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authorTomita Moeko <tomitamoeko@gmail.com>2025-05-06 01:02:57 +0800
committerCédric Le Goater <clg@redhat.com>2025-05-09 12:42:27 +0200
commitdd69d846046f697863ebbd18f9a3544d36720476 (patch)
tree1e5bd7b0543d8ce5dbe5615f0107c76e97cc82a7
parent07f86929e5e1f8506fbdd4c3522c91d74b206ad3 (diff)
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vfio/igd: Restrict legacy mode to Gen6-9 devices
Intel only provides legacy VBIOS for IGD up to Gen9, and there is no CSM support on later devices. Additionally, Seabios can only handle 32-bit BDSM register used until Gen9. Since legacy mode requires VGA capability, restrict it to Gen6 through Gen9 devices. Link: https://lore.kernel.org/qemu-devel/20250325172239.27926-1-tomitamoeko@gmail.com/T/ Signed-off-by: Tomita Moeko <tomitamoeko@gmail.com> Reviewed-by: Corvin Köhne <c.koehne@beckhoff.com> Reviewed-by: Alex Williamson <alex.williamson@redhat.com> Tested-by: Alex Williamson <alex.williamson@redhat.com> Link: https://lore.kernel.org/qemu-devel/20250505170305.23622-2-tomitamoeko@gmail.com Signed-off-by: Cédric Le Goater <clg@redhat.com>
-rw-r--r--docs/igd-assign.txt1
-rw-r--r--hw/vfio/igd.c6
2 files changed, 6 insertions, 1 deletions
diff --git a/docs/igd-assign.txt b/docs/igd-assign.txt
index 3aed795..95beb76 100644
--- a/docs/igd-assign.txt
+++ b/docs/igd-assign.txt
@@ -47,6 +47,7 @@ Intel document [1] shows how to dump VBIOS to file. For UEFI Option ROM, see
QEMU also provides a "Legacy" mode that implicitly enables full functionality
on IGD, it is automatically enabled when
+* IGD generation is 6 to 9 (Sandy Bridge to Comet Lake)
* Machine type is i440fx
* IGD is assigned to guest BDF 00:02.0
* ROM BAR or romfile is present
diff --git a/hw/vfio/igd.c b/hw/vfio/igd.c
index d7e4728..e06484c 100644
--- a/hw/vfio/igd.c
+++ b/hw/vfio/igd.c
@@ -517,11 +517,13 @@ static bool vfio_pci_igd_config_quirk(VFIOPCIDevice *vdev, Error **errp)
/*
* For backward compatibility, enable legacy mode when
+ * - Device geneation is 6 to 9 (including both)
* - Machine type is i440fx (pc_piix)
* - IGD device is at guest BDF 00:02.0
* - Not manually disabled by x-igd-legacy-mode=off
*/
if ((vdev->igd_legacy_mode != ON_OFF_AUTO_OFF) &&
+ (gen >= 6 && gen <= 9) &&
!strcmp(MACHINE_GET_CLASS(qdev_get_machine())->family, "pc_piix") &&
(&vdev->pdev == pci_find_device(pci_device_root_bus(&vdev->pdev),
0, PCI_DEVFN(0x2, 0)))) {
@@ -566,7 +568,9 @@ static bool vfio_pci_igd_config_quirk(VFIOPCIDevice *vdev, Error **errp)
vdev->features |= VFIO_FEATURE_ENABLE_IGD_LPC;
} else if (vdev->igd_legacy_mode == ON_OFF_AUTO_ON) {
error_setg(&err,
- "Machine is not i440fx or assigned BDF is not 00:02.0");
+ "Machine is not i440fx, assigned BDF is not 00:02.0, "
+ "or device %04x (gen %d) doesn't support legacy mode",
+ vdev->device_id, gen);
goto error;
}