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From: Sean Christopherson <seanjc@google.com>
To: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
	Nathan Chancellor <nathan@kernel.org>,
	Emanuele Giuseppe Esposito <eesposit@redhat.com>,
	Jim Mattson <jmattson@google.com>
Subject: Re: [PATCH 5/6] KVM: x86: Virtualize FLUSH_L1D and passthrough MSR_IA32_FLUSH_CMD
Date: Thu, 23 Mar 2023 15:17:50 -0700	[thread overview]
Message-ID: <ZBzQDv9gIHIhOP8Y@google.com> (raw)
In-Reply-To: <20230323050753.rufixzrzt2sf3avv@desk>

On Wed, Mar 22, 2023, Pawan Gupta wrote:
> On Tue, Mar 21, 2023 at 06:14:39PM -0700, Sean Christopherson wrote:
> > diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
> > index 85bb535fc321..b32edaf5a74b 100644
> > --- a/arch/x86/kvm/svm/svm.c
> > +++ b/arch/x86/kvm/svm/svm.c
> > @@ -95,6 +95,7 @@ static const struct svm_direct_access_msrs {
> >  #endif
> >  	{ .index = MSR_IA32_SPEC_CTRL,			.always = false },
> >  	{ .index = MSR_IA32_PRED_CMD,			.always = false },
> > +	{ .index = MSR_IA32_FLUSH_CMD,			.always = false },
> >  	{ .index = MSR_IA32_LASTBRANCHFROMIP,		.always = false },
> >  	{ .index = MSR_IA32_LASTBRANCHTOIP,		.always = false },
> >  	{ .index = MSR_IA32_LASTINTFROMIP,		.always = false },
> > @@ -4140,6 +4141,10 @@ static void svm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
> >  		set_msr_interception(vcpu, svm->msrpm, MSR_IA32_PRED_CMD, 0,
> >  				     !!guest_has_pred_cmd_msr(vcpu));
> >  
> > +	if (boot_cpu_has(X86_FEATURE_FLUSH_L1D))
> 
> Just curious, will this ever be true on AMD hardware? AFAIK,
> X86_FEATURE_FLUSH_L1D is Intel-defined CPU feature.

Don't know myself, but I assume/home there was actual motivation behind adding
support for AMD.

  reply	other threads:[~2023-03-23 22:17 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-03-22  1:14 [PATCH 0/6] KVM: x86: Unhost the *_CMD MSR mess Sean Christopherson
2023-03-22  1:14 ` [PATCH 1/6] KVM: x86: Revert MSR_IA32_FLUSH_CMD.FLUSH_L1D enabling Sean Christopherson
2023-03-22  8:15   ` Mathias Krause
2023-03-22  1:14 ` [PATCH 2/6] KVM: VMX: Passthrough MSR_IA32_PRED_CMD based purely on host+guest CPUID Sean Christopherson
2023-03-27  3:46   ` Xiaoyao Li
2023-03-22  1:14 ` [PATCH 3/6] KVM: SVM: " Sean Christopherson
2023-03-22  1:14 ` [PATCH 4/6] KVM: x86: Move MSR_IA32_PRED_CMD WRMSR emulation to common code Sean Christopherson
2023-03-27  6:41   ` Xiaoyao Li
2023-03-22  1:14 ` [PATCH 5/6] KVM: x86: Virtualize FLUSH_L1D and passthrough MSR_IA32_FLUSH_CMD Sean Christopherson
2023-03-23  5:07   ` Pawan Gupta
2023-03-23 22:17     ` Sean Christopherson [this message]
2023-03-24  8:48       ` Zhi Wang
2023-03-27  3:33   ` Xiaoyao Li
2023-03-27 15:37     ` Jim Mattson
2023-03-27 16:00       ` Sean Christopherson
2023-03-22  1:14 ` [PATCH 6/6] KVM: SVM: Return the local "r" variable from svm_set_msr() Sean Christopherson
2023-03-23 22:46 ` [PATCH 0/6] KVM: x86: Unhost the *_CMD MSR mess Sean Christopherson
2023-03-27 15:19 ` Paolo Bonzini
2023-03-27 15:28   ` Sean Christopherson
2023-03-27 15:46     ` Paolo Bonzini
2023-04-12 19:49 ` Paolo Bonzini
2023-04-12 20:00   ` Sean Christopherson

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