tree a5b87c639298951bfee39ba9e2b14f36d9dd6af8
parent e90e51d5f01d2baae5dcce280866bbb96816e978
author Paolo Bonzini <pbonzini@redhat.com> 1638261967 -0500
committer Paolo Bonzini <pbonzini@redhat.com> 1638276048 -0500

KVM: fix avic_set_running for preemptable kernels

avic_set_running() passes the current CPU to avic_vcpu_load(), albeit
via vcpu->cpu rather than smp_processor_id().  If the thread is migrated
while avic_set_running runs, the call to avic_vcpu_load() can use a stale
value for the processor id.  Avoid this by blocking preemption over the
entire execution of avic_set_running().

Reported-by: Sean Christopherson <seanjc@google.com>
Fixes: 8221c1370056 ("svm: Manage vcpu load/unload when enable AVIC")
Cc: stable@vger.kernel.org
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>