Commit e52d58d54a ("iommu/amd: Use cmpxchg_double() when updating
128-bit IRTE") removed an assumption that modify_irte_ga always set
the valid bit, which requires the callers to set the appropriate value
for the struct irte_ga.valid bit before calling the function.
Similar to the commit 26e495f341 ("iommu/amd: Restore IRTE.RemapEn
bit after programming IRTE"), which is for the function
amd_iommu_deactivate_guest_mode().
The same change is also needed for the amd_iommu_activate_guest_mode().
Otherwise, this could trigger IO_PAGE_FAULT for the VFIO based VMs with
AVIC enabled.
Fixes: e52d58d54a ("iommu/amd: Use cmpxchg_double() when updating 128-bit IRTE")
Reported-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Tested-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Link: https://lore.kernel.org/r/20200916111720.43913-1-suravee.suthikulpanit@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
When using 128-bit interrupt-remapping table entry (IRTE) (a.k.a GA mode),
current driver disables interrupt remapping when it updates the IRTE
so that the upper and lower 64-bit values can be updated safely.
However, this creates a small window, where the interrupt could
arrive and result in IO_PAGE_FAULT (for interrupt) as shown below.
IOMMU Driver Device IRQ
============ ===========
irte.RemapEn=0
...
change IRTE IRQ from device ==> IO_PAGE_FAULT !!
...
irte.RemapEn=1
This scenario has been observed when changing irq affinity on a system
running I/O-intensive workload, in which the destination APIC ID
in the IRTE is updated.
Instead, use cmpxchg_double() to update the 128-bit IRTE at once without
disabling the interrupt remapping. However, this means several features,
which require GA (128-bit IRTE) support will also be affected if cmpxchg16b
is not supported (which is unprecedented for AMD processors w/ IOMMU).
Fixes: 880ac60e25 ("iommu/amd: Introduce interrupt remapping ops structure")
Reported-by: Sean Osborne <sean.m.osborne@oracle.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Tested-by: Erik Rockstrom <erik.rockstrom@oracle.com>
Reviewed-by: Joao Martins <joao.m.martins@oracle.com>
Link: https://lore.kernel.org/r/20200903093822.52012-3-suravee.suthikulpanit@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Quite some non OF/ACPI users of irqdomains allocate firmware nodes of type
IRQCHIP_FWNODE_NAMED or IRQCHIP_FWNODE_NAMED_ID and free them right after
creating the irqdomain. The only purpose of these FW nodes is to convey
name information. When this was introduced the core code did not store the
pointer to the node in the irqdomain. A recent change stored the firmware
node pointer in irqdomain for other reasons and missed to notice that the
usage sites which do the alloc_fwnode/create_domain/free_fwnode sequence
are broken by this. Storing a dangling pointer is dangerous itself, but in
case that the domain is destroyed later on this leads to a double free.
Remove the freeing of the firmware node after creating the irqdomain from
all affected call sites to cure this.
Fixes: 711419e504 ("irqdomain: Add the missing assignment of domain->fwnode for named fwnode")
Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/873661qakd.fsf@nanos.tec.linutronix.de
