From 0a3869e14d4a5e1016aad6bc6c5b70f82bc0dbbe Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Thu, 1 Jun 2023 18:15:18 -0700 Subject: [PATCH] KVM: x86/mmu: Trigger APIC-access page reload iff vendor code cares Request an APIC-access page reload when the backing page is migrated (or unmapped) if and only if vendor code actually plugs the backing pfn into structures that reside outside of KVM's MMU. This avoids kicking all vCPUs in the (hopefully infrequent) scenario where the backing page is migrated/invalidated. Unlike VMX's APICv, SVM's AVIC doesn't plug the backing pfn directly into the VMCB and so doesn't need a hook to invalidate an out-of-MMU "mapping". Reviewed-by: Paolo Bonzini Link: https://lore.kernel.org/r/20230602011518.787006-4-seanjc@google.com Signed-off-by: Sean Christopherson --- arch/x86/kvm/mmu/mmu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 01a11ce68e570..beb507d82adfd 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -1600,7 +1600,8 @@ bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) if (tdp_mmu_enabled) flush = kvm_tdp_mmu_unmap_gfn_range(kvm, range, flush); - if (range->slot->id == APIC_ACCESS_PAGE_PRIVATE_MEMSLOT) + if (kvm_x86_ops.set_apic_access_page_addr && + range->slot->id == APIC_ACCESS_PAGE_PRIVATE_MEMSLOT) kvm_make_all_cpus_request(kvm, KVM_REQ_APIC_PAGE_RELOAD); return flush; -- 2.39.5