From 0e20f5e25556c00ee813469d373b00abcf298708 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Fri, 13 Dec 2019 13:25:25 +0000 Subject: [PATCH] KVM: arm/arm64: Cleanup MMIO handling Our MMIO handling is a bit odd, in the sense that it uses an intermediate per-vcpu structure to store the various decoded information that describe the access. But the same information is readily available in the HSR/ESR_EL2 field, and we actually use this field to populate the structure. Let's simplify the whole thing by getting rid of the superfluous structure and save a (tiny) bit of space in the vcpu structure. [32bit fix courtesy of Olof Johansson ] Signed-off-by: Marc Zyngier --- arch/arm/include/asm/kvm_emulate.h | 5 +- arch/arm/include/asm/kvm_host.h | 12 +++-- arch/arm/include/asm/kvm_hyp.h | 1 + arch/arm/include/asm/kvm_mmio.h | 28 ----------- arch/arm64/include/asm/kvm_emulate.h | 3 +- arch/arm64/include/asm/kvm_host.h | 12 +++-- arch/arm64/include/asm/kvm_mmio.h | 27 ----------- virt/kvm/arm/mmio.c | 70 +++++++++------------------- virt/kvm/arm/mmu.c | 1 - 9 files changed, 42 insertions(+), 117 deletions(-) delete mode 100644 arch/arm/include/asm/kvm_mmio.h delete mode 100644 arch/arm64/include/asm/kvm_mmio.h diff --git a/arch/arm/include/asm/kvm_emulate.h b/arch/arm/include/asm/kvm_emulate.h index 08d9805f613b..3944305e81df 100644 --- a/arch/arm/include/asm/kvm_emulate.h +++ b/arch/arm/include/asm/kvm_emulate.h @@ -9,7 +9,6 @@ #include #include -#include #include #include @@ -220,7 +219,7 @@ static inline bool kvm_vcpu_dabt_is_cm(struct kvm_vcpu *vcpu) } /* Get Access Size from a data abort */ -static inline int kvm_vcpu_dabt_get_as(struct kvm_vcpu *vcpu) +static inline unsigned int kvm_vcpu_dabt_get_as(struct kvm_vcpu *vcpu) { switch ((kvm_vcpu_get_hsr(vcpu) >> 22) & 0x3) { case 0: @@ -231,7 +230,7 @@ static inline int kvm_vcpu_dabt_get_as(struct kvm_vcpu *vcpu) return 4; default: kvm_err("Hardware is weird: SAS 0b11 is reserved\n"); - return -EFAULT; + return 4; } } diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index 556cd818eccf..bd2233805d99 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -14,7 +14,6 @@ #include #include #include -#include #include #include @@ -202,9 +201,6 @@ struct kvm_vcpu_arch { /* Don't run the guest (internal implementation need) */ bool pause; - /* IO related fields */ - struct kvm_decode mmio_decode; - /* Cache some mmu pages needed inside spinlock regions */ struct kvm_mmu_memory_cache mmu_page_cache; @@ -300,6 +296,14 @@ int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run, static inline void handle_exit_early(struct kvm_vcpu *vcpu, struct kvm_run *run, int exception_index) {} +/* MMIO helpers */ +void kvm_mmio_write_buf(void *buf, unsigned int len, unsigned long data); +unsigned long kvm_mmio_read_buf(const void *buf, unsigned int len); + +int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run); +int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run, + phys_addr_t fault_ipa); + static inline void __cpu_init_hyp_mode(phys_addr_t pgd_ptr, unsigned long hyp_stack_ptr, unsigned long vector_ptr) diff --git a/arch/arm/include/asm/kvm_hyp.h b/arch/arm/include/asm/kvm_hyp.h index 40e9034db601..3c1b55ecc578 100644 --- a/arch/arm/include/asm/kvm_hyp.h +++ b/arch/arm/include/asm/kvm_hyp.h @@ -10,6 +10,7 @@ #include #include #include +#include #include #define __hyp_text __section(.hyp.text) notrace diff --git a/arch/arm/include/asm/kvm_mmio.h b/arch/arm/include/asm/kvm_mmio.h deleted file mode 100644 index 32fbf82e3ebc..000000000000 --- a/arch/arm/include/asm/kvm_mmio.h +++ /dev/null @@ -1,28 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-only */ -/* - * Copyright (C) 2012 - Virtual Open Systems and Columbia University - * Author: Christoffer Dall - */ - -#ifndef __ARM_KVM_MMIO_H__ -#define __ARM_KVM_MMIO_H__ - -#include -#include -#include - -struct kvm_decode { - unsigned long rt; - bool sign_extend; - /* Not used on 32-bit arm */ - bool sixty_four; -}; - -void kvm_mmio_write_buf(void *buf, unsigned int len, unsigned long data); -unsigned long kvm_mmio_read_buf(const void *buf, unsigned int len); - -int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run); -int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run, - phys_addr_t fault_ipa); - -#endif /* __ARM_KVM_MMIO_H__ */ diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h index 53ea7637b7b2..688c63412cc2 100644 --- a/arch/arm64/include/asm/kvm_emulate.h +++ b/arch/arm64/include/asm/kvm_emulate.h @@ -17,7 +17,6 @@ #include #include #include -#include #include #include #include @@ -341,7 +340,7 @@ static inline bool kvm_vcpu_dabt_is_cm(const struct kvm_vcpu *vcpu) return !!(kvm_vcpu_get_hsr(vcpu) & ESR_ELx_CM); } -static inline int kvm_vcpu_dabt_get_as(const struct kvm_vcpu *vcpu) +static inline unsigned int kvm_vcpu_dabt_get_as(const struct kvm_vcpu *vcpu) { return 1 << ((kvm_vcpu_get_hsr(vcpu) & ESR_ELx_SAS) >> ESR_ELx_SAS_SHIFT); } diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index c61260cf63c5..f6a77ddab956 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -24,7 +24,6 @@ #include #include #include -#include #include #define __KVM_HAVE_ARCH_INTC_INITIALIZED @@ -325,9 +324,6 @@ struct kvm_vcpu_arch { /* Don't run the guest (internal implementation need) */ bool pause; - /* IO related fields */ - struct kvm_decode mmio_decode; - /* Cache some mmu pages needed inside spinlock regions */ struct kvm_mmu_memory_cache mmu_page_cache; @@ -491,6 +487,14 @@ int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run, void handle_exit_early(struct kvm_vcpu *vcpu, struct kvm_run *run, int exception_index); +/* MMIO helpers */ +void kvm_mmio_write_buf(void *buf, unsigned int len, unsigned long data); +unsigned long kvm_mmio_read_buf(const void *buf, unsigned int len); + +int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run); +int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run, + phys_addr_t fault_ipa); + int kvm_perf_init(void); int kvm_perf_teardown(void); diff --git a/arch/arm64/include/asm/kvm_mmio.h b/arch/arm64/include/asm/kvm_mmio.h deleted file mode 100644 index b204501a0c39..000000000000 --- a/arch/arm64/include/asm/kvm_mmio.h +++ /dev/null @@ -1,27 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-only */ -/* - * Copyright (C) 2012 - Virtual Open Systems and Columbia University - * Author: Christoffer Dall - */ - -#ifndef __ARM64_KVM_MMIO_H__ -#define __ARM64_KVM_MMIO_H__ - -#include -#include - -struct kvm_decode { - unsigned long rt; - bool sign_extend; - /* Witdth of the register accessed by the faulting instruction is 64-bits */ - bool sixty_four; -}; - -void kvm_mmio_write_buf(void *buf, unsigned int len, unsigned long data); -unsigned long kvm_mmio_read_buf(const void *buf, unsigned int len); - -int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run); -int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run, - phys_addr_t fault_ipa); - -#endif /* __ARM64_KVM_MMIO_H__ */ diff --git a/virt/kvm/arm/mmio.c b/virt/kvm/arm/mmio.c index 1bb71acd53f2..aedfcff99ac5 100644 --- a/virt/kvm/arm/mmio.c +++ b/virt/kvm/arm/mmio.c @@ -5,7 +5,6 @@ */ #include -#include #include #include @@ -92,26 +91,23 @@ int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run) vcpu->mmio_needed = 0; - if (!run->mmio.is_write) { - len = run->mmio.len; - if (len > sizeof(unsigned long)) - return -EINVAL; - + if (!kvm_vcpu_dabt_iswrite(vcpu)) { + len = kvm_vcpu_dabt_get_as(vcpu); data = kvm_mmio_read_buf(run->mmio.data, len); - if (vcpu->arch.mmio_decode.sign_extend && + if (kvm_vcpu_dabt_issext(vcpu) && len < sizeof(unsigned long)) { mask = 1U << ((len * 8) - 1); data = (data ^ mask) - mask; } - if (!vcpu->arch.mmio_decode.sixty_four) + if (!kvm_vcpu_dabt_issf(vcpu)) data = data & 0xffffffff; trace_kvm_mmio(KVM_TRACE_MMIO_READ, len, run->mmio.phys_addr, &data); data = vcpu_data_host_to_guest(vcpu, data, len); - vcpu_set_reg(vcpu, vcpu->arch.mmio_decode.rt, data); + vcpu_set_reg(vcpu, kvm_vcpu_dabt_get_rd(vcpu), data); } /* @@ -123,36 +119,6 @@ int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run) return 0; } -static int decode_hsr(struct kvm_vcpu *vcpu, bool *is_write, int *len) -{ - unsigned long rt; - int access_size; - bool sign_extend; - bool sixty_four; - - if (kvm_vcpu_dabt_iss1tw(vcpu)) { - /* page table accesses IO mem: tell guest to fix its TTBR */ - kvm_inject_dabt(vcpu, kvm_vcpu_get_hfar(vcpu)); - return 1; - } - - access_size = kvm_vcpu_dabt_get_as(vcpu); - if (unlikely(access_size < 0)) - return access_size; - - *is_write = kvm_vcpu_dabt_iswrite(vcpu); - sign_extend = kvm_vcpu_dabt_issext(vcpu); - sixty_four = kvm_vcpu_dabt_issf(vcpu); - rt = kvm_vcpu_dabt_get_rd(vcpu); - - *len = access_size; - vcpu->arch.mmio_decode.sign_extend = sign_extend; - vcpu->arch.mmio_decode.rt = rt; - vcpu->arch.mmio_decode.sixty_four = sixty_four; - - return 0; -} - int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run, phys_addr_t fault_ipa) { @@ -164,15 +130,10 @@ int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run, u8 data_buf[8]; /* - * Prepare MMIO operation. First decode the syndrome data we get - * from the CPU. Then try if some in-kernel emulation feels - * responsible, otherwise let user space do its magic. + * No valid syndrome? Ask userspace for help if it has + * voluntered to do so, and bail out otherwise. */ - if (kvm_vcpu_dabt_isvalid(vcpu)) { - ret = decode_hsr(vcpu, &is_write, &len); - if (ret) - return ret; - } else { + if (!kvm_vcpu_dabt_isvalid(vcpu)) { if (vcpu->kvm->arch.return_nisv_io_abort_to_user) { run->exit_reason = KVM_EXIT_ARM_NISV; run->arm_nisv.esr_iss = kvm_vcpu_dabt_iss_nisv_sanitized(vcpu); @@ -184,7 +145,20 @@ int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run, return -ENOSYS; } - rt = vcpu->arch.mmio_decode.rt; + /* Page table accesses IO mem: tell guest to fix its TTBR */ + if (kvm_vcpu_dabt_iss1tw(vcpu)) { + kvm_inject_dabt(vcpu, kvm_vcpu_get_hfar(vcpu)); + return 1; + } + + /* + * Prepare MMIO operation. First decode the syndrome data we get + * from the CPU. Then try if some in-kernel emulation feels + * responsible, otherwise let user space do its magic. + */ + is_write = kvm_vcpu_dabt_iswrite(vcpu); + len = kvm_vcpu_dabt_get_as(vcpu); + rt = kvm_vcpu_dabt_get_rd(vcpu); if (is_write) { data = vcpu_data_guest_to_host(vcpu, vcpu_get_reg(vcpu, rt), diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c index e3ad95013192..a4fa81d75e84 100644 --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -14,7 +14,6 @@ #include #include #include -#include #include #include #include