From 1dc643205953c2ff2e1d95dbdc2e784675abb38c Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Thu, 15 Jan 2026 09:34:27 -0800 Subject: [PATCH] KVM: nVMX: Remove explicit filtering of GUEST_INTR_STATUS from shadow VMCS fields Drop KVM's filtering of GUEST_INTR_STATUS when generating the shadow VMCS bitmap now that KVM drops GUEST_INTR_STATUS from the set of supported vmcs12 fields if the field isn't supported by hardware, and initialization of the shadow VMCS fields omits unsupported vmcs12 fields. Note, there is technically a small functional change here, as the vmcs12 filtering only requires support for Virtual Interrupt Delivery, whereas the shadow VMCS code being removed required "full" APICv support, i.e. required Virtual Interrupt Delivery *and* APIC Register Virtualizaton *and* Posted Interrupt support. Opportunistically tweak the comment to more precisely explain why the PML and VMX preemption timer fields need to be explicitly checked. Reviewed-by: Xiaoyao Li Link: https://patch.msgid.link/20260115173427.716021-5-seanjc@google.com Signed-off-by: Sean Christopherson --- arch/x86/kvm/vmx/nested.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index f7950d8465a97..a5529a4bc87df 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -118,9 +118,10 @@ static void init_vmcs_shadow_fields(void) continue; /* - * PML and the preemption timer can be emulated, but the - * processor cannot vmwrite to fields that don't exist - * on bare metal. + * KVM emulates PML and the VMX preemption timer irrespective + * of hardware support, but shadowing their related VMCS fields + * requires hardware support as the CPU will reject VMWRITEs to + * fields that don't exist. */ switch (field) { case GUEST_PML_INDEX: @@ -131,10 +132,6 @@ static void init_vmcs_shadow_fields(void) if (!cpu_has_vmx_preemption_timer()) continue; break; - case GUEST_INTR_STATUS: - if (!cpu_has_vmx_apicv()) - continue; - break; default: break; } -- 2.47.3