4.18-stable review patch. If anyone has any objections, please let me know.
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From: Sean Christopherson sean.j.christopherson@intel.com
commit 8065dbd1ee0ef04321d80da7999b4f0086e0a407 upstream.
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 sean.j.christopherson@intel.com Cc: stable@vger.kernel.org Signed-off-by: Radim Krčmář rkrcmar@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- 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(-)
--- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1199,7 +1199,7 @@ 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, @@ -1208,15 +1208,13 @@ int x86_emulate_instruction(struct kvm_v 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); --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -4960,7 +4960,7 @@ static int make_mmu_pages_available(stru 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;
--- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5810,7 +5810,7 @@ static bool reexecute_instruction(struct 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) {