* [Qemu-devel] [PULL 1/1] Revert "vfio/pci-quirks.c: Disable stolen memory for igd VFIO"
2017-03-31 17:01 [Qemu-devel] [PULL 0/1] VFIO fixes 2017-03-31 Alex Williamson
@ 2017-03-31 17:01 ` Alex Williamson
2017-03-31 17:40 ` [Qemu-devel] [PULL 0/1] VFIO fixes 2017-03-31 Peter Maydell
1 sibling, 0 replies; 3+ messages in thread
From: Alex Williamson @ 2017-03-31 17:01 UTC (permalink / raw)
To: qemu-devel; +Cc: Xiong Zhang
From: Xiong Zhang <xiong.y.zhang@intel.com>
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.
Signed-off-by: Xiong Zhang <xiong.y.zhang@intel.com>
[aw: Gen9+ is SkyLake and newer]
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---
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 e995e32deedf..e9b493b939db 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);
^ permalink raw reply related [flat|nested] 3+ messages in thread