diff options
| author | Radim Krčmář <rkrcmar@redhat.com> | 2016-12-15 18:06:48 +0100 |
|---|---|---|
| committer | Radim Krčmář <rkrcmar@redhat.com> | 2017-01-09 14:47:48 +0100 |
| commit | 5bd5db385b3e13c702365574c0b7350c6ea45e84 (patch) | |
| tree | f2ab889b6410e6b29479a2249d69c788b717b590 /kernel/range.c | |
| parent | b4535b58ae0df8b7cf0fe92a0c23aa3cf862e3cc (diff) | |
KVM: x86: allow hotplug of VCPU with APIC ID over 0xff
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.
Fixes: 682f732ecf73 ("KVM: x86: bump MAX_VCPUS to 288")
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'kernel/range.c')
0 files changed, 0 insertions, 0 deletions