[PATCH v2 15/46] KVM: x86: Set BSP bit in reset BSP vCPU's APIC base by default

From: Sean Christopherson
Date: Tue Jul 13 2021 - 12:34:25 EST


Set the BSP bit appropriately during local APIC "reset" instead of
relying on vendor code to clean up at a later point. This is a step
towards consolidating the local APIC, VMX, and SVM xAPIC initialization
code.

Reviewed-by: Reiji Watanabe <reijiw@xxxxxxxxxx>
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/lapic.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index acb201d16b5e..0fb282b64c8f 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -2321,6 +2321,7 @@ EXPORT_SYMBOL_GPL(kvm_apic_update_apicv);
void kvm_lapic_reset(struct kvm_vcpu *vcpu, bool init_event)
{
struct kvm_lapic *apic = vcpu->arch.apic;
+ u64 msr_val;
int i;

if (!apic)
@@ -2330,8 +2331,10 @@ void kvm_lapic_reset(struct kvm_vcpu *vcpu, bool init_event)
hrtimer_cancel(&apic->lapic_timer.timer);

if (!init_event) {
- kvm_lapic_set_base(vcpu, APIC_DEFAULT_PHYS_BASE |
- MSR_IA32_APICBASE_ENABLE);
+ msr_val = APIC_DEFAULT_PHYS_BASE | MSR_IA32_APICBASE_ENABLE;
+ if (kvm_vcpu_is_reset_bsp(vcpu))
+ msr_val |= MSR_IA32_APICBASE_BSP;
+ kvm_lapic_set_base(vcpu, msr_val);
kvm_apic_set_xapic_id(apic, vcpu->vcpu_id);
}
kvm_apic_set_version(apic->vcpu);
--
2.32.0.93.g670b81a890-goog