6.12-stable review patch. If anyone has any objections, please let me know.
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From: Dongli Zhang dongli.zhang@oracle.com
commit 29763138830916f46daaa50e83e7f4f907a3236b upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/kvm/vmx/nested.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -18,6 +18,7 @@ #include "trace.h" #include "vmx.h" #include "smm.h" +#include "x86_ops.h"
static bool __read_mostly enable_shadow_vmcs = 1; module_param_named(enable_shadow_vmcs, enable_shadow_vmcs, bool, S_IRUGO); @@ -5051,7 +5052,7 @@ 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) {