* Kevin O'Connor (kevin@xxxxxxxxxxxx) wrote: > On Wed, Mar 11, 2015 at 04:52:03PM +0000, Dr. David Alan Gilbert wrote: > > * Kevin O'Connor (kevin@xxxxxxxxxxxx) wrote: > > > So, I couldn't get this to fail on my older AMD machine at all with > > > the default SeaBIOS code. But, when I change the code with the patch > > > below, it failed right away. > [...] > > > And the failed debug output looks like: > > > > > > SeaBIOS (version rel-1.8.0-7-gd23eba6-dirty-20150311_121819-morn.localdomain) > > > [...] > > > cmos_smp_count0=20 > > > [...] > > > cmos_smp_count=1 > > > cmos_smp_count2=1/20 > > > Found 1 cpu(s) max supported 20 cpu(s) > > > > > > I'm going to check the assembly for a compiler error, but is it > > > possible QEMU is returning incorrect data in cmos index 0x5f? > > I checked the SeaBIOS assembler and it looks sane. So, I think the > question is, why is QEMU sometimes returning a 0 instead of 127 from > cmos 0x5f. My reading of the logs I've just created is that qemu doesn't think it's ever being asked to read 5f in the failed case: good: pc_cmos_init 5f setting smp_cpus=20 cmos: read index=0x0f val=0x00 cmos: read index=0x34 val=0x00 cmos: read index=0x35 val=0x3f cmos: read index=0x38 val=0x30 cmos: read index=0x3d val=0x12 cmos: read index=0x38 val=0x30 cmos: read index=0x0b val=0x02 cmos: read index=0x0d val=0x80 cmos: read index=0x5f val=0x13 Yeh! cmos: read index=0x0f val=0x00 cmos: read index=0x0f val=0x00 cmos: read index=0x0f val=0x00 bad: pc_cmos_init 5f setting smp_cpus=20 cmos: read index=0x0f val=0x00 cmos: read index=0x34 val=0x00 cmos: read index=0x35 val=0x3f cmos: read index=0x38 val=0x30 cmos: read index=0x3d val=0x12 cmos: read index=0x38 val=0x30 cmos: read index=0x0b val=0x02 cmos: read index=0x0d val=0x80 Oh! cmos: read index=0x0f val=0x00 cmos: read index=0x0f val=0x00 cmos: read index=0x0f val=0x00 Dave > > > > David, any chance you can recompile seabios and double check your > > > output? > > > > Done; > > > > =========== Working =========== > > SeaBIOS (version rel-1.8.0-0-g4c59f5d-dirty-20150311_164408-dgilbert-t530) > [...] > > cmos_smp_count0=20 > > cmos_smp_count=20 > > cmos_smp_count2=20/20 > > Found 20 cpu(s) max supported 20 cpu(s) > [...] > > =========== Broken =========== > > SeaBIOS (version rel-1.8.0-0-g4c59f5d-dirty-20150311_164408-dgilbert-t530) > [...] > > cmos_smp_count0=20 > > cmos_smp_count=1 > > cmos_smp_count2=1/20 > > Found 1 cpu(s) max supported 20 cpu(s) > > That's the same pattern I see. > > -Kevin -- Dr. David Alan Gilbert / dgilbert@xxxxxxxxxx / Manchester, UK -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
