From 98eb2f8b145cee711984d42eff5d6f19b6b1df69 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Thu, 27 Mar 2014 09:51:52 +0100 Subject: [PATCH] KVM: vmx: speed up emulation of invalid guest state About 25% of the time spent in emulation of invalid guest state is wasted in checking whether emulation is required for the next instruction. However, this almost never changes except when a segment register (or TR or LDTR) changes, or when there is a mode transition (i.e. CR0 changes). In fact, vmx_set_segment and vmx_set_cr0 already modify vmx->emulation_required (except that the former for some reason uses |= instead of just an assignment). So there is no need to call guest_state_valid in the emulation loop. Emulation performance test results indicate 1650-2600 cycles for common instructions, versus 2300-3200 before this patch on a Sandy Bridge Xeon. Signed-off-by: Paolo Bonzini --- Reading git-format-patch failed