linux-kernel - [PATCH v3 07/11] KVM: x86: SVM: remove avic's broken code that updated APIC ID

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Message-Id: <20220301182639.559568-8-mlevitsk@redhat.com>
Date:   Tue,  1 Mar 2022 20:26:35 +0200
From:   Maxim Levitsky <mlevitsk@...hat.com>
To:     kvm@...r.kernel.org
Cc:     Vitaly Kuznetsov <vkuznets@...hat.com>,
        Ingo Molnar <mingo@...hat.com>,
        Sean Christopherson <seanjc@...gle.com>,
        Jani Nikula <jani.nikula@...ux.intel.com>,
        Daniel Vetter <daniel@...ll.ch>,
        Zhi Wang <zhi.a.wang@...el.com>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Tvrtko Ursulin <tvrtko.ursulin@...ux.intel.com>,
        David Airlie <airlied@...ux.ie>,
        Wanpeng Li <wanpengli@...cent.com>,
        Joonas Lahtinen <joonas.lahtinen@...ux.intel.com>,
        x86@...nel.org, intel-gvt-dev@...ts.freedesktop.org,
        Joerg Roedel <joro@...tes.org>,
        Zhenyu Wang <zhenyuw@...ux.intel.com>,
        Rodrigo Vivi <rodrigo.vivi@...el.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        "H. Peter Anvin" <hpa@...or.com>, Borislav Petkov <bp@...en8.de>,
        Jim Mattson <jmattson@...gle.com>,
        intel-gfx@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
        Thomas Gleixner <tglx@...utronix.de>,
        dri-devel@...ts.freedesktop.org,
        Maxim Levitsky <mlevitsk@...hat.com>
Subject: [PATCH v3 07/11] KVM: x86: SVM: remove avic's broken code that updated APIC ID

Now that KVM doesn't allow to change APIC ID in case AVIC is
enabled, remove buggy AVIC code that tried to do so.

Signed-off-by: Maxim Levitsky <mlevitsk@...hat.com>
---
 arch/x86/kvm/svm/avic.c | 35 -----------------------------------
 1 file changed, 35 deletions(-)

diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c
index d5ce0868c5a74..90f106d4af45e 100644
--- a/arch/x86/kvm/svm/avic.c
+++ b/arch/x86/kvm/svm/avic.c
@@ -441,35 +441,6 @@ static int avic_handle_ldr_update(struct kvm_vcpu *vcpu)
 	return ret;
 }
 
-static int avic_handle_apic_id_update(struct kvm_vcpu *vcpu)
-{
-	u64 *old, *new;
-	struct vcpu_svm *svm = to_svm(vcpu);
-	u32 id = kvm_xapic_id(vcpu->arch.apic);
-
-	if (vcpu->vcpu_id == id)
-		return 0;
-
-	old = avic_get_physical_id_entry(vcpu, vcpu->vcpu_id);
-	new = avic_get_physical_id_entry(vcpu, id);
-	if (!new || !old)
-		return 1;
-
-	/* We need to move physical_id_entry to new offset */
-	*new = *old;
-	*old = 0ULL;
-	to_svm(vcpu)->avic_physical_id_cache = new;
-
-	/*
-	 * Also update the guest physical APIC ID in the logical
-	 * APIC ID table entry if already setup the LDR.
-	 */
-	if (svm->ldr_reg)
-		avic_handle_ldr_update(vcpu);
-
-	return 0;
-}
-
 static void avic_handle_dfr_update(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
@@ -488,10 +459,6 @@ static int avic_unaccel_trap_write(struct kvm_vcpu *vcpu)
 				AVIC_UNACCEL_ACCESS_OFFSET_MASK;
 
 	switch (offset) {
-	case APIC_ID:
-		if (avic_handle_apic_id_update(vcpu))
-			return 0;
-		break;
 	case APIC_LDR:
 		if (avic_handle_ldr_update(vcpu))
 			return 0;
@@ -583,8 +550,6 @@ int avic_init_vcpu(struct vcpu_svm *svm)
 
 void avic_apicv_post_state_restore(struct kvm_vcpu *vcpu)
 {
-	if (avic_handle_apic_id_update(vcpu) != 0)
-		return;
 	avic_handle_dfr_update(vcpu);
 	avic_handle_ldr_update(vcpu);
 }
-- 
2.26.3