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authorSean Christopherson <seanjc@google.com>2023-01-06 01:12:41 +0000
committerPaolo Bonzini <pbonzini@redhat.com>2023-01-13 10:45:24 -0500
commit1459f5c6b8b8dfbc16adf4844421d46459c9ab1f (patch)
tree84edceb8ece4c5826bfbb96c069c3117c2dd70e9 /arch/x86/kvm/lapic.c
parente0bead97e7590da888148feb9e9133bc278c534b (diff)
KVM: x86: Handle APICv updates for APIC "mode" changes via request
Use KVM_REQ_UPDATE_APICV to react to APIC "mode" changes, i.e. to handle the APIC being hardware enabled/disabled and/or x2APIC being toggled. There is no need to immediately update APICv state, the only requirement is that APICv be updating prior to the next VM-Enter. Making a request will allow piggybacking KVM_REQ_UPDATE_APICV to "inhibit" the APICv memslot when x2APIC is enabled. Doing that directly from kvm_lapic_set_base() isn't feasible as KVM's SRCU must not be held when modifying memslots (to avoid deadlock), and may or may not be held when kvm_lapic_set_base() is called, i.e. KVM can't do the right thing without tracking that is rightly buried behind CONFIG_PROVE_RCU=y. Suggested-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20230106011306.85230-9-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/lapic.c')
-rw-r--r--arch/x86/kvm/lapic.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 2183a9b8efa5..3ed74ad60516 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -2401,7 +2401,7 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value)
kvm_apic_set_x2apic_id(apic, vcpu->vcpu_id);
if ((old_value ^ value) & (MSR_IA32_APICBASE_ENABLE | X2APIC_ENABLE)) {
- kvm_vcpu_update_apicv(vcpu);
+ kvm_make_request(KVM_REQ_APICV_UPDATE, vcpu);
static_call_cond(kvm_x86_set_virtual_apic_mode)(vcpu);
}