Andy Lutomirski f6577a5fa1 x86, kvm, vmx: Always use LOAD_IA32_EFER if available ... At least on Sandy Bridge, letting the CPU switch IA32_EFER is much faster than switching it manually. I benchmarked this using the vmexit kvm-unit-test (single run, but GOAL multiplied by 5 to do more iterations): Test Before After Change cpuid 2000 1932 -3.40% vmcall 1914 1817 -5.07% mov_from_cr8 13 13 0.00% mov_to_cr8 19 19 0.00% inl_from_pmtimer 19164 10619 -44.59% inl_from_qemu 15662 10302 -34.22% inl_from_kernel 3916 3802 -2.91% outl_to_kernel 2230 2194 -1.61% mov_dr 172 176 2.33% ipi (skipped) (skipped) ipi+halt (skipped) (skipped) ple-round-robin 13 13 0.00% wr_tsc_adjust_msr 1920 1845 -3.91% rd_tsc_adjust_msr 1892 1814 -4.12% mmio-no-eventfd:pci-mem 16394 11165 -31.90% mmio-wildcard-eventfd:pci-mem 4607 4645 0.82% mmio-datamatch-eventfd:pci-mem 4601 4610 0.20% portio-no-eventfd:pci-io 11507 7942 -30.98% portio-wildcard-eventfd:pci-io 2239 2225 -0.63% portio-datamatch-eventfd:pci-io 2250 2234 -0.71% I haven't explicitly computed the significance of these numbers, but this isn't subtle. Signed-off-by: Andy Lutomirski <luto@amacapital.net> [The results were reproducible on all of Nehalem, Sandy Bridge and Ivy Bridge. The slowness of manual switching is because writing to EFER with WRMSR triggers a TLB flush, even if the only bit you're touching is SCE (so the page table format is not affected). Doing the write as part of vmentry/vmexit, instead, does not flush the TLB, probably because all processors that have EPT also have VPID. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>		2014-11-12 12:35:02 +01:00
..
boot	Merge branch 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2014-10-23 14:45:09 -07:00
configs	x86: Add "make tinyconfig" to configure the tiniest possible kernel	2014-08-08 16:30:24 -07:00
crypto	Revert "crypto: aesni - disable "by8" AVX CTR optimization"	2014-10-02 14:40:28 +08:00
ia32	x86_64, entry: Fix out of bounds read on sysenter	2014-10-31 18:47:09 -07:00
include	KVM: x86: MOV to CR3 can set bit 63	2014-11-07 15:44:07 +01:00
kernel	kvm: kvmclock: use get_cpu() and put_cpu()	2014-11-03 12:07:33 +01:00
kvm	x86, kvm, vmx: Always use LOAD_IA32_EFER if available	2014-11-12 12:35:02 +01:00
lguest
lib	Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2014-10-13 18:14:50 +02:00
math-emu
mm	x86, pageattr: Prevent overflow in slow_virt_to_phys() for X86_PAE	2014-10-29 10:57:21 +01:00
net	x86: bpf_jit: fix two bugs in eBPF JIT compiler	2014-10-14 13:13:14 -04:00
oprofile	percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t	2014-08-28 08:58:57 -04:00
pci	xen: features and fixes for 3.18-rc0	2014-10-11 20:29:01 -04:00
platform	Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2014-10-31 14:30:16 -07:00
power	nosave: consolidate __nosave_{begin,end} in <asm/sections.h>	2014-10-09 22:26:04 -04:00
purgatory	arch/x86/purgatory/Makefile: try to use automatic variable in kexec purgatory makefile	2014-10-14 02:18:21 +02:00
realmode
syscalls	bpf: enable bpf syscall on x64 and i386	2014-09-26 15:05:14 -04:00
tools	x86/relocs: Make per_cpu_load_addr static	2014-09-24 15:17:47 +02:00
um	Merge git://git.infradead.org/users/eparis/audit	2014-10-19 16:25:56 -07:00
vdso	x86/vdso: Fix vdso2c's special_pages[] error checking	2014-09-24 09:55:38 +02:00
video
xen	x86/xen: panic on bad Xen-provided memory map	2014-10-23 16:24:02 +01:00
.gitignore	x86/build: Add arch/x86/purgatory/ make generated files to gitignore	2014-10-09 09:29:46 +02:00
Kbuild	kexec: create a new config option CONFIG_KEXEC_FILE for new syscall	2014-08-29 16:28:16 -07:00
Kconfig	perf/x86: Fix compile warnings for intel_uncore	2014-10-28 10:51:03 +01:00
Kconfig.cpu
Kconfig.debug
Makefile	Merge branch 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2014-10-13 18:17:33 +02:00
Makefile_32.cpu
Makefile.um