On the Lenovo ThinkPad X201, when Intel VT-d is enabled in the BIOS, the
kernel boots with errors related to DMAR, the graphical interface appeared
quite choppy, and the system resets erratically within a minute after it
booted:
DMAR: DRHD: handling fault status reg 3
DMAR: [DMA Write NO_PASID] Request device [00:02.0] fault addr 0xb97ff000
[fault reason 0x05] PTE Write access is not set
Upon comparing boot logs with VT-d on/off, I found that the Intel Calpella
quirk (`quirk_calpella_no_shadow_gtt()') correctly applied the igfx IOMMU
disable/quirk correctly:
pci 0000:00:00.0: DMAR: BIOS has allocated no shadow GTT; disabling IOMMU
for graphics
Whereas with VT-d on, it went into the "else" branch, which then
triggered the DMAR handling fault above:
... else if (!disable_igfx_iommu) {
/* we have to ensure the gfx device is idle before we flush */
pci_info(dev, "Disabling batched IOTLB flush on Ironlake\n");
iommu_set_dma_strict();
}
Now, this is not exactly scientific, but moving 0x0044 to quirk_iommu_igfx
seems to have fixed the aforementioned issue. Running a few `git blame'
runs on the function, I have found that the quirk was originally
introduced as a fix specific to ThinkPad X201:
commit
9eecabcb9a92 ("intel-iommu: Abort IOMMU setup for igfx if BIOS gave
no shadow GTT space")
Which was later revised twice to the "else" branch we saw above:
- 2011: commit
6fbcfb3e467a ("intel-iommu: Workaround IOTLB hang on
Ironlake GPU")
- 2024: commit
ba00196ca41c ("iommu/vt-d: Decouple igfx_off from graphic
identity mapping")
I'm uncertain whether further testings on this particular laptops were
done in 2011 and (honestly I'm not sure) 2024, but I would be happy to do
some distro-specific testing if that's what would be required to verify
this patch.
P.S., I also see IDs 0x0040, 0x0062, and 0x006a listed under the same
`quirk_calpella_no_shadow_gtt()' quirk, but I'm not sure how similar these
chipsets are (if they share the same issue with VT-d or even, indeed, if
this issue is specific to a bug in the Lenovo BIOS). With regards to
0x0062, it seems to be a Centrino wireless card, but not a chipset?
I have also listed a couple (distro and kernel) bug reports below as
references (some of them are from 7-8 years ago!), as they seem to be
similar issue found on different Westmere/Ironlake, Haswell, and Broadwell
hardware setups.
Cc: stable@vger.kernel.org
Fixes:
6fbcfb3e467a ("intel-iommu: Workaround IOTLB hang on Ironlake GPU")
Fixes:
ba00196ca41c ("iommu/vt-d: Decouple igfx_off from graphic identity mapping")
Link: https://groups.google.com/g/qubes-users/c/4NP4goUds2c?pli=1
Link: https://bugs.archlinux.org/task/65362
Link: https://bbs.archlinux.org/viewtopic.php?id=230323
Reported-by: Wenhao Sun <weiguangtwk@outlook.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=197029
Signed-off-by: Mingcong Bai <jeffbai@aosc.io>
Link: https://lore.kernel.org/r/20250415133330.12528-1-jeffbai@aosc.io
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e40, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e90, quirk_iommu_igfx);
+/* QM57/QS57 integrated gfx malfunctions with dmar */
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x0044, quirk_iommu_igfx);
+
/* Broadwell igfx malfunctions with dmar */
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x1606, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x160B, quirk_iommu_igfx);
}
}
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x0040, quirk_calpella_no_shadow_gtt);
-DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x0044, quirk_calpella_no_shadow_gtt);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x0062, quirk_calpella_no_shadow_gtt);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x006a, quirk_calpella_no_shadow_gtt);