From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrew Cooper <andrew.cooper3@citrix.com>
Subject: Re: [PATCHv2 2/3] x86/fpu: Add a per-domain field to
 set the width of FIP/FDP
Date: Tue, 23 Feb 2016 11:10:24 +0000
Message-ID: <56CC3E20.9070105@citrix.com>
References: <1456225539-9162-1-git-send-email-david.vrabel@citrix.com>
	<1456225539-9162-3-git-send-email-david.vrabel@citrix.com>
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To: David Vrabel <david.vrabel@citrix.com>, xen-devel@lists.xenproject.org
Cc: Jan Beulich <jbeulich@suse.com>
List-Id: xen-devel@lists.xenproject.org

On 23/02/16 11:05, David Vrabel wrote:
> @@ -653,6 +657,12 @@ int arch_domain_create(struct domain *d, unsigned int domcr_flags,
>      /* PV/PVH guests get an emulated PIT too for video BIOSes to use. */
>      pit_init(d, cpu_khz);
>  
> +    /*
> +     * If the FPU not to save FCS/FDS then we can always save/restore

"If the FPU does not" ?

> @@ -284,7 +284,11 @@ void xsave(struct vcpu *v, uint64_t mask)
>              return;
>          }
>  
> -        if ( word_size > 0 &&
> +        /*
> +         * If the FIP/FDP[63:32] are both zero, it is safe to use the
> +         * 32-bit restore to also restore the selectors.
> +         */

This comment is presumably applicable to the fxsave path?

The functional content of the patch, Reviewed-by: Andrew Cooper
<andrew.cooper3@citrix.com>