[patch 0/8] PCI/MSI, x86: Cure a couple of inconsistencies

From: Thomas Gleixner
Date: Wed Jul 21 2021 - 15:28:22 EST

A recent discussion about the PCI/MSI management for virtio unearthed a
violation of the MSI-X specification vs. writing the MSI-X message: under
certain circumstances the entry is written without being masked.

While looking at that and the related violation of the x86 non-remapped
interrupt affinity mechanism a few other issues were discovered by

The following series addresses these.

Note this does not fix the virtio issue, but while staring at the above
problems I came up with a plan to address this. I'm still trying to
convince myself that I can get away without sprinkling locking all over the
place, so don't hold your breath that this will materialize tomorrow.

The series is also available from git:

git://git.kernel.org/pub/scm/linux/kernel/git/tglx/devel.git irq/msi


arch/x86/kernel/apic/io_apic.c | 6 +-
arch/x86/kernel/apic/msi.c | 11 +++-
arch/x86/kernel/hpet.c | 2
drivers/pci/msi.c | 98 +++++++++++++++++++++++++++--------------
include/linux/irq.h | 2
kernel/irq/chip.c | 5 +-
6 files changed, 85 insertions(+), 39 deletions(-)