linux-stable.git/drivers/vfio, branch v4.9.236 Linux kernel stable tree vfio/pci: Fix SR-IOV VF handling with MMIO blocking 2020-09-12T09:47:38+00:00 Alex Williamson alex.williamson@redhat.com 2020-06-25T17:04:23+00:00 54764e8dfbd4fd2bf615aa5a2445ce7faa216cbc commit ebfa440ce38b7e2e04c3124aa89c8a9f4094cf21 upstream. SR-IOV VFs do not implement the memory enable bit of the command register, therefore this bit is not set in config space after pci_enable_device(). This leads to an unintended difference between PF and VF in hand-off state to the user. We can correct this by setting the initial value of the memory enable bit in our virtualized config space. There's really no need however to ever fault a user on a VF though as this would only indicate an error in the user's management of the enable bit, versus a PF where the same access could trigger hardware faults. Fixes: abafbc551fdd ("vfio-pci: Invalidate mmaps and block MMIO access on disabled memory") Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit ebfa440ce38b7e2e04c3124aa89c8a9f4094cf21 upstream.

SR-IOV VFs do not implement the memory enable bit of the command
register, therefore this bit is not set in config space after
pci_enable_device().  This leads to an unintended difference
between PF and VF in hand-off state to the user.  We can correct
this by setting the initial value of the memory enable bit in our
virtualized config space.  There's really no need however to
ever fault a user on a VF though as this would only indicate an
error in the user's management of the enable bit, versus a PF
where the same access could trigger hardware faults.

Fixes: abafbc551fdd ("vfio-pci: Invalidate mmaps and block MMIO access on disabled memory")
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vfio-pci: Invalidate mmaps and block MMIO access on disabled memory 2020-09-12T09:47:37+00:00 Alex Williamson alex.williamson@redhat.com 2020-04-22T19:48:11+00:00 5f2c69e2ef24a79b6909a6dc6b249a17909965f8 commit abafbc551fddede3e0a08dee1dcde08fc0eb8476 upstream. Accessing the disabled memory space of a PCI device would typically result in a master abort response on conventional PCI, or an unsupported request on PCI express. The user would generally see these as a -1 response for the read return data and the write would be silently discarded, possibly with an uncorrected, non-fatal AER error triggered on the host. Some systems however take it upon themselves to bring down the entire system when they see something that might indicate a loss of data, such as this discarded write to a disabled memory space. To avoid this, we want to try to block the user from accessing memory spaces while they're disabled. We start with a semaphore around the memory enable bit, where writers modify the memory enable state and must be serialized, while readers make use of the memory region and can access in parallel. Writers include both direct manipulation via the command register, as well as any reset path where the internal mechanics of the reset may both explicitly and implicitly disable memory access, and manipulation of the MSI-X configuration, where the MSI-X vector table resides in MMIO space of the device. Readers include the read and write file ops to access the vfio device fd offsets as well as memory mapped access. In the latter case, we make use of our new vma list support to zap, or invalidate, those memory mappings in order to force them to be faulted back in on access. Our semaphore usage will stall user access to MMIO spaces across internal operations like reset, but the user might experience new behavior when trying to access the MMIO space while disabled via the PCI command register. Access via read or write while disabled will return -EIO and access via memory maps will result in a SIGBUS. This is expected to be compatible with known use cases and potentially provides better error handling capabilities than present in the hardware, while avoiding the more readily accessible and severe platform error responses that might otherwise occur. Fixes: CVE-2020-12888 Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> [Ajay: Regenerated the patch for v4.9] Signed-off-by: Ajay Kaher <akaher@vmware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit abafbc551fddede3e0a08dee1dcde08fc0eb8476 upstream.

Accessing the disabled memory space of a PCI device would typically
result in a master abort response on conventional PCI, or an
unsupported request on PCI express.  The user would generally see
these as a -1 response for the read return data and the write would be
silently discarded, possibly with an uncorrected, non-fatal AER error
triggered on the host.  Some systems however take it upon themselves
to bring down the entire system when they see something that might
indicate a loss of data, such as this discarded write to a disabled
memory space.

To avoid this, we want to try to block the user from accessing memory
spaces while they're disabled.  We start with a semaphore around the
memory enable bit, where writers modify the memory enable state and
must be serialized, while readers make use of the memory region and
can access in parallel.  Writers include both direct manipulation via
the command register, as well as any reset path where the internal
mechanics of the reset may both explicitly and implicitly disable
memory access, and manipulation of the MSI-X configuration, where the
MSI-X vector table resides in MMIO space of the device.  Readers
include the read and write file ops to access the vfio device fd
offsets as well as memory mapped access.  In the latter case, we make
use of our new vma list support to zap, or invalidate, those memory
mappings in order to force them to be faulted back in on access.

Our semaphore usage will stall user access to MMIO spaces across
internal operations like reset, but the user might experience new
behavior when trying to access the MMIO space while disabled via the
PCI command register.  Access via read or write while disabled will
return -EIO and access via memory maps will result in a SIGBUS.  This
is expected to be compatible with known use cases and potentially
provides better error handling capabilities than present in the
hardware, while avoiding the more readily accessible and severe
platform error responses that might otherwise occur.

Fixes: CVE-2020-12888
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
[Ajay: Regenerated the patch for v4.9]
Signed-off-by: Ajay Kaher <akaher@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vfio-pci: Fault mmaps to enable vma tracking 2020-09-12T09:47:37+00:00 Alex Williamson alex.williamson@redhat.com 2020-04-28T19:12:20+00:00 de5dcf9226b35e498c67d43a840e5443d518ea90 commit 11c4cd07ba111a09f49625f9e4c851d83daf0a22 upstream. Rather than calling remap_pfn_range() when a region is mmap'd, setup a vm_ops handler to support dynamic faulting of the range on access. This allows us to manage a list of vmas actively mapping the area that we can later use to invalidate those mappings. The open callback invalidates the vma range so that all tracking is inserted in the fault handler and removed in the close handler. Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> [Ajay: Regenerated the patch for v4.9] Signed-off-by: Ajay Kaher <akaher@vmware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 11c4cd07ba111a09f49625f9e4c851d83daf0a22 upstream.

Rather than calling remap_pfn_range() when a region is mmap'd, setup
a vm_ops handler to support dynamic faulting of the range on access.
This allows us to manage a list of vmas actively mapping the area that
we can later use to invalidate those mappings.  The open callback
invalidates the vma range so that all tracking is inserted in the
fault handler and removed in the close handler.

Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
[Ajay: Regenerated the patch for v4.9]
Signed-off-by: Ajay Kaher <akaher@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vfio/type1: Support faulting PFNMAP vmas 2020-09-12T09:47:37+00:00 Alex Williamson alex.williamson@redhat.com 2020-04-28T23:02:24+00:00 33c25edfe15d6f914a26e74dd23468d5417ea3a0 commit 41311242221e3482b20bfed10fa4d9db98d87016 upstream. With conversion to follow_pfn(), DMA mapping a PFNMAP range depends on the range being faulted into the vma. Add support to manually provide that, in the same way as done on KVM with hva_to_pfn_remapped(). Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> [Ajay: Regenerated the patch for v4.9] Signed-off-by: Ajay Kaher <akaher@vmware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 41311242221e3482b20bfed10fa4d9db98d87016 upstream.

With conversion to follow_pfn(), DMA mapping a PFNMAP range depends on
the range being faulted into the vma.  Add support to manually provide
that, in the same way as done on KVM with hva_to_pfn_remapped().

Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
[Ajay: Regenerated the patch for v4.9]
Signed-off-by: Ajay Kaher <akaher@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vfio-pci: Mask cap zero 2020-06-30T19:38:25+00:00 Alex Williamson alex.williamson@redhat.com 2020-04-08T17:45:28+00:00 4481d24699f0c1d528202c7659cef2c1251c104a [ Upstream commit bc138db1b96264b9c1779cf18d5a3b186aa90066 ] The PCI Code and ID Assignment Specification changed capability ID 0 from reserved to a NULL capability in the v1.1 revision. The NULL capability is defined to include only the 16-bit capability header, ie. only the ID and next pointer. Unfortunately vfio-pci creates a map of config space, where ID 0 is used to reserve the standard type 0 header. Finding an actual capability with this ID therefore results in a bogus range marked in that map and conflicts with subsequent capabilities. As this seems to be a dummy capability anyway and we already support dropping capabilities, let's hide this one rather than delving into the potentially subtle dependencies within our map. Seen on an NVIDIA Tesla T4. Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit bc138db1b96264b9c1779cf18d5a3b186aa90066 ]

The PCI Code and ID Assignment Specification changed capability ID 0
from reserved to a NULL capability in the v1.1 revision.  The NULL
capability is defined to include only the 16-bit capability header,
ie. only the ID and next pointer.  Unfortunately vfio-pci creates a
map of config space, where ID 0 is used to reserve the standard type
0 header.  Finding an actual capability with this ID therefore results
in a bogus range marked in that map and conflicts with subsequent
capabilities.  As this seems to be a dummy capability anyway and we
already support dropping capabilities, let's hide this one rather than
delving into the potentially subtle dependencies within our map.

Seen on an NVIDIA Tesla T4.

Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
vfio/pci: fix memory leaks in alloc_perm_bits() 2020-06-30T19:38:21+00:00 Qian Cai cai@lca.pw 2020-05-10T16:16:56+00:00 58d4c2ef8851f4c17ad8dec44339a5b590155ecf [ Upstream commit 3e63b94b6274324ff2e7d8615df31586de827c4e ] vfio_pci_disable() calls vfio_config_free() but forgets to call free_perm_bits() resulting in memory leaks, unreferenced object 0xc000000c4db2dee0 (size 16): comm "qemu-kvm", pid 4305, jiffies 4295020272 (age 3463.780s) hex dump (first 16 bytes): 00 00 ff 00 ff ff ff ff ff ff ff ff ff ff 00 00 ................ backtrace: [<00000000a6a4552d>] alloc_perm_bits+0x58/0xe0 [vfio_pci] [<00000000ac990549>] vfio_config_init+0xdf0/0x11b0 [vfio_pci] init_pci_cap_msi_perm at drivers/vfio/pci/vfio_pci_config.c:1125 (inlined by) vfio_msi_cap_len at drivers/vfio/pci/vfio_pci_config.c:1180 (inlined by) vfio_cap_len at drivers/vfio/pci/vfio_pci_config.c:1241 (inlined by) vfio_cap_init at drivers/vfio/pci/vfio_pci_config.c:1468 (inlined by) vfio_config_init at drivers/vfio/pci/vfio_pci_config.c:1707 [<000000006db873a1>] vfio_pci_open+0x234/0x700 [vfio_pci] [<00000000630e1906>] vfio_group_fops_unl_ioctl+0x8e0/0xb84 [vfio] [<000000009e34c54f>] ksys_ioctl+0xd8/0x130 [<000000006577923d>] sys_ioctl+0x28/0x40 [<000000006d7b1cf2>] system_call_exception+0x114/0x1e0 [<0000000008ea7dd5>] system_call_common+0xf0/0x278 unreferenced object 0xc000000c4db2e330 (size 16): comm "qemu-kvm", pid 4305, jiffies 4295020272 (age 3463.780s) hex dump (first 16 bytes): 00 ff ff 00 ff ff ff ff ff ff ff ff ff ff 00 00 ................ backtrace: [<000000004c71914f>] alloc_perm_bits+0x44/0xe0 [vfio_pci] [<00000000ac990549>] vfio_config_init+0xdf0/0x11b0 [vfio_pci] [<000000006db873a1>] vfio_pci_open+0x234/0x700 [vfio_pci] [<00000000630e1906>] vfio_group_fops_unl_ioctl+0x8e0/0xb84 [vfio] [<000000009e34c54f>] ksys_ioctl+0xd8/0x130 [<000000006577923d>] sys_ioctl+0x28/0x40 [<000000006d7b1cf2>] system_call_exception+0x114/0x1e0 [<0000000008ea7dd5>] system_call_common+0xf0/0x278 Fixes: 89e1f7d4c66d ("vfio: Add PCI device driver") Signed-off-by: Qian Cai <cai@lca.pw> [aw: rolled in follow-up patch] Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 3e63b94b6274324ff2e7d8615df31586de827c4e ]

vfio_pci_disable() calls vfio_config_free() but forgets to call
free_perm_bits() resulting in memory leaks,

unreferenced object 0xc000000c4db2dee0 (size 16):
  comm "qemu-kvm", pid 4305, jiffies 4295020272 (age 3463.780s)
  hex dump (first 16 bytes):
    00 00 ff 00 ff ff ff ff ff ff ff ff ff ff 00 00  ................
  backtrace:
    [<00000000a6a4552d>] alloc_perm_bits+0x58/0xe0 [vfio_pci]
    [<00000000ac990549>] vfio_config_init+0xdf0/0x11b0 [vfio_pci]
    init_pci_cap_msi_perm at drivers/vfio/pci/vfio_pci_config.c:1125
    (inlined by) vfio_msi_cap_len at drivers/vfio/pci/vfio_pci_config.c:1180
    (inlined by) vfio_cap_len at drivers/vfio/pci/vfio_pci_config.c:1241
    (inlined by) vfio_cap_init at drivers/vfio/pci/vfio_pci_config.c:1468
    (inlined by) vfio_config_init at drivers/vfio/pci/vfio_pci_config.c:1707
    [<000000006db873a1>] vfio_pci_open+0x234/0x700 [vfio_pci]
    [<00000000630e1906>] vfio_group_fops_unl_ioctl+0x8e0/0xb84 [vfio]
    [<000000009e34c54f>] ksys_ioctl+0xd8/0x130
    [<000000006577923d>] sys_ioctl+0x28/0x40
    [<000000006d7b1cf2>] system_call_exception+0x114/0x1e0
    [<0000000008ea7dd5>] system_call_common+0xf0/0x278
unreferenced object 0xc000000c4db2e330 (size 16):
  comm "qemu-kvm", pid 4305, jiffies 4295020272 (age 3463.780s)
  hex dump (first 16 bytes):
    00 ff ff 00 ff ff ff ff ff ff ff ff ff ff 00 00  ................
  backtrace:
    [<000000004c71914f>] alloc_perm_bits+0x44/0xe0 [vfio_pci]
    [<00000000ac990549>] vfio_config_init+0xdf0/0x11b0 [vfio_pci]
    [<000000006db873a1>] vfio_pci_open+0x234/0x700 [vfio_pci]
    [<00000000630e1906>] vfio_group_fops_unl_ioctl+0x8e0/0xb84 [vfio]
    [<000000009e34c54f>] ksys_ioctl+0xd8/0x130
    [<000000006577923d>] sys_ioctl+0x28/0x40
    [<000000006d7b1cf2>] system_call_exception+0x114/0x1e0
    [<0000000008ea7dd5>] system_call_common+0xf0/0x278

Fixes: 89e1f7d4c66d ("vfio: Add PCI device driver")
Signed-off-by: Qian Cai <cai@lca.pw>
[aw: rolled in follow-up patch]
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
vfio/type1: Fix VA->PA translation for PFNMAP VMAs in vaddr_get_pfn() 2020-05-05T17:14:39+00:00 Sean Christopherson sean.j.christopherson@intel.com 2020-04-16T22:50:57+00:00 f9980f56a16056f03e81a00cae1aa1b824962fc9 commit 5cbf3264bc715e9eb384e2b68601f8c02bb9a61d upstream. Use follow_pfn() to get the PFN of a PFNMAP VMA instead of assuming that vma->vm_pgoff holds the base PFN of the VMA. This fixes a bug where attempting to do VFIO_IOMMU_MAP_DMA on an arbitrary PFNMAP'd region of memory calculates garbage for the PFN. Hilariously, this only got detected because the first "PFN" calculated by vaddr_get_pfn() is PFN 0 (vma->vm_pgoff==0), and iommu_iova_to_phys() uses PA==0 as an error, which triggers a WARN in vfio_unmap_unpin() because the translation "failed". PFN 0 is now unconditionally reserved on x86 in order to mitigate L1TF, which causes is_invalid_reserved_pfn() to return true and in turns results in vaddr_get_pfn() returning success for PFN 0. Eventually the bogus calculation runs into PFNs that aren't reserved and leads to failure in vfio_pin_map_dma(). The subsequent call to vfio_remove_dma() attempts to unmap PFN 0 and WARNs. WARNING: CPU: 8 PID: 5130 at drivers/vfio/vfio_iommu_type1.c:750 vfio_unmap_unpin+0x2e1/0x310 [vfio_iommu_type1] Modules linked in: vfio_pci vfio_virqfd vfio_iommu_type1 vfio ... CPU: 8 PID: 5130 Comm: sgx Tainted: G W 5.6.0-rc5-705d787c7fee-vfio+ #3 Hardware name: Intel Corporation Mehlow UP Server Platform/Moss Beach Server, BIOS CNLSE2R1.D00.X119.B49.1803010910 03/01/2018 RIP: 0010:vfio_unmap_unpin+0x2e1/0x310 [vfio_iommu_type1] Code: <0f> 0b 49 81 c5 00 10 00 00 e9 c5 fe ff ff bb 00 10 00 00 e9 3d fe RSP: 0018:ffffbeb5039ebda8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff9a55cbf8d480 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff9a52b771c200 RBP: 0000000000000000 R08: 0000000000000040 R09: 00000000fffffff2 R10: 0000000000000001 R11: ffff9a51fa896000 R12: 0000000184010000 R13: 0000000184000000 R14: 0000000000010000 R15: ffff9a55cb66ea08 FS: 00007f15d3830b40(0000) GS:ffff9a55d5600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000561cf39429e0 CR3: 000000084f75f005 CR4: 00000000003626e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: vfio_remove_dma+0x17/0x70 [vfio_iommu_type1] vfio_iommu_type1_ioctl+0x9e3/0xa7b [vfio_iommu_type1] ksys_ioctl+0x92/0xb0 __x64_sys_ioctl+0x16/0x20 do_syscall_64+0x4c/0x180 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f15d04c75d7 Code: <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 81 48 2d 00 f7 d8 64 89 01 48 Fixes: 73fa0d10d077 ("vfio: Type1 IOMMU implementation") Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 5cbf3264bc715e9eb384e2b68601f8c02bb9a61d upstream.

Use follow_pfn() to get the PFN of a PFNMAP VMA instead of assuming that
vma->vm_pgoff holds the base PFN of the VMA.  This fixes a bug where
attempting to do VFIO_IOMMU_MAP_DMA on an arbitrary PFNMAP'd region of
memory calculates garbage for the PFN.

Hilariously, this only got detected because the first "PFN" calculated
by vaddr_get_pfn() is PFN 0 (vma->vm_pgoff==0), and iommu_iova_to_phys()
uses PA==0 as an error, which triggers a WARN in vfio_unmap_unpin()
because the translation "failed".  PFN 0 is now unconditionally reserved
on x86 in order to mitigate L1TF, which causes is_invalid_reserved_pfn()
to return true and in turns results in vaddr_get_pfn() returning success
for PFN 0.  Eventually the bogus calculation runs into PFNs that aren't
reserved and leads to failure in vfio_pin_map_dma().  The subsequent
call to vfio_remove_dma() attempts to unmap PFN 0 and WARNs.

  WARNING: CPU: 8 PID: 5130 at drivers/vfio/vfio_iommu_type1.c:750 vfio_unmap_unpin+0x2e1/0x310 [vfio_iommu_type1]
  Modules linked in: vfio_pci vfio_virqfd vfio_iommu_type1 vfio ...
  CPU: 8 PID: 5130 Comm: sgx Tainted: G        W         5.6.0-rc5-705d787c7fee-vfio+ #3
  Hardware name: Intel Corporation Mehlow UP Server Platform/Moss Beach Server, BIOS CNLSE2R1.D00.X119.B49.1803010910 03/01/2018
  RIP: 0010:vfio_unmap_unpin+0x2e1/0x310 [vfio_iommu_type1]
  Code: <0f> 0b 49 81 c5 00 10 00 00 e9 c5 fe ff ff bb 00 10 00 00 e9 3d fe
  RSP: 0018:ffffbeb5039ebda8 EFLAGS: 00010246
  RAX: 0000000000000000 RBX: ffff9a55cbf8d480 RCX: 0000000000000000
  RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff9a52b771c200
  RBP: 0000000000000000 R08: 0000000000000040 R09: 00000000fffffff2
  R10: 0000000000000001 R11: ffff9a51fa896000 R12: 0000000184010000
  R13: 0000000184000000 R14: 0000000000010000 R15: ffff9a55cb66ea08
  FS:  00007f15d3830b40(0000) GS:ffff9a55d5600000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000561cf39429e0 CR3: 000000084f75f005 CR4: 00000000003626e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   vfio_remove_dma+0x17/0x70 [vfio_iommu_type1]
   vfio_iommu_type1_ioctl+0x9e3/0xa7b [vfio_iommu_type1]
   ksys_ioctl+0x92/0xb0
   __x64_sys_ioctl+0x16/0x20
   do_syscall_64+0x4c/0x180
   entry_SYSCALL_64_after_hwframe+0x44/0xa9
  RIP: 0033:0x7f15d04c75d7
  Code: <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 81 48 2d 00 f7 d8 64 89 01 48

Fixes: 73fa0d10d077 ("vfio: Type1 IOMMU implementation")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vfio_pci: Enable memory accesses before calling pci_map_rom 2020-01-29T09:24:16+00:00 Eric Auger eric.auger@redhat.com 2019-02-15T16:16:06+00:00 aecc7621fedccf2df40375f9f7bff26ead3d050a [ Upstream commit 0cfd027be1d6def4a462cdc180c055143af24069 ] pci_map_rom/pci_get_rom_size() performs memory access in the ROM. In case the Memory Space accesses were disabled, readw() is likely to trigger a synchronous external abort on some platforms. In case memory accesses were disabled, re-enable them before the call and disable them back again just after. Fixes: 89e1f7d4c66d ("vfio: Add PCI device driver") Signed-off-by: Eric Auger <eric.auger@redhat.com> Suggested-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 0cfd027be1d6def4a462cdc180c055143af24069 ]

pci_map_rom/pci_get_rom_size() performs memory access in the ROM.
In case the Memory Space accesses were disabled, readw() is likely
to trigger a synchronous external abort on some platforms.

In case memory accesses were disabled, re-enable them before the
call and disable them back again just after.

Fixes: 89e1f7d4c66d ("vfio: Add PCI device driver")
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
vfio/pci: call irq_bypass_unregister_producer() before freeing irq 2019-12-21T09:42:31+00:00 Jiang Yi giangyi@amazon.com 2019-11-27T16:49:10+00:00 017df5edfa2388a3f9eca11228d148e2939d04b3 commit d567fb8819162099035e546b11a736e29c2af0ea upstream. Since irq_bypass_register_producer() is called after request_irq(), we should do tear-down in reverse order: irq_bypass_unregister_producer() then free_irq(). Specifically free_irq() may release resources required by the irqbypass del_producer() callback. Notably an example provided by Marc Zyngier on arm64 with GICv4 that he indicates has the potential to wedge the hardware: free_irq(irq) __free_irq(irq) irq_domain_deactivate_irq(irq) its_irq_domain_deactivate() [unmap the VLPI from the ITS] kvm_arch_irq_bypass_del_producer(cons, prod) kvm_vgic_v4_unset_forwarding(kvm, irq, ...) its_unmap_vlpi(irq) [Unmap the VLPI from the ITS (again), remap the original LPI] Signed-off-by: Jiang Yi <giangyi@amazon.com> Cc: stable@vger.kernel.org # v4.4+ Fixes: 6d7425f109d26 ("vfio: Register/unregister irq_bypass_producer") Link: https://lore.kernel.org/kvm/20191127164910.15888-1-giangyi@amazon.com Reviewed-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> [aw: commit log] Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit d567fb8819162099035e546b11a736e29c2af0ea upstream.

Since irq_bypass_register_producer() is called after request_irq(), we
should do tear-down in reverse order: irq_bypass_unregister_producer()
then free_irq().

Specifically free_irq() may release resources required by the
irqbypass del_producer() callback.  Notably an example provided by
Marc Zyngier on arm64 with GICv4 that he indicates has the potential
to wedge the hardware:

 free_irq(irq)
   __free_irq(irq)
     irq_domain_deactivate_irq(irq)
       its_irq_domain_deactivate()
         [unmap the VLPI from the ITS]

 kvm_arch_irq_bypass_del_producer(cons, prod)
   kvm_vgic_v4_unset_forwarding(kvm, irq, ...)
     its_unmap_vlpi(irq)
       [Unmap the VLPI from the ITS (again), remap the original LPI]

Signed-off-by: Jiang Yi <giangyi@amazon.com>
Cc: stable@vger.kernel.org # v4.4+
Fixes: 6d7425f109d26 ("vfio: Register/unregister irq_bypass_producer")
Link: https://lore.kernel.org/kvm/20191127164910.15888-1-giangyi@amazon.com
Reviewed-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
[aw: commit log]
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vfio/spapr_tce: Get rid of possible infinite loop 2019-12-05T14:34:47+00:00 Alexey Kardashevskiy aik@ozlabs.ru 2018-10-02T03:22:31+00:00 95c653522a6117287ff046881e08bdc2f079bec9 [ Upstream commit 517ad4ae8aa93dccdb9a88c27257ecb421c9e848 ] As a part of cleanup, the SPAPR TCE IOMMU subdriver releases preregistered memory. If there is a bug in memory release, the loop in tce_iommu_release() becomes infinite; this actually happened to me. This makes the loop finite and prints a warning on every failure to make the code more bug prone. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 517ad4ae8aa93dccdb9a88c27257ecb421c9e848 ]

As a part of cleanup, the SPAPR TCE IOMMU subdriver releases preregistered
memory. If there is a bug in memory release, the loop in
tce_iommu_release() becomes infinite; this actually happened to me.

This makes the loop finite and prints a warning on every failure to make
the code more bug prone.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>