Hello, I have no idea if this is a regression or not. I suspect it might not be, and has always been broken.
Either way, I'm seeing occasional single interrupt remapping errors when booting a range of Intel systems (XEN) x2APIC mode is already enabled by BIOS. (XEN) Using APIC driver x2apic_cluster ... (XEN) Platform timer is 23.999MHz HPET (XEN) Detected 2194.922 MHz processor. ... (XEN) HVM: HAP page sizes: 4kB, 2MB, 1GB (XEN) alt table ffff82d08047a070 -> ffff82d080486c6c (XEN) [VT-D]INTR-REMAP: Request device [0000:f0:1f.0] fault index 0, iommu reg = ffff82c00072d000 (XEN) [VT-D]INTR-REMAP: reason 22 - Present field in the IRTE entry is clear (XEN) microcode: CPU2 updated from revision 0x5000021 to 0x500002b, date = 2019-08-12 From other debugging, I know that this happens after CPU 1 (which is a hyperthread) has passed through start_secondary(). f0:1f.0 is one of the IO-APICs, and if I've cross referenced the DMAR and APIC tables properly, is the IO-APIC on the PCH, making the problematic IRQ GSI0. This suggests that we have an error setting up the timer IRQ (as the HPET isn't MSI-capable), but we have already allegedly used it successfully earlier on boot. I haven't investigated further yet, but it is an intermittent issue (i.e. doesn't reproduce on each boot). My gut feeling is that we have something which corrects itself as a side effect of a later action. ~Andrew _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
