From: Sean Christopherson <seanjc@google.com>
To: Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Yosry Ahmed <yosry@kernel.org>,
Shivansh Dhiman <shivansh.dhiman@amd.com>,
Nikunj A Dadhania <nikunj@amd.com>,
Ravi Bangoria <ravi.bangoria@amd.com>,
Tom Lendacky <thomas.lendacky@amd.com>
Subject: [PATCH v6 09/12] KVM: nSVM: Open code check on LBR virtualization being enabled in vmcb12
Date: Wed, 30 Sep 2026 12:36:31 -0700 [thread overview]
Message-ID: <20260930193634.3415089-10-seanjc@google.com> (raw)
In-Reply-To: <20260930193634.3415089-1-seanjc@google.com>
Now that KVM clears ENABLE_V_LBR if LBR virtualization isn't supported when
caching vmcb12 control fields, i.e. now that the logic is a simple
one-liner, open the check and drop the now-superfluous wrapper.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/svm/nested.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index aca2bbc66f47..d3f249cd0f2d 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -738,11 +738,6 @@ static int nested_svm_load_cr3(struct kvm_vcpu *vcpu, unsigned long cr3,
return 0;
}
-static bool nested_vmcb12_has_lbrv(struct kvm_vcpu *vcpu)
-{
- return to_svm(vcpu)->nested.ctl.misc_ctl2 & SVM_MISC2_ENABLE_V_LBR;
-}
-
static void nested_vmcb02_prepare_save(struct vcpu_svm *svm)
{
struct vmcb_ctrl_area_cached *control = &svm->nested.ctl;
@@ -817,7 +812,7 @@ static void nested_vmcb02_prepare_save(struct vcpu_svm *svm)
vmcb_mark_dirty(vmcb02, VMCB_DR);
}
- if (nested_vmcb12_has_lbrv(vcpu)) {
+ if (control->misc_ctl2 & SVM_MISC2_ENABLE_V_LBR) {
/*
* Reserved bits of DEBUGCTL are ignored. Be consistent with
* svm_set_msr's definition of reserved bits.
@@ -1310,7 +1305,7 @@ static int nested_svm_vmexit_update_vmcb12(struct kvm_vcpu *vcpu)
if (guest_cpu_cap_has(vcpu, X86_FEATURE_NRIPS))
vmcb12->control.next_rip = vmcb02->control.next_rip;
- if (nested_vmcb12_has_lbrv(vcpu))
+ if (svm->nested.ctl.misc_ctl2 & SVM_MISC2_ENABLE_V_LBR)
svm_copy_lbrs(&vmcb12->save, &vmcb02->save);
vmcb12->control.event_inj = 0;
@@ -1387,7 +1382,7 @@ void nested_svm_vmexit(struct vcpu_svm *svm)
if (!nested_exit_on_intr(svm))
kvm_make_request(KVM_REQ_EVENT, &svm->vcpu);
- if (!nested_vmcb12_has_lbrv(vcpu)) {
+ if (!(svm->nested.ctl.misc_ctl2 & SVM_MISC2_ENABLE_V_LBR)) {
svm_copy_lbrs(&vmcb01->save, &vmcb02->save);
vmcb_mark_dirty(vmcb01, VMCB_LBR);
}
--
2.56.0.rc1.315.gc6ed9934b7-goog
next prev parent reply other threads:[~2026-09-30 19:36 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-30 19:36 [PATCH v6 00/12] KVM: x86: Bus Lock Detect fixes and SVM support Sean Christopherson
2026-09-30 19:36 ` [PATCH v6 01/12] KVM: x86: Preserve DR6.BLD (Bus Lock Detect) when delivering #DB payload Sean Christopherson
2026-09-30 23:46 ` Shivansh Dhiman
2026-09-30 19:36 ` [PATCH v6 02/12] KVM: x86: Rename kvm_dr6_fixed() => kvm_get_dr6_fixed_1() Sean Christopherson
2026-09-30 19:36 ` [PATCH v6 03/12] KVM: Return an "unsigned long", not "u64" for the fixed-1 DR6 bits Sean Christopherson
2026-09-30 19:36 ` [PATCH v6 04/12] KVM: x86: Force fixed-1 bits in DR6 after synchronizing with hardware Sean Christopherson
2026-09-30 19:36 ` [PATCH v6 05/12] KVM: x86: Set guest's fixed-1 DR6 bits when delivering #DB payload Sean Christopherson
2026-09-30 19:36 ` [PATCH v6 06/12] KVM: x86: Kill off DR6_FIXED_1 to prevent future misuse Sean Christopherson
2026-09-30 19:36 ` [PATCH v6 07/12] KVM: SVM: Add helper to query if LBR virtualization needs to be enabled Sean Christopherson
2026-09-30 19:36 ` [PATCH v6 08/12] KVM: nSVM: Disable LBRV in nested control cache when unsupported Sean Christopherson
2026-09-30 19:36 ` Sean Christopherson [this message]
2026-09-30 19:36 ` [PATCH v6 10/12] KVM: nSVM: Don't assume all active-low bits DR6 are fixed-1 Sean Christopherson
2026-09-30 19:36 ` [PATCH v6 11/12] KVM: SVM: Add a vCPU-aware helper to get supported DEBUGCTL bits Sean Christopherson
2026-09-30 19:36 ` [PATCH v6 12/12] KVM: SVM: Add support for virtualizating Bus Lock Detect Sean Christopherson
2026-09-30 19:54 ` sashiko-bot
2026-09-30 20:20 ` Sean Christopherson
2026-10-02 21:07 ` [PATCH v6 00/12] KVM: x86: Bus Lock Detect fixes and SVM support Sean Christopherson
2026-10-05 5:46 ` Shivansh Dhiman
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