|
+
|
|
+ vq = d->vqs + idx;
|
|
+
|
|
+ mutex_lock(&vq->mutex);
|
|
+
|
|
+ switch (ioctl) {
|
|
+ case VHOST_SET_VRING_NUM:
|
|
+ /* Resizing ring with an active backend?
|
|
+ * You don't want to do that. */
|
|
+ if (vq->private_data) {
|
|
+ r = -EBUSY;
|
|
+ break;
|
|
+ }
|
|
+ r = copy_from_user(&s, argp, sizeof s);
|
|
+ if (r < 0)
|
|
+ break;
|
|
+ if (!s.num || s.num > 0xffff || (s.num & (s.num - 1))) {
|
|
+ r = -EINVAL;
|
|
+ break;
|
|
+ }
|
|
+ vq->num = s.num;
|
|
+ break;
|
|
+ case VHOST_SET_VRING_BASE:
|
|
+ /* Moving base with an active backend?
|
|
+ * You don't want to do that. */
|
|
+ if (vq->private_data) {
|
|
+ r = -EBUSY;
|
|
+ break;
|
|
+ }
|
|
+ r = copy_from_user(&s, argp, sizeof s);
|
|
+ if (r < 0)
|
|
+ break;
|
|
+ if (s.num > 0xffff) {
|
|
+ r = -EINVAL;
|
|
+ break;
|
|
+ }
|
|
+ vq->last_avail_idx = s.num;
|
|
+ /* Forget the cached index value. */
|
|
+ vq->avail_idx = vq->last_avail_idx;
|
|
+ break;
|
|
+ case VHOST_GET_VRING_BASE:
|
|
+ s.index = idx;
|
|
+ s.num = vq->last_avail_idx;
|
|
+ r = copy_to_user(argp, &s, sizeof s);
|
|
+ break;
|
|
+ case VHOST_SET_VRING_ADDR:
|
|
+ r = copy_from_user(&a, argp, sizeof a);
|
|
+ if (r < 0)
|
|
+ break;
|
|
+ if (a.flags & ~(0x1 << VHOST_VRING_F_LOG)) {
|
|
+ r = -EOPNOTSUPP;
|
|
+ break;
|
|
+ }
|
|
+ /* For 32bit, verify that the top 32bits of the user
|
|
+ data are set to zero. */
|
|
+ if ((u64)(unsigned long)a.desc_user_addr != a.desc_user_addr ||
|
|
+ (u64)(unsigned long)a.used_user_addr != a.used_user_addr ||
|
|
+ (u64)(unsigned long)a.avail_user_addr != a.avail_user_addr) {
|
|
+ r = -EFAULT;
|
|
+ break;
|
|
+ }
|
|
+ if ((a.avail_user_addr & (sizeof *vq->avail->ring - 1)) ||
|
|
+ (a.used_user_addr & (sizeof *vq->used->ring - 1)) ||
|
|
+ (a.log_guest_addr & (sizeof *vq->used->ring - 1))) {
|
|
+ r = -EINVAL;
|
|
+ break;
|
|
+ }
|
|
+
|
|
+ /* We only verify access here if backend is configured.
|
|
+ * If it is not, we don't as size might not have been setup.
|
|
+ * We will verify when backend is configured. */
|
|
+ if (vq->private_data) {
|
|
+ if (!vq_access_ok(vq->num,
|
|
+ (void __user *)(unsigned long)a.desc_user_addr,
|
|
+ (void __user *)(unsigned long)a.avail_user_addr,
|
|
+ (void __user *)(unsigned long)a.used_user_addr)) {
|
|
+ r = -EINVAL;
|
|
+ break;
|
|
+ }
|
|
+
|
|
+ /* Also validate log access for used ring if enabled. */
|
|
+ if ((a.flags & (0x1 << VHOST_VRING_F_LOG)) &&
|
|
+ !log_access_ok(vq->log_base, a.log_guest_addr,
|
|
+ sizeof *vq->used +
|
|
+ vq->num * sizeof *vq->used->ring)) {
|
|
+ r = -EINVAL;
|
|
+ break;
|
|
+ }
|
|
+ }
|
|
+
|
|
+ r = init_used(vq, (struct vring_used __user *)(unsigned long)
|
|
+ a.used_user_addr);
|
|
+ if (r)
|
|
+ break;
|
|
+ vq->log_used = !!(a.flags & (0x1 << VHOST_VRING_F_LOG));
|
|
+ vq->desc = (void __user *)(unsigned long)a.desc_user_addr;
|
|
+ vq->avail = (void __user *)(unsigned long)a.avail_user_addr;
|
|
+ vq->log_addr = a.log_guest_addr;
|
|
+ vq->used = (void __user *)(unsigned long)a.used_user_addr;
|
|
+ break;
|
|
+ case VHOST_SET_VRING_KICK:
|
|
+ r = copy_from_user(&f, argp, sizeof f);
|
|
+ if (r < 0)
|
|
+ break;
|
|
+ eventfp = f.fd == -1 ? NULL : eventfd_fget(f.fd);
|
|
+ if (IS_ERR(eventfp))
|
|
+ return PTR_ERR(eventfp);
|
|
+ if (eventfp != vq->kick) {
|
|
+ pollstop = filep = vq->kick;
|
|
+ pollstart = vq->kick = eventfp;
|
|
+ } else
|
|
+ filep = eventfp;
|
|
+ break;
|
|
+ case VHOST_SET_VRING_CALL:
|
|
+ r = copy_from_user(&f, argp, sizeof f);
|
|
+ if (r < 0)
|
|
+ break;
|
|
+ eventfp = f.fd == -1 ? NULL : eventfd_fget(f.fd);
|
|
+ if (IS_ERR(eventfp))
|
|
+ return PTR_ERR(eventfp);
|
|
+ if (eventfp != vq->call) {
|
|
+ filep = vq->call;
|
|
+ ctx = vq->call_ctx;
|
|
+ vq->call = eventfp;
|
|
+ vq->call_ctx = eventfp ?
|
|
+ eventfd_ctx_fileget(eventfp) : NULL;
|
|
+ } else
|
|
+ filep = eventfp;
|
|
+ break;
|
|
+ case VHOST_SET_VRING_ERR:
|
|
+ r = copy_from_user(&f, argp, sizeof f);
|
|
+ if (r < 0)
|
|
+ break;
|
|
+ eventfp = f.fd == -1 ? NULL : eventfd_fget(f.fd);
|
|
+ if (IS_ERR(eventfp))
|
|
+ return PTR_ERR(eventfp);
|
|
+ if (eventfp != vq->error) {
|
|
+ filep = vq->error;
|
|
+ vq->error = eventfp;
|
|
+ ctx = vq->error_ctx;
|
|
+ vq->error_ctx = eventfp ?
|
|
+ eventfd_ctx_fileget(eventfp) : NULL;
|
|
+ } else
|
|
+ filep = eventfp;
|
|
+ break;
|
|
+ default:
|
|
+ r = -ENOIOCTLCMD;
|
|
+ }
|
|
+
|
|
+ if (pollstop && vq->handle_kick)
|
|
+ vhost_poll_stop(&vq->poll);
|
|
+
|
|
+ if (ctx)
|
|
+ eventfd_ctx_put(ctx);
|
|
+ if (filep)
|
|
+ fput(filep);
|
|
+
|
|
+ if (pollstart && vq->handle_kick)
|
|
+ vhost_poll_start(&vq->poll, vq->kick);
|
|
+
|
|
+ mutex_unlock(&vq->mutex);
|
|
+
|
|
+ if (pollstop && vq->handle_kick)
|
|
+ vhost_poll_flush(&vq->poll);
|
|
+ return r;
|
|
+}
|
|
+
|
|
+/* Caller must have device mutex */
|
|
+long vhost_dev_ioctl(struct vhost_dev *d, unsigned int ioctl, unsigned long arg)
|
|
+{
|
|
+ void __user *argp = (void __user *)arg;
|
|
+ struct file *eventfp, *filep = NULL;
|
|
+ struct eventfd_ctx *ctx = NULL;
|
|
+ u64 p;
|
|
+ long r;
|
|
+ int i, fd;
|
|
+
|
|
+ /* If you are not the owner, you can become one */
|
|
+ if (ioctl == VHOST_SET_OWNER) {
|
|
+ r = vhost_dev_set_owner(d);
|
|
+ goto done;
|
|
+ }
|
|
+
|
|
+ /* You must be the owner to do anything else */
|
|
+ r = vhost_dev_check_owner(d);
|
|
+ if (r)
|
|
+ goto done;
|
|
+
|
|
+ switch (ioctl) {
|
|
+ case VHOST_SET_MEM_TABLE:
|
|
+ r = vhost_set_memory(d, argp);
|
|
+ break;
|
|
+ case VHOST_SET_LOG_BASE:
|
|
+ r = copy_from_user(&p, argp, sizeof p);
|
|
+ if (r < 0)
|
|
+ break;
|
|
+ if ((u64)(unsigned long)p != p) {
|
|
+ r = -EFAULT;
|
|
+ break;
|
|
+ }
|
|
+ for (i = 0; i < d->nvqs; ++i) {
|
|
+ struct vhost_virtqueue *vq;
|
|
+ void __user *base = (void __user *)(unsigned long)p;
|
|
+ vq = d->vqs + i;
|
|
+ mutex_lock(&vq->mutex);
|
|
+ /* If ring is inactive, will check when it's enabled. */
|
|
+ if (vq->private_data && !vq_log_access_ok(vq, base))
|
|
+ r = -EFAULT;
|
|
+ else
|
|
+ vq->log_base = base;
|
|
+ mutex_unlock(&vq->mutex);
|
|
+ }
|
|
+ break;
|
|
+ case VHOST_SET_LOG_FD:
|
|
+ r = get_user(fd, (int __user *)argp);
|
|
+ if (r < 0)
|
|
+ break;
|
|
+ eventfp = fd == -1 ? NULL : eventfd_fget(fd);
|
|
+ if (IS_ERR(eventfp)) {
|
|
+ r = PTR_ERR(eventfp);
|
|
+ break;
|
|
+ }
|
|
+ if (eventfp != d->log_file) {
|
|
+ filep = d->log_file;
|
|
+ ctx = d->log_ctx;
|
|
+ d->log_ctx = eventfp ?
|
|
+ eventfd_ctx_fileget(eventfp) : NULL;
|
|
+ } else
|
|
+ filep = eventfp;
|
|
+ for (i = 0; i < d->nvqs; ++i) {
|
|
+ mutex_lock(&d->vqs[i].mutex);
|
|
+ d->vqs[i].log_ctx = d->log_ctx;
|
|
+ mutex_unlock(&d->vqs[i].mutex);
|
|
+ }
|
|
+ if (ctx)
|
|
+ eventfd_ctx_put(ctx);
|
|
+ if (filep)
|
|
+ fput(filep);
|
|
+ break;
|
|
+ default:
|
|
+ r = vhost_set_vring(d, ioctl, argp);
|
|
+ break;
|
|
+ }
|
|
+done:
|
|
+ return r;
|
|
+}
|
|
+
|
|
+static const struct vhost_memory_region *find_region(struct vhost_memory *mem,
|
|
+ __u64 addr, __u32 len)
|
|
+{
|
|
+ struct vhost_memory_region *reg;
|
|
+ int i;
|
|
+ /* linear search is not brilliant, but we really have on the order of 6
|
|
+ * regions in practice */
|
|
+ for (i = 0; i < mem->nregions; ++i) {
|
|
+ reg = mem->regions + i;
|
|
+ if (reg->guest_phys_addr <= addr &&
|
|
+ reg->guest_phys_addr + reg->memory_size - 1 >= addr)
|
|
+ return reg;
|
|
+ }
|
|
+ return NULL;
|
|
+}
|
|
+
|
|
+/* TODO: This is really inefficient. We need something like get_user()
|
|
+ * (instruction directly accesses the data, with an exception table entry
|
|
+ * returning -EFAULT). See Documentation/x86/exception-tables.txt.
|
|
+ */
|
|
+static int set_bit_to_user(int nr, void __user *addr)
|
|
+{
|
|
+ unsigned long log = (unsigned long)addr;
|
|
+ struct page *page;
|
|
+ void *base;
|
|
+ int bit = nr + (log % PAGE_SIZE) * 8;
|
|
+ int r;
|
|
+ r = get_user_pages_fast(log, 1, 1, &page);
|
|
+ if (r)
|
|
+ return r;
|
|
+ base = kmap_atomic(page, KM_USER0);
|
|
+ set_bit(bit, base);
|
|
+ kunmap_atomic(base, KM_USER0);
|
|
+ set_page_dirty_lock(page);
|
|
+ put_page(page);
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+static int log_write(void __user *log_base,
|
|
+ u64 write_address, u64 write_length)
|
|
+{
|
|
+ int r;
|
|
+ if (!write_length)
|
|
+ return 0;
|
|
+ write_address /= VHOST_PAGE_SIZE;
|
|
+ for (;;) {
|
|
+ u64 base = (u64)(unsigned long)log_base;
|
|
+ u64 log = base + write_address / 8;
|
|
+ int bit = write_address % 8;
|
|
+ if ((u64)(unsigned long)log != log)
|
|
+ return -EFAULT;
|
|
+ r = set_bit_to_user(bit, (void __user *)(unsigned long)log);
|
|
+ if (r < 0)
|
|
+ return r;
|
|
+ if (write_length <= VHOST_PAGE_SIZE)
|
|
+ break;
|
|
+ write_length -= VHOST_PAGE_SIZE;
|
|
+ write_address += VHOST_PAGE_SIZE;
|
|
+ }
|
|
+ return r;
|
|
+}
|
|
+
|
|
+int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
|
|
+ unsigned int log_num, u64 len)
|
|
+{
|
|
+ int i, r;
|
|
+
|
|
+ /* Make sure data written is seen before log. */
|
|
+ wmb();
|
|
+ for (i = 0; i < log_num; ++i) {
|
|
+ u64 l = min(log[i].len, len);
|
|
+ r = log_write(vq->log_base, log[i].addr, l);
|
|
+ if (r < 0)
|
|
+ return r;
|
|
+ len -= l;
|
|
+ if (!len)
|
|
+ return 0;
|
|
+ }
|
|
+ if (vq->log_ctx)
|
|
+ eventfd_signal(vq->log_ctx, 1);
|
|
+ /* Length written exceeds what we have stored. This is a bug. */
|
|
+ BUG();
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+int translate_desc(struct vhost_dev *dev, u64 addr, u32 len,
|
|
+ struct iovec iov[], int iov_size)
|
|
+{
|
|
+ const struct vhost_memory_region *reg;
|
|
+ struct vhost_memory *mem;
|
|
+ struct iovec *_iov;
|
|
+ u64 s = 0;
|
|
+ int ret = 0;
|
|
+
|
|
+ rcu_read_lock();
|
|
+
|
|
+ mem = rcu_dereference(dev->memory);
|
|
+ while ((u64)len > s) {
|
|
+ u64 size;
|
|
+ if (ret >= iov_size) {
|
|
+ ret = -ENOBUFS;
|
|
+ break;
|
|
+ }
|
|
+ reg = find_region(mem, addr, len);
|
|
+ if (!reg) {
|
|
+ ret = -EFAULT;
|
|
+ break;
|
|
+ }
|
|
+ _iov = iov + ret;
|
|
+ size = reg->memory_size - addr + reg->guest_phys_addr;
|
|
+ _iov->iov_len = min((u64)len, size);
|
|
+ _iov->iov_base = (void *)(unsigned long)
|
|
+ (reg->userspace_addr + addr - reg->guest_phys_addr);
|
|
+ s += size;
|
|
+ addr += size;
|
|
+ ++ret;
|
|
+ }
|
|
+
|
|
+ rcu_read_unlock();
|
|
+ return ret;
|
|
+}
|
|
+
|
|
+/* Each buffer in the virtqueues is actually a chain of descriptors. This
|
|
+ * function returns the next descriptor in the chain,
|
|
+ * or -1U if we're at the end. */
|
|
+static unsigned next_desc(struct vring_desc *desc)
|
|
+{
|
|
+ unsigned int next;
|
|
+
|
|
+ /* If this descriptor says it doesn't chain, we're done. */
|
|
+ if (!(desc->flags & VRING_DESC_F_NEXT))
|
|
+ return -1U;
|
|
+
|
|
+ /* Check they're not leading us off end of descriptors. */
|
|
+ next = desc->next;
|
|
+ /* Make sure compiler knows to grab that: we don't want it changing! */
|
|
+ /* We will use the result as an index in an array, so most
|
|
+ * architectures only need a compiler barrier here. */
|
|
+ read_barrier_depends();
|
|
+
|
|
+ return next;
|
|
+}
|
|
+
|
|
+static unsigned get_indirect(struct vhost_dev *dev, struct vhost_virtqueue *vq,
|
|
+ struct iovec iov[], unsigned int iov_size,
|
|
+ unsigned int *out_num, unsigned int *in_num,
|
|
+ struct vhost_log *log, unsigned int *log_num,
|
|
+ struct vring_desc *indirect)
|
|
+{
|
|
+ struct vring_desc desc;
|
|
+ unsigned int i = 0, count, found = 0;
|
|
+ int ret;
|
|
+
|
|
+ /* Sanity check */
|
|
+ if (indirect->len % sizeof desc) {
|
|
+ vq_err(vq, "Invalid length in indirect descriptor: "
|
|
+ "len 0x%llx not multiple of 0x%zx\n",
|
|
+ (unsigned long long)indirect->len,
|
|
+ sizeof desc);
|
|
+ return -EINVAL;
|
|
+ }
|
|
+
|
|
+ ret = translate_desc(dev, indirect->addr, indirect->len, vq->indirect,
|
|
+ ARRAY_SIZE(vq->indirect));
|
|
+ if (ret < 0) {
|
|
+ vq_err(vq, "Translation failure %d in indirect.\n", ret);
|
|
+ return ret;
|
|
+ }
|
|
+
|
|
+ /* We will use the result as an address to read from, so most
|
|
+ * architectures only need a compiler barrier here. */
|
|
+ read_barrier_depends();
|
|
+
|
|
+ count = indirect->len / sizeof desc;
|
|
+ /* Buffers are chained via a 16 bit next field, so
|
|
+ * we can have at most 2^16 of these. */
|
|
+ if (count > USHORT_MAX + 1) {
|
|
+ vq_err(vq, "Indirect buffer length too big: %d\n",
|
|
+ indirect->len);
|
|
+ return -E2BIG;
|
|
+ }
|
|
+
|
|
+ do {
|
|
+ unsigned iov_count = *in_num + *out_num;
|
|
+ if (++found > count) {
|
|
+ vq_err(vq, "Loop detected: last one at %u "
|
|
+ "indirect size %u\n",
|
|
+ i, count);
|
|
+ return -EINVAL;
|
|
+ }
|
|
+ if (memcpy_fromiovec((unsigned char *)&desc, vq->indirect,
|
|
+ sizeof desc)) {
|
|
+ vq_err(vq, "Failed indirect descriptor: idx %d, %zx\n",
|
|
+ i, (size_t)indirect->addr + i * sizeof desc);
|
|
+ return -EINVAL;
|
|
+ }
|
|
+ if (desc.flags & VRING_DESC_F_INDIRECT) {
|
|
+ vq_err(vq, "Nested indirect descriptor: idx %d, %zx\n",
|
|
+ i, (size_t)indirect->addr + i * sizeof desc);
|
|
+ return -EINVAL;
|
|
+ }
|
|
+
|
|
+ ret = translate_desc(dev, desc.addr, desc.len, iov + iov_count,
|
|
+ iov_size - iov_count);
|
|
+ if (ret < 0) {
|
|
+ vq_err(vq, "Translation failure %d indirect idx %d\n",
|
|
+ ret, i);
|
|
+ return ret;
|
|
+ }
|
|
+ /* If this is an input descriptor, increment that count. */
|
|
+ if (desc.flags & VRING_DESC_F_WRITE) {
|
|
+ *in_num += ret;
|
|
+ if (unlikely(log)) {
|
|
+ log[*log_num].addr = desc.addr;
|
|
+ log[*log_num].len = desc.len;
|
|
+ ++*log_num;
|
|
+ }
|
|
+ } else {
|
|
+ /* If it's an output descriptor, they're all supposed
|
|
+ * to come before any input descriptors. */
|
|
+ if (*in_num) {
|
|
+ vq_err(vq, "Indirect descriptor "
|
|
+ "has out after in: idx %d\n", i);
|
|
+ return -EINVAL;
|
|
+ }
|
|
+ *out_num += ret;
|
|
+ }
|
|
+ } while ((i = next_desc(&desc)) != -1);
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+/* This looks in the virtqueue and for the first available buffer, and converts
|
|
+ * it to an iovec for convenient access. Since descriptors consist of some
|
|
+ * number of output then some number of input descriptors, it's actually two
|
|
+ * iovecs, but we pack them into one and note how many of each there were.
|
|
+ *
|
|
+ * This function returns the descriptor number found, or vq->num (which
|
|
+ * is never a valid descriptor number) if none was found. */
|
|
+unsigned vhost_get_vq_desc(struct vhost_dev *dev, struct vhost_virtqueue *vq,
|
|
+ struct iovec iov[], unsigned int iov_size,
|
|
+ unsigned int *out_num, unsigned int *in_num,
|
|
+ struct vhost_log *log, unsigned int *log_num)
|
|
+{
|
|
+ struct vring_desc desc;
|
|
+ unsigned int i, head, found = 0;
|
|
+ u16 last_avail_idx;
|
|
+ int ret;
|
|
+
|
|
+ /* Check it isn't doing very strange things with descriptor numbers. */
|
|
+ last_avail_idx = vq->last_avail_idx;
|
|
+ if (get_user(vq->avail_idx, &vq->avail->idx)) {
|
|
+ vq_err(vq, "Failed to access avail idx at %p\n",
|
|
+ &vq->avail->idx);
|
|
+ return vq->num;
|
|
+ }
|
|
+
|
|
+ if ((u16)(vq->avail_idx - last_avail_idx) > vq->num) {
|
|
+ vq_err(vq, "Guest moved used index from %u to %u",
|
|
+ last_avail_idx, vq->avail_idx);
|
|
+ return vq->num;
|
|
+ }
|
|
+
|
|
+ /* If there's nothing new since last we looked, return invalid. */
|
|
+ if (vq->avail_idx == last_avail_idx)
|
|
+ return vq->num;
|
|
+
|
|
+ /* Only get avail ring entries after they have been exposed by guest. */
|
|
+ rmb();
|
|
+
|
|
+ /* Grab the next descriptor number they're advertising, and increment
|
|
+ * the index we've seen. */
|
|
+ if (get_user(head, &vq->avail->ring[last_avail_idx % vq->num])) {
|
|
+ vq_err(vq, "Failed to read head: idx %d address %p\n",
|
|
+ last_avail_idx,
|
|
+ &vq->avail->ring[last_avail_idx % vq->num]);
|
|
+ return vq->num;
|
|
+ }
|
|
+
|
|
+ /* If their number is silly, that's an error. */
|
|
+ if (head >= vq->num) {
|
|
+ vq_err(vq, "Guest says index %u > %u is available",
|
|
+ head, vq->num);
|
|
+ return vq->num;
|
|
+ }
|
|
+
|
|
+ /* When we start there are none of either input nor output. */
|
|
+ *out_num = *in_num = 0;
|
|
+ if (unlikely(log))
|
|
+ *log_num = 0;
|
|
+
|
|
+ i = head;
|
|
+ do {
|
|
+ unsigned iov_count = *in_num + *out_num;
|
|
+ if (i >= vq->num) {
|
|
+ vq_err(vq, "Desc index is %u > %u, head = %u",
|
|
+ i, vq->num, head);
|
|
+ return vq->num;
|
|
+ }
|
|
+ if (++found > vq->num) {
|
|
+ vq_err(vq, "Loop detected: last one at %u "
|
|
+ "vq size %u head %u\n",
|
|
+ i, vq->num, head);
|
|
+ return vq->num;
|
|
+ }
|
|
+ ret = copy_from_user(&desc, vq->desc + i, sizeof desc);
|
|
+ if (ret) {
|
|
+ vq_err(vq, "Failed to get descriptor: idx %d addr %p\n",
|
|
+ i, vq->desc + i);
|
|
+ return vq->num;
|
|
+ }
|
|
+ if (desc.flags & VRING_DESC_F_INDIRECT) {
|
|
+ ret = get_indirect(dev, vq, iov, iov_size,
|
|
+ out_num, in_num,
|
|
+ log, log_num, &desc);
|
|
+ if (ret < 0) {
|
|
+ vq_err(vq, "Failure detected "
|
|
+ "in indirect descriptor at idx %d\n", i);
|
|
+ return vq->num;
|
|
+ }
|
|
+ continue;
|
|
+ }
|
|
+
|
|
+ ret = translate_desc(dev, desc.addr, desc.len, iov + iov_count,
|
|
+ iov_size - iov_count);
|
|
+ if (ret < 0) {
|
|
+ vq_err(vq, "Translation failure %d descriptor idx %d\n",
|
|
+ ret, i);
|
|
+ return vq->num;
|
|
+ }
|
|
+ if (desc.flags & VRING_DESC_F_WRITE) {
|
|
+ /* If this is an input descriptor,
|
|
+ * increment that count. */
|
|
+ *in_num += ret;
|
|
+ if (unlikely(log)) {
|
|
+ log[*log_num].addr = desc.addr;
|
|
+ log[*log_num].len = desc.len;
|
|
+ ++*log_num;
|
|
+ }
|
|
+ } else {
|
|
+ /* If it's an output descriptor, they're all supposed
|
|
+ * to come before any input descriptors. */
|
|
+ if (*in_num) {
|
|
+ vq_err(vq, "Descriptor has out after in: "
|
|
+ "idx %d\n", i);
|
|
+ return vq->num;
|
|
+ }
|
|
+ *out_num += ret;
|
|
+ }
|
|
+ } while ((i = next_desc(&desc)) != -1);
|
|
+
|
|
+ /* On success, increment avail index. */
|
|
+ vq->last_avail_idx++;
|
|
+ return head;
|
|
+}
|
|
+
|
|
+/* Reverse the effect of vhost_get_vq_desc. Useful for error handling. */
|
|
+void vhost_discard_vq_desc(struct vhost_virtqueue *vq)
|
|
+{
|
|
+ vq->last_avail_idx--;
|
|
+}
|
|
+
|
|
+/* After we've used one of their buffers, we tell them about it. We'll then
|
|
+ * want to notify the guest, using eventfd. */
|
|
+int vhost_add_used(struct vhost_virtqueue *vq, unsigned int head, int len)
|
|
+{
|
|
+ struct vring_used_elem *used;
|
|
+
|
|
+ /* The virtqueue contains a ring of used buffers. Get a pointer to the
|
|
+ * next entry in that used ring. */
|
|
+ used = &vq->used->ring[vq->last_used_idx % vq->num];
|
|
+ if (put_user(head, &used->id)) {
|
|
+ vq_err(vq, "Failed to write used id");
|
|
+ return -EFAULT;
|
|
+ }
|
|
+ if (put_user(len, &used->len)) {
|
|
+ vq_err(vq, "Failed to write used len");
|
|
+ return -EFAULT;
|
|
+ }
|
|
+ /* Make sure buffer is written before we update index. */
|
|
+ wmb();
|
|
+ if (put_user(vq->last_used_idx + 1, &vq->used->idx)) {
|
|
+ vq_err(vq, "Failed to increment used idx");
|
|
+ return -EFAULT;
|
|
+ }
|
|
+ if (unlikely(vq->log_used)) {
|
|
+ /* Make sure data is seen before log. */
|
|
+ wmb();
|
|
+ log_write(vq->log_base, vq->log_addr + sizeof *vq->used->ring *
|
|
+ (vq->last_used_idx % vq->num),
|
|
+ sizeof *vq->used->ring);
|
|
+ log_write(vq->log_base, vq->log_addr, sizeof *vq->used->ring);
|
|
+ if (vq->log_ctx)
|
|
+ eventfd_signal(vq->log_ctx, 1);
|
|
+ }
|
|
+ vq->last_used_idx++;
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+/* This actually signals the guest, using eventfd. */
|
|
+void vhost_signal(struct vhost_dev *dev, struct vhost_virtqueue *vq)
|
|
+{
|
|
+ __u16 flags = 0;
|
|
+ if (get_user(flags, &vq->avail->flags)) {
|
|
+ vq_err(vq, "Failed to get flags");
|
|
+ return;
|
|
+ }
|
|
+
|
|
+ /* If they don't want an interrupt, don't signal, unless empty. */
|
|
+ if ((flags & VRING_AVAIL_F_NO_INTERRUPT) &&
|
|
+ (vq->avail_idx != vq->last_avail_idx ||
|
|
+ !vhost_has_feature(dev, VIRTIO_F_NOTIFY_ON_EMPTY)))
|
|
+ return;
|
|
+
|
|
+ /* Signal the Guest tell them we used something up. */
|
|
+ if (vq->call_ctx)
|
|
+ eventfd_signal(vq->call_ctx, 1);
|
|
+}
|
|
+
|
|
+/* And here's the combo meal deal. Supersize me! */
|
|
+void vhost_add_used_and_signal(struct vhost_dev *dev,
|
|
+ struct vhost_virtqueue *vq,
|
|
+ unsigned int head, int len)
|
|
+{
|
|
+ vhost_add_used(vq, head, len);
|
|
+ vhost_signal(dev, vq);
|
|
+}
|
|
+
|
|
+/* OK, now we need to know about added descriptors. */
|
|
+bool vhost_enable_notify(struct vhost_virtqueue *vq)
|
|
+{
|
|
+ u16 avail_idx;
|
|
+ int r;
|
|
+ if (!(vq->used_flags & VRING_USED_F_NO_NOTIFY))
|
|
+ return false;
|
|
+ vq->used_flags &= ~VRING_USED_F_NO_NOTIFY;
|
|
+ r = put_user(vq->used_flags, &vq->used->flags);
|
|
+ if (r) {
|
|
+ vq_err(vq, "Failed to enable notification at %p: %d\n",
|
|
+ &vq->used->flags, r);
|
|
+ return false;
|
|
+ }
|
|
+ /* They could have slipped one in as we were doing that: make
|
|
+ * sure it's written, then check again. */
|
|
+ mb();
|
|
+ r = get_user(avail_idx, &vq->avail->idx);
|
|
+ if (r) {
|
|
+ vq_err(vq, "Failed to check avail idx at %p: %d\n",
|
|
+ &vq->avail->idx, r);
|
|
+ return false;
|
|
+ }
|
|
+
|
|
+ return avail_idx != vq->last_avail_idx;
|
|
+}
|
|
+
|
|
+/* We don't need to be notified again. */
|
|
+void vhost_disable_notify(struct vhost_virtqueue *vq)
|
|
+{
|
|
+ int r;
|
|
+ if (vq->used_flags & VRING_USED_F_NO_NOTIFY)
|
|
+ return;
|
|
+ vq->used_flags |= VRING_USED_F_NO_NOTIFY;
|
|
+ r = put_user(vq->used_flags, &vq->used->flags);
|
|
+ if (r)
|
|
+ vq_err(vq, "Failed to enable notification at %p: %d\n",
|
|
+ &vq->used->flags, r);
|
|
+}
|
|
+
|
|
+int vhost_init(void)
|
|
+{
|
|
+ vhost_workqueue = create_singlethread_workqueue("vhost");
|
|
+ if (!vhost_workqueue)
|
|
+ return -ENOMEM;
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+void vhost_cleanup(void)
|
|
+{
|
|
+ destroy_workqueue(vhost_workqueue);
|
|
+}
|
|
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
|
|
new file mode 100644
|
|
index 0000000..44591ba
|
|
--- /dev/null
|
|
+++ b/drivers/vhost/vhost.h
|
|
@@ -0,0 +1,161 @@
|
|
+#ifndef _VHOST_H
|
|
+#define _VHOST_H
|
|
+
|
|
+#include <linux/eventfd.h>
|
|
+#include <linux/vhost.h>
|
|
+#include <linux/mm.h>
|
|
+#include <linux/mutex.h>
|
|
+#include <linux/workqueue.h>
|
|
+#include <linux/poll.h>
|
|
+#include <linux/file.h>
|
|
+#include <linux/skbuff.h>
|
|
+#include <linux/uio.h>
|
|
+#include <linux/virtio_config.h>
|
|
+#include <linux/virtio_ring.h>
|
|
+
|
|
+struct vhost_device;
|
|
+
|
|
+enum {
|
|
+ /* Enough place for all fragments, head, and virtio net header. */
|
|
+ VHOST_NET_MAX_SG = MAX_SKB_FRAGS + 2,
|
|
+};
|
|
+
|
|
+/* Poll a file (eventfd or socket) */
|
|
+/* Note: there's nothing vhost specific about this structure. */
|
|
+struct vhost_poll {
|
|
+ poll_table table;
|
|
+ wait_queue_head_t *wqh;
|
|
+ wait_queue_t wait;
|
|
+ /* struct which will handle all actual work. */
|
|
+ struct work_struct work;
|
|
+ unsigned long mask;
|
|
+};
|
|
+
|
|
+void vhost_poll_init(struct vhost_poll *poll, work_func_t func,
|
|
+ unsigned long mask);
|
|
+void vhost_poll_start(struct vhost_poll *poll, struct file *file);
|
|
+void vhost_poll_stop(struct vhost_poll *poll);
|
|
+void vhost_poll_flush(struct vhost_poll *poll);
|
|
+void vhost_poll_queue(struct vhost_poll *poll);
|
|
+
|
|
+struct vhost_log {
|
|
+ u64 addr;
|
|
+ u64 len;
|
|
+};
|
|
+
|
|
+/* The virtqueue structure describes a queue attached to a device. */
|
|
+struct vhost_virtqueue {
|
|
+ struct vhost_dev *dev;
|
|
+
|
|
+ /* The actual ring of buffers. */
|
|
+ struct mutex mutex;
|
|
+ unsigned int num;
|
|
+ struct vring_desc __user *desc;
|
|
+ struct vring_avail __user *avail;
|
|
+ struct vring_used __user *used;
|
|
+ struct file *kick;
|
|
+ struct file *call;
|
|
+ struct file *error;
|
|
+ struct eventfd_ctx *call_ctx;
|
|
+ struct eventfd_ctx *error_ctx;
|
|
+ struct eventfd_ctx *log_ctx;
|
|
+
|
|
+ struct vhost_poll poll;
|
|
+
|
|
+ /* The routine to call when the Guest pings us, or timeout. */
|
|
+ work_func_t handle_kick;
|
|
+
|
|
+ /* Last available index we saw. */
|
|
+ u16 last_avail_idx;
|
|
+
|
|
+ /* Caches available index value from user. */
|
|
+ u16 avail_idx;
|
|
+
|
|
+ /* Last index we used. */
|
|
+ u16 last_used_idx;
|
|
+
|
|
+ /* Used flags */
|
|
+ u16 used_flags;
|
|
+
|
|
+ /* Log writes to used structure. */
|
|
+ bool log_used;
|
|
+ u64 log_addr;
|
|
+
|
|
+ struct iovec indirect[VHOST_NET_MAX_SG];
|
|
+ struct iovec iov[VHOST_NET_MAX_SG];
|
|
+ struct iovec hdr[VHOST_NET_MAX_SG];
|
|
+ size_t hdr_size;
|
|
+ /* We use a kind of RCU to access private pointer.
|
|
+ * All readers access it from workqueue, which makes it possible to
|
|
+ * flush the workqueue instead of synchronize_rcu. Therefore readers do
|
|
+ * not need to call rcu_read_lock/rcu_read_unlock: the beginning of
|
|
+ * work item execution acts instead of rcu_read_lock() and the end of
|
|
+ * work item execution acts instead of rcu_read_lock().
|
|
+ * Writers use virtqueue mutex. */
|
|
+ void *private_data;
|
|
+ /* Log write descriptors */
|
|
+ void __user *log_base;
|
|
+ struct vhost_log log[VHOST_NET_MAX_SG];
|
|
+};
|
|
+
|
|
+struct vhost_dev {
|
|
+ /* Readers use RCU to access memory table pointer
|
|
+ * log base pointer and features.
|
|
+ * Writers use mutex below.*/
|
|
+ struct vhost_memory *memory;
|
|
+ struct mm_struct *mm;
|
|
+ struct mutex mutex;
|
|
+ unsigned acked_features;
|
|
+ struct vhost_virtqueue *vqs;
|
|
+ int nvqs;
|
|
+ struct file *log_file;
|
|
+ struct eventfd_ctx *log_ctx;
|
|
+};
|
|
+
|
|
+long vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue *vqs, int nvqs);
|
|
+long vhost_dev_check_owner(struct vhost_dev *);
|
|
+long vhost_dev_reset_owner(struct vhost_dev *);
|
|
+void vhost_dev_cleanup(struct vhost_dev *);
|
|
+long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, unsigned long arg);
|
|
+int vhost_vq_access_ok(struct vhost_virtqueue *vq);
|
|
+int vhost_log_access_ok(struct vhost_dev *);
|
|
+
|
|
+unsigned vhost_get_vq_desc(struct vhost_dev *, struct vhost_virtqueue *,
|
|
+ struct iovec iov[], unsigned int iov_count,
|
|
+ unsigned int *out_num, unsigned int *in_num,
|
|
+ struct vhost_log *log, unsigned int *log_num);
|
|
+void vhost_discard_vq_desc(struct vhost_virtqueue *);
|
|
+
|
|
+int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
|
|
+void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *);
|
|
+void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *,
|
|
+ unsigned int head, int len);
|
|
+void vhost_disable_notify(struct vhost_virtqueue *);
|
|
+bool vhost_enable_notify(struct vhost_virtqueue *);
|
|
+
|
|
+int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
|
|
+ unsigned int log_num, u64 len);
|
|
+
|
|
+int vhost_init(void);
|
|
+void vhost_cleanup(void);
|
|
+
|
|
+#define vq_err(vq, fmt, ...) do { \
|
|
+ pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
|
|
+ if ((vq)->error_ctx) \
|
|
+ eventfd_signal((vq)->error_ctx, 1);\
|
|
+ } while (0)
|
|
+
|
|
+enum {
|
|
+ VHOST_FEATURES = (1 << VIRTIO_F_NOTIFY_ON_EMPTY) |
|
|
+ (1 << VIRTIO_RING_F_INDIRECT_DESC) |
|
|
+ (1 << VHOST_F_LOG_ALL) |
|
|
+ (1 << VHOST_NET_F_VIRTIO_NET_HDR),
|
|
+};
|
|
+
|
|
+static inline int vhost_has_feature(struct vhost_dev *dev, int bit)
|
|
+{
|
|
+ unsigned acked_features = rcu_dereference(dev->acked_features);
|
|
+ return acked_features & (1 << bit);
|
|
+}
|
|
+
|
|
+#endif
|
|
diff --git a/include/linux/Kbuild b/include/linux/Kbuild
|
|
index 756f831..d930807 100644
|
|
--- a/include/linux/Kbuild
|
|
+++ b/include/linux/Kbuild
|
|
@@ -362,6 +362,7 @@ unifdef-y += uio.h
|
|
unifdef-y += unistd.h
|
|
unifdef-y += usbdevice_fs.h
|
|
unifdef-y += utsname.h
|
|
+unifdef-y += vhost.h
|
|
unifdef-y += videodev2.h
|
|
unifdef-y += videodev.h
|
|
unifdef-y += virtio_config.h
|
|
diff --git a/include/linux/if_tun.h b/include/linux/if_tun.h
|
|
index 3f5fd52..404abe0 100644
|
|
--- a/include/linux/if_tun.h
|
|
+++ b/include/linux/if_tun.h
|
|
@@ -86,4 +86,18 @@ struct tun_filter {
|
|
__u8 addr[0][ETH_ALEN];
|
|
};
|
|
|
|
+#ifdef __KERNEL__
|
|
+#if defined(CONFIG_TUN) || defined(CONFIG_TUN_MODULE)
|
|
+struct socket *tun_get_socket(struct file *);
|
|
+#else
|
|
+#include <linux/err.h>
|
|
+#include <linux/errno.h>
|
|
+struct file;
|
|
+struct socket;
|
|
+static inline struct socket *tun_get_socket(struct file *f)
|
|
+{
|
|
+ return ERR_PTR(-EINVAL);
|
|
+}
|
|
+#endif /* CONFIG_TUN */
|
|
+#endif /* __KERNEL__ */
|
|
#endif /* __IF_TUN_H */
|
|
diff --git a/include/linux/miscdevice.h b/include/linux/miscdevice.h
|
|
index adaf3c1..8b5f7cc 100644
|
|
--- a/include/linux/miscdevice.h
|
|
+++ b/include/linux/miscdevice.h
|
|
@@ -30,6 +30,7 @@
|
|
#define HPET_MINOR 228
|
|
#define FUSE_MINOR 229
|
|
#define KVM_MINOR 232
|
|
+#define VHOST_NET_MINOR 233
|
|
#define MISC_DYNAMIC_MINOR 255
|
|
|
|
struct device;
|
|
diff --git a/include/linux/vhost.h b/include/linux/vhost.h
|
|
new file mode 100644
|
|
index 0000000..e847f1e
|
|
--- /dev/null
|
|
+++ b/include/linux/vhost.h
|
|
@@ -0,0 +1,130 @@
|
|
+#ifndef _LINUX_VHOST_H
|
|
+#define _LINUX_VHOST_H
|
|
+/* Userspace interface for in-kernel virtio accelerators. */
|
|
+
|
|
+/* vhost is used to reduce the number of system calls involved in virtio.
|
|
+ *
|
|
+ * Existing virtio net code is used in the guest without modification.
|
|
+ *
|
|
+ * This header includes interface used by userspace hypervisor for
|
|
+ * device configuration.
|
|
+ */
|
|
+
|
|
+#include <linux/types.h>
|
|
+#include <linux/compiler.h>
|
|
+#include <linux/ioctl.h>
|
|
+#include <linux/virtio_config.h>
|
|
+#include <linux/virtio_ring.h>
|
|
+
|
|
+struct vhost_vring_state {
|
|
+ unsigned int index;
|
|
+ unsigned int num;
|
|
+};
|
|
+
|
|
+struct vhost_vring_file {
|
|
+ unsigned int index;
|
|
+ int fd; /* Pass -1 to unbind from file. */
|
|
+
|
|
+};
|
|
+
|
|
+struct vhost_vring_addr {
|
|
+ unsigned int index;
|
|
+ /* Option flags. */
|
|
+ unsigned int flags;
|
|
+ /* Flag values: */
|
|
+ /* Whether log address is valid. If set enables logging. */
|
|
+#define VHOST_VRING_F_LOG 0
|
|
+
|
|
+ /* Start of array of descriptors (virtually contiguous) */
|
|
+ __u64 desc_user_addr;
|
|
+ /* Used structure address. Must be 32 bit aligned */
|
|
+ __u64 used_user_addr;
|
|
+ /* Available structure address. Must be 16 bit aligned */
|
|
+ __u64 avail_user_addr;
|
|
+ /* Logging support. */
|
|
+ /* Log writes to used structure, at offset calculated from specified
|
|
+ * address. Address must be 32 bit aligned. */
|
|
+ __u64 log_guest_addr;
|
|
+};
|
|
+
|
|
+struct vhost_memory_region {
|
|
+ __u64 guest_phys_addr;
|
|
+ __u64 memory_size; /* bytes */
|
|
+ __u64 userspace_addr;
|
|
+ __u64 flags_padding; /* No flags are currently specified. */
|
|
+};
|
|
+
|
|
+/* All region addresses and sizes must be 4K aligned. */
|
|
+#define VHOST_PAGE_SIZE 0x1000
|
|
+
|
|
+struct vhost_memory {
|
|
+ __u32 nregions;
|
|
+ __u32 padding;
|
|
+ struct vhost_memory_region regions[0];
|
|
+};
|
|
+
|
|
+/* ioctls */
|
|
+
|
|
+#define VHOST_VIRTIO 0xAF
|
|
+
|
|
+/* Features bitmask for forward compatibility. Transport bits are used for
|
|
+ * vhost specific features. */
|
|
+#define VHOST_GET_FEATURES _IOR(VHOST_VIRTIO, 0x00, __u64)
|
|
+#define VHOST_SET_FEATURES _IOW(VHOST_VIRTIO, 0x00, __u64)
|
|
+
|
|
+/* Set current process as the (exclusive) owner of this file descriptor. This
|
|
+ * must be called before any other vhost command. Further calls to
|
|
+ * VHOST_OWNER_SET fail until VHOST_OWNER_RESET is called. */
|
|
+#define VHOST_SET_OWNER _IO(VHOST_VIRTIO, 0x01)
|
|
+/* Give up ownership, and reset the device to default values.
|
|
+ * Allows subsequent call to VHOST_OWNER_SET to succeed. */
|
|
+#define VHOST_RESET_OWNER _IO(VHOST_VIRTIO, 0x02)
|
|
+
|
|
+/* Set up/modify memory layout */
|
|
+#define VHOST_SET_MEM_TABLE _IOW(VHOST_VIRTIO, 0x03, struct vhost_memory)
|
|
+
|
|
+/* Write logging setup. */
|
|
+/* Memory writes can optionally be logged by setting bit at an offset
|
|
+ * (calculated from the physical address) from specified log base.
|
|
+ * The bit is set using an atomic 32 bit operation. */
|
|
+/* Set base address for logging. */
|
|
+#define VHOST_SET_LOG_BASE _IOW(VHOST_VIRTIO, 0x04, __u64)
|
|
+/* Specify an eventfd file descriptor to signal on log write. */
|
|
+#define VHOST_SET_LOG_FD _IOW(VHOST_VIRTIO, 0x07, int)
|
|
+
|
|
+/* Ring setup. */
|
|
+/* Set number of descriptors in ring. This parameter can not
|
|
+ * be modified while ring is running (bound to a device). */
|
|
+#define VHOST_SET_VRING_NUM _IOW(VHOST_VIRTIO, 0x10, struct vhost_vring_state)
|
|
+/* Set addresses for the ring. */
|
|
+#define VHOST_SET_VRING_ADDR _IOW(VHOST_VIRTIO, 0x11, struct vhost_vring_addr)
|
|
+/* Base value where queue looks for available descriptors */
|
|
+#define VHOST_SET_VRING_BASE _IOW(VHOST_VIRTIO, 0x12, struct vhost_vring_state)
|
|
+/* Get accessor: reads index, writes value in num */
|
|
+#define VHOST_GET_VRING_BASE _IOWR(VHOST_VIRTIO, 0x12, struct vhost_vring_state)
|
|
+
|
|
+/* The following ioctls use eventfd file descriptors to signal and poll
|
|
+ * for events. */
|
|
+
|
|
+/* Set eventfd to poll for added buffers */
|
|
+#define VHOST_SET_VRING_KICK _IOW(VHOST_VIRTIO, 0x20, struct vhost_vring_file)
|
|
+/* Set eventfd to signal when buffers have beed used */
|
|
+#define VHOST_SET_VRING_CALL _IOW(VHOST_VIRTIO, 0x21, struct vhost_vring_file)
|
|
+/* Set eventfd to signal an error */
|
|
+#define VHOST_SET_VRING_ERR _IOW(VHOST_VIRTIO, 0x22, struct vhost_vring_file)
|
|
+
|
|
+/* VHOST_NET specific defines */
|
|
+
|
|
+/* Attach virtio net ring to a raw socket, or tap device.
|
|
+ * The socket must be already bound to an ethernet device, this device will be
|
|
+ * used for transmit. Pass fd -1 to unbind from the socket and the transmit
|
|
+ * device. This can be used to stop the ring (e.g. for migration). */
|
|
+#define VHOST_NET_SET_BACKEND _IOW(VHOST_VIRTIO, 0x30, struct vhost_vring_file)
|
|
+
|
|
+/* Feature bits */
|
|
+/* Log all write descriptors. Can be changed while device is active. */
|
|
+#define VHOST_F_LOG_ALL 26
|
|
+/* vhost-net should add virtio_net_hdr for RX, and strip for TX packets. */
|
|
+#define VHOST_NET_F_VIRTIO_NET_HDR 27
|
|
+
|
|
+#endif
|
|
diff --git a/mm/mmu_context.c b/mm/mmu_context.c
|
|
index ded9081..0777654 100644
|
|
--- a/mm/mmu_context.c
|
|
+++ b/mm/mmu_context.c
|
|
@@ -5,6 +5,7 @@
|
|
|
|
#include <linux/mm.h>
|
|
#include <linux/mmu_context.h>
|
|
+#include <linux/module.h>
|
|
#include <linux/sched.h>
|
|
|
|
#include <asm/mmu_context.h>
|
|
@@ -37,6 +38,7 @@ void use_mm(struct mm_struct *mm)
|
|
if (active_mm != mm)
|
|
mmdrop(active_mm);
|
|
}
|
|
+EXPORT_SYMBOL_GPL(use_mm);
|
|
|
|
/*
|
|
* unuse_mm
|
|
@@ -56,3 +58,4 @@ void unuse_mm(struct mm_struct *mm)
|
|
enter_lazy_tlb(mm, tsk);
|
|
task_unlock(tsk);
|
|
}
|
|
+EXPORT_SYMBOL_GPL(unuse_mm);
|