Re: [PATCH 2/2] Provide fast path for "rep ins" emulation if possible.
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On 06/05/2012 08:19 PM, Gleb Natapov wrote: > On Tue, Jun 05, 2012 at 07:07:39PM +0300, Avi Kivity wrote: >> > + >> > + count = (PAGE_SIZE - offset_in_page(linear_addr))/size; >> > + >> > + if (count == 0) /* 'in' crosses page boundry */ >> > + return EMULATE_FAIL; >> > + >> > + count = min(count, rcx); >> > + >> > + r = __kvm_fast_string_pio_in(vcpu, size, port, linear_addr, count); >> > + >> > + if (r != EMULATE_DO_MMIO) >> > + return r; >> > + >> > + vcpu->arch.fast_string_pio_ctxt.linear_addr = linear_addr; >> > + vcpu->arch.complete_userspace_io = complete_fast_string_pio; >> > + return EMULATE_DO_MMIO; >> > +} >> > +EXPORT_SYMBOL_GPL(kvm_fast_string_pio_in); >> >> Perhaps a better way to do it is to move the code into the emulator, >> which already handles all the checks and masks, and just avoid >> x86_decode_insn()/x86_emulate_insn(). >> > I do not see how it would be better. Emulator works on different data > structures that should be prepared and the only functions that we can > reuse (as far as I see) are register_address_increment() and ad_mask() > anyway. Also linearize(). Remember the hardware segment checks are only applied to the first iteration. -- error compiling committee.c: too many arguments to function -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html