According to Table C-1 of Intel SDM 3C, a VM exit happens on an I/O instruction when "use I/O bitmaps" VM-execution control was 0 _and_ the "unconditional I/O exiting" VM-execution control was 1. So we can't just check "unconditional I/O exiting" alone. This patch was improved by suggestion from Jan Kiszka. Signed-off-by: Zhihui Zhang <zzhsuny@xxxxxxxxx> --- arch/x86/kvm/vmx.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index b2fe1c2..45617db 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -6460,11 +6460,8 @@ static bool nested_vmx_exit_handled_io(struct kvm_vcpu *vcpu, int size; u8 b; - if (nested_cpu_has(vmcs12, CPU_BASED_UNCOND_IO_EXITING)) - return 1; - if (!nested_cpu_has(vmcs12, CPU_BASED_USE_IO_BITMAPS)) - return 0; + return nested_cpu_has(vmcs12, CPU_BASED_UNCOND_IO_EXITING); exit_qualification = vmcs_readl(EXIT_QUALIFICATION); -- 1.8.1.2 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
