After updating from v5.8 to v5.9-rc2 I noticed some problems when
booting a system with kernel cmdline "intel_iommu=on,igfx_off".
The following stacktrace was produced:
<6>[ 0.000000] Command line: BOOT_IMAGE=/isolinux/bzImage console=tty1
intel_iommu=on,igfx_off
...
<6>[ 3.341682] DMAR: Host address width 39
<6>[ 3.341684] DMAR: DRHD base: 0x000000fed90000 flags: 0x0
<6>[ 3.341702] DMAR: dmar0: reg_base_addr fed90000 ver 1:0 cap
1c0000c40660462 ecap 19e2ff0505e
<6>[ 3.341705] DMAR: DRHD base: 0x000000fed91000 flags: 0x1
<6>[ 3.341711] DMAR: dmar1: reg_base_addr fed91000 ver 1:0 cap
d2008c40660462 ecap f050da
<6>[ 3.341713] DMAR: RMRR base: 0x0000009aa9f000 end: 0x0000009aabefff
<6>[ 3.341716] DMAR: RMRR base: 0x0000009d000000 end: 0x0000009f7fffff
<6>[ 3.341726] DMAR: No ATSR found
<1>[ 3.341772] BUG: kernel NULL pointer dereference, address:
0000000000000038
<1>[ 3.341774] #PF: supervisor write access in kernel mode
<1>[ 3.341776] #PF: error_code(0x0002) - not-present page
<6>[ 3.341777] PGD 0 P4D 0
<4>[ 3.341780] Oops: 0002 [#1] SMP PTI
<4>[ 3.341783] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.9.0-devel+ #2
<4>[ 3.341785] Hardware name: LENOVO 20HGS0TW00/20HGS0TW00, BIOS N1WET46S
(1.25s ) 03/30/2018
<4>[ 3.341790] RIP: 0010:intel_iommu_init+0xed0/0x1136
<4>[ 3.341792] Code: fe e9 61 02 00 00 bb f4 ff ff ff e9 57 02 00 00 48 63
d1 48 c1 e2 04 48 03 50 20 48 8b 12 48 85 d2 74 0b 48 8b 92 d0 02 00 00 <48> 89
7a 38 ff c1 e9 15 f5 ff ff 48 c7 c7 60 99 ac a7 49 c7 c7 a0
<4>[ 3.341796] RSP: 0000:ffff96d180073dd0 EFLAGS: 00010282
<4>[ 3.341798] RAX: ffff8c91037a7d20 RBX: 0000000000000000 RCX:
0000000000000000
<4>[ 3.341800] RDX: 0000000000000000 RSI: 0000000000000000 RDI:
ffffffffffffffff
<4>[ 3.341802] RBP: ffff96d180073e90 R08: 0000000000000001 R09:
ffff8c91039fe3c0
<4>[ 3.341804] R10: 0000000000000226 R11: 0000000000000226 R12:
000000000000000b
<4>[ 3.341806] R13: ffff8c910367c650 R14: ffffffffa8426d60 R15:
0000000000000000
<4>[ 3.341808] FS: 0000000000000000(0000) GS:ffff8c9107480000(0000)
knlGS:0000000000000000
<4>[ 3.341810] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
<4>[ 3.341812] CR2: 0000000000000038 CR3: 00000004b100a001 CR4:
00000000003706e0
<4>[ 3.341814] Call Trace:
<4>[ 3.341820] ? _raw_spin_unlock_irqrestore+0x1f/0x30
<4>[ 3.341824] ? call_rcu+0x10e/0x320
<4>[ 3.341828] ? trace_hardirqs_on+0x2c/0xd0
<4>[ 3.341831] ? rdinit_setup+0x2c/0x2c
<4>[ 3.341834] ? e820__memblock_setup+0x8b/0x8b
<4>[ 3.341836] pci_iommu_init+0x16/0x3f
<4>[ 3.341839] do_one_initcall+0x46/0x1e4
<4>[ 3.341842] kernel_init_freeable+0x169/0x1b2
<4>[ 3.341845] ? rest_init+0x9f/0x9f
<4>[ 3.341847] kernel_init+0xa/0x101
<4>[ 3.341849] ret_from_fork+0x22/0x30
<4>[ 3.341851] Modules linked in:
<4>[ 3.341854] CR2: 0000000000000038
<4>[ 3.341860] ---[ end trace 3653722a6f936f18 ]---
I could track the problem down to the dev_iommu_priv_set call in the function
init_no_remapping_devices in the path where !dmar_map_gfx. It turned out that
the dev->iommu entry is NULL at this time.
Lu Baolu <baolu...@linux.intel.com> suggested for dev_iommu_priv_set
to automatically allocate the iommu entry by using the function
dev_iommu_get to retrieve that pointer. This function allocates the
entry if needed.
Fixes: 01b9d4e21148 ("iommu/vt-d: Use dev_iommu_priv_get/set()")
Signed-off-by: Torsten Hilbrich <torsten.hilbr...@secunet.com>
Tested-by: Torsten Hilbrich <torsten.hilbr...@secunet.com>
Link: https://lists.linuxfoundation.org/pipermail/iommu/2020-August/048098.html
---
drivers/iommu/iommu.c | 22 ++++++++++++++++++++++
include/linux/iommu.h | 11 ++---------
2 files changed, 24 insertions(+), 9 deletions(-)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 609bd25bf154..3edca2a31296 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2849,3 +2849,25 @@ int iommu_sva_get_pasid(struct iommu_sva *handle)
return ops->sva_get_pasid(handle);
}
EXPORT_SYMBOL_GPL(iommu_sva_get_pasid);
+
+void *dev_iommu_priv_get(struct device *dev)
+{
+ struct dev_iommu *param = dev_iommu_get(dev);
+
+ if (WARN_ON(!param))
+ return ERR_PTR(-ENOMEM);
+
+ return param->priv;
+}
+EXPORT_SYMBOL_GPL(dev_iommu_priv_get);
+
+void dev_iommu_priv_set(struct device *dev, void *priv)
+{
+ struct dev_iommu *param = dev_iommu_get(dev);
+
+ if (WARN_ON(!param))
+ return;
+
+ param->priv = priv;
+}
+EXPORT_SYMBOL_GPL(dev_iommu_priv_set);
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index fee209efb756..e3e725cf64b3 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -609,15 +609,8 @@ static inline void dev_iommu_fwspec_set(struct device *dev,
dev->iommu->fwspec = fwspec;
}
-static inline void *dev_iommu_priv_get(struct device *dev)
-{
- return dev->iommu->priv;
-}
-
-static inline void dev_iommu_priv_set(struct device *dev, void *priv)
-{
- dev->iommu->priv = priv;
-}
+void *dev_iommu_priv_get(struct device *dev);
+void dev_iommu_priv_set(struct device *dev, void *priv);
int iommu_probe_device(struct device *dev);
void iommu_release_device(struct device *dev);
--
2.26.2
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