From mboxrd@z Thu Jan  1 00:00:00 1970
From: Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: [PATCH v1 2/3] kvm: svm: Add kvm_fast_pio_in support
Date: Mon, 21 Nov 2016 15:50:29 +0100
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References: <147916172660.16347.15695649975899246333.stgit@brijesh-build-machine>
 <147916175150.16347.2494044229416144843.stgit@brijesh-build-machine>
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Cc: Thomas.Lendacky@amd.com, rkrcmar@redhat.com, joro@8bytes.org,
        x86@kernel.org, linux-kernel@vger.kernel.org, mingo@redhat.com,
        hpa@zytor.com, tglx@linutronix.de, bp@suse.de
To: Brijesh Singh <brijesh.singh@amd.com>, kvm@vger.kernel.org
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On 14/11/2016 23:15, Brijesh Singh wrote:
> +	/* For size less than 4 we merge, else we zero extend */
> +	val = (size < 4) ? kvm_register_read(vcpu, VCPU_REGS_RAX) : 0;

Are you sure it shouldn't always zero extend the high 32-bits?  So "val"
should be declared as u32.

Paolo

> +	ret = emulator_pio_in_emulated(&vcpu->arch.emulate_ctxt, size, port,
> +				       &val, 1);
> +	if (ret) {
> +		kvm_register_write(vcpu, VCPU_REGS_RAX, val);
> +		return ret;
> +	}