Re: [0/5] vmd: generate and expose ACPI tables to the guest via fw_cfg
Miguel Landaeta <[email protected]>
| Newsgroups | gmane.os.openbsd.tech |
|---|---|
| Message-ID | <CAEA1CYT+E0zvPwfOWXnFv6YEWNCDhf3YSVs1we2fXsJ=-XfqSQ@mail.gmail.com> |
On Tue 16 Jun 2026 at 00:42, Mike Larkin <[email protected]> wrote: > > how do you deliver IPIs without a lapic? I haven’t emulated fully a LAPIC yet only a few bits. I guess for this PoC I found out that I don’t need one yet but my approach could be wrong, of course. The guest sends IPIs by writing the x2APIC ICR MSR (0x830). That’s a wrmsr, so it traps as an MSR exit rather than hitting a LAPIC register page. vmm decodes the delivery mode, destination and vector and forwards a synthetic exit to vmd, which injects the vector on the target vcpu’s next entry via the VMX entry-interruption field, similar to how it’s done for i8259 PIC vectors. So delivery is hardware event injection, not an APIC, I haven’t emulated/modelled APIC register file (IRR/ISR/TPR/EOI). >