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From: Sean Christopherson <seanjc@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>, Jiri Kosina <trivial@kernel.org>
Cc: Sean Christopherson <seanjc@google.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
	kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 8/9] KVM: SVM: Don't manually emulate RDPMC if nrips=0
Date: Thu,  4 Feb 2021 16:57:49 -0800	[thread overview]
Message-ID: <20210205005750.3841462-9-seanjc@google.com> (raw)
In-Reply-To: <20210205005750.3841462-1-seanjc@google.com>

Remove bizarre code that causes KVM to run RDPMC through the emulator
when nrips is disabled.  Accelerated emulation of RDPMC doesn't rely on
any additional data from the VMCB, and SVM has generic handling for
updating RIP to skip instructions when nrips is disabled.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/kvm/svm/svm.c | 10 +---------
 1 file changed, 1 insertion(+), 9 deletions(-)

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 74f37f282050..b6acc73d356a 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -2434,14 +2434,6 @@ static int rsm_interception(struct kvm_vcpu *vcpu)
 	return kvm_emulate_instruction_from_buffer(vcpu, rsm_ins_bytes, 2);
 }
 
-static int rdpmc_interception(struct kvm_vcpu *vcpu)
-{
-	if (!nrips)
-		return emulate_on_interception(vcpu);
-
-	return kvm_emulate_rdpmc(vcpu);
-}
-
 static bool check_selective_cr0_intercepted(struct kvm_vcpu *vcpu,
 					    unsigned long val)
 {
@@ -3068,7 +3060,7 @@ static int (*const svm_exit_handlers[])(struct kvm_vcpu *vcpu) = {
 	[SVM_EXIT_SMI]				= kvm_emulate_as_nop,
 	[SVM_EXIT_INIT]				= kvm_emulate_as_nop,
 	[SVM_EXIT_VINTR]			= interrupt_window_interception,
-	[SVM_EXIT_RDPMC]			= rdpmc_interception,
+	[SVM_EXIT_RDPMC]			= kvm_emulate_rdpmc,
 	[SVM_EXIT_CPUID]			= kvm_emulate_cpuid,
 	[SVM_EXIT_IRET]                         = iret_interception,
 	[SVM_EXIT_INVD]                         = kvm_emulate_invd,
-- 
2.30.0.365.g02bc693789-goog


  parent reply	other threads:[~2021-02-05  1:05 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-05  0:57 [PATCH 0/9] KVM: x86: Move common exit handlers to x86.c Sean Christopherson
2021-02-05  0:57 ` [PATCH 1/9] KVM: SVM: Move AVIC vCPU kicking snippet to helper function Sean Christopherson
2021-02-05  0:57 ` [PATCH 2/9] KVM: SVM: Remove an unnecessary forward declaration Sean Christopherson
2021-02-05  0:57 ` [PATCH 3/9] KVM: SVM: Pass @vcpu to exit handlers (and many, many other places) Sean Christopherson
2021-02-05  0:57 ` [PATCH 4/9] KVM: nSVM: Add VMLOAD/VMSAVE helper to deduplicate code Sean Christopherson
2021-02-05  0:57 ` [PATCH 5/9] KVM: x86: Move XSETBV emulation to common code Sean Christopherson
2021-02-05  0:57 ` [PATCH 6/9] KVM: x86: Move trivial instruction-based exit handlers " Sean Christopherson
2021-02-05  0:57 ` [PATCH 7/9] KVM: x86: Move RDPMC emulation " Sean Christopherson
2021-02-05  0:57 ` Sean Christopherson [this message]
2021-02-05  0:57 ` [PATCH 9/9] KVM: SVM: Skip intercepted PAUSE instructions after emulation Sean Christopherson
2021-02-05  8:20 ` [PATCH 0/9] KVM: x86: Move common exit handlers to x86.c Paolo Bonzini

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