----- Original Message -----
From: "Timothy Pearson" <redacted>
To: "linuxppc-dev" <redacted>
Cc: "Ritesh Harjani" <ritesh.list@gmail.com>
Sent: Friday, August 14, 2026 9:56:30 AM
Subject: [BUG] Continuously increasing spurious interrupts inside pSeries guest on PowerNV host
With kernel 6.12 (Debian stable) we see a continuously increasing spurious
interrupt count inside a pSeries guest running on a PowerNV host:
cat /proc/interrupts
CPU0
16: 0 XIVE-IPI 0 Edge IPI-0
17: 0 XIVE-IRQ 4096 Edge RAS_EPOW
21: 2 XIVE-IRQ 4353 Edge hvc_console
23: 0 XIVE-IRQ 4097 Edge RAS_HOTPLUG
24: 0 pSeries-PCI-MSI 0 Edge virtio0-config
25: 50995 pSeries-PCI-MSI 1 Edge virtio0-input.0
26: 45569 pSeries-PCI-MSI 2 Edge virtio0-output.0
27: 0 pSeries-PCI-MSI 16384 Edge virtio1-config
28: 6 pSeries-PCI-MSI 16385 Edge virtio1-input
LOC: 5781 Local timer interrupts for timer event device
BCT: 0 Broadcast timer interrupts for timer event device
LOC: 2 Local timer interrupts for others
SPU: 449927 Spurious interrupts
PMI: 0 Performance monitoring interrupts
MCE: 0 Machine check exceptions
NMI: 0 System Reset interrupts
WDG: 0 Watchdog soft-NMI interrupts
DBL: 0 Doorbell interrupts
The spurious interrupts are apparently from the virtio0-[input|output] devices.
Actually, I don't know where the spurious interrupts are coming from. This is in XIVE mode. Switching to XICS mode via -M pseries,ic-mode=xics greatly reduces the rate of spurious interrupts, but does not eliminate them.
I don't recall this being an issue on the 5.x series kernels, but do not have the ability to test either those or the 7.x series at the moment.