linux-kernel - [RFC PATCH v2 06/10] KVM: x86: SVM: remove avic's broken code that updated APIC ID

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Thu, 21 Apr 2022 08:12:40 +0300
From:   Maxim Levitsky <mlevitsk@...hat.com>
To:     kvm@...r.kernel.org
Cc:     Rodrigo Vivi <rodrigo.vivi@...el.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        intel-gfx@...ts.freedesktop.org,
        Joonas Lahtinen <joonas.lahtinen@...ux.intel.com>,
        Jani Nikula <jani.nikula@...ux.intel.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        linux-kernel@...r.kernel.org, Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Tvrtko Ursulin <tvrtko.ursulin@...ux.intel.com>,
        "H. Peter Anvin" <hpa@...or.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Zhi Wang <zhi.a.wang@...el.com>,
        Daniel Vetter <daniel@...ll.ch>,
        intel-gvt-dev@...ts.freedesktop.org,
        dri-devel@...ts.freedesktop.org, x86@...nel.org,
        David Airlie <airlied@...ux.ie>,
        Sean Christopherson <seanjc@...gle.com>,
        Ingo Molnar <mingo@...hat.com>, Joerg Roedel <joro@...tes.org>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Borislav Petkov <bp@...en8.de>,
        Zhenyu Wang <zhenyuw@...ux.intel.com>,
        Maxim Levitsky <mlevitsk@...hat.com>
Subject: [RFC PATCH v2 06/10] 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 9b859218af59c..f375ca1d6518e 100644
--- a/arch/x86/kvm/svm/avic.c
+++ b/arch/x86/kvm/svm/avic.c
@@ -442,35 +442,6 @@ 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);
@@ -489,10 +460,6 @@ 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;
@@ -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