* [PATCH] x86/kvm/nVMX: don't skip emulated instruction twice when vmptr address is not backed
@ 2019-01-09 17:22 Vitaly Kuznetsov
2019-01-09 17:27 ` Sean Christopherson
2019-01-09 17:51 ` Cornelia Huck
0 siblings, 2 replies; 3+ messages in thread
From: Vitaly Kuznetsov @ 2019-01-09 17:22 UTC (permalink / raw)
To: kvm
Cc: Paolo Bonzini, Radim Krčmář,
linux-kernel, Andrew Jones, Cornelia Huck, Jim Mattson,
Sean Christopherson
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@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
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 ||
--
2.20.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] x86/kvm/nVMX: don't skip emulated instruction twice when vmptr address is not backed
2019-01-09 17:22 [PATCH] x86/kvm/nVMX: don't skip emulated instruction twice when vmptr address is not backed Vitaly Kuznetsov
@ 2019-01-09 17:27 ` Sean Christopherson
2019-01-09 17:51 ` Cornelia Huck
1 sibling, 0 replies; 3+ messages in thread
From: Sean Christopherson @ 2019-01-09 17:27 UTC (permalink / raw)
To: Vitaly Kuznetsov
Cc: kvm, Paolo Bonzini, Radim Krčmář,
linux-kernel, Andrew Jones, Cornelia Huck, Jim Mattson
On Wed, Jan 09, 2019 at 06:22:56PM +0100, Vitaly Kuznetsov 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@redhat.com>
> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
> ---
> 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 ||
> --
> 2.20.1
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] x86/kvm/nVMX: don't skip emulated instruction twice when vmptr address is not backed
2019-01-09 17:22 [PATCH] x86/kvm/nVMX: don't skip emulated instruction twice when vmptr address is not backed Vitaly Kuznetsov
2019-01-09 17:27 ` Sean Christopherson
@ 2019-01-09 17:51 ` Cornelia Huck
1 sibling, 0 replies; 3+ messages in thread
From: Cornelia Huck @ 2019-01-09 17:51 UTC (permalink / raw)
To: Vitaly Kuznetsov
Cc: kvm, Paolo Bonzini, Radim Krčmář,
linux-kernel, Andrew Jones, Jim Mattson, Sean Christopherson
On Wed, 9 Jan 2019 18:22:56 +0100
Vitaly Kuznetsov <vkuznets@redhat.com> 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@redhat.com>
> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> ---
> 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@redhat.com>
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2019-01-09 17:51 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2019-01-09 17:22 [PATCH] x86/kvm/nVMX: don't skip emulated instruction twice when vmptr address is not backed Vitaly Kuznetsov
2019-01-09 17:27 ` Sean Christopherson
2019-01-09 17:51 ` Cornelia Huck
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