diff options
| author | Zhihui Zhang <zzhsuny@gmail.com> | 2013-12-30 15:56:29 -0500 |
|---|---|---|
| committer | Marcelo Tosatti <mtosatti@redhat.com> | 2014-01-08 19:01:40 -0200 |
| commit | 2f0a6397dd3cac2fb05b46cad08c1d532c04d6b8 (patch) | |
| tree | 2a68f99698169b20ed597e36bddfa9725275b712 /arch/x86/kvm/vmx.c | |
| parent | 171800328f6e2443e0e356de5b41fb7e0fff4448 (diff) | |
KVM: VMX: check use I/O bitmap first before unconditional I/O exit
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.
Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Zhihui Zhang <zzhsuny@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'arch/x86/kvm/vmx.c')
| -rw-r--r-- | arch/x86/kvm/vmx.c | 5 |
1 files changed, 1 insertions, 4 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 9cc54842ae1..0abf8b783f1 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -6521,11 +6521,8 @@ 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); |