diff options
| author | Sean Christopherson <seanjc@google.com> | 2026-02-03 11:07:09 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-03-19 16:15:02 +0100 |
| commit | f137c496bacbefb12a3680e407925b240c7e5b7c (patch) | |
| tree | 8b2a3f450cf964e0417a39228241a2f8910d6706 /arch/x86/kvm/svm/svm.c | |
| parent | cb979700c40f592473704be14a8441b3a4451255 (diff) | |
KVM: SVM: Initialize AVIC VMCB fields if AVIC is enabled with in-kernel APIC
commit 3989a6d036c8ec82c0de3614bed23a1dacd45de5 upstream.
Initialize all per-vCPU AVIC control fields in the VMCB if AVIC is enabled
in KVM and the VM has an in-kernel local APIC, i.e. if it's _possible_ the
vCPU could activate AVIC at any point in its lifecycle. Configuring the
VMCB if and only if AVIC is active "works" purely because of optimizations
in kvm_create_lapic() to speculatively set apicv_active if AVIC is enabled
*and* to defer updates until the first KVM_RUN. In quotes because KVM
likely won't do the right thing if kvm_apicv_activated() is false, i.e. if
a vCPU is created while APICv is inhibited at the VM level for whatever
reason. E.g. if the inhibit is *removed* before KVM_REQ_APICV_UPDATE is
handled in KVM_RUN, then __kvm_vcpu_update_apicv() will elide calls to
vendor code due to seeing "apicv_active == activate".
Cleaning up the initialization code will also allow fixing a bug where KVM
incorrectly leaves CR8 interception enabled when AVIC is activated without
creating a mess with respect to whether AVIC is activated or not.
Cc: stable@vger.kernel.org
Fixes: 67034bb9dd5e ("KVM: SVM: Add irqchip_split() checks before enabling AVIC")
Fixes: 6c3e4422dd20 ("svm: Add support for dynamic APICv")
Reviewed-by: Naveen N Rao (AMD) <naveen@kernel.org>
Reviewed-by: Jim Mattson <jmattson@google.com>
Link: https://patch.msgid.link/20260203190711.458413-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/kvm/svm/svm.c')
| -rw-r--r-- | arch/x86/kvm/svm/svm.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index a58548b35b85..a1a5da6e4b01 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -1141,7 +1141,7 @@ static void init_vmcb(struct kvm_vcpu *vcpu, bool init_event) svm_clr_intercept(svm, INTERCEPT_PAUSE); } - if (kvm_vcpu_apicv_active(vcpu)) + if (enable_apicv && irqchip_in_kernel(vcpu->kvm)) avic_init_vmcb(svm, vmcb); if (vnmi) |