linux-kernel - Re: [RESEND PATCH 04/13] KVM: x86: Drop EMULTYPE_NO_UD_ON

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Message-ID: <874l28p6my.fsf@vitty.brq.redhat.com>
Date:   Fri, 23 Aug 2019 11:34:29 +0200
From:   Vitaly Kuznetsov <vkuznets@...hat.com>
To:     Sean Christopherson <sean.j.christopherson@...el.com>
Cc:     Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org, Paolo Bonzini <pbonzini@...hat.com>,
        Radim Krčmář <rkrcmar@...hat.com>
Subject: Re: [RESEND PATCH 04/13] KVM: x86: Drop EMULTYPE_NO_UD_ON_FAIL as a standalone type

Sean Christopherson <sean.j.christopherson@...el.com> writes:

> The "no #UD on fail" is used only in the VMWare case, and for the VMWare
> scenario it really means "#GP instead of #UD on fail".  Remove the flag
> in preparation for moving all fault injection into the emulation flow
> itself, which in turn will allow eliminating EMULATE_DONE and company.
>
> Signed-off-by: Sean Christopherson <sean.j.christopherson@...el.com>
> ---
>  arch/x86/include/asm/kvm_host.h | 1 -
>  arch/x86/kvm/svm.c              | 3 +--
>  arch/x86/kvm/vmx/vmx.c          | 3 +--
>  arch/x86/kvm/x86.c              | 2 +-
>  4 files changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index 44a5ce57a905..dd6bd9ed0839 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -1318,7 +1318,6 @@ enum emulation_result {
>  #define EMULTYPE_TRAP_UD	    (1 << 1)
>  #define EMULTYPE_SKIP		    (1 << 2)
>  #define EMULTYPE_ALLOW_RETRY	    (1 << 3)
> -#define EMULTYPE_NO_UD_ON_FAIL	    (1 << 4)
>  #define EMULTYPE_VMWARE		    (1 << 5)
>  int kvm_emulate_instruction(struct kvm_vcpu *vcpu, int emulation_type);
>  int kvm_emulate_instruction_from_buffer(struct kvm_vcpu *vcpu,
> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> index 1f220a85514f..5a42f9c70014 100644
> --- a/arch/x86/kvm/svm.c
> +++ b/arch/x86/kvm/svm.c
> @@ -2772,8 +2772,7 @@ static int gp_interception(struct vcpu_svm *svm)
>  
>  	WARN_ON_ONCE(!enable_vmware_backdoor);
>  
> -	er = kvm_emulate_instruction(vcpu,
> -		EMULTYPE_VMWARE | EMULTYPE_NO_UD_ON_FAIL);
> +	er = kvm_emulate_instruction(vcpu, EMULTYPE_VMWARE);
>  	if (er == EMULATE_USER_EXIT)
>  		return 0;
>  	else if (er != EMULATE_DONE)
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index 18286e5b5983..6ecf773825e2 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -4509,8 +4509,7 @@ static int handle_exception_nmi(struct kvm_vcpu *vcpu)
>  
>  	if (!vmx->rmode.vm86_active && is_gp_fault(intr_info)) {
>  		WARN_ON_ONCE(!enable_vmware_backdoor);
> -		er = kvm_emulate_instruction(vcpu,
> -			EMULTYPE_VMWARE | EMULTYPE_NO_UD_ON_FAIL);
> +		er = kvm_emulate_instruction(vcpu, EMULTYPE_VMWARE);
>  		if (er == EMULATE_USER_EXIT)
>  			return 0;
>  		else if (er != EMULATE_DONE)
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index fe847f8eb947..e0f0e14d8fac 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -6210,7 +6210,7 @@ static int handle_emulation_failure(struct kvm_vcpu *vcpu, int emulation_type)
>  	++vcpu->stat.insn_emulation_fail;
>  	trace_kvm_emulate_insn_failed(vcpu);
>  
> -	if (emulation_type & EMULTYPE_NO_UD_ON_FAIL)
> +	if (emulation_type & EMULTYPE_VMWARE)
>  		return EMULATE_FAIL;
>  
>  	kvm_queue_exception(vcpu, UD_VECTOR);

Reviewed-by: Vitaly Kuznetsov <vkuznets@...hat.com>

-- 
Vitaly