linux-kernel - [PATCH RESEND 15/30] KVM: x86: SVM: remove avic's broken code that updated APIC ID

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Message-Id: <20220207155447.840194-16-mlevitsk@redhat.com>
Date:   Mon,  7 Feb 2022 17:54:32 +0200
From:   Maxim Levitsky <mlevitsk@...hat.com>
To:     kvm@...r.kernel.org
Cc:     Tony Luck <tony.luck@...el.com>,
        "Chang S. Bae" <chang.seok.bae@...el.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Wanpeng Li <wanpengli@...cent.com>,
        Ingo Molnar <mingo@...hat.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Pawan Gupta <pawan.kumar.gupta@...ux.intel.com>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        linux-kernel@...r.kernel.org,
        Rodrigo Vivi <rodrigo.vivi@...el.com>,
        "H. Peter Anvin" <hpa@...or.com>,
        intel-gvt-dev@...ts.freedesktop.org,
        Joonas Lahtinen <joonas.lahtinen@...ux.intel.com>,
        Joerg Roedel <joro@...tes.org>,
        Sean Christopherson <seanjc@...gle.com>,
        David Airlie <airlied@...ux.ie>,
        Zhi Wang <zhi.a.wang@...el.com>,
        Brijesh Singh <brijesh.singh@....com>,
        Jim Mattson <jmattson@...gle.com>, x86@...nel.org,
        Daniel Vetter <daniel@...ll.ch>,
        Borislav Petkov <bp@...en8.de>,
        Zhenyu Wang <zhenyuw@...ux.intel.com>,
        Kan Liang <kan.liang@...ux.intel.com>,
        Jani Nikula <jani.nikula@...ux.intel.com>,
        Maxim Levitsky <mlevitsk@...hat.com>
Subject: [PATCH RESEND 15/30] 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 8f23e7d239097..768252b3dfee6 100644
--- a/arch/x86/kvm/svm/avic.c
+++ b/arch/x86/kvm/svm/avic.c
@@ -440,35 +440,6 @@ 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 vcpu_svm *svm)
 				AVIC_UNACCEL_ACCESS_OFFSET_MASK;
 
 	switch (offset) {
-	case APIC_ID:
-		if (avic_handle_apic_id_update(&svm->vcpu))
-			return 0;
-		break;
 	case APIC_LDR:
 		if (avic_handle_ldr_update(&svm->vcpu))
 			return 0;
@@ -584,8 +551,6 @@ 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