Re: [PATCH] get rid of mmu_only parameter in emulator_write_emulated()

[Gleb Natapov <gleb@redhat.com>]

On Tue, Apr 13, 2010 at 10:24:40AM +0300, Avi Kivity wrote:
> On 04/13/2010 10:21 AM, Gleb Natapov wrote:
> >May be I am missing something here, but it seams we can call
> >kvm_mmu_pte_write() directly from emulator_cmpxchg_emulated()
> >instead of passing mmu_only down to emulator_write_emulated_onepage()
> >and call it there.
> >
> >
> >@@ -3460,7 +3444,9 @@ static int emulator_cmpxchg_emulated(unsigned long addr,
> >  	if (!exchanged)
> >  		return X86EMUL_CMPXCHG_FAILED;
> >
> >-	return __emulator_write_emulated(addr, new, bytes, vcpu, true);
> >+	kvm_mmu_pte_write(vcpu, gpa, new, bytes, 1);
> >+
> >+	return X86EMUL_CONTINUE;
> >
> 
> The written range might cross a page boundary, which
> kvm_mmu_pte_write() is not prepared to handle.
> 
Don't we emulate exchange as write in this case?

	if (((gpa + bytes - 1) & PAGE_MASK) != (gpa & PAGE_MASK))
		goto emul_write;

--
			Gleb.