From patchwork Mon Sep 12 16:21:26 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Cooper X-Patchwork-Id: 9327005 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 0E5BD60839 for ; Mon, 12 Sep 2016 16:24:30 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 00E4F28E39 for ; Mon, 12 Sep 2016 16:24:30 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E9CE728E43; Mon, 12 Sep 2016 16:24:29 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id A5B3D28E39 for ; Mon, 12 Sep 2016 16:24:29 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1bjTzn-0007Bc-Aj; Mon, 12 Sep 2016 16:22:11 +0000 Received: from mail6.bemta6.messagelabs.com ([193.109.254.103]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1bjTzm-0007Ai-5n for xen-devel@lists.xen.org; Mon, 12 Sep 2016 16:22:10 +0000 Received: from [193.109.254.147] by server-3.bemta-6.messagelabs.com id 4E/56-04595-136D6D75; Mon, 12 Sep 2016 16:22:09 +0000 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFuplkeJIrShJLcpLzFFi42JxWrrBXtfw2rV wg1fXuS2WfFzM4sDocXT3b6YAxijWzLyk/IoE1oxbt28wF5znrXg/YS5bA+NVji5GTg4JAX+J oxuPsIHYbAL6ErtffGICsUUE1CVOd1xk7WLk4GAW0JVY9VMDxBQWiJe4Os8CxGQRUJXoeC0OU swr4CHxfN9DNoiBchLnj/9kBrE5BTwlGnacZQSxhYBqFjd/ZIGw1SSu9V9ih+gVlDg58wlYnF lAQuLgixfMEHO4JW6fnso8gZFvFpKyWUjKFjAyrWJUL04tKkst0jXVSyrKTM8oyU3MzNE1NDD Ty00tLk5MT81JTCrWS87P3cQIDCYGINjBOP2y/yFGSQ4mJVHeJMFr4UJ8SfkplRmJxRnxRaU5 qcWHGGU4OJQkeK9cAcoJFqWmp1akZeYAwxomLcHBoyTCexskzVtckJhbnJkOkTrFqCglzityF SghAJLIKM2Da4PF0iVGWSlhXkagQ4R4ClKLcjNLUOVfMYpzMCoJ86aCjOfJzCuBm/4KaDET0O KnWy+DLC5JREhJNTCGx/ytnHWWTac42u1AkwlvX7vUbpV5W2uP2NkE3pselepnobbhdRLXatv rums3S+XeviV80obdfnOhAucu5X6Z6xdutFluW/+z91vthu5u3p+ThOeo/tu5yuPvzj/XJvu+ zVqTLNWpNZs1uqbyeeflzdamnUaya/+3ytx3nyudq+tzeovds2glluKMREMt5qLiRACMaZzJo AIAAA== X-Env-Sender: prvs=0565cf92a=Andrew.Cooper3@citrix.com X-Msg-Ref: server-8.tower-27.messagelabs.com!1473697326!48619840!2 X-Originating-IP: [66.165.176.63] X-SpamReason: No, hits=0.0 required=7.0 tests=sa_preprocessor: VHJ1c3RlZCBJUDogNjYuMTY1LjE3Ni42MyA9PiAzMDYwNDg=\n, received_headers: No Received headers X-StarScan-Received: X-StarScan-Version: 8.84; banners=-,-,- X-VirusChecked: Checked Received: (qmail 32657 invoked from network); 12 Sep 2016 16:22:08 -0000 Received: from smtp02.citrix.com (HELO SMTP02.CITRIX.COM) (66.165.176.63) by server-8.tower-27.messagelabs.com with RC4-SHA encrypted SMTP; 12 Sep 2016 16:22:08 -0000 X-IronPort-AV: E=Sophos;i="5.30,323,1470700800"; d="scan'208";a="385835422" From: Andrew Cooper To: Xen-devel Date: Mon, 12 Sep 2016 17:21:26 +0100 Message-ID: <1473697289-4289-4-git-send-email-andrew.cooper3@citrix.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1473697289-4289-1-git-send-email-andrew.cooper3@citrix.com> References: <1473697289-4289-1-git-send-email-andrew.cooper3@citrix.com> MIME-Version: 1.0 X-DLP: MIA2 Cc: Andrew Cooper Subject: [Xen-devel] [PATCH v2 3/6] x86/domctl: Simplfy XEN_DOMCTL_getvcpuextstate when xsave is not in use X-BeenThere: xen-devel@lists.xen.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" X-Virus-Scanned: ClamAV using ClamSMTP Older guests will not use xsave even if it is available. As such, their xcr0_accum will be 0 at the point of migrate. If it is empty, forgo the memory allocation and serialisation into a zero-length buffer. Signed-off-by: Andrew Cooper Reviewed-by: Jan Beulich --- xen/arch/x86/domctl.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/xen/arch/x86/domctl.c b/xen/arch/x86/domctl.c index 815bd33..5aa9f3a 100644 --- a/xen/arch/x86/domctl.c +++ b/xen/arch/x86/domctl.c @@ -1087,11 +1087,13 @@ long arch_do_domctl( ret = -EFAULT; offset += sizeof(v->arch.xcr0_accum); - if ( !ret ) + + /* Serialise xsave state, if there is any. */ + if ( !ret && size > PV_XSAVE_HDR_SIZE ) { - void *xsave_area; + unsigned int xsave_size = size - PV_XSAVE_HDR_SIZE; + void *xsave_area = xmalloc_bytes(xsave_size); - xsave_area = xmalloc_bytes(size); if ( !xsave_area ) { ret = -ENOMEM; @@ -1099,11 +1101,10 @@ long arch_do_domctl( goto vcpuextstate_out; } - expand_xsave_states(v, xsave_area, - size - PV_XSAVE_HDR_SIZE); + expand_xsave_states(v, xsave_area, xsave_size); if ( copy_to_guest_offset(evc->buffer, offset, xsave_area, - size - PV_XSAVE_HDR_SIZE) ) + xsave_size) ) ret = -EFAULT; xfree(xsave_area); }