From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35487) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WzjW6-0005LD-4J for qemu-devel@nongnu.org; Wed, 25 Jun 2014 05:29:29 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WzjVx-0005PG-9a for qemu-devel@nongnu.org; Wed, 25 Jun 2014 05:29:22 -0400 Received: from mga02.intel.com ([134.134.136.20]:6711) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WzjVx-0005PA-3f for qemu-devel@nongnu.org; Wed, 25 Jun 2014 05:29:13 -0400 Message-ID: <53AA9650.1060503@intel.com> Date: Wed, 25 Jun 2014 17:28:48 +0800 From: "Chen, Tiejun" MIME-Version: 1.0 References: <1403662641-28526-1-git-send-email-tiejun.chen@intel.com> <1403662641-28526-3-git-send-email-tiejun.chen@intel.com> <20140625064545.GB25563@redhat.com> <53AA8404.8040708@intel.com> <20140625082850.GB32652@redhat.com> <53AA8AAB.30100@intel.com> <20140625084347.GE32652@redhat.com> <53AA8CC2.7090406@intel.com> <20140625090420.GG32652@redhat.com> <53AA92F6.1090803@intel.com> <20140625092141.GL32652@redhat.com> In-Reply-To: <20140625092141.GL32652@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [v5][PATCH 2/5] xen, gfx passthrough: create pseudo intel isa bridge List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: peter.maydell@linaro.org, xen-devel@lists.xensource.com, stefano.stabellini@eu.citrix.com, allen.m.kay@intel.com, qemu-devel@nongnu.org, Kelly.Zytaruk@amd.com, yang.z.zhang@intel.com, anthony@codemonkey.ws, anthony.perard@citrix.com, pbonzini@redhat.com On 2014/6/25 17:21, Michael S. Tsirkin wrote: > On Wed, Jun 25, 2014 at 05:14:30PM +0800, Chen, Tiejun wrote: >> On 2014/6/25 17:04, Michael S. Tsirkin wrote: >>> On Wed, Jun 25, 2014 at 04:48:02PM +0800, Chen, Tiejun wrote: >>>> On 2014/6/25 16:43, Michael S. Tsirkin wrote: >>>>> On Wed, Jun 25, 2014 at 04:39:07PM +0800, Chen, Tiejun wrote: >>>>>>> In fact it's exactly what passthrough does. >>>>>>> I wonder if more bits from ./hw/i386/kvm/pci-assign.c >>>>>>> can be reused. How do you poke at the host device? sysfs? >>>>>> >>>>>> Yes, sysfs. >>>>>> >>>>>> Thanks >>>>>> Tiejun >>>>> >>>>> Then you should be able to re-use large chunks of >>>>> ./hw/i386/kvm/pci-assign.c: basically everything >>>>> that deals with emulation. >>>> >>>> Do you mean those hooks to get info from the real device? Xen have its own >>>> wrapper, xen_host_pci_get_block(), so we always go there in xen scenario. >>>> >>>> Thanks >>>> Tiejun >>> >>> Yes and that's not good. We have two pieces of code doing mostly >>> identical things slightly differently. >>> hw/i386/kvm/pci-assign.c is a bit younger so it's cleaner, >>> but these really need to be unified. >>> >> >> Sorry, take a look at this again, >> >> xen_host_pci_get_block(XenHostPCIDevice *d, int pos, uint8_t *buf, int len) >> | >> + xen_host_pci_config_read(d, pos, buf, len) >> | >> + pread(d->config_fd, buf, len, pos) >> >> I thinks this should be same as kvm. >> >> Thanks >> Tiejun > > get_block is trivial. > > I really mean the whole PT infrastructure for > - discovering host devices through sysfs > - virtualizing devices > > rom, bars, msi ... > the list goes on. > > logic is mostly the same. > Looks you mean we can unify the entire PT infrastructure between kvm and xen inside qemu. But I'm afraid its not easy to do in a short time, so maybe we can queue this as next phase. Thanks Tiejun