KVM: x86: Check for nested events if there is an injectable interrupt
authorBandan Das <bsd@redhat.com>
Tue, 8 Jul 2014 04:30:23 +0000 (00:30 -0400)
committerPaolo Bonzini <pbonzini@redhat.com>
Tue, 8 Jul 2014 08:06:42 +0000 (10:06 +0200)
commit9242b5b60df8b13b469bc6b7be08ff6ebb551ad3
treec490ce887713f72c5ba0df7c214693abf7fa60f4
parentcd3de83f147601356395b57a8673e9c5ff1e59d1
KVM: x86: Check for nested events if there is an injectable interrupt

With commit b6b8a1451fc40412c57d1 that introduced
vmx_check_nested_events, checks for injectable interrupts happen
at different points in time for L1 and L2 that could potentially
cause a race. The regression occurs because KVM_REQ_EVENT is always
set when nested_run_pending is set even if there's no pending interrupt.
Consequently, there could be a small window when check_nested_events
returns without exiting to L1, but an interrupt comes through soon
after and it incorrectly, gets injected to L2 by inject_pending_event
Fix this by adding a call to check for nested events too when a check
for injectable interrupt returns true

Signed-off-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
arch/x86/kvm/x86.c