[cc +Zhang, Xiong Y]
Intel, any comments?
On Mon, 24 Jul 2017 15:07:29 +0300
Dmitry Fleytman <dmi...@daynix.com> wrote:
> There is a claim that GMS memory is unused however
> Intel Windows 10 drivers starting from V.4534 (10/7/2016)
> allocate extra ~4G memory when GMS size set to 0.
>
> This patch fixes this issue by seting IGD GMS memory
> size to minimum by changing default value of x-igd-gms
> device parameter.
>
> Signed-off-by: Dmitry Fleytman <dmi...@daynix.com>
> ---
> hw/vfio/pci-quirks.c | 13 +++++++++----
> hw/vfio/pci.c | 2 +-
> 2 files changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/hw/vfio/pci-quirks.c b/hw/vfio/pci-quirks.c
> index 349085e..197cb90 100644
> --- a/hw/vfio/pci-quirks.c
> +++ b/hw/vfio/pci-quirks.c
> @@ -1527,10 +1527,15 @@ static void vfio_probe_igd_bar4_quirk(VFIOPCIDevice
> *vdev, int nr)
> }
>
> /*
> - * Assume we have no GMS memory, but allow it to be overrided by device
> - * option (experimental). The spec doesn't actually allow zero GMS when
> - * when IVD (IGD VGA Disable) is clear, but the claim is that it's
> unused,
> - * so let's not waste VM memory for it.
> + * There is a claim that GMS memory is unused and we want to waste for it
> + * as less VM memory as possible, however Intel Windows 10 drivers
> starting
> + * from V.4534 (10/7/2016) allocate extra ~4G memory when GMS size set
> to 0.
> + * The spec as well doesn't actually allow zero GMS when IVD
> + * (IGD VGA Disable) is clear.
> + *
> + * Therefore we set GMS memory size to minimal by default via device
> + * option x-igd-gms (experimental) and allow further tweaking of this
> + * parameter.
> */
> gmch &= ~((gen < 8 ? 0x1f : 0xff) << (gen < 8 ? 3 : 8));
>
> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
> index d4051cb..bda07b7 100644
> --- a/hw/vfio/pci.c
> +++ b/hw/vfio/pci.c
> @@ -2982,7 +2982,7 @@ static Property vfio_pci_dev_properties[] = {
> sub_vendor_id, PCI_ANY_ID),
> DEFINE_PROP_UINT32("x-pci-sub-device-id", VFIOPCIDevice,
> sub_device_id, PCI_ANY_ID),
> - DEFINE_PROP_UINT32("x-igd-gms", VFIOPCIDevice, igd_gms, 0),
> + DEFINE_PROP_UINT32("x-igd-gms", VFIOPCIDevice, igd_gms, 1),
> /*
> * TODO - support passed fds... is this necessary?
> * DEFINE_PROP_STRING("vfiofd", VFIOPCIDevice, vfiofd_name),
