linux.git/kernel/irq/msi.c, branch v6.6

x86/pci/xen: populate MSI sysfs entries

2023-05-24T16:08:49+00:00

Commit bf5e758f02fc ("genirq/msi: Simplify sysfs handling") reworked the
creation of sysfs entries for MSI IRQs. The creation used to be in
msi_domain_alloc_irqs_descs_locked after calling ops->domain_alloc_irqs.
Then it moved into __msi_domain_alloc_irqs which is an implementation of
domain_alloc_irqs. However, Xen comes with the only other implementation
of domain_alloc_irqs and hence doesn't run the sysfs population code
anymore.

Commit 6c796996ee70 ("x86/pci/xen: Fixup fallout from the PCI/MSI
overhaul") set the flag MSI_FLAG_DEV_SYSFS for the xen msi_domain_info
but that doesn't actually have an effect because Xen uses it's own
domain_alloc_irqs implementation.

Fix this by making use of the fallback functions for sysfs population.

Fixes: bf5e758f02fc ("genirq/msi: Simplify sysfs handling")
Signed-off-by: Maximilian Heyne 
Reviewed-by: Juergen Gross 
Link: https://lore.kernel.org/r/20230503131656.15928-1-mheyne@amazon.de
Signed-off-by: Juergen Gross

Merge tag 'irq-urgent-2023-03-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2023-03-05T19:19:16+00:00

Pull irq updates from Thomas Gleixner:
 "A set of updates for the interrupt susbsystem:

   - Prevent possible NULL pointer derefences in
     irq_data_get_affinity_mask() and irq_domain_create_hierarchy()

   - Take the per device MSI lock before invoking code which relies on
     it being hold

   - Make sure that MSI descriptors are unreferenced before freeing
     them. This was overlooked when the platform MSI code was converted
     to use core infrastructure and results in a fals positive warning

   - Remove dead code in the MSI subsystem

   - Clarify the documentation for pci_msix_free_irq()

   - More kobj_type constification"

* tag 'irq-urgent-2023-03-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq/msi, platform-msi: Ensure that MSI descriptors are unreferenced
  genirq/msi: Drop dead domain name assignment
  irqdomain: Add missing NULL pointer check in irq_domain_create_hierarchy()
  genirq/irqdesc: Make kobj_type structures constant
  PCI/MSI: Clarify usage of pci_msix_free_irq()
  genirq/msi: Take the per-device MSI lock before validating the control structure
  genirq/ipi: Fix NULL pointer deref in irq_data_get_affinity_mask()

genirq/msi, platform-msi: Ensure that MSI descriptors are unreferenced

2023-03-02T17:09:44+00:00

Miquel reported a warning in the MSI core which is triggered when
interrupts are freed via platform_msi_device_domain_free().

This code got reworked to use core functions for freeing the MSI
descriptors, but nothing took care to clear the msi_desc->irq entry, which
then triggers the warning in msi_free_msi_desc() which uses desc->irq to
validate that the descriptor has been torn down. The same issue exists in
msi_domain_populate_irqs().

Up to the point that msi_free_msi_descs() grew a warning for this case,
this went un-noticed.

Provide the counterpart of msi_domain_populate_irqs() and invoke it in
platform_msi_device_domain_free() before freeing the interrupts and MSI
descriptors and also in the error path of msi_domain_populate_irqs().

Fixes: 2f2940d16823 ("genirq/msi: Remove filter from msi_free_descs_free_range()")
Reported-by: Miquel Raynal 
Signed-off-by: Thomas Gleixner 
Tested-by: Miquel Raynal 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/87mt4wkwnv.ffs@tglx

genirq/msi: Drop dead domain name assignment

2023-02-24T19:54:58+00:00

Since commit d59f6617eef0 ("genirq: Allow fwnode to carry name
information only") an IRQ domain is always given a name during
allocation (e.g. used for the debugfs entry).

Drop the unused fallback name assignment when creating MSI domains.

Signed-off-by: Johan Hovold 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/r/20230224130509.27814-1-johan+linaro@kernel.org

Merge tag 'v6.2' into iommufd.git for-next

2023-02-21T15:11:03+00:00

Resolve conflicts from the signature change in iommu_map:

 - drivers/infiniband/hw/usnic/usnic_uiom.c
   Switch iommu_map_atomic() to iommu_map(.., GFP_ATOMIC)

 - drivers/vfio/vfio_iommu_type1.c
   Following indenting change for GFP_KERNEL

Signed-off-by: Jason Gunthorpe

genirq/msi: Take the per-device MSI lock before validating the control structure

2023-02-20T21:29:54+00:00

Calling msi_ctrl_valid() ultimately results in calling
msi_get_device_domain(), which requires holding the device MSI lock.

However, in msi_domain_populate_irqs() the lock is taken right after having
called msi_ctrl_valid(), which is just a tad too late.

Take the lock before invoking msi_ctrl_valid().

Fixes: 40742716f294 ("genirq/msi: Make msi_add_simple_msi_descs() device domain aware")
Reported-by: "Russell King (Oracle)" 
Signed-off-by: Marc Zyngier 
Signed-off-by: Thomas Gleixner 
Tested-by: Russell King (Oracle) 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/Y/Opu6ETe3ZzZ/8E@shell.armlinux.org.uk
Link: https://lore.kernel.org/r/20230220190101.314446-1-maz@kernel.org

genirq/msi: Free the fwnode created by msi_create_device_irq_domain()

2023-01-17T21:57:04+00:00

msi_create_device_irq_domain() creates a firmware node for the new domain,
which is never freed. kmemleak reports:

unreferenced object 0xffff888120ba9a00 (size 96):
  comm "systemd-modules", pid 221, jiffies 4294893411 (age 635.732s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 e0 19 8b 83 ff ff ff ff  ................
    00 00 00 00 00 00 00 00 18 9a ba 20 81 88 ff ff  ........... ....
  backtrace:
    [<000000008cdbc98d>] __irq_domain_alloc_fwnode+0x51/0x2b0
    [<00000000c57acf9d>] msi_create_device_irq_domain+0x283/0x670
    [<000000009b567982>] __pci_enable_msix_range+0x49e/0xdb0
    [<0000000077cc1445>] pci_alloc_irq_vectors_affinity+0x11f/0x1c0
    [<00000000532e9ef5>] mlx5_irq_table_create+0x24c/0x940 [mlx5_core]
    [<00000000fabd2b80>] mlx5_load+0x1fa/0x680 [mlx5_core]
    [<000000006bb22ae4>] mlx5_init_one+0x485/0x670 [mlx5_core]
    [<00000000eaa5e1ad>] probe_one+0x4c2/0x720 [mlx5_core]
    [<00000000df8efb43>] local_pci_probe+0xd6/0x170
    [<0000000085cb9924>] pci_device_probe+0x231/0x6e0

Use the proper free operation for the firmware wnode so the name is freed
during error unwind of msi_create_device_irq_domain() and also free the
node in msi_remove_device_irq_domain() if it was automatically allocated.

To avoid extra NULL pointer checks make irq_domain_free_fwnode() tolerant
of NULL.

Fixes: 27a6dea3ebaa ("genirq/msi: Provide msi_create/free_device_irq_domain()")
Reported-by: Omri Barazi 
Signed-off-by: Jason Gunthorpe 
Signed-off-by: Thomas Gleixner 
Tested-by: Kalle Valo 
Tested-by: Leon Romanovsky 
Link: https://lore.kernel.org/r/0-v2-24af6665e2da+c9-msi_leak_jgg@nvidia.com

irq/s390: Add arch_is_isolated_msi() for s390

2023-01-11T20:27:23+00:00

s390 doesn't use irq_domains, so it has no place to set
IRQ_DOMAIN_FLAG_ISOLATED_MSI. Instead of continuing to abuse the iommu
subsystem to convey this information add a simple define which s390 can
make statically true. The define will cause msi_device_has_isolated() to
return true.

Remove IOMMU_CAP_INTR_REMAP from the s390 iommu driver.

Link: https://lore.kernel.org/r/8-v3-3313bb5dd3a3+10f11-secure_msi_jgg@nvidia.com
Reviewed-by: Matthew Rosato 
Tested-by: Matthew Rosato 
Reviewed-by: Kevin Tian 
Signed-off-by: Jason Gunthorpe

genirq/msi: Rename IRQ_DOMAIN_MSI_REMAP to IRQ_DOMAIN_ISOLATED_MSI

2023-01-11T20:27:23+00:00

What x86 calls "interrupt remapping" is one way to achieve isolated MSI,
make it clear this is talking about isolated MSI, no matter how it is
achieved. This matches the new driver facing API name of
msi_device_has_isolated_msi()

No functional change.

Link: https://lore.kernel.org/r/6-v3-3313bb5dd3a3+10f11-secure_msi_jgg@nvidia.com
Tested-by: Matthew Rosato 
Reviewed-by: Kevin Tian 
Reviewed-by: Thomas Gleixner 
Signed-off-by: Jason Gunthorpe

genirq/msi: Add msi_device_has_isolated_msi()

2023-01-11T20:21:08+00:00

This will replace irq_domain_check_msi_remap() in following patches.

The new API makes it more clear what "msi_remap" actually means from a
functional perspective instead of identifying an implementation specific
HW feature.

Isolated MSI means that HW modeled by an irq_domain on the path from the
initiating device to the CPU will validate that the MSI message specifies
an interrupt number that the device is authorized to trigger. This must
block devices from triggering interrupts they are not authorized to
trigger.  Currently authorization means the MSI vector is one assigned to
the device.

This is interesting for securing VFIO use cases where a rouge MSI (eg
created by abusing a normal PCI MemWr DMA) must not allow the VFIO
userspace to impact outside its security domain, eg userspace triggering
interrupts on kernel drivers, a VM triggering interrupts on the
hypervisor, or a VM triggering interrupts on another VM.

As this is actually modeled as a per-irq_domain property, not a global
platform property, correct the interface to accept the device parameter
and scan through only the part of the irq_domains hierarchy originating
from the source device.

Locate the new code in msi.c as it naturally only works with
CONFIG_GENERIC_MSI_IRQ, which also requires CONFIG_IRQ_DOMAIN and
IRQ_DOMAIN_HIERARCHY.

Link: https://lore.kernel.org/r/1-v3-3313bb5dd3a3+10f11-secure_msi_jgg@nvidia.com
Tested-by: Matthew Rosato 
Reviewed-by: Kevin Tian 
Reviewed-by: Thomas Gleixner 
Signed-off-by: Jason Gunthorpe