Re: [PATCH] KVM: nVMX: fix comments of handle_vmon()

From: Yu Zhang
Date: Wed Sep 08 2021 - 09:01:54 EST


On Wed, Sep 08, 2021 at 11:55:59AM +0200, Vitaly Kuznetsov wrote:
> Indeed,
>
> Reviewed-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
>
> On a slightly related note: we don't seem to reset
> 'vmx->nested.vmxon_ptr' upon VMXOFF emulation; this is not a problem per
> se as we never access it when !vmx->nested.vmxon but I'd still suggest
> we do something like
>
> diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
> index bc6327950657..8beb41d02d21 100644
> --- a/arch/x86/kvm/vmx/nested.c
> +++ b/arch/x86/kvm/vmx/nested.c
> @@ -290,6 +290,7 @@ static void free_nested(struct kvm_vcpu *vcpu)
>
> vmx->nested.vmxon = false;
> vmx->nested.smm.vmxon = false;
> + vmx->nested.vmxon_ptr = -1ull;
> free_vpid(vmx->nested.vpid02);
> vmx->nested.posted_intr_nv = -1;
> vmx->nested.current_vmptr = -1ull;
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index d7c5257eb5c0..2214e6bd4713 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -6884,6 +6884,7 @@ static int vmx_create_vcpu(struct kvm_vcpu *vcpu)
>
> vcpu_setup_sgx_lepubkeyhash(vcpu);
>
> + vmx->nested.vmxon_ptr = -1ull;
> vmx->nested.posted_intr_nv = -1;
> vmx->nested.current_vmptr = -1ull;
> vmx->nested.hv_evmcs_vmptr = EVMPTR_INVALID;
>
> to avoid issues in the future.
>
Thanks, Vitaly. And above suggestion sounds reasonable to me. :)

I can add this in V2 later, if no one objects.

B.R.
Yu