From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [PATCH RFC 0/1] KVM: ioctl for reading/writing guest memory Date: Tue, 03 Feb 2015 13:59:57 +0100 Message-ID: <54D0C64D.8090400@redhat.com> References: <1422965498-11500-1-git-send-email-thuth@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Cc: agraf@suse.de, cornelia.huck@de.ibm.com, borntraeger@de.ibm.com To: Thomas Huth , kvm@vger.kernel.org, qemu-devel@nongnu.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:51097 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965535AbbBCNAO (ORCPT ); Tue, 3 Feb 2015 08:00:14 -0500 In-Reply-To: <1422965498-11500-1-git-send-email-thuth@linux.vnet.ibm.com> Sender: kvm-owner@vger.kernel.org List-ID: On 03/02/2015 13:11, Thomas Huth wrote: > The userspace (QEMU) then can simply call this ioctl when it wants > to read or write from/to virtual guest memory. Then kernel then takes > the IPTE-lock, walks the MMU table of the guest to find out the > physical address that corresponds to the virtual address, copies > the requested amount of bytes from the userspace buffer to guest > memory or the other way round, and finally frees the IPTE-lock again. > > Does that sound like a viable solution (IMHO it does ;-))? Or should > I maybe try to pursue another approach? It looks feasible to me as well. Paolo From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42830) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YId5T-0001g3-Kz for qemu-devel@nongnu.org; Tue, 03 Feb 2015 08:00:16 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YId5O-00027L-M5 for qemu-devel@nongnu.org; Tue, 03 Feb 2015 08:00:15 -0500 Received: from mx1.redhat.com ([209.132.183.28]:38506) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YId5O-00026Z-De for qemu-devel@nongnu.org; Tue, 03 Feb 2015 08:00:10 -0500 Message-ID: <54D0C64D.8090400@redhat.com> Date: Tue, 03 Feb 2015 13:59:57 +0100 From: Paolo Bonzini MIME-Version: 1.0 References: <1422965498-11500-1-git-send-email-thuth@linux.vnet.ibm.com> In-Reply-To: <1422965498-11500-1-git-send-email-thuth@linux.vnet.ibm.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH RFC 0/1] KVM: ioctl for reading/writing guest memory List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Thomas Huth , kvm@vger.kernel.org, qemu-devel@nongnu.org Cc: cornelia.huck@de.ibm.com, borntraeger@de.ibm.com, agraf@suse.de On 03/02/2015 13:11, Thomas Huth wrote: > The userspace (QEMU) then can simply call this ioctl when it wants > to read or write from/to virtual guest memory. Then kernel then takes > the IPTE-lock, walks the MMU table of the guest to find out the > physical address that corresponds to the virtual address, copies > the requested amount of bytes from the userspace buffer to guest > memory or the other way round, and finally frees the IPTE-lock again. > > Does that sound like a viable solution (IMHO it does ;-))? Or should > I maybe try to pursue another approach? It looks feasible to me as well. Paolo