iommu/vt-d: Exclude devices using RMRRs from IOMMU API domains

The user of the IOMMU API domain expects to have full control of
the IOVA space for the domain.  RMRRs are fundamentally incompatible
with that idea.  We can neither map the RMRR into the IOMMU API
domain, nor can we guarantee that the device won't continue DMA with
the area described by the RMRR as part of the new domain.  Therefore
we must prevent such devices from being used by the IOMMU API.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: stable@vger.kernel.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>
iommu/vt-d: Fix race setting IRQ CPU affinity while freeing IRQ

A user process setting the CPU affinity of an IRQ for a KVM
direct-assigned device via /proc/irq/<IRQ#>/smp_affinity can race with
the IRQ being released by QEMU, resulting in a NULL iommu pointer
dereference in get_irte(), causing this crash:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000090
 IP: [<ffffffff8190a652>] intel_ioapic_set_affinity+0x82/0x1b0
 PGD 99172e067 PUD 1026979067 PMD 0
 Oops: 0000 [#1] SMP
 Modules linked in:
 CPU: 1 PID: 3354 Comm: affin Not tainted 3.16.0-rc7-00007-g31dab71 #1
 Hardware name: Supermicro SYS-F617R2-RT+/X9DRFR, BIOS 3.0a 01/29/2014
 task: ffff881025b0e720 ti: ffff88099173c000 task.ti: ffff88099173c000
 RIP: 0010:[<ffffffff8190a652>]  [<ffffffff8190a652>] intel_ioapic_set_affinity+0x82/0x1b0
 RSP: 0018:ffff88099173fdb0  EFLAGS: 00010046
 RAX: 0000000000000082 RBX: ffff880a36294600 RCX: 0000000000000082
 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8266af00
 RBP: ffff88099173fdf8 R08: 0000000000000000 R09: ffff88103ec00490
 R10: 0000000000000000 R11: 0000000000000000 R12: ffff88099173fe90
 R13: 000000000000005f R14: ffff880faa38fe80 R15: ffff880faa38fe80
 FS:  00007f7161f05740(0000) GS:ffff88107fc40000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000090 CR3: 000000099140d000 CR4: 00000000001427e0
 Stack:
  ffffffff81c44740 ffff88099173fdc8 ffffffff00000000 00000000c991fd3b
  ffff880a36294600 ffff88099173fe90 ffff88099173fe90 0000000000000000
  0000000000000286 ffff88099173fe08 ffffffff8190aac5 ffff88099173fe28
 Call Trace:
  [<ffffffff8190aac5>] set_remapped_irq_affinity+0x25/0x40
  [<ffffffff811322dc>] irq_do_set_affinity+0x1c/0x50
  [<ffffffff81132458>] irq_set_affinity_locked+0x98/0xd0
  [<ffffffff811324d6>] __irq_set_affinity+0x46/0x70
  [<ffffffff811362dc>] write_irq_affinity.isra.6+0xdc/0x100
  [<ffffffff8113631c>] irq_affinity_list_proc_write+0x1c/0x20
  [<ffffffff8129f30d>] proc_reg_write+0x3d/0x80
  [<ffffffff812384a7>] vfs_write+0xb7/0x1f0
  [<ffffffff81243619>] ? putname+0x29/0x40
  [<ffffffff812390c5>] SyS_write+0x55/0xd0
  [<ffffffff81adc729>] system_call_fastpath+0x16/0x1b
 Code: ff 48 85 d2 74 68 4c 8b 7a 30 4d 85 ff 74 5f 48 c7 c7 00 af 66 82 e8 9e 1b 1d 00 49 8b 57 20 41 0f b7 77 28 48 c7 c7 00 af 66 82 <48> 8b 8a 90 00 00 00 41 0f b7 57 2a 01 f2 48 89 c6 48 63 d2 48
 RIP  [<ffffffff8190a652>] intel_ioapic_set_affinity+0x82/0x1b0
  RSP <ffff88099173fdb0>
 CR2: 0000000000000090

Signed-off-by: Greg Edwards <gedwards@ddn.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>