Liran Alon <liran.alon@xxxxxxxxxx> 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@xxxxxxxxxx>
(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@xxxxxxxxxx>
> ---
> 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
