From 8065dbd1ee0ef04321d80da7999b4f0086e0a407 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Thu, 23 Aug 2018 13:56:48 -0700 Subject: [PATCH] KVM: x86: Invert emulation re-execute behavior to make it opt-in MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Re-execution of an instruction after emulation decode failure is intended to be used only when emulating shadow page accesses. Invert the flag to make allowing re-execution opt-in since that behavior is by far in the minority. Signed-off-by: Sean Christopherson Cc: stable@vger.kernel.org Signed-off-by: Radim Krčmář --- arch/x86/include/asm/kvm_host.h | 8 +++----- arch/x86/kvm/mmu.c | 2 +- arch/x86/kvm/x86.c | 2 +- 3 files changed, 5 insertions(+), 7 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 3b220b86c8e4..a69ea11f3bab 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1238,7 +1238,7 @@ enum emulation_result { #define EMULTYPE_TRAP_UD (1 << 1) #define EMULTYPE_SKIP (1 << 2) #define EMULTYPE_RETRY (1 << 3) -#define EMULTYPE_NO_REEXECUTE (1 << 4) +#define EMULTYPE_ALLOW_REEXECUTE (1 << 4) #define EMULTYPE_NO_UD_ON_FAIL (1 << 5) #define EMULTYPE_VMWARE (1 << 6) int x86_emulate_instruction(struct kvm_vcpu *vcpu, unsigned long cr2, @@ -1247,15 +1247,13 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, unsigned long cr2, static inline int emulate_instruction(struct kvm_vcpu *vcpu, int emulation_type) { - return x86_emulate_instruction(vcpu, 0, - emulation_type | EMULTYPE_NO_REEXECUTE, NULL, 0); + return x86_emulate_instruction(vcpu, 0, emulation_type, NULL, 0); } static inline int kvm_emulate_instruction_from_buffer(struct kvm_vcpu *vcpu, void *insn, int insn_len) { - return x86_emulate_instruction(vcpu, 0, EMULTYPE_NO_REEXECUTE, - insn, insn_len); + return x86_emulate_instruction(vcpu, 0, 0, insn, insn_len); } void kvm_enable_efer_bits(u64); diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index a282321329b5..4508c34eef20 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -5217,7 +5217,7 @@ static int make_mmu_pages_available(struct kvm_vcpu *vcpu) int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u64 error_code, void *insn, int insn_len) { - int r, emulation_type = EMULTYPE_RETRY; + int r, emulation_type = EMULTYPE_RETRY | EMULTYPE_ALLOW_REEXECUTE; enum emulation_result er; bool direct = vcpu->arch.mmu.direct_map; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 506bd2b4b8bb..d6f85ea23101 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5870,7 +5870,7 @@ static bool reexecute_instruction(struct kvm_vcpu *vcpu, gva_t cr2, gpa_t gpa = cr2; kvm_pfn_t pfn; - if (emulation_type & EMULTYPE_NO_REEXECUTE) + if (!(emulation_type & EMULTYPE_ALLOW_REEXECUTE)) return false; if (!vcpu->arch.mmu.direct_map) { -- 2.30.2