On Thu, 30 Mar 2017 18:27:21 +0800
Xiong Zhang <xiong.y.zh...@intel.com> 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 <xiong.y.zh...@intel.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 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);
