From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46995) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XqCMJ-0002dZ-A1 for qemu-devel@nongnu.org; Sun, 16 Nov 2014 21:48:12 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XqCME-00021p-7p for qemu-devel@nongnu.org; Sun, 16 Nov 2014 21:48:07 -0500 Received: from mga11.intel.com ([192.55.52.93]:13157) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XqCME-00021P-27 for qemu-devel@nongnu.org; Sun, 16 Nov 2014 21:48:02 -0500 Message-ID: <546961DC.4040300@intel.com> Date: Mon, 17 Nov 2014 10:47:56 +0800 From: "Chen, Tiejun" MIME-Version: 1.0 References: <1415172179-7965-1-git-send-email-tiejun.chen@intel.com> <1415172179-7965-2-git-send-email-tiejun.chen@intel.com> <20141105140906.GA4912@redhat.com> In-Reply-To: <20141105140906.GA4912@redhat.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC][PATCH 2/2] xen:i386:pc_piix: create isa bridge specific to IGD passthrough List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: xen-devel@lists.xensource.com, allen.m.kay@intel.com, qemu-devel@nongnu.org, aliguori@amazon.com, pbonzini@redhat.com, rth@twiddle.net On 2014/11/5 22:09, Michael S. Tsirkin wrote: > On Wed, Nov 05, 2014 at 03:22:59PM +0800, Tiejun Chen wrote: >> Currently IGD drivers always need to access PCH by 1f.0, and >> PCH vendor/device id is used to identify the card. >> >> Signed-off-by: Tiejun Chen >> --- >> hw/i386/pc_piix.c | 28 +++++++++++++++++++++++++++- >> 1 file changed, 27 insertions(+), 1 deletion(-) >> >> diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c >> index b559181..b19c7a9 100644 >> --- a/hw/i386/pc_piix.c >> +++ b/hw/i386/pc_piix.c >> @@ -50,7 +50,7 @@ >> #include "cpu.h" >> #include "qemu/error-report.h" >> #ifdef CONFIG_XEN >> -# include >> +#include >> #endif >> >> #define MAX_IDE_BUS 2 >> @@ -452,6 +452,31 @@ static void pc_init_isa(MachineState *machine) >> } >> >> #ifdef CONFIG_XEN >> +static void xen_igd_passthrough_isa_bridge_create(PCIBus *bus) >> +{ >> + struct PCIDevice *dev; >> + Error *local_err = NULL; >> + uint16_t device_id = 0xffff; >> + >> + /* Currently IGD drivers always need to access PCH by 1f.0. */ >> + dev = pci_create_simple(bus, PCI_DEVFN(0x1f, 0), >> + "xen-igd-passthrough-isa-bridge"); >> + >> + /* Identify PCH card with its own real vendor/device ids. >> + * Here that vendor id is always PCI_VENDOR_ID_INTEL. >> + */ >> + if (dev) { >> + device_id = object_property_get_int(OBJECT(dev), "device-id", >> + &local_err); >> + if (!local_err && device_id != 0xffff) { >> + pci_config_set_device_id(dev->config, device_id); >> + return; >> + } >> + } >> + >> + fprintf(stderr, "xen set xen-igd-passthrough-isa-bridge failed\n"); >> +} >> + >> static void pc_xen_hvm_init(MachineState *machine) >> { >> PCIBus *bus; >> @@ -461,6 +486,7 @@ static void pc_xen_hvm_init(MachineState *machine) >> bus = pci_find_primary_bus(); >> if (bus != NULL) { >> pci_create_simple(bus, -1, "xen-platform"); >> + xen_igd_passthrough_isa_bridge_create(bus); >> } >> } >> #endif > > Can't we defer this step until the GPU is added? Sounds great but I can't figure out where we can to do this exactly. > This way there won't be need to poke at host device > directly, you could get all info from dev->config > of the host device. As I understand We have two steps here: #1 At first I have to write something to check if we're registering 00:02.0 & IGD, right? But where? While registering each pci device? #2 Then if that condition is matched, we register this ISA bridge on its associated bus. Thanks Tiejun > Additionally the correct bridge would be initialized automatically. > > >> -- >> 1.9.1 >