[PATCH 0/13][Jammy linux-azure] Azure: Enable vPCI multi-MSI interrupts

[Tim Gardner]

BugLink: https://bugs.launchpad.net/bugs/1990184

SRU Justification

[Impact]

This is a 2nd attempt with this patch set. The first attempt [1] caused a regression.

The Hyper-V vPCI driver (pci-hyperv) doesn't work with a PCIe devcie that supports
multiple MSI interrupts (Note: MSI-X has been working fine). Recently Jeffrey Hugo
<quic_jhugo at quicinc.com> made 4 patches to the vPCI driver so multiple-MSI can work
now.

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=08e61e861a0e47e5e1a3fb78406afd6b0cea6b6d

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=455880dfe292a2bdd3b4ad6a107299fce610e64b

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b4b77778ecc5bfbd4e77de1b2fd5c1dd3c655f1f

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a2bad844a67b1c7740bda63e87453baf63c3a7f7

[1] https://bugs.launchpad.net/bugs/1981577

[Test Plan]

Microsoft tested: " I tested the kernel and it worked as expected, i.e. we still have
the multi-MSI capability and I no longer see the soft lockup issue with fio + NVMe +
the L64s_v2 VM size."

[Where things could go wrong]

vPCI devices may not get interrupts

[Other Info]

SF: #00339521