6.1-stable review patch. If anyone has any objections, please let me know.
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From: Dongli Zhang dongli.zhang@oracle.com
[ Upstream commit 29763138830916f46daaa50e83e7f4f907a3236b ]
If an APICv status updated was pended while L2 was active, immediately refresh vmcs01's controls instead of pending KVM_REQ_APICV_UPDATE as kvm_vcpu_update_apicv() only calls into vendor code if a change is necessary.
E.g. if APICv is inhibited, and then activated while L2 is running:
kvm_vcpu_update_apicv() | -> __kvm_vcpu_update_apicv() | -> apic->apicv_active = true | -> vmx_refresh_apicv_exec_ctrl() | -> vmx->nested.update_vmcs01_apicv_status = true | -> return
Then L2 exits to L1:
__nested_vmx_vmexit() | -> kvm_make_request(KVM_REQ_APICV_UPDATE)
vcpu_enter_guest(): KVM_REQ_APICV_UPDATE -> kvm_vcpu_update_apicv() | -> __kvm_vcpu_update_apicv() | -> return // because if (apic->apicv_active == activate)
Reported-by: Chao Gao chao.gao@intel.com Closes: https://lore.kernel.org/all/aQ2jmnN8wUYVEawF@intel.com Fixes: 7c69661e225c ("KVM: nVMX: Defer APICv updates while L2 is active until L1 is active") Cc: stable@vger.kernel.org Signed-off-by: Dongli Zhang dongli.zhang@oracle.com [sean: write changelog] Link: https://patch.msgid.link/20251205231913.441872-3-seanjc@google.com Signed-off-by: Sean Christopherson seanjc@google.com [ exported vmx_refresh_apicv_exec_ctrl() and added declaration in vmx.h ] Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/kvm/vmx/nested.c | 2 +- arch/x86/kvm/vmx/vmx.c | 2 +- arch/x86/kvm/vmx/vmx.h | 1 + 3 files changed, 3 insertions(+), 2 deletions(-)
--- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -4847,7 +4847,7 @@ void nested_vmx_vmexit(struct kvm_vcpu *
if (vmx->nested.update_vmcs01_apicv_status) { vmx->nested.update_vmcs01_apicv_status = false; - kvm_make_request(KVM_REQ_APICV_UPDATE, vcpu); + vmx_refresh_apicv_exec_ctrl(vcpu); }
if (vmx->nested.update_vmcs01_hwapic_isr) { --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -4387,7 +4387,7 @@ static u32 vmx_vmexit_ctrl(void) ~(VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL | VM_EXIT_LOAD_IA32_EFER); }
-static void vmx_refresh_apicv_exec_ctrl(struct kvm_vcpu *vcpu) +void vmx_refresh_apicv_exec_ctrl(struct kvm_vcpu *vcpu) { struct vcpu_vmx *vmx = to_vmx(vcpu);
--- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -408,6 +408,7 @@ void __vmx_set_segment(struct kvm_vcpu * u64 construct_eptp(struct kvm_vcpu *vcpu, hpa_t root_hpa, int root_level);
bool vmx_guest_inject_ac(struct kvm_vcpu *vcpu); +void vmx_refresh_apicv_exec_ctrl(struct kvm_vcpu *vcpu); void vmx_update_exception_bitmap(struct kvm_vcpu *vcpu); bool vmx_nmi_blocked(struct kvm_vcpu *vcpu); bool __vmx_interrupt_blocked(struct kvm_vcpu *vcpu);