On Wed, 9 Jan 2019 18:22:56 +0100
Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> wrote:
> Since commit 09abb5e3e5e50 ("KVM: nVMX: call kvm_skip_emulated_instruction
> in nested_vmx_{fail,succeed}") nested_vmx_failValid() results in
> kvm_skip_emulated_instruction() so doing it again in handle_vmptrld() when
> vmptr address is not backed is wrong, we end up advancing RIP twice.
>
> Fixes: fca91f6d60b6e ("kvm: nVMX: Set VM instruction error for VMPTRLD of unbacked page")
> Reported-by: Cornelia Huck <cohuck@xxxxxxxxxx>
> Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
> ---
> arch/x86/kvm/vmx/nested.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
> index 3170e291215d..2616bd2c7f2c 100644
> --- a/arch/x86/kvm/vmx/nested.c
> +++ b/arch/x86/kvm/vmx/nested.c
> @@ -4540,9 +4540,8 @@ static int handle_vmptrld(struct kvm_vcpu *vcpu)
> * given physical address won't match the required
> * VMCS12_REVISION identifier.
> */
> - nested_vmx_failValid(vcpu,
> + return nested_vmx_failValid(vcpu,
> VMXERR_VMPTRLD_INCORRECT_VMCS_REVISION_ID);
> - return kvm_skip_emulated_instruction(vcpu);
> }
> new_vmcs12 = kmap(page);
> if (new_vmcs12->hdr.revision_id != VMCS12_REVISION ||
Not that I would be a nested vmx expert, but this looks correct.
Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx>
