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Groups > linux.kernel > #1537848
| From | Radim Krčmář <rkrcmar@redhat.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH 4/4] KVM: x86: allow hotplug of VCPU with APIC ID over 0xff |
| Date | 2016-12-07 16:50 +0100 |
| Message-ID | <sLMDL-1V4-5@gated-at.bofh.it> (permalink) |
| References | <sK20h-82t-3@gated-at.bofh.it> <sK20i-82t-47@gated-at.bofh.it> <sLJcR-8nG-11@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
2016-12-07 13:03+0100, Paolo Bonzini: > On 02/12/2016 20:44, Radim Krčmář wrote: >> LAPIC after reset is in xAPIC mode, which poses a problem for hotplug of >> VCPUs with high APIC ID, because reset VCPU is waiting for INIT/SIPI, >> but there is no way to uniquely address it using xAPIC. >> >> From many possible options, we chose the one that also works on real >> hardware: accepting interrupts addressed to LAPIC's x2APIC ID even in >> xAPIC mode. >> >> KVM intentionally differs from real hardware, because real hardware >> (Knights Landing) does just "x2apic_id & 0xff" to decide whether to >> accept the interrupt in xAPIC mode and it can deliver one interrupt to >> more than one physical destination, e.g. 0x123 to 0x123 and 0x23. >> >> Add a capability to let userspace know that we do something now. > > I wouldn't even bother with the capability. It's a bit borderline for > stable, but I think it's okay. We can always Cc and let the maintainer > reject it. Ok, David also mentioned that I should tone down compatibility ... Thanks to both, I'll prepare v2.
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[PATCH 0/4] KVM: x86: allow hotplug of VCPU with APIC ID over 0xff Radim Krčmář <rkrcmar@redhat.com> - 2016-12-02 20:50 +0100
[PATCH 2/4] KVM: x86: replace kvm_apic_id with kvm_{x,x2}apic_id Radim Krčmář <rkrcmar@redhat.com> - 2016-12-02 20:50 +0100
[PATCH 3/4] KVM: x86: make interrupt delivery fast and slow path behave the same Radim Krčmář <rkrcmar@redhat.com> - 2016-12-02 20:50 +0100
[PATCH 4/4] KVM: x86: allow hotplug of VCPU with APIC ID over 0xff Radim Krčmář <rkrcmar@redhat.com> - 2016-12-02 20:50 +0100
Re: [PATCH 4/4] KVM: x86: allow hotplug of VCPU with APIC ID over 0xff David Hildenbrand <david@redhat.com> - 2016-12-05 15:40 +0100
Re: [PATCH 4/4] KVM: x86: allow hotplug of VCPU with APIC ID over 0xff Radim Krčmář <rkrcmar@redhat.com> - 2016-12-05 17:10 +0100
Re: [PATCH 4/4] KVM: x86: allow hotplug of VCPU with APIC ID over 0xff David Hildenbrand <david@redhat.com> - 2016-12-05 19:10 +0100
Re: [PATCH 4/4] KVM: x86: allow hotplug of VCPU with APIC ID over 0xff Radim Krčmář <rkrcmar@redhat.com> - 2016-12-05 22:00 +0100
Re: [PATCH 4/4] KVM: x86: allow hotplug of VCPU with APIC ID over 0xff David Hildenbrand <david@redhat.com> - 2016-12-06 10:50 +0100
Re: [PATCH 4/4] KVM: x86: allow hotplug of VCPU with APIC ID over 0xff Radim Krčmář <rkrcmar@redhat.com> - 2016-12-06 14:00 +0100
Re: [PATCH 4/4] KVM: x86: allow hotplug of VCPU with APIC ID over 0xff Paolo Bonzini <pbonzini@redhat.com> - 2016-12-07 13:10 +0100
Re: [PATCH 4/4] KVM: x86: allow hotplug of VCPU with APIC ID over 0xff Radim Krčmář <rkrcmar@redhat.com> - 2016-12-07 16:50 +0100
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