On 11.03.2026 16:27, Jan Beulich wrote: > On 09.03.2026 13:31, Julian Vetter wrote: >> @@ -618,6 +620,21 @@ static int cf_check ioapic_check(const struct domain >> *d, hvm_domain_context_t *h >> e->fields.reserved[0] || e->fields.reserved[1] || >> e->fields.reserved[2] || e->fields.reserved2 ) >> return -EINVAL; >> + >> + /* >> + * An RTE in the saved state has ext_dest_id bits set. Check that >> + * the destination Xen has extended destination ID support enabled, >> + * otherwise interrupt routing to APIC IDs > 255 would be broken >> + * after restore. >> + */ >> + if ( e->fields.ext_dest_id && !d->arch.hvm.ext_dest_id_enabled ) > > This won't build, as the ext_dest_id_enabled field appears only in patch 6. > But yes, that looks to be the opt-in mechanism I mentioned above.
Actually no, how could it be. That's for the DM to invoke. Jan
