From: Sean Christopherson <seanjc@google.com>
To: Greg Edwards <gedwards@ddn.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Paolo Bonzini <pbonzini@redhat.com>,
Maxim Levitsky <mlevitsk@redhat.com>
Subject: Re: [PATCH v3] KVM: x86: Allow APICv APIC ID inhibit to be cleared
Date: Fri, 18 Nov 2022 16:04:15 +0000 [thread overview]
Message-ID: <Y3es/yLTo1dXSzAF@google.com> (raw)
In-Reply-To: <20221117183247.94314-1-gedwards@ddn.com>
On Thu, Nov 17, 2022, Greg Edwards wrote:
> Legacy kernels prior to commit 4399c03c6780 ("x86/apic: Remove
> verify_local_APIC()") write the APIC ID of the boot CPU twice to verify
> a functioning local APIC. This results in APIC acceleration inhibited
> on these kernels for reason APICV_INHIBIT_REASON_APIC_ID_MODIFIED.
>
> Allow the APICV_INHIBIT_REASON_APIC_ID_MODIFIED inhibit reason to be
> cleared if/when all APICs in xAPIC mode set their APIC ID back to the
> expected vcpu_id value.
>
> Fold the functionality previously in kvm_lapic_xapic_id_updated() into
> kvm_recalculate_apic_map(), as this allows examining all APICs in one
> pass.
>
> Fixes: 3743c2f02517 ("KVM: x86: inhibit APICv/AVIC on changes to APIC ID or APIC base")
> Signed-off-by: Greg Edwards <gedwards@ddn.com>
> ---
Reviewed-by: Sean Christopherson <seanjc@google.com>
next prev parent reply other threads:[~2022-11-18 16:04 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-14 20:20 [PATCH] KVM: x86: Allow APICv APIC ID inhibit to be cleared on legacy kernels Greg Edwards
2022-11-14 21:30 ` Sean Christopherson
2022-11-14 23:53 ` Greg Edwards
2022-11-16 20:51 ` [PATCH v2] KVM: x86: Allow APICv APIC ID inhibit to be cleared Greg Edwards
2022-11-16 21:23 ` Sean Christopherson
2022-11-17 18:33 ` [PATCH v3] " Greg Edwards
2022-11-18 16:04 ` Sean Christopherson [this message]
2022-11-21 15:18 ` Maxim Levitsky
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