From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39037) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ctbaE-00019j-NY for qemu-devel@nongnu.org; Thu, 30 Mar 2017 11:02:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ctbaB-0005RD-Le for qemu-devel@nongnu.org; Thu, 30 Mar 2017 11:01:54 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42818) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ctbaB-0005PF-DL for qemu-devel@nongnu.org; Thu, 30 Mar 2017 11:01:51 -0400 Date: Thu, 30 Mar 2017 09:01:48 -0600 From: Alex Williamson Message-ID: <20170330090148.16048141@t450s.home> In-Reply-To: <1490869641-29873-1-git-send-email-xiong.y.zhang@intel.com> References: <1490869641-29873-1-git-send-email-xiong.y.zhang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] Revert "vfio/pci-quirks.c: Disable stolen memory for igd VFIO" List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Xiong Zhang Cc: qemu-devel@nongnu.org On Thu, 30 Mar 2017 18:27:21 +0800 Xiong Zhang wrote: > This reverts commit c2b2e158cc7b1cb431bd6039824ec13c3184a775. > > The original patch intend to prevent linux i915 driver from using > stolen meory. But this patch breaks windows IGD driver loading on > Gen9+, as IGD HW will use stolen memory on Gen9+, once windows IGD > driver see zero size stolen memory, it will unload. > Meanwhile stolen memory will be disabled in 915 when i915 run as > a guest. Does this mean that legacy mode IGD assignment is not going to work on Gen9+ with Windows? Will it continue to work with Gen8-? Please clarify Gen9+, is this Kaby Lake? I assume this patch is intended for QEMU 2.9, it's helpful to make that explicit during the rc freeze. Thanks, Alex > Signed-off-by: Xiong Zhang > --- > hw/vfio/pci-quirks.c | 65 ++++++++++++++++++++++------------------------------ > 1 file changed, 27 insertions(+), 38 deletions(-) > > diff --git a/hw/vfio/pci-quirks.c b/hw/vfio/pci-quirks.c > index e995e32..e9b493b 100644 > --- a/hw/vfio/pci-quirks.c > +++ b/hw/vfio/pci-quirks.c > @@ -1367,45 +1367,14 @@ static void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr) > uint16_t cmd_orig, cmd; > Error *err = NULL; > > - /* This must be an Intel VGA device. */ > - if (!vfio_pci_is(vdev, PCI_VENDOR_ID_INTEL, PCI_ANY_ID) || > - !vfio_is_vga(vdev) || nr != 4) { > - return; > - } > - > - /* > - * IGD is not a standard, they like to change their specs often. We > - * only attempt to support back to SandBridge and we hope that newer > - * devices maintain compatibility with generation 8. > - */ > - gen = igd_gen(vdev); > - if (gen != 6 && gen != 8) { > - error_report("IGD device %s is unsupported by IGD quirks, " > - "try SandyBridge or newer", vdev->vbasedev.name); > - return; > - } > - > - /* > - * Regardless of running in UPT or legacy mode, the guest graphics > - * driver may attempt to use stolen memory, however only legacy mode > - * has BIOS support for reserving stolen memory in the guest VM. > - * Emulate the GMCH register in all cases and zero out the stolen > - * memory size here. Legacy mode may request allocation and re-write > - * this below. > - */ > - gmch = vfio_pci_read_config(&vdev->pdev, IGD_GMCH, 4); > - gmch &= ~((gen < 8 ? 0x1f : 0xff) << (gen < 8 ? 3 : 8)); > - > - /* GMCH is read-only, emulated */ > - pci_set_long(vdev->pdev.config + IGD_GMCH, gmch); > - pci_set_long(vdev->pdev.wmask + IGD_GMCH, 0); > - pci_set_long(vdev->emulated_config_bits + IGD_GMCH, ~0); > - > /* > - * This must be at address 00:02.0 for us to even onsider enabling > - * legacy mode. The vBIOS has dependencies on the PCI bus address. > + * This must be an Intel VGA device at address 00:02.0 for us to even > + * consider enabling legacy mode. The vBIOS has dependencies on the > + * PCI bus address. > */ > - if (&vdev->pdev != pci_find_device(pci_device_root_bus(&vdev->pdev), > + if (!vfio_pci_is(vdev, PCI_VENDOR_ID_INTEL, PCI_ANY_ID) || > + !vfio_is_vga(vdev) || nr != 4 || > + &vdev->pdev != pci_find_device(pci_device_root_bus(&vdev->pdev), > 0, PCI_DEVFN(0x2, 0))) { > return; > } > @@ -1425,6 +1394,18 @@ static void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr) > } > > /* > + * IGD is not a standard, they like to change their specs often. We > + * only attempt to support back to SandBridge and we hope that newer > + * devices maintain compatibility with generation 8. > + */ > + gen = igd_gen(vdev); > + if (gen != 6 && gen != 8) { > + error_report("IGD device %s is unsupported in legacy mode, " > + "try SandyBridge or newer", vdev->vbasedev.name); > + return; > + } > + > + /* > * Most of what we're doing here is to enable the ROM to run, so if > * there's no ROM, there's no point in setting up this quirk. > * NB. We only seem to get BIOS ROMs, so a UEFI VM would need CSM support. > @@ -1479,6 +1460,8 @@ static void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr) > goto out; > } > > + gmch = vfio_pci_read_config(&vdev->pdev, IGD_GMCH, 4); > + > /* > * If IGD VGA Disable is clear (expected) and VGA is not already enabled, > * try to enable it. Probably shouldn't be using legacy mode without VGA, > @@ -1549,11 +1532,12 @@ static void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr) > * when IVD (IGD VGA Disable) is clear, but the claim is that it's unused, > * so let's not waste VM memory for it. > */ > + gmch &= ~((gen < 8 ? 0x1f : 0xff) << (gen < 8 ? 3 : 8)); > + > if (vdev->igd_gms) { > if (vdev->igd_gms <= 0x10) { > gms_mb = vdev->igd_gms * 32; > gmch |= vdev->igd_gms << (gen < 8 ? 3 : 8); > - pci_set_long(vdev->pdev.config + IGD_GMCH, gmch); > } else { > error_report("Unsupported IGD GMS value 0x%x", vdev->igd_gms); > vdev->igd_gms = 0; > @@ -1573,6 +1557,11 @@ static void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr) > fw_cfg_add_file(fw_cfg_find(), "etc/igd-bdsm-size", > bdsm_size, sizeof(*bdsm_size)); > > + /* GMCH is read-only, emulated */ > + pci_set_long(vdev->pdev.config + IGD_GMCH, gmch); > + pci_set_long(vdev->pdev.wmask + IGD_GMCH, 0); > + pci_set_long(vdev->emulated_config_bits + IGD_GMCH, ~0); > + > /* BDSM is read-write, emulated. The BIOS needs to be able to write it */ > pci_set_long(vdev->pdev.config + IGD_BDSM, 0); > pci_set_long(vdev->pdev.wmask + IGD_BDSM, ~0);