mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-05-02 10:59:18 -04:00
aa7528fe35
It was noticed that the IRTE configured for guest OS kernel
was over-written while the guest was running. As a result,
vt-d Posted Interrupts configured for the guest are not being
delivered directly, and instead bounces off the host. Every
interrupt delivery takes a VM Exit.
It was noticed that the following stack is doing the over-write:
[ 147.463177] modify_irte+0x171/0x1f0
[ 147.463405] intel_ir_set_affinity+0x5c/0x80
[ 147.463641] msi_domain_set_affinity+0x32/0x90
[ 147.463881] irq_do_set_affinity+0x37/0xd0
[ 147.464125] irq_set_affinity_locked+0x9d/0xb0
[ 147.464374] __irq_set_affinity+0x42/0x70
[ 147.464627] write_irq_affinity.isra.5+0xe1/0x110
[ 147.464895] proc_reg_write+0x38/0x70
[ 147.465150] __vfs_write+0x36/0x180
[ 147.465408] ? handle_mm_fault+0xdf/0x200
[ 147.465671] ? _cond_resched+0x15/0x30
[ 147.465936] vfs_write+0xad/0x1a0
[ 147.466204] SyS_write+0x52/0xc0
[ 147.466472] do_syscall_64+0x74/0x1a0
[ 147.466744] entry_SYSCALL_64_after_hwframe+0x3d/0xa2
reversing the sense of force check in intel_ir_reconfigure_irte()
restores proper posted interrupt functionality
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Fixes: d491bdff88 ('iommu/vt-d: Reevaluate vector configuration on activate()')
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.