From mboxrd@z Thu Jan  1 00:00:00 1970
From: Avi Kivity <avi@redhat.com>
Subject: Re: [PATCH] get rid of mmu_only parameter in emulator_write_emulated()
Date: Tue, 13 Apr 2010 10:24:40 +0300
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References: <20100413072156.GF23554@redhat.com>
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Cc: kvm@vger.kernel.org, mtosatti@redhat.com
To: Gleb Natapov <gleb@redhat.com>
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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.

-- 
Do not meddle in the internals of kernels, for they are subtle and quick to panic.