ElkhartLake and TigerLake devices were tested in legacy mode with Linux
and Windows VMs. Both are working properly. It's likely that other Intel
GPUs of gen 11 and 12 like IceLake device are working too. However,
we're only adding known good devices for now.

Signed-off-by: Corvin Köhne <c.koehne@beckhoff.com>
---
 hw/vfio/igd.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/hw/vfio/igd.c b/hw/vfio/igd.c
index 0d68c6a451..8a41b16421 100644
--- a/hw/vfio/igd.c
+++ b/hw/vfio/igd.c
@@ -88,6 +88,12 @@ static int igd_gen(VFIOPCIDevice *vdev)
     case 0x2200:
     case 0x5900:
         return 8;
+    /* ElkhartLake */
+    case 0x4500:
+        return 11;
+    /* TigerLake */
+    case 0x9A00:
+        return 12;
     }
 
     /*
-- 
2.46.0

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Diese E-Mail enthält vertrauliche Informationen. Sollten Sie sie irrtümlich erhalten haben, dürfen Sie diese E-Mail oder ihre Anhänge nicht lesen, verwenden, kopieren oder weitergeben. Sollten Sie die Mail versehentlich erhalten haben, teilen Sie mir dies bitte umgehend per Antwort-E-Mail mit und löschen Sie diese E-Mail dann aus Ihrem System. Vielen Dank

Beckhoff Automation GmbH & Co. KG | Managing Director: Dipl. Phys. Hans Beckhoff
Registered office: Verl, Germany | Register court: Guetersloh HRA 7075

The stolen memory is required for the GOP (EFI) driver and the Windows
driver. While the GOP driver seems to work with any stolen memory size,
the Windows driver will crash if the size doesn't match the size
allocated by the host BIOS. For that reason, it doesn't make sense to
overwrite the stolen memory size. It's true that this wastes some VM
memory. In the worst case, the stolen memory can take up more than a GB.
However, that's uncommon. Additionally, it's likely that a bunch of RAM
is assigned to VMs making use of GPU passthrough.

Signed-off-by: Corvin Köhne <c.koehne@beckhoff.com>
---
 hw/vfio/igd.c | 35 ++++++++++++++++++-----------------
 1 file changed, 18 insertions(+), 17 deletions(-)

diff --git a/hw/vfio/igd.c b/hw/vfio/igd.c
index 8a41b16421..0751c43eae 100644
--- a/hw/vfio/igd.c
+++ b/hw/vfio/igd.c
@@ -478,6 +478,23 @@ void vfio_probe_igd_bar0_quirk(VFIOPCIDevice *vdev, int nr)
     QLIST_INSERT_HEAD(&vdev->bars[nr].quirks, quirk, next);
 }
 
+static int igd_get_stolen_mb(int gen, uint32_t gmch)
+{
+    int gms;
+
+    if (gen < 8) {
+        gms = (gmch >> 3) & 0x1f;
+    } else {
+        gms = (gmch >> 8) & 0xff;
+    }
+
+    if (gms > 0x10) {
+        error_report("Unsupported IGD GMS value 0x%x", gms);
+        return 0;
+    }
+    return gms * 32;
+}
+
 void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr)
 {
     g_autofree struct vfio_region_info *rom = NULL;
@@ -655,23 +672,7 @@ void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr)
         ggms_mb = 1 << ggms_mb;
     }
 
-    /*
-     * Assume we have no GMS memory, but allow it to be overridden 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.
-     */
-    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);
-        } else {
-            error_report("Unsupported IGD GMS value 0x%x", vdev->igd_gms);
-            vdev->igd_gms = 0;
-        }
-    }
+    gms_mb = igd_get_stolen_mb(gen, gmch);
 
     /*
      * Request reserved memory for stolen memory via fw_cfg.  VM firmware
-- 
2.46.0

This email contains confidential information. If you have received it in error, you must not read, use, copy or pass on this e-mail or its attachments. If you have received the e-mail in error, please inform me immediately by reply e-mail and then delete this e-mail from your system. Thank you
 
Diese E-Mail enthält vertrauliche Informationen. Sollten Sie sie irrtümlich erhalten haben, dürfen Sie diese E-Mail oder ihre Anhänge nicht lesen, verwenden, kopieren oder weitergeben. Sollten Sie die Mail versehentlich erhalten haben, teilen Sie mir dies bitte umgehend per Antwort-E-Mail mit und löschen Sie diese E-Mail dann aus Ihrem System. Vielen Dank

Beckhoff Automation GmbH & Co. KG | Managing Director: Dipl. Phys. Hans Beckhoff
Registered office: Verl, Germany | Register court: Guetersloh HRA 7075

We have to update the calculation of the stolen memory size because
we've seen devices using values of 0xf0 and above for the graphics mode
select field. The new calculation was taken from the linux kernel [1].

[1] https://github.com/torvalds/linux/blob/7c626ce4bae1ac14f60076d00eafe71af30450ba/arch/x86/kernel/early-quirks.c#L455-L460

Signed-off-by: Corvin Köhne <c.koehne@beckhoff.com>
---
 hw/vfio/igd.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/hw/vfio/igd.c b/hw/vfio/igd.c
index 0751c43eae..a95d441f68 100644
--- a/hw/vfio/igd.c
+++ b/hw/vfio/igd.c
@@ -488,11 +488,18 @@ static int igd_get_stolen_mb(int gen, uint32_t gmch)
         gms = (gmch >> 8) & 0xff;
     }
 
-    if (gms > 0x10) {
-        error_report("Unsupported IGD GMS value 0x%x", gms);
-        return 0;
+    if (gen < 9) {
+        if (gms > 0x10) {
+            error_report("Unsupported IGD GMS value 0x%x", gms);
+            return 0;
+        }
+        return gms * 32;
+    } else {
+        if (gms < 0xf0)
+            return gms * 32;
+        else
+            return gms * 4 + 4;
     }
-    return gms * 32;
 }
 
 void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr)
-- 
2.46.0

This email contains confidential information. If you have received it in error, you must not read, use, copy or pass on this e-mail or its attachments. If you have received the e-mail in error, please inform me immediately by reply e-mail and then delete this e-mail from your system. Thank you
 
Diese E-Mail enthält vertrauliche Informationen. Sollten Sie sie irrtümlich erhalten haben, dürfen Sie diese E-Mail oder ihre Anhänge nicht lesen, verwenden, kopieren oder weitergeben. Sollten Sie die Mail versehentlich erhalten haben, teilen Sie mir dies bitte umgehend per Antwort-E-Mail mit und löschen Sie diese E-Mail dann aus Ihrem System. Vielen Dank

Beckhoff Automation GmbH & Co. KG | Managing Director: Dipl. Phys. Hans Beckhoff
Registered office: Verl, Germany | Register court: Guetersloh HRA 7075