2017-11-06 22:39 GMT+08:00 Liran Alon <liran.alon@xxxxxxxxxx>:
> In case of instruction-decode failure or emulation failure,
> x86_emulate_instruction() will call reexecute_instruction() which will
> attempt to use the cr2 value passed to x86_emulate_instruction().
> However, when x86_emulate_instruction() is called from
> emulate_instruction(), cr2 is not passed (passed as 0) and therefore
> it doesn't make sense to execute reexecute_instruction() logic at all.
>
> Fixes: 51d8b66199e9 ("KVM: cleanup emulate_instruction")
>
> Signed-off-by: Liran Alon <liran.alon@xxxxxxxxxx>
> Reviewed-by: Nikita Leshenko <nikita.leshchenko@xxxxxxxxxx>
> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Reviewed-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>
> ---
> arch/x86/include/asm/kvm_host.h | 3 ++-
> arch/x86/kvm/vmx.c | 2 +-
> 2 files changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index c73e493adf07..bc1347949cef 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -1156,7 +1156,8 @@ 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, NULL, 0);
> + return x86_emulate_instruction(vcpu, 0,
> + emulation_type | EMULTYPE_NO_REEXECUTE, NULL, 0);
> }
>
> void kvm_enable_efer_bits(u64);
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index 2b63d9edc207..258d1843f0cb 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -6569,7 +6569,7 @@ static int handle_invalid_guest_state(struct kvm_vcpu *vcpu)
> if (kvm_test_request(KVM_REQ_EVENT, vcpu))
> return 1;
>
> - err = emulate_instruction(vcpu, EMULTYPE_NO_REEXECUTE);
> + err = emulate_instruction(vcpu, 0);
>
> if (err == EMULATE_USER_EXIT) {
> ++vcpu->stat.mmio_exits;
> --
> 1.9.1
>
