linux-kernel - [PATCH v2 06/59] KVM: SVM: Drop pointless masking of default APIC base when setting V_APIC

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Message-ID: <20250523010004.3240643-7-seanjc@google.com>
Date: Thu, 22 May 2025 17:59:11 -0700
From: Sean Christopherson <seanjc@...gle.com>
To: Sean Christopherson <seanjc@...gle.com>, Paolo Bonzini <pbonzini@...hat.com>, 
	Joerg Roedel <joro@...tes.org>, David Woodhouse <dwmw2@...radead.org>, 
	Lu Baolu <baolu.lu@...ux.intel.com>
Cc: kvm@...r.kernel.org, iommu@...ts.linux.dev, linux-kernel@...r.kernel.org, 
	Sairaj Kodilkar <sarunkod@....com>, Vasant Hegde <vasant.hegde@....com>, 
	Maxim Levitsky <mlevitsk@...hat.com>, Joao Martins <joao.m.martins@...cle.com>, 
	Francesco Lavra <francescolavra.fl@...il.com>, David Matlack <dmatlack@...gle.com>
Subject: [PATCH v2 06/59] KVM: SVM: Drop pointless masking of default APIC
 base when setting V_APIC_BAR

Drop VMCB_AVIC_APIC_BAR_MASK, it's just a regurgitation of the maximum
theoretical 4KiB-aligned physical address, i.e. is not novel in any way,
and its only usage is to mask the default APIC base, which is 4KiB aligned
and (obviously) a legal physical address.

No functional change intended.

Tested-by: Sairaj Kodilkar <sarunkod@....com>
Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/include/asm/svm.h | 2 --
 arch/x86/kvm/svm/avic.c    | 2 +-
 2 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h
index ad954a1a6656..89a666952b01 100644
--- a/arch/x86/include/asm/svm.h
+++ b/arch/x86/include/asm/svm.h
@@ -260,8 +260,6 @@ struct __attribute__ ((__packed__)) vmcb_control_area {
 
 #define AVIC_DOORBELL_PHYSICAL_ID_MASK			GENMASK_ULL(11, 0)
 
-#define VMCB_AVIC_APIC_BAR_MASK				0xFFFFFFFFFF000ULL
-
 #define AVIC_UNACCEL_ACCESS_WRITE_MASK		1
 #define AVIC_UNACCEL_ACCESS_OFFSET_MASK		0xFF0
 #define AVIC_UNACCEL_ACCESS_VECTOR_MASK		0xFFFFFFFF
diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c
index c981ce764b45..5344ae76c590 100644
--- a/arch/x86/kvm/svm/avic.c
+++ b/arch/x86/kvm/svm/avic.c
@@ -244,7 +244,7 @@ void avic_init_vmcb(struct vcpu_svm *svm, struct vmcb *vmcb)
 	vmcb->control.avic_backing_page = bpa & AVIC_HPA_MASK;
 	vmcb->control.avic_logical_id = lpa & AVIC_HPA_MASK;
 	vmcb->control.avic_physical_id = ppa & AVIC_HPA_MASK;
-	vmcb->control.avic_vapic_bar = APIC_DEFAULT_PHYS_BASE & VMCB_AVIC_APIC_BAR_MASK;
+	vmcb->control.avic_vapic_bar = APIC_DEFAULT_PHYS_BASE;
 
 	if (kvm_apicv_activated(svm->vcpu.kvm))
 		avic_activate_vmcb(svm);
-- 
2.49.0.1151.ga128411c76-goog