From mboxrd@z Thu Jan  1 00:00:00 1970
From: Wanpeng Li <wanpeng.li@linux.intel.com>
Subject: Re: [CFT PATCH 2/2] KVM: x86: support XSAVES usage in the host
Date: Mon, 24 Nov 2014 10:10:09 +0800
Message-ID: <20141124021009.GB27849@kernel>
References: <1416594678-13011-1-git-send-email-pbonzini@redhat.com>
 <1416594678-13011-3-git-send-email-pbonzini@redhat.com>
Reply-To: Wanpeng Li <wanpeng.li@linux.intel.com>
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Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
	Fenghua Yu <fenghua.yu@intel.com>, stable@vger.kernel.org,
	Nadav Amit <namit@cs.technion.ac.il>,
	Andy Lutomirski <luto@amacapital.net>
To: Paolo Bonzini <pbonzini@redhat.com>
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Hi Paolo,
On Fri, Nov 21, 2014 at 07:31:18PM +0100, Paolo Bonzini wrote:
[...]
>+		u64 feature = valid & -valid;
>+		int index = fls64(feature) - 1;
>+		void *src = get_xsave_addr(xsave, feature);
>+
>+	        if (src) {
>+			u32 size, offset, ecx, edx;
>+			cpuid_count(XSTATE_CPUID, index,
>+				    &size, &offset, &ecx, &edx);
>+	                memcpy(dest + offset, src, size);

The offset you get is still for compact format, so you almost convert compat 
format to compat format instead of convert compact format to standard format. 
In addition, I think convert standard format to compact format should be 
implemented in put path.

Regards,
Wanpeng Li