From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Vrabel Subject: Re: [PATCHv4] xen/gntdev: add ioctl for grant copy Date: Mon, 14 Dec 2015 14:21:55 +0000 Message-ID: <566ED083.1010501@citrix.com> References: <1448988229-16092-1-git-send-email-david.vrabel@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta3.messagelabs.com ([195.245.230.39]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1a8U0n-0003ZY-BH for xen-devel@lists.xenproject.org; Mon, 14 Dec 2015 14:22:01 +0000 In-Reply-To: <1448988229-16092-1-git-send-email-david.vrabel@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: David Vrabel , xen-devel@lists.xenproject.org Cc: Boris Ostrovsky List-Id: xen-devel@lists.xenproject.org On 01/12/15 16:43, David Vrabel wrote: > Add IOCTL_GNTDEV_GRANT_COPY to allow applications to copy between user > space buffers and grant references. > > This interface is similar to the GNTTABOP_copy hypercall ABI except > the local buffers are provided using a virtual address (instead of a > GFN and offset). To avoid userspace from having to page align its > buffers the driver will use two or more ops if required. > > If the ioctl returns 0, the application must check the status of each > segment with the segments status field. If the ioctl returns a -ve > error code (EINVAL or EFAULT), the status of individual ops is > undefined. Konrad, Boris, any comments? David