linux-kernel - Re: [syzbot ci] Re: AMD: Add Secure AVIC KVM Support

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Message-ID: <aefdae17-d5ad-4749-8b7b-e253d68f86cc@amd.com>
Date: Tue, 23 Sep 2025 15:47:30 +0530
From: "Upadhyay, Neeraj" <neeraj.upadhyay@....com>
To: syzbot ci <syzbot+ci3162984bece220f0@...kaller.appspotmail.com>,
 bp@...en8.de, david.kaplan@....com, huibo.wang@....com, kvm@...r.kernel.org,
 linux-kernel@...r.kernel.org, naveen.rao@....com, nikunj@....com,
 pbonzini@...hat.com, santosh.shukla@....com, seanjc@...gle.com,
 suravee.suthikulpanit@....com, thomas.lendacky@....com, tiala@...rosoft.com,
 vasant.hegde@....com
Cc: syzbot@...ts.linux.dev, syzkaller-bugs@...glegroups.com
Subject: Re: [syzbot ci] Re: AMD: Add Secure AVIC KVM Support



On 9/23/2025 3:32 PM, syzbot ci wrote:
> syzbot ci has tested the following series
> 
> [v2] AMD: Add Secure AVIC KVM Support
> https://lore.kernel.org/all/20250923050317.205482-1-Neeraj.Upadhyay@amd.com
> * [RFC PATCH v2 01/17] KVM: x86/lapic: Differentiate protected APIC interrupt mechanisms
> * [RFC PATCH v2 02/17] x86/cpufeatures: Add Secure AVIC CPU feature
> * [RFC PATCH v2 03/17] KVM: SVM: Add support for Secure AVIC capability in KVM
> * [RFC PATCH v2 04/17] KVM: SVM: Set guest APIC protection flags for Secure AVIC
> * [RFC PATCH v2 05/17] KVM: SVM: Do not intercept SECURE_AVIC_CONTROL MSR for SAVIC guests
> * [RFC PATCH v2 06/17] KVM: SVM: Implement interrupt injection for Secure AVIC
> * [RFC PATCH v2 07/17] KVM: SVM: Add IPI Delivery Support for Secure AVIC
> * [RFC PATCH v2 08/17] KVM: SVM: Do not inject exception for Secure AVIC
> * [RFC PATCH v2 09/17] KVM: SVM: Do not intercept exceptions for Secure AVIC guests
> * [RFC PATCH v2 10/17] KVM: SVM: Set VGIF in VMSA area for Secure AVIC guests
> * [RFC PATCH v2 11/17] KVM: SVM: Enable NMI support for Secure AVIC guests
> * [RFC PATCH v2 12/17] KVM: SVM: Add VMGEXIT handler for Secure AVIC backing page
> * [RFC PATCH v2 13/17] KVM: SVM: Add IOAPIC EOI support for Secure AVIC guests
> * [RFC PATCH v2 14/17] KVM: x86/ioapic: Disable RTC EOI tracking for protected APIC guests
> * [RFC PATCH v2 15/17] KVM: SVM: Check injected timers for Secure AVIC guests
> * [RFC PATCH v2 16/17] KVM: x86/cpuid: Disable paravirt APIC features for protected APIC
> * [RFC PATCH v2 17/17] KVM: SVM: Advertise Secure AVIC support for SNP guests
> 
> and found the following issue:
> general protection fault in kvm_apply_cpuid_pv_features_quirk
> 
> Full report is available here:
> https://ci.syzbot.org/series/887b895e-0315-498c-99e5-966704f16fb5
> 
> ***
> 
> general protection fault in kvm_apply_cpuid_pv_features_quirk
> 

Thanks for the report. I will update the check to below:

       if (lapic_in_kernel(vcpu) && vcpu->arch.apic->guest_apic_protected)
               best->eax &= ~((1 << KVM_FEATURE_PV_EOI) |
                              (1 << KVM_FEATURE_PV_SEND_IPI));


- Neeraj