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| author | Paolo Bonzini <pbonzini@redhat.com> | 2014-03-27 11:36:25 +0100 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2014-07-11 09:13:58 +0200 |
| commit | 54cfdb3e95d4f70409a7d3432a42cffc9a232be7 (patch) | |
| tree | 01ad8c40d9c316b7359fb7e7605ba0c9b85a75eb /arch/x86/include/asm/kvm_emulate.h | |
| parent | KVM: emulate: protect checks on ctxt->d by a common "if (unlikely())" (diff) | |
| download | linux-54cfdb3e95d4f70409a7d3432a42cffc9a232be7.tar.xz linux-54cfdb3e95d4f70409a7d3432a42cffc9a232be7.zip | |
KVM: emulate: speed up emulated moves
We can just blindly move all 16 bytes of ctxt->src's value to ctxt->dst.
write_register_operand will take care of writing only the lower bytes.
Avoiding a call to memcpy (the compiler optimizes it out) gains about
200 cycles on kvm-unit-tests for register-to-register moves, and makes
them about as fast as arithmetic instructions.
We could perhaps get a larger speedup by moving all instructions _except_
moves out of x86_emulate_insn, removing opcode_len, and replacing the
switch statement with an inlined em_mov.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/include/asm/kvm_emulate.h')
| -rw-r--r-- | arch/x86/include/asm/kvm_emulate.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h index 0e0151c13b2c..432447370044 100644 --- a/arch/x86/include/asm/kvm_emulate.h +++ b/arch/x86/include/asm/kvm_emulate.h @@ -233,7 +233,7 @@ struct operand { union { unsigned long val; u64 val64; - char valptr[sizeof(unsigned long) + 2]; + char valptr[sizeof(sse128_t)]; sse128_t vec_val; u64 mm_val; void *data; |