From: Sean Christopherson <seanjc@google.com>
Date: Wed, 11 Jun 2025 22:45:13 +0000 (-0700)
Subject: KVM: SVM: Add helper to deduplicate code for getting AVIC backing page
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3338c639da15a87cf57edc79de8409c98b704d87;p=thirdparty%2Fkernel%2Fstable.git

KVM: SVM: Add helper to deduplicate code for getting AVIC backing page

Add a helper to get the physical address of the AVIC backing page, both
to deduplicate code and to prepare for getting the address directly from
apic->regs, at which point it won't be all that obvious that the address
in question is what SVM calls the AVIC backing page.

No functional change intended.

Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Tested-by: Sairaj Kodilkar <sarunkod@amd.com>
Reviewed-by: Naveen N Rao (AMD) <naveen@kernel.org>
Link: https://lore.kernel.org/r/20250611224604.313496-12-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
---

diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c
index 61ea794a4dce..75317c189409 100644
--- a/arch/x86/kvm/svm/avic.c
+++ b/arch/x86/kvm/svm/avic.c
@@ -235,14 +235,18 @@ free_avic:
 	return err;
 }
 
+static phys_addr_t avic_get_backing_page_address(struct vcpu_svm *svm)
+{
+	return __sme_set(page_to_phys(svm->avic_backing_page));
+}
+
 void avic_init_vmcb(struct vcpu_svm *svm, struct vmcb *vmcb)
 {
 	struct kvm_svm *kvm_svm = to_kvm_svm(svm->vcpu.kvm);
-	phys_addr_t bpa = __sme_set(page_to_phys(svm->avic_backing_page));
 	phys_addr_t lpa = __sme_set(page_to_phys(kvm_svm->avic_logical_id_table_page));
 	phys_addr_t ppa = __sme_set(page_to_phys(kvm_svm->avic_physical_id_table_page));
 
-	vmcb->control.avic_backing_page = bpa;
+	vmcb->control.avic_backing_page = avic_get_backing_page_address(svm);
 	vmcb->control.avic_logical_id = lpa;
 	vmcb->control.avic_physical_id = ppa;
 	vmcb->control.avic_vapic_bar = APIC_DEFAULT_PHYS_BASE;
@@ -306,7 +310,7 @@ static int avic_init_backing_page(struct kvm_vcpu *vcpu)
 	BUILD_BUG_ON(__PHYSICAL_MASK_SHIFT >
 		     fls64(AVIC_PHYSICAL_ID_ENTRY_BACKING_PAGE_MASK));
 
-	new_entry = __sme_set(page_to_phys(svm->avic_backing_page)) |
+	new_entry = avic_get_backing_page_address(svm) |
 		    AVIC_PHYSICAL_ID_ENTRY_VALID_MASK;
 	WRITE_ONCE(*entry, new_entry);
 
@@ -846,7 +850,7 @@ get_pi_vcpu_info(struct kvm *kvm, struct kvm_kernel_irq_routing_entry *e,
 	pr_debug("SVM: %s: use GA mode for irq %u\n", __func__,
 		 irq.vector);
 	*svm = to_svm(vcpu);
-	vcpu_info->pi_desc_addr = __sme_set(page_to_phys((*svm)->avic_backing_page));
+	vcpu_info->pi_desc_addr = avic_get_backing_page_address(*svm);
 	vcpu_info->vector = irq.vector;
 
 	return 0;
@@ -907,7 +911,7 @@ int avic_pi_update_irte(struct kvm_kernel_irqfd *irqfd, struct kvm *kvm,
 			enable_remapped_mode = false;
 
 			/* Try to enable guest_mode in IRTE */
-			pi.base = __sme_set(page_to_phys(svm->avic_backing_page));
+			pi.base = avic_get_backing_page_address(svm);
 			pi.ga_tag = AVIC_GATAG(to_kvm_svm(kvm)->avic_vm_id,
 						     svm->vcpu.vcpu_id);
 			pi.is_guest_mode = true;