Files
linux/arch
Paolo Bonzini 6addfc4299 KVM: x86: avoid useless set of KVM_REQ_EVENT after emulation
Despite the provisions to emulate up to 130 consecutive instructions, in
practice KVM will emulate just one before exiting handle_invalid_guest_state,
because x86_emulate_instruction always sets KVM_REQ_EVENT.

However, we only need to do this if an interrupt could be injected,
which happens a) if an interrupt shadow bit (STI or MOV SS) has gone
away; b) if the interrupt flag has just been set (other instructions
than STI can set it without enabling an interrupt shadow).

This cuts another 700-900 cycles from the cost of emulating an
instruction (measured on a Sandy Bridge Xeon: 1650-2600 cycles
before the patch on kvm-unit-tests, 925-1700 afterwards).

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-07-11 09:13:57 +02:00
..
2014-05-01 10:09:47 -07:00
2014-04-18 14:20:36 +02:00
2014-04-18 14:20:43 +02:00
2014-03-18 16:39:33 -04:00