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| author | Paolo Bonzini <pbonzini@redhat.com> | 2017-12-20 13:55:39 +0100 |
|---|---|---|
| committer | Radim Krčmář <rkrcmar@redhat.com> | 2018-01-16 16:50:13 +0100 |
| commit | 74a497fae754bd970ad0573c26d0a3c5e784fa0c (patch) | |
| tree | 2b502c8817fe37b9d021fdd9c306dc1f2e678237 /lib/nmi_backtrace.c | |
| parent | KVM: VMX: split list of shadowed VMCS field to a separate file (diff) | |
| download | linux-74a497fae754bd970ad0573c26d0a3c5e784fa0c.tar.xz linux-74a497fae754bd970ad0573c26d0a3c5e784fa0c.zip | |
KVM: nVMX: track dirty state of non-shadowed VMCS fields
VMCS12 fields that are not handled through shadow VMCS are rarely
written, and thus they are also almost constant in the vmcs02. We can
thus optimize prepare_vmcs02 by skipping all the work for non-shadowed
fields in the common case.
This patch introduces the (pretty simple) tracking infrastructure; the
next patches will move work to prepare_vmcs02_full and save a few hundred
clock cycles per VMRESUME on a Haswell Xeon E5 system:
before after
cpuid 14159 13869
vmcall 15290 14951
inl_from_kernel 17703 17447
outl_to_kernel 16011 14692
self_ipi_sti_nop 16763 15825
self_ipi_tpr_sti_nop 17341 15935
wr_tsc_adjust_msr 14510 14264
rd_tsc_adjust_msr 15018 14311
mmio-wildcard-eventfd:pci-mem 16381 14947
mmio-datamatch-eventfd:pci-mem 18620 17858
portio-wildcard-eventfd:pci-io 15121 14769
portio-datamatch-eventfd:pci-io 15761 14831
(average savings 748, stdev 460).
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Diffstat (limited to 'lib/nmi_backtrace.c')
0 files changed, 0 insertions, 0 deletions