4.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
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@xxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Radim Krčmář <rkrcmar@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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) {
