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From: Wei Liu <wei.liu2@citrix.com>
To: Jan Beulich <JBeulich@suse.com>
Cc: xen-devel <xen-devel@lists.xenproject.org>,
	Shuai Ruan <shuai.ruan@linux.intel.com>,
	Wei Liu <wei.liu2@citrix.com>,
	Andrew Cooper <andrew.cooper3@citrix.com>
Subject: Re: [PATCH] x86/xstate: don't clobber or leak state when using XSAVES
Date: Mon, 25 Apr 2016 12:39:04 +0100	[thread overview]
Message-ID: <20160425113904.GG11686@citrix.com> (raw)
In-Reply-To: <571DDE6A02000078000E51D3@prv-mh.provo.novell.com>

On Mon, Apr 25, 2016 at 01:07:54AM -0600, Jan Beulich wrote:
> Commit 4d27280572 ("x86/xsaves: fix overwriting between non-lazy/lazy
> xsaves") switched to always saving full state when using compacted
> format (which is the only one XSAVES allows). It didn't, however, also
> adjust the restore side: In order to save full state, we also need to
> make sure we always load full state, or else the subject vCPU's state
> would get clobbered by that of the vCPU which happened to last have in
> use the respective component(s).
> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> ---
> As to inclusion in 4.7: This is a fiy to a _latent_ bug, i.e. not one
> currently exposed (since XSTATE_XSAVES_ONLY is zero right now).
> Nevertheless I think we should avoid releasing code with such an issue.
> 

I agree. Subject to review from Andrew / Shuai:

Release-acked-by: Wei Liu <wei.liu2@citrix.com>

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  reply	other threads:[~2016-04-25 11:37 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-04-25  7:07 [PATCH] x86/xstate: don't clobber or leak state when using XSAVES Jan Beulich
2016-04-25 11:39 ` Wei Liu [this message]
2016-04-26  9:25 ` Andrew Cooper
2016-04-29  1:21 ` Shuai Ruan
     [not found] ` <20160429012139.GA4359@shuai.ruan@linux.intel.com>
2016-04-29  9:13   ` Wei Liu
2016-05-05  1:20     ` Shuai Ruan

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