Messages in this thread | | | From | Vitaly Kuznetsov <> | Subject | Re: [PATCH] KVM: nVMX: set rflags to specify success in handle_invvpid() default case | Date | Thu, 23 Jan 2020 09:55:44 +0100 |
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linmiaohe <linmiaohe@huawei.com> writes:
> From: Miaohe Lin <linmiaohe@huawei.com> > > In handle_invvpid() default case, we just skip emulated instruction and > forget to set rflags to specify success. This would result in indefinite > rflags value and thus indeterminate return value for guest. > > Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> > --- > Chinese New Year is coming. Happy Spring Festival! ^_^
Happy Spring Festival!
> --- > arch/x86/kvm/vmx/nested.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c > index 7608924ee8c1..985d3307ec56 100644 > --- a/arch/x86/kvm/vmx/nested.c > +++ b/arch/x86/kvm/vmx/nested.c > @@ -5165,7 +5165,7 @@ static int handle_invvpid(struct kvm_vcpu *vcpu) > break; > default: > WARN_ON_ONCE(1); > - return kvm_skip_emulated_instruction(vcpu); > + break; > } > > return nested_vmx_succeed(vcpu);
Your patch seems to do the right thing, however, I started wondering if WARN_ON_ONCE() is the right thing to do. SDM says that "If an unsupported INVVPID type is specified, the instruction fails." and this is similar to INVEPT and I decided to check what handle_invept() does. Well, it does BUG_ON().
Are we doing the right thing in any of these cases?
-- Vitaly
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