qemu/0003-scsi-pvscsi-limit-process-IO-loop-to-ring-size.patch

36 lines
1.4 KiB
Diff
Raw Normal View History

From: Prasad J Pandit <pjp@fedoraproject.org>
Date: Wed, 14 Sep 2016 15:09:12 +0530
Subject: [PATCH] scsi: pvscsi: limit process IO loop to ring size
Vmware Paravirtual SCSI emulator while processing IO requests
could run into an infinite loop if 'pvscsi_ring_pop_req_descr'
always returned positive value. Limit IO loop to the ring size.
Cc: qemu-stable@nongnu.org
Reported-by: Li Qiang <liqiang6-s@360.cn>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Message-Id: <1473845952-30785-1-git-send-email-ppandit@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit d251157ac1928191af851d199a9ff255d330bec9)
---
hw/scsi/vmw_pvscsi.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/hw/scsi/vmw_pvscsi.c b/hw/scsi/vmw_pvscsi.c
index babac5a..a5ce7de 100644
--- a/hw/scsi/vmw_pvscsi.c
+++ b/hw/scsi/vmw_pvscsi.c
@@ -247,8 +247,11 @@ static hwaddr
pvscsi_ring_pop_req_descr(PVSCSIRingInfo *mgr)
{
uint32_t ready_ptr = RS_GET_FIELD(mgr, reqProdIdx);
+ uint32_t ring_size = PVSCSI_MAX_NUM_PAGES_REQ_RING
+ * PVSCSI_MAX_NUM_REQ_ENTRIES_PER_PAGE;
- if (ready_ptr != mgr->consumed_ptr) {
+ if (ready_ptr != mgr->consumed_ptr
+ && ready_ptr - mgr->consumed_ptr < ring_size) {
uint32_t next_ready_ptr =
mgr->consumed_ptr++ & mgr->txr_len_mask;
uint32_t next_ready_page =