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>
Currently, Linux logs the two messages below.
[ 0.979142] pci 0000:00:00.2: AMD-Vi: Extended features (0xf77ef22294ada):
[ 0.979546] PPR NX GT IA GA PC GA_vAPIC
The log level of these lines differs though. The first one has level
*info*, while the second has level *warn*, which is confusing.
$ dmesg -T --level=info | grep "Extended features"
[Tue Jun 16 21:46:58 2020] pci 0000:00:00.2: AMD-Vi: Extended features (0xf77ef22294ada):
$ dmesg -T --level=warn | grep "PPR"
[Tue Jun 16 21:46:58 2020] PPR NX GT IA GA PC GA_vAPIC
The problem is, that commit 3928aa3f57 ("iommu/amd: Detect and enable
guest vAPIC support") introduced a newline, causing `pr_cont()`, used to
print the features, to default back to the default log level.
/**
* pr_cont - Continues a previous log message in the same line.
* @fmt: format string
* @...: arguments for the format string
*
* This macro expands to a printk with KERN_CONT loglevel. It should only be
* used when continuing a log message with no newline ('\n') enclosed. Otherwise
* it defaults back to KERN_DEFAULT loglevel.
*/
#define pr_cont(fmt, ...) \
printk(KERN_CONT fmt, ##__VA_ARGS__)
So, remove the line break, so only one line is logged.
Fixes: 3928aa3f57 ("iommu/amd: Detect and enable guest vAPIC support")
Signed-off-by: Paul Menzel <pmenzel@molgen.mpg.de>
Reviewed-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: iommu@lists.linux-foundation.org
Link: https://lore.kernel.org/r/20200616220420.19466-1-pmenzel@molgen.mpg.de
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Move all files related to the AMD IOMMU driver into its own
subdirectory.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Reviewed-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Link: https://lore.kernel.org/r/20200609130303.26974-2-joro@8bytes.org
