From: Vitaly Kuznetsov <vkuznets@redhat.com>
To: Sean Christopherson <seanjc@google.com>,
Gerd Hoffmann <kraxel@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
kvm@vger.kernel.org, rcu@vger.kernel.org,
linux-kernel@vger.kernel.org, Kevin Tian <kevin.tian@intel.com>,
Yan Zhao <yan.y.zhao@intel.com>, Yiwei Zhang <zzyiwei@google.com>,
Lai Jiangshan <jiangshanlai@gmail.com>,
"Paul E. McKenney" <paulmck@kernel.org>,
Josh Triplett <josh@joshtriplett.org>
Subject: Re: [PATCH 5/5] KVM: VMX: Always honor guest PAT on CPUs that support self-snoop
Date: Fri, 30 Aug 2024 15:47:11 +0200 [thread overview]
Message-ID: <871q26unq8.fsf@redhat.com> (raw)
In-Reply-To: <vuwlkftomgsnzsywjyxw6rcnycg3bve3o53svvxg3vd6xpok7o@k4ktmx5tqtmz>
Gerd Hoffmann <kraxel@redhat.com> writes:
>> Necroposting!
>>
>> Turns out that this change broke "bochs-display" driver in QEMU even
>> when the guest is modern (don't ask me 'who the hell uses bochs for
>> modern guests', it was basically a configuration error :-). E.g:
>
> qemu stdvga (the default display device) is affected too.
>
So far, I was only able to verify that the issue has nothing to do with
OVMF and multi-vcpu, it reproduces very well with
$ qemu-kvm -machine q35,accel=kvm,kernel-irqchip=split -name guest=c10s
-cpu host -smp 1 -m 16384 -drive file=/var/lib/libvirt/images/c10s-bios.qcow2,if=none,id=drive-ide0-0-0
-device ide-hd,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0,bootindex=1
-vnc :0 -device VGA -monitor stdio --no-reboot
Comparing traces of working and broken cases, I couldn't find anything
suspicious but I may had missed something of course. For now, it seems
like a userspace misbehavior resulting in a segfault.
--
Vitaly
next prev parent reply other threads:[~2024-08-30 13:47 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-09 1:09 [PATCH 0/5] KVM: VMX: Drop MTRR virtualization, honor guest PAT Sean Christopherson
2024-03-09 1:09 ` [PATCH 1/5] KVM: x86: Remove VMX support for virtualizing guest MTRR memtypes Sean Christopherson
2024-03-11 7:44 ` Yan Zhao
2024-03-12 0:08 ` Sean Christopherson
2024-03-12 1:10 ` Dongli Zhang
2024-03-12 17:08 ` Sean Christopherson
2024-03-14 10:31 ` Dongli Zhang
2024-03-14 14:47 ` Sean Christopherson
2024-03-09 1:09 ` [PATCH 2/5] KVM: VMX: Drop support for forcing UC memory when guest CR0.CD=1 Sean Christopherson
2024-03-09 1:09 ` [PATCH 3/5] srcu: Add an API for a memory barrier after SRCU read lock Sean Christopherson
2024-03-09 1:09 ` [PATCH 4/5] KVM: x86: Ensure a full memory barrier is emitted in the VM-Exit path Sean Christopherson
2024-06-20 22:38 ` Paolo Bonzini
2024-06-20 23:42 ` Paul E. McKenney
2024-06-21 0:52 ` Yan Zhao
2024-03-09 1:09 ` [PATCH 5/5] KVM: VMX: Always honor guest PAT on CPUs that support self-snoop Sean Christopherson
2024-03-11 1:16 ` Yan Zhao
2024-03-12 0:25 ` Sean Christopherson
2024-03-12 7:30 ` Tian, Kevin
2024-03-12 16:07 ` Sean Christopherson
2024-03-13 1:18 ` Yan Zhao
2024-03-13 8:52 ` Tian, Kevin
2024-03-13 8:55 ` Yan Zhao
2024-03-13 15:09 ` Sean Christopherson
2024-03-14 0:12 ` Yan Zhao
2024-03-14 1:00 ` Sean Christopherson
2024-03-25 3:43 ` Chao Gao
2024-04-01 22:29 ` Sean Christopherson
2024-08-30 9:35 ` Vitaly Kuznetsov
2024-08-30 11:05 ` Gerd Hoffmann
2024-08-30 13:47 ` Vitaly Kuznetsov [this message]
2024-08-30 13:52 ` Sean Christopherson
2024-08-30 14:06 ` Vitaly Kuznetsov
2024-08-30 14:37 ` Vitaly Kuznetsov
2024-08-30 16:13 ` Sean Christopherson
2024-09-02 8:23 ` Gerd Hoffmann
2024-09-02 1:44 ` Yan Zhao
2024-09-02 9:49 ` Vitaly Kuznetsov
2024-09-03 0:25 ` Yan Zhao
2024-09-03 15:30 ` Sean Christopherson
2024-09-03 16:20 ` Vitaly Kuznetsov
2024-09-04 2:28 ` Yan Zhao
2024-09-04 12:17 ` Yan Zhao
2024-09-05 0:41 ` Sean Christopherson
2024-09-05 9:43 ` Yan Zhao
2024-09-09 5:30 ` Yan Zhao
2024-09-09 13:24 ` Paolo Bonzini
2024-09-09 16:04 ` Sean Christopherson
2024-09-10 1:05 ` Yan Zhao
2024-09-04 11:47 ` Vitaly Kuznetsov
2024-10-07 13:28 ` Linux regression tracking (Thorsten Leemhuis)
2024-10-07 13:38 ` Vitaly Kuznetsov
2024-10-07 14:04 ` Linux regression tracking (Thorsten Leemhuis)
2024-03-22 9:29 ` [PATCH 0/5] KVM: VMX: Drop MTRR virtualization, honor guest PAT Ma, Yongwei
2024-03-22 13:08 ` Yan Zhao
2024-03-25 6:56 ` Ma, XiangfeiX
2024-03-25 8:02 ` Ma, XiangfeiX
2024-06-05 23:20 ` Sean Christopherson
2024-06-06 0:03 ` Paul E. McKenney
-- strict thread matches above, loose matches on Subject: below --
2025-04-10 1:13 [PATCH 5/5] KVM: VMX: Always honor guest PAT on CPUs that support self-snoop Myrsky Lintu
2025-04-10 5:12 ` Yan Zhao
2025-04-10 10:05 ` Myrsky Lintu
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