From: Vitaly Kuznetsov <vkuznets@redhat.com>
To: Igor Mammedov <imammedo@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
kvm@vger.kernel.org, Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>,
linux-kernel@vger.kernel.org,
Sean Christopherson <seanjc@google.com>
Subject: Re: [PATCH 2/2] KVM: x86: Forbid KVM_SET_CPUID{,2} after KVM_RUN
Date: Fri, 14 Jan 2022 13:25:10 +0100 [thread overview]
Message-ID: <87ee5amrmh.fsf@redhat.com> (raw)
In-Reply-To: <20220114122237.54fa8c91@redhat.com>
Igor Mammedov <imammedo@redhat.com> writes:
> On Fri, 14 Jan 2022 10:31:50 +0100
> Vitaly Kuznetsov <vkuznets@redhat.com> wrote:
>
>> Igor Mammedov <imammedo@redhat.com> writes:
>>
>>
>> > However, a problem of failing KVM_SET_CPUID2 during VCPU re-plug
>> > is still there and re-plug will fail if KVM rejects repeated KVM_SET_CPUID2
>> > even if ioctl called with exactly the same CPUID leafs as the 1st call.
>> >
>>
>> Assuming APIC id change doesn not need to be supported, I can send v2
>> here with an empty allowlist.
> As you mentioned in another thread black list would be better
> to address Sean's concerns or just revert problematic commit.
>
Personally, I'm leaning towards the blocklist approach even if just for
'documenting' the fact that KVM doesn't correctly handle the
change. Compared to a comment in the code, such approach could help
someone save tons of debugging time (if anyone ever decides do something
weird, like changing MAXPHYADDR on the fly).
--
Vitaly
next prev parent reply other threads:[~2022-01-14 12:25 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-22 17:58 [PATCH 0/2] KVM: x86: Forbid KVM_SET_CPUID{,2} after KVM_RUN Vitaly Kuznetsov
2021-11-22 17:58 ` [PATCH 1/2] KVM: selftests: Avoid KVM_SET_CPUID2 after KVM_RUN in hyperv_features test Vitaly Kuznetsov
2021-11-22 17:58 ` [PATCH 2/2] KVM: x86: Forbid KVM_SET_CPUID{,2} after KVM_RUN Vitaly Kuznetsov
2021-11-26 12:20 ` Paolo Bonzini
2021-12-27 17:32 ` Igor Mammedov
2022-01-02 17:31 ` Paolo Bonzini
2022-01-03 8:04 ` Vitaly Kuznetsov
2022-01-03 9:40 ` Igor Mammedov
2022-01-03 12:56 ` Vitaly Kuznetsov
2022-01-05 8:17 ` Igor Mammedov
2022-01-05 9:12 ` Vitaly Kuznetsov
2022-01-05 9:10 ` Paolo Bonzini
2022-01-05 10:09 ` Vitaly Kuznetsov
2022-01-07 9:02 ` Vitaly Kuznetsov
2022-01-07 18:15 ` Paolo Bonzini
2022-01-11 8:00 ` Igor Mammedov
2022-01-12 13:58 ` Vitaly Kuznetsov
2022-01-12 18:39 ` Paolo Bonzini
2022-01-13 9:27 ` Vitaly Kuznetsov
2022-01-13 14:28 ` Maxim Levitsky
2022-01-13 14:36 ` Vitaly Kuznetsov
2022-01-13 14:41 ` Maxim Levitsky
2022-01-13 14:59 ` Vitaly Kuznetsov
2022-01-13 16:26 ` Sean Christopherson
2022-01-13 16:30 ` Maxim Levitsky
2022-01-13 22:33 ` Sean Christopherson
2022-01-14 8:28 ` Maxim Levitsky
2022-01-14 16:08 ` Sean Christopherson
2022-01-14 8:55 ` Igor Mammedov
2022-01-14 9:31 ` Vitaly Kuznetsov
2022-01-14 11:22 ` Igor Mammedov
2022-01-14 12:25 ` Vitaly Kuznetsov [this message]
2022-01-14 17:00 ` Sean Christopherson
2022-01-17 9:55 ` Vitaly Kuznetsov
2022-01-17 11:20 ` Paolo Bonzini
2022-01-17 13:02 ` Vitaly Kuznetsov
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