On 2013-04-15 14:46, Paolo Bonzini wrote:
> KVM does not use the activity state VMCS field, and does not support
> it in nested VMX either (the corresponding bits in the misc VMX feature
> MSR are zero).  Fail entry if the activity state is set to anything but
> "active".

Ah, that indeed simplifies the issue.

> 
> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
> ---
>  arch/x86/kvm/vmx.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index c75c25d..589e79a 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -7223,6 +7223,11 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool 
> launch)
>               return 1;
>       }
>  
> +     if (vmcs12->guest_activity_state != 0) {

GUEST_ACTIVITY_ACTIVE, please.

> +             nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD);
> +             return 1;
> +     }
> +
>       if ((vmcs12->cpu_based_vm_exec_control & CPU_BASED_USE_MSR_BITMAPS) &&
>                       !IS_ALIGNED(vmcs12->msr_bitmap, PAGE_SIZE)) {
>               /*TODO: Also verify bits beyond physical address width are 0*/
> 

That means we also do not need to read and write the corresponding VMCS
field on L1/L2 transitions - avoids any risk of setting it to an
unsupported value. So I would fold it into this change.

Jan

-- 
Siemens AG, Corporate Technology, CT RTC ITP SDP-DE
Corporate Competence Center Embedded Linux
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to