* [PATCH] KVM: VMX: Remove proprietary handling of unexpected exit-reasons
@ 2019-09-29 14:50 Liran Alon
2019-09-30 7:34 ` Vitaly Kuznetsov
0 siblings, 1 reply; 6+ messages in thread
From: Liran Alon @ 2019-09-29 14:50 UTC (permalink / raw)
To: pbonzini, rkrcmar, kvm
Cc: tao3.xu, sean.j.christopherson, jmattson, vkuznets, Liran Alon
Commit bf653b78f960 ("KVM: vmx: Introduce handle_unexpected_vmexit
and handle WAITPKG vmexit") introduced proprietary handling of
specific exit-reasons that should not be raised by CPU because
KVM configures VMCS such that they should never be raised.
However, since commit 7396d337cfad ("KVM: x86: Return to userspace
with internal error on unexpected exit reason"), VMX & SVM
exit handlers were modified to generically handle all unexpected
exit-reasons by returning to userspace with internal error.
Therefore, there is no need for proprietary handling of specific
unexpected exit-reasons (This proprietary handling also introduced
inconsistency for these exit-reasons to silently skip guest instruction
instead of return to userspace on internal-error).
Fixes: bf653b78f960 ("KVM: vmx: Introduce handle_unexpected_vmexit and handle WAITPKG vmexit")
Signed-off-by: Liran Alon <liran.alon@oracle.com>
---
arch/x86/kvm/vmx/vmx.c | 12 ------------
1 file changed, 12 deletions(-)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index d4575ffb3cec..e31317fc8c95 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -5538,14 +5538,6 @@ static int handle_encls(struct kvm_vcpu *vcpu)
return 1;
}
-static int handle_unexpected_vmexit(struct kvm_vcpu *vcpu)
-{
- kvm_skip_emulated_instruction(vcpu);
- WARN_ONCE(1, "Unexpected VM-Exit Reason = 0x%x",
- vmcs_read32(VM_EXIT_REASON));
- return 1;
-}
-
/*
* The exit handlers return 1 if the exit was handled fully and guest execution
* may resume. Otherwise they set the kvm_run parameter to indicate what needs
@@ -5597,15 +5589,11 @@ static int (*kvm_vmx_exit_handlers[])(struct kvm_vcpu *vcpu) = {
[EXIT_REASON_INVVPID] = handle_vmx_instruction,
[EXIT_REASON_RDRAND] = handle_invalid_op,
[EXIT_REASON_RDSEED] = handle_invalid_op,
- [EXIT_REASON_XSAVES] = handle_unexpected_vmexit,
- [EXIT_REASON_XRSTORS] = handle_unexpected_vmexit,
[EXIT_REASON_PML_FULL] = handle_pml_full,
[EXIT_REASON_INVPCID] = handle_invpcid,
[EXIT_REASON_VMFUNC] = handle_vmx_instruction,
[EXIT_REASON_PREEMPTION_TIMER] = handle_preemption_timer,
[EXIT_REASON_ENCLS] = handle_encls,
- [EXIT_REASON_UMWAIT] = handle_unexpected_vmexit,
- [EXIT_REASON_TPAUSE] = handle_unexpected_vmexit,
};
static const int kvm_vmx_max_exit_handlers =
--
2.20.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] KVM: VMX: Remove proprietary handling of unexpected exit-reasons
2019-09-29 14:50 [PATCH] KVM: VMX: Remove proprietary handling of unexpected exit-reasons Liran Alon
@ 2019-09-30 7:34 ` Vitaly Kuznetsov
2019-09-30 16:35 ` Jim Mattson
0 siblings, 1 reply; 6+ messages in thread
From: Vitaly Kuznetsov @ 2019-09-30 7:34 UTC (permalink / raw)
To: Liran Alon
Cc: tao3.xu, sean.j.christopherson, jmattson, Liran Alon, pbonzini,
rkrcmar, kvm
Liran Alon <liran.alon@oracle.com> writes:
> Commit bf653b78f960 ("KVM: vmx: Introduce handle_unexpected_vmexit
> and handle WAITPKG vmexit") introduced proprietary handling of
> specific exit-reasons that should not be raised by CPU because
> KVM configures VMCS such that they should never be raised.
>
> However, since commit 7396d337cfad ("KVM: x86: Return to userspace
> with internal error on unexpected exit reason"), VMX & SVM
> exit handlers were modified to generically handle all unexpected
> exit-reasons by returning to userspace with internal error.
>
> Therefore, there is no need for proprietary handling of specific
> unexpected exit-reasons (This proprietary handling also introduced
> inconsistency for these exit-reasons to silently skip guest instruction
> instead of return to userspace on internal-error).
>
> Fixes: bf653b78f960 ("KVM: vmx: Introduce handle_unexpected_vmexit and handle WAITPKG vmexit")
>
> Signed-off-by: Liran Alon <liran.alon@oracle.com>
(It's been awhile since in software world the word 'proprietary' became
an opposite of free/open-source to me so I have to admit your subject
line really got me interested :-)
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> ---
> arch/x86/kvm/vmx/vmx.c | 12 ------------
> 1 file changed, 12 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index d4575ffb3cec..e31317fc8c95 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -5538,14 +5538,6 @@ static int handle_encls(struct kvm_vcpu *vcpu)
> return 1;
> }
>
> -static int handle_unexpected_vmexit(struct kvm_vcpu *vcpu)
> -{
> - kvm_skip_emulated_instruction(vcpu);
> - WARN_ONCE(1, "Unexpected VM-Exit Reason = 0x%x",
> - vmcs_read32(VM_EXIT_REASON));
> - return 1;
> -}
> -
> /*
> * The exit handlers return 1 if the exit was handled fully and guest execution
> * may resume. Otherwise they set the kvm_run parameter to indicate what needs
> @@ -5597,15 +5589,11 @@ static int (*kvm_vmx_exit_handlers[])(struct kvm_vcpu *vcpu) = {
> [EXIT_REASON_INVVPID] = handle_vmx_instruction,
> [EXIT_REASON_RDRAND] = handle_invalid_op,
> [EXIT_REASON_RDSEED] = handle_invalid_op,
> - [EXIT_REASON_XSAVES] = handle_unexpected_vmexit,
> - [EXIT_REASON_XRSTORS] = handle_unexpected_vmexit,
> [EXIT_REASON_PML_FULL] = handle_pml_full,
> [EXIT_REASON_INVPCID] = handle_invpcid,
> [EXIT_REASON_VMFUNC] = handle_vmx_instruction,
> [EXIT_REASON_PREEMPTION_TIMER] = handle_preemption_timer,
> [EXIT_REASON_ENCLS] = handle_encls,
> - [EXIT_REASON_UMWAIT] = handle_unexpected_vmexit,
> - [EXIT_REASON_TPAUSE] = handle_unexpected_vmexit,
> };
>
> static const int kvm_vmx_max_exit_handlers =
--
Vitaly
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] KVM: VMX: Remove proprietary handling of unexpected exit-reasons
2019-09-30 7:34 ` Vitaly Kuznetsov
@ 2019-09-30 16:35 ` Jim Mattson
2019-09-30 17:20 ` Sean Christopherson
0 siblings, 1 reply; 6+ messages in thread
From: Jim Mattson @ 2019-09-30 16:35 UTC (permalink / raw)
To: Vitaly Kuznetsov
Cc: Liran Alon, tao3.xu, Sean Christopherson, Paolo Bonzini,
Radim Krčmář, kvm list
On Mon, Sep 30, 2019 at 12:34 AM Vitaly Kuznetsov <vkuznets@redhat.com> wrote:
>
> Liran Alon <liran.alon@oracle.com> writes:
>
> > Commit bf653b78f960 ("KVM: vmx: Introduce handle_unexpected_vmexit
> > and handle WAITPKG vmexit") introduced proprietary handling of
> > specific exit-reasons that should not be raised by CPU because
> > KVM configures VMCS such that they should never be raised.
> >
> > However, since commit 7396d337cfad ("KVM: x86: Return to userspace
> > with internal error on unexpected exit reason"), VMX & SVM
> > exit handlers were modified to generically handle all unexpected
> > exit-reasons by returning to userspace with internal error.
> >
> > Therefore, there is no need for proprietary handling of specific
> > unexpected exit-reasons (This proprietary handling also introduced
> > inconsistency for these exit-reasons to silently skip guest instruction
> > instead of return to userspace on internal-error).
> >
> > Fixes: bf653b78f960 ("KVM: vmx: Introduce handle_unexpected_vmexit and handle WAITPKG vmexit")
> >
> > Signed-off-by: Liran Alon <liran.alon@oracle.com>
>
> (It's been awhile since in software world the word 'proprietary' became
> an opposite of free/open-source to me so I have to admit your subject
> line really got me interested :-)
>
> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
I agree that proprietary is an unusual word choice.
Reviewed-by: Jim Mattson <jmattson@google.com>
> > ---
> > arch/x86/kvm/vmx/vmx.c | 12 ------------
> > 1 file changed, 12 deletions(-)
> >
> > diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> > index d4575ffb3cec..e31317fc8c95 100644
> > --- a/arch/x86/kvm/vmx/vmx.c
> > +++ b/arch/x86/kvm/vmx/vmx.c
> > @@ -5538,14 +5538,6 @@ static int handle_encls(struct kvm_vcpu *vcpu)
> > return 1;
> > }
> >
> > -static int handle_unexpected_vmexit(struct kvm_vcpu *vcpu)
> > -{
> > - kvm_skip_emulated_instruction(vcpu);
> > - WARN_ONCE(1, "Unexpected VM-Exit Reason = 0x%x",
> > - vmcs_read32(VM_EXIT_REASON));
> > - return 1;
> > -}
> > -
> > /*
> > * The exit handlers return 1 if the exit was handled fully and guest execution
> > * may resume. Otherwise they set the kvm_run parameter to indicate what needs
> > @@ -5597,15 +5589,11 @@ static int (*kvm_vmx_exit_handlers[])(struct kvm_vcpu *vcpu) = {
> > [EXIT_REASON_INVVPID] = handle_vmx_instruction,
> > [EXIT_REASON_RDRAND] = handle_invalid_op,
> > [EXIT_REASON_RDSEED] = handle_invalid_op,
> > - [EXIT_REASON_XSAVES] = handle_unexpected_vmexit,
> > - [EXIT_REASON_XRSTORS] = handle_unexpected_vmexit,
> > [EXIT_REASON_PML_FULL] = handle_pml_full,
> > [EXIT_REASON_INVPCID] = handle_invpcid,
> > [EXIT_REASON_VMFUNC] = handle_vmx_instruction,
> > [EXIT_REASON_PREEMPTION_TIMER] = handle_preemption_timer,
> > [EXIT_REASON_ENCLS] = handle_encls,
> > - [EXIT_REASON_UMWAIT] = handle_unexpected_vmexit,
> > - [EXIT_REASON_TPAUSE] = handle_unexpected_vmexit,
> > };
> >
> > static const int kvm_vmx_max_exit_handlers =
>
> --
> Vitaly
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] KVM: VMX: Remove proprietary handling of unexpected exit-reasons
2019-09-30 16:35 ` Jim Mattson
@ 2019-09-30 17:20 ` Sean Christopherson
2019-10-01 0:33 ` Liran Alon
0 siblings, 1 reply; 6+ messages in thread
From: Sean Christopherson @ 2019-09-30 17:20 UTC (permalink / raw)
To: Jim Mattson
Cc: Vitaly Kuznetsov, Liran Alon, tao3.xu, Paolo Bonzini,
Radim Krčmář, kvm list
On Mon, Sep 30, 2019 at 09:35:59AM -0700, Jim Mattson wrote:
> On Mon, Sep 30, 2019 at 12:34 AM Vitaly Kuznetsov <vkuznets@redhat.com> wrote:
> >
> > Liran Alon <liran.alon@oracle.com> writes:
> >
> > > Commit bf653b78f960 ("KVM: vmx: Introduce handle_unexpected_vmexit
> > > and handle WAITPKG vmexit") introduced proprietary handling of
> > > specific exit-reasons that should not be raised by CPU because
> > > KVM configures VMCS such that they should never be raised.
> > >
> > > However, since commit 7396d337cfad ("KVM: x86: Return to userspace
> > > with internal error on unexpected exit reason"), VMX & SVM
> > > exit handlers were modified to generically handle all unexpected
> > > exit-reasons by returning to userspace with internal error.
> > >
> > > Therefore, there is no need for proprietary handling of specific
> > > unexpected exit-reasons (This proprietary handling also introduced
> > > inconsistency for these exit-reasons to silently skip guest instruction
> > > instead of return to userspace on internal-error).
> > >
> > > Fixes: bf653b78f960 ("KVM: vmx: Introduce handle_unexpected_vmexit and handle WAITPKG vmexit")
> > >
> > > Signed-off-by: Liran Alon <liran.alon@oracle.com>
> >
> > (It's been awhile since in software world the word 'proprietary' became
> > an opposite of free/open-source to me so I have to admit your subject
> > line really got me interested :-)
> >
> > Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
>
> I agree that proprietary is an unusual word choice.
It's one way to get quick reviews though :-)
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] KVM: VMX: Remove proprietary handling of unexpected exit-reasons
2019-09-30 17:20 ` Sean Christopherson
@ 2019-10-01 0:33 ` Liran Alon
2019-10-01 14:30 ` Paolo Bonzini
0 siblings, 1 reply; 6+ messages in thread
From: Liran Alon @ 2019-10-01 0:33 UTC (permalink / raw)
To: Sean Christopherson
Cc: Jim Mattson, Vitaly Kuznetsov, tao3.xu, Paolo Bonzini,
Radim Krčmář, kvm list
> On 30 Sep 2019, at 20:20, Sean Christopherson <sean.j.christopherson@intel.com> wrote:
>
> On Mon, Sep 30, 2019 at 09:35:59AM -0700, Jim Mattson wrote:
>> On Mon, Sep 30, 2019 at 12:34 AM Vitaly Kuznetsov <vkuznets@redhat.com> wrote:
>>>
>>> Liran Alon <liran.alon@oracle.com> writes:
>>>
>>>> Commit bf653b78f960 ("KVM: vmx: Introduce handle_unexpected_vmexit
>>>> and handle WAITPKG vmexit") introduced proprietary handling of
>>>> specific exit-reasons that should not be raised by CPU because
>>>> KVM configures VMCS such that they should never be raised.
>>>>
>>>> However, since commit 7396d337cfad ("KVM: x86: Return to userspace
>>>> with internal error on unexpected exit reason"), VMX & SVM
>>>> exit handlers were modified to generically handle all unexpected
>>>> exit-reasons by returning to userspace with internal error.
>>>>
>>>> Therefore, there is no need for proprietary handling of specific
>>>> unexpected exit-reasons (This proprietary handling also introduced
>>>> inconsistency for these exit-reasons to silently skip guest instruction
>>>> instead of return to userspace on internal-error).
>>>>
>>>> Fixes: bf653b78f960 ("KVM: vmx: Introduce handle_unexpected_vmexit and handle WAITPKG vmexit")
>>>>
>>>> Signed-off-by: Liran Alon <liran.alon@oracle.com>
>>>
>>> (It's been awhile since in software world the word 'proprietary' became
>>> an opposite of free/open-source to me so I have to admit your subject
>>> line really got me interested :-)
>>>
>>> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
>>
>> I agree that proprietary is an unusual word choice.
>
> It's one way to get quick reviews though :-)
OK Ok I apologise for my bad English. ^_^
Paolo, feel free to reword this commit title & message to something else when applying…
-Liran
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] KVM: VMX: Remove proprietary handling of unexpected exit-reasons
2019-10-01 0:33 ` Liran Alon
@ 2019-10-01 14:30 ` Paolo Bonzini
0 siblings, 0 replies; 6+ messages in thread
From: Paolo Bonzini @ 2019-10-01 14:30 UTC (permalink / raw)
To: Liran Alon, Sean Christopherson
Cc: Jim Mattson, Vitaly Kuznetsov, tao3.xu,
Radim Krčmář, kvm list
On 01/10/19 02:33, Liran Alon wrote:
> OK Ok I apologise for my bad English. ^_^
> Paolo, feel free to reword this commit title & message to something else when applying…
I'll replace it with "specialized", no problem. I agree with Sean's
assessment. :)
Paolo
^ permalink raw reply [flat|nested] 6+ messages in thread
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2019-09-29 14:50 [PATCH] KVM: VMX: Remove proprietary handling of unexpected exit-reasons Liran Alon
2019-09-30 7:34 ` Vitaly Kuznetsov
2019-09-30 16:35 ` Jim Mattson
2019-09-30 17:20 ` Sean Christopherson
2019-10-01 0:33 ` Liran Alon
2019-10-01 14:30 ` Paolo Bonzini
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