Re: [kvm-devel] FreeBSD image hangs during boot

[Laurent V. <Lau...@bu...>]

Aurelien Jarno wrote:
> Hi all,
>=20
> That's not something new, but I never seen the problem mentioned here.
> FreeBSD does not work on KVM, approximately since the lapic merge.
>=20
> However, that does not seem related to lapic, as using -no-kvm-irqchip
> does not help. With -no-kvm I get a page fault in kernel mode, while th=
e
> normal QEMU (0.9.0 or CVS) does not have this problem.
>=20
> This can be easily reproduced with the latest installation CD:
> ftp://ftp.freebsd.org/pub/FreeBSD/ISO-IMAGES-i386/6.2/6.2-RELEASE-i386-=
bootonly.iso
>=20
> Cheers,
> Aurelien
>=20

Digging in the FreeBSD sources I found the origin of the problem:

I added some ACPI traces:

   rsirq-0234 [13] RsIrqResource         : Invalid interrupt polarity/tri=
gger in
 resource list, 10

Which is in /sys/contrib/dev/acpica/rsirq.c :


       /*
         * Check for HE, LL interrupts
         */
        switch (Temp8 & 0x09)
        {
        case 0x01: /* HE */
            OutputStruct->Data.Irq.EdgeLevel =3D ACPI_EDGE_SENSITIVE;
            OutputStruct->Data.Irq.ActiveHighLow =3D ACPI_ACTIVE_HIGH;
            break;

        case 0x08: /* LL */
            OutputStruct->Data.Irq.EdgeLevel =3D ACPI_LEVEL_SENSITIVE;
            OutputStruct->Data.Irq.ActiveHighLow =3D ACPI_ACTIVE_LOW;
            break;

        default:
            /*
             * Only _LL and _HE polarity/trigger interrupts
             * are allowed (ACPI spec, section "IRQ Format")
             * so 0x00 and 0x09 are illegal.
             */
            ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
                "Invalid interrupt polarity/trigger in resource list, %X\=
n", Tem
p8));
            return_ACPI_STATUS (AE_BAD_DATA);
        }

Conclusion, in kvm-userspace/bios/acpi-dsdt.dsl, if you have "ActiveHigh"=
, you
must have "Edge" instead of "Level":

-                    IRQ (Level, ActiveHigh, Shared)
+                    IRQ (Edge, ActiveHigh, Shared)

But I found nothing in ACPI specification explaining the freeBSD behavior=
=2E

Avi, if you think this anlysis is correct I can provide the patch changin=
g
"Level" to "Edge"...

Laurent

--=20
---------------- Lau...@bu...  -----------------
"Given enough eyeballs, all bugs are shallow" E. S. Raymond