On 17.11.2022 11:23, Roger Pau Monné wrote: > On Thu, Nov 17, 2022 at 10:27:41AM +0100, Jan Beulich wrote: >> On 16.11.2022 17:42, Roger Pau Monne wrote: >>> Currently Xen will passthrough any Local APIC NMI Structure found in >>> the native ACPI MADT table to a PVH dom0. This is wrong because PVH >>> doesn't have access to the physical local APIC, and instead gets an >>> emulated local APIC by Xen, that doesn't have the LINT0 or LINT1 >>> pins wired to anything. Furthermore the ACPI Processor UIDs used in >>> the APIC NMI Structures are likely to not match the ones generated by >>> Xen for the Local x2APIC Structures, creating confusion to dom0. >> >> Plus we should have passed through Local x2APIC NMI Structures then as >> well. > > Sadly this is not possible for PVH dom0, Linux will use the ACPI > Processor UID as vCPU ID in hypercalls, so if the UIDs don't start at > 0 and are sequential Linux will panic during boot because vCPU > operations will fail.
Sure - I was merely hinting at the original attempt having been incomplete (besides being flawed as per the description here). Jan
