[PATCH 5/7] Intel pci: Remove Host Bridge devices from identity mapping

From: Mike Travis
Date: Sat May 28 2011 - 14:16:29 EST

When using the 1:1 (identity) PCI DMA remapping, PCI Host Bridge
devices that do not use the IOMMU causes a kernel panic. Fix that
by not inserting those devices into the si_domain.

Signed-off-by: Mike Travis <travis@xxxxxxx>
Reviewed-by: Mike Habeck <habeck@xxxxxxx>
Cc: stable@xxxxxxxxxx
---

Specific panic message:

IOMMU 0 0xfd020000: using Queued invalidation
IOMMU 1 0xfd040000: using Queued invalidation
IOMMU 2 0xfd060000: using Queued invalidation
IOMMU 3 0xfd080000: using Queued invalidation
IOMMU 4 0xfd0a0000: using Queued invalidation
IOMMU 5 0xfd0c0000: using Queued invalidation
IOMMU: hardware identity mapping for device 1000:3e:00.0
Failed to setup IOMMU pass-through
BUG: unable to handle kernel NULL pointer dereference at 000000000000001c
IP: [<ffffffff816378fd>] _raw_spin_lock_irqsave+0xc/0x23
PGD 0
Oops: 0002 [#1] SMP
last sysfs file:
CPU 512
Modules linked in:

Pid: 1, comm: swapper Not tainted 2.6.39-rc7+ #2 Intel Corp. Stoutland Platform
RIP: 0010:[<ffffffff816378fd>] [<ffffffff816378fd>] _raw_spin_lock_irqsave+0xc/0x23
RSP: 0000:ffff88105fd99d00 EFLAGS: 00010046
RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000007
RDX: 0000000000010000 RSI: 00000000000000b8 RDI: 000000000000001c
RBP: ffff88105fd99d00 R08: 0000000000000000 R09: ffff88107d400470
R10: 000000000000000a R11: 0000000000000086 R12: 000000000000001c
R13: 00000000000000b8 R14: ffff88107d82947c R15: 0000000000000286
FS: 0000000000000000(0000) GS:ffff88107fd00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 000000000000001c CR3: 0000000001c03000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process swapper (pid: 1, threadinfo ffff88105fd98000, task ffff88105fd90000)
Stack:
ffff88105fd99d20 ffffffff812ad179 ffff88107d829400 ffff8b6ffe820f00
ffff88105fd99d40 ffffffff8108eb2f ffff88105fd99d40 ffff88107d829400
ffff88105fd99d80 ffffffff8108e396 ffff8beffa854c00 ffff88107d829400
Call Trace:
[<ffffffff812ad179>] dmar_msi_mask+0x17/0x3b
[<ffffffff8108eb2f>] irq_shutdown+0x43/0x4e
[<ffffffff8108e396>] __free_irq+0xd1/0x15d
[<ffffffff8108e47b>] free_irq+0x59/0x72
[<ffffffff812b09b3>] free_dmar_iommu+0x10a/0x1cb
[<ffffffff812acc7f>] free_iommu+0x16/0x30
[<ffffffff81e85564>] intel_iommu_init+0x8c1/0x9de
[<ffffffff81e608c7>] ? dma32_reserve_bootmem+0x6/0x6
[<ffffffff81e608dd>] pci_iommu_init+0x16/0x41
[<ffffffff81000218>] do_one_initcall+0x7c/0x130
[<ffffffff81e5b8a2>] kernel_init+0xf9/0x17e
[<ffffffff8163eab4>] kernel_thread_helper+0x4/0x10
[<ffffffff81e5b7a9>] ? do_early_param+0x89/0x89
[<ffffffff8163eab0>] ? gs_change+0xb/0xb
Code: b8 00 00 01 00 48 89 e5 f0 0f c1 07 0f b7 d0 c1 e8 10 39 c2 74 07 f3 90 0f b7 17 eb f5 c9 c3 55 48 89 e5 9c 58 fa ba 00 00 01 00 <f0> 0f c1 17 0f b7 ca c1 ea 10 39 d1 74 07 f3 90 0f b7 0f eb f5
RIP [<ffffffff816378fd>] _raw_spin_lock_irqsave+0xc/0x23
RSP <ffff88105fd99d00>
CR2: 000000000000001c
---[ end trace 32b2ebdae113b4c3 ]---
swapper used greatest stack depth: 3952 bytes left
Kernel panic - not syncing: Attempted to kill init!
Pid: 1, comm: swapper Tainted: G D 2.6.39-rc7+ #2
Call Trace:
[<ffffffff81040993>] panic+0xb7/0x1be
[<ffffffff810338f5>] ? task_rq_unlock+0xc/0xe
[<ffffffff810340d4>] ? sched_move_task+0xb0/0xbb
[<ffffffff8107c479>] ? __put_css_set+0x24/0x150
[<ffffffff81043d0c>] do_exit+0xa9/0x775
[<ffffffff81040ccb>] ? spin_unlock_irqrestore+0x9/0xb
[<ffffffff81638931>] oops_end+0xb3/0xbb
[<ffffffff81027a01>] no_context+0x1f5/0x204
[<ffffffff81027b92>] __bad_area_nosemaphore+0x182/0x1a5
[<ffffffff81290b55>] ? __delay+0xa/0xc
[<ffffffff81290b90>] ? __const_udelay+0x39/0x3b
[<ffffffff81027c2b>] bad_area_nosemaphore+0xe/0x10
[<ffffffff8163a65c>] do_page_fault+0x170/0x320
[<ffffffff81290b55>] ? __delay+0xa/0xc
[<ffffffff8130f8ec>] ? wait_for_xmitr+0x24/0x89
[<ffffffff81040b9a>] ? __call_console_drivers+0x78/0x8a
[<ffffffff8163e36e>] ? apic_timer_interrupt+0xe/0x20
[<ffffffff81637edf>] page_fault+0x1f/0x30
[<ffffffff816378fd>] ? _raw_spin_lock_irqsave+0xc/0x23
[<ffffffff812ad179>] dmar_msi_mask+0x17/0x3b
[<ffffffff8108eb2f>] irq_shutdown+0x43/0x4e
[<ffffffff8108e396>] __free_irq+0xd1/0x15d
[<ffffffff8108e47b>] free_irq+0x59/0x72
[<ffffffff812b09b3>] free_dmar_iommu+0x10a/0x1cb
[<ffffffff812acc7f>] free_iommu+0x16/0x30
[<ffffffff81e85564>] intel_iommu_init+0x8c1/0x9de
[<ffffffff81e608c7>] ? dma32_reserve_bootmem+0x6/0x6
[<ffffffff81e608dd>] pci_iommu_init+0x16/0x41
[<ffffffff81000218>] do_one_initcall+0x7c/0x130
[<ffffffff81e5b8a2>] kernel_init+0xf9/0x17e
[<ffffffff8163eab4>] kernel_thread_helper+0x4/0x10
[<ffffffff81e5b7a9>] ? do_early_param+0x89/0x89
[<ffffffff8163eab0>] ? gs_change+0xb/0xb

---
drivers/pci/intel-iommu.c | 5 +++++
1 file changed, 5 insertions(+)

--- linux.orig/drivers/pci/intel-iommu.c
+++ linux/drivers/pci/intel-iommu.c
@@ -47,6 +47,8 @@
#define ROOT_SIZE VTD_PAGE_SIZE
#define CONTEXT_SIZE VTD_PAGE_SIZE

+#define IS_BRIDGE_HOST_DEVICE(pdev) \
+ ((pdev->class >> 8) == PCI_CLASS_BRIDGE_HOST)
#define IS_GFX_DEVICE(pdev) ((pdev->class >> 16) == PCI_BASE_CLASS_DISPLAY)
#define IS_ISA_DEVICE(pdev) ((pdev->class >> 8) == PCI_CLASS_BRIDGE_ISA)
#define IS_AZALIA(pdev) ((pdev)->vendor == 0x8086 && (pdev)->device == 0x3a3e)
@@ -2214,6 +2216,9 @@ static int __init iommu_prepare_static_i
return -EFAULT;

for_each_pci_dev(pdev) {
+ /* Skip Host/PCI Bridge devices */
+ if (IS_BRIDGE_HOST_DEVICE(pdev))
+ continue;
if (iommu_should_identity_map(pdev, 1)) {
printk(KERN_INFO "IOMMU: %s identity mapping for device %s\n",
hw ? "hardware" : "software", pci_name(pdev));

--
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