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),
--
2.9.4
