Hi Alex,
> MSI routing updates aren't currently handled by pci-assign or
> vfio-pci (when using KVM acceleration), which means that trying to
> set interrupt SMP affinity in the guest has no effect unless MSI is
> completely disabled and re-enabled. This series fixes this for both
> device assignment backends using similar schemes. We store the last
> MSIMessage programmed to KVM and do updates to the MSI route when it
> changes. pci-assign takes a little bit of refactoring to make this
> happen cleanly. Thanks,
I am using the MSI affinity for assigned devices patch 1 to 4. I have setup the
guest such that VCPU0 is pinned to PCPU1, VCPU1 is pinned to PCPU2, VCPU2 is
pinned to PCPU3 and VCPU3 is pinned to PCPU4. I do this by taskset after the
guest boots. I then start generating interrupts affined to VCPU3. I see all the
interrupts directly delivered to VCPU 3. Now i do the same test but interrupt
affined to VCPU 2. Although the interrupts are delivered to VCPU2 there are
lot of "Rescheduling interrupts" in VCPU 3. I have checked the smp_affinity and
it is updated to VCPU 2.
Wanted to know your feedback on this usecase and what might be the impact.
CPU0 CPU1 CPU2 CPU3 0: 211 0
0 0 IO-APIC-edge timer 4: 60940 0 0
0 IO-APIC-edge serial 8: 65 0 0
0 IO-APIC-edge rtc0 9: 0 0 0 0
IO-APIC-fasteoi acpi 40: 0 0 0 0
PCI-MSI-edge virtio1-config 41: 1910 0 0
0 PCI-MSI-edge virtio1-requests 42: 0 0 0
0 PCI-MSI-edge virtio0-config 43: 127 0 0
0 PCI-MSI-edge virtio0-input 44: 1 0
0 0 PCI-MSI-edge virtio0-output 45: 1 0
3377 11194 PCI-MSI-edge FPGA_DEVNMI: 0 0
0 0 Non-maskable interruptsLOC: 225880 231572 223670
223612 Local timer interruptsSPU: 0 0 0 0
Spurious interruptsPMI: 0 0 0 0
Performance monitoring interruptsIWI: 0 0 0
0 IRQ work interruptsRTR: 0 0 0 0 APIC
ICR read retriesRES: 14 20 21 3398 Rescheduling
interrupts-------> Many RES Interrtups!!!!!!CAL: 0 14
14 16 Function call interruptsTLB: 0 0 0
0 TLB shootdowns
thanks,Krishna
