linux/arch/x86
Paolo Bonzini 98eb2f8b14 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 <pbonzini@redhat.com>
2014-07-11 09:13:56 +02:00
..
boot Merge branch 'next' (accumulated 3.16 merge window patches) into master 2014-06-08 11:31:16 -07:00
configs
crypto
ia32
include KVM: x86: fix TSC matching 2014-07-09 18:09:57 +02:00
kernel Merge branch 'x86-irq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-06-12 20:03:47 -07:00
kvm KVM: vmx: speed up emulation of invalid guest state 2014-07-11 09:13:56 +02:00
lguest
lib Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-06-12 19:18:49 -07:00
math-emu
mm Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-06-12 19:18:49 -07:00
net net: filter: cleanup A/X name usage 2014-06-11 00:13:16 -07:00
oprofile
pci x86: enable DMA CMA with swiotlb 2014-06-04 16:53:57 -07:00
platform x86: intel-mid: add watchdog platform code for Merrifield 2014-06-10 21:48:20 +02:00
power
realmode
syscalls
tools
um
vdso x86/vdso: Fix vdso_install 2014-06-13 10:31:48 -07:00
video
xen Merge branch 'x86/vdso' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next 2014-06-05 08:05:29 -07:00
.gitignore
Kbuild
Kconfig Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-06-12 18:48:15 -07:00
Kconfig.cpu
Kconfig.debug
Makefile
Makefile_32.cpu
Makefile.um