I finally got it to work by using the XenTimerDxe. The reason why it works is because the UEFI service SetTimer() needs one Timer Architectural Protocol to be installed. In case of standard QEMU, the 8254 PIT is the one registering the service, while for microvm the Xen timer does the job.
It's interesting to notice that XenTimerDxe is not specific to Xen as it simply relies on the local APIC timer that generates an interrupt on IRQ0, which is eventually the local APIC vector 32. So now I'm wondering how I'm gonna make OvmfPkgX64 work for both QEMU and Cloud Hypervisor since only one Timer Architectural Protocol can be registered. Do you think it would be acceptable to move OvmfPkgX64 to XenTimerDxe instead of 8254 legacy PIT? Thanks, Sebastien On Fri, 2022-01-07 at 14:06 +0100, Sebastien Boeuf wrote: > On Fri, 2022-01-07 at 13:07 +0100, kra...@redhat.com wrote: > > Hi, > > > > > > microvm has no lpc bridge, so I had to do it in a different way > > > > ... > > > > > > Cloud Hypervisor doesn't emulate any LPC bridge or ISA bus. > > > > Ok, doing it microvm-style makes sense then. > > Ok thanks for the confirmation. Hopefully it won't conflict with what > QEMU uses/needs. > > > > > > > Works fine for me. > > > > > > > > qemu-system-x86_64 -nographic -machine microvm,rtc=on -bios > > > > Build/MicrovmX64/DEBUG_GCC5/FV/MICROVM.fd > > > > > > Thanks for the confirmation, something might be wrong with the > > > interrupt used for my serial device. > > > > tianocore doesn't use interrupts (other than timer). > > Yes I realized that by diving into the code. I can see microvm using > the Xen timer while OvmfPkgX64 uses 8254 PIT. > > > > > > Cloud Hypervisor only has an IOAPIC, it doesn't rely on any PIC, > > > which > > > is why I'm not sure what might be missing to get the EFI shell to > > > receive the interrupts. > > > > PIC is optional for microvm too, and everything works fine for me > > with > > "-machine microvm,rtc=on,pic=off,pit=off" > > Yes that's interesting and after some investigations I think the > problem is that I don't get TerminalConInTimerHandler handler to be > triggered. I can see the handler is correctly registered but for some > reasons, it's never used. I'm wondering if that might be an issue > related to a lack of timer support. Especially I see the UEFI service > SetTimer() is being used for the polling mechanism, so I wonder what > is > the backend for it. > > > > > take care, > > Gerd > > > --------------------------------------------------------------------- Intel Corporation SAS (French simplified joint stock company) Registered headquarters: "Les Montalets"- 2, rue de Paris, 92196 Meudon Cedex, France Registration Number: 302 456 199 R.C.S. NANTERRE Capital: 4,572,000 Euros This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). Any review or distribution by others is strictly prohibited. If you are not the intended recipient, please contact the sender and delete all copies. -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#85330): https://edk2.groups.io/g/devel/message/85330 Mute This Topic: https://groups.io/mt/88235445/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
