KVM: x86: use kvm_read_guest_page for emulator accesses

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Emulator accesses are always done a page at a time, either by the emulator
itself (for fetches) or because we need to query the MMU for address
translations.  Speed up these accesses by using kvm_read_guest_page
and, in the case of fetches, by inlining kvm_read_guest_virt_helper and
dropping the loop around kvm_read_guest_page.

This final tweak saves 30-100 more clock cycles (4-10%), bringing the
count (as measured by kvm-unit-tests) down to 720-1100 clock cycles on
a Sandy Bridge Xeon host, compared to 2300-3200 before the whole series
and 925-1700 after the first two low-hanging fruit changes.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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Paolo Bonzini 2014-05-13 14:02:13 +02:00

parent 719d5a9b24

commit 44583cba91

1 changed files with 19 additions and 4 deletions

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arch/x86/kvm/x86.c

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