Re: [Qemu-devel] E5-2620v2 - emulation stop error

Dr. David Alan Gilbert
2015-03-12T09:59:12Z

* Andrey Korolyov (andrey@xdel.ru) wrote:
> On Wed, Mar 11, 2015 at 10:59 PM, Dr. David Alan Gilbert
> <dgilbert@redhat.com> wrote:
> > * Andrey Korolyov (andrey@xdel.ru) wrote:
> >> On Wed, Mar 11, 2015 at 10:33 PM, Dr. David Alan Gilbert
> >> <dgilbert@redhat.com> wrote:
> >> > * Kevin O'Connor (kevin@koconnor.net) wrote:
> >> >> On Wed, Mar 11, 2015 at 02:45:31PM -0400, Kevin O'Connor wrote:
> >> >> > On Wed, Mar 11, 2015 at 02:40:39PM -0400, Kevin O'Connor wrote:
> >> >> > > For what it's worth, I can't seem to trigger the problem if I move the
> >> >> > > cmos read above the SIPI/LAPIC code (see patch below).
> >> >> >
> >> >> > Ugh!
> >> >> >
> >> >> > That's a seabios bug. Main processor modifies the rtc index
> >> >> > (rtc_read()) while APs try to clear the NMI bit by modifying the rtc
> >> >> > index (romlayout.S:transition32).
> >> >> >
> >> >> > I'll put together a fix.
> >> >>
> >> >> The seabios patch below resolves the issue for me.
> >> >
> >> > Thanks! Looks good here.
> >> >
> >> > Andrey, Paolo, Bandan: Does it fix it for you as well?
> >> >
> >>
> >> Thanks Kevin, Dave,
> >>
> >> I`m afraid that I`m hitting something different not only because
> >> different suberror code but also because of mine version of seabios -
> >> I am using 1.7.5 and corresponding code in the proposed patch looks
> >> different - there is no smp-related code patch is about of. Those
> >> mentioned devices went to production successfully and I`m afraid I
> >> cannot afford playing on them anymore, even if I re-trigger the issue
> >> with patched 1.8.1-rc, there is no way to switch to a different kernel
> >> and retest due to specific conditions of this production suite. I`ve
> >> ordered a pair of new shoes^W 2620v2-s which should arrive to me next
> >
> > Well I was testing on a pair of 'E5-2620 v2'; but as you saw my test case
> > was pretty simple. If you can suggest any flags I should add etc to the
> > test I'd be happy to give it a go.
> >
> > Dave
>
> Here is mine launch string:
>
> qemu-system-x86_64 -enable-kvm -name vmtest -S -machine
> pc-i440fx-2.1,accel=kvm,usb=off -cpu SandyBridge,+kvm_pv_eoi -m 512
> -realtime mlock=off -smp 12,sockets=1,cores=12,threads=12 -numa
> node,nodeid=0,cpus=0-11,mem=512 -nographic -no-user-config -nodefaults
> -device sga -rtc base=utc,driftfix=slew -global
> kvm-pit.lost_tick_policy=discard -no-hpet -no-shutdown -global
> PIIX4_PM.disable_s3=1 -global PIIX4_PM.disable_s4=1 -boot strict=on
> -device nec-usb-xhci,id=usb,bus=pci.0,addr=0x4 -device
> virtio-serial-pci,id=virtio-serial0,bus=pci.0,addr=0x5 -m
> 512,slots=31,maxmem=16384M -object
> memory-backend-ram,id=mem0,size=512M -device
> pc-dimm,id=dimm0,node=0,memdev=mem0
>
> I omitted disk backend in this example, but there is a chance that my
> problem is not reproducible without some calls made explicitly by a
> bootloader (not sure what to say for mid-runtime failures).

It seems to survive OK:

while true; do (sleep 1; echo -e '\001cc\n'; sleep 5; echo -e 'q\n')|/opt/qemu-try-world3/bin/qemu-system-x86_64 -enable-kvm -name vmtest -S -machine pc-i440fx-2.1,accel=kvm,usb=off -cpu SandyBridge,+kvm_pv_eoi -m 512 -realtime mlock=off -smp 12,sockets=1,cores=12,threads=12 -numa node,nodeid=0,cpus=0-11,mem=512 -nographic -no-user-config -device sga -rtc base=utc,driftfix=slew -global kvm-pit.lost_tick_policy=discard -no-hpet -no-shutdown -global PIIX4_PM.disable_s3=1 -global PIIX4_PM.disable_s4=1 -boot strict=on -device nec-usb-xhci,id=usb,bus=pci.0,addr=0x4 -device virtio-serial-pci,id=virtio-serial0,bus=pci.0,addr=0x5 -m 512,slots=31,maxmem=16384M -object memory-backend-ram,id=mem0,size=512M -device pc-dimm,id=dimm0,node=0,memdev=mem0 ~/pi.vfd 2>&1 | tee /tmp/qemu.op; grep "internal
error" /tmp/qemu.op -q && break; done

Dave

>
> >
> >> Monday, so I`ll be able to test a) against 1.8.0-release, b) against
> >> patched bios code, c) reproduce initial error on master/3.19 (may be
> >> I`ll take them before weekend by going into this computer shop in
> >> person). Until then, I have a very deep feeling that mine issue is not
> >> there :) Also I became very curious on how a lack of IDT feature may
> >> completely eliminate the issue appearance for me, the only possible
> >> explanation is a clock-related race which is kinda stupid suggestion
> >> and unlikely to exist in nature.
> >>
> >> Thanks again for everyone for throughout testing and ideas!
> >>
> >> >
> >> >> -Kevin
> >> >>
> >> >>
> >> >> --- a/src/romlayout.S
> >> >> +++ b/src/romlayout.S
> >> >> @@ -22,7 +22,8 @@
> >> >> // %edx = return location (in 32bit mode)
> >> >> // Clobbers: ecx, flags, segment registers, cr0, idt/gdt
> >> >> DECLFUNC transition32
> >> >> -transition32_for_smi:
> >> >> +transition32_nmi_off:
> >> >> + // transition32 when NMI and A20 are already initialized
> >> >> movl %eax, %ecx
> >> >> jmp 1f
> >> >> transition32:
> >> >> @@ -205,7 +206,7 @@ __farcall16:
> >> >> entry_smi:
> >> >> // Transition to 32bit mode.
> >> >> movl $1f + BUILD_BIOS_ADDR, %edx
> >> >> - jmp transition32_for_smi
> >> >> + jmp transition32_nmi_off
> >> >> .code32
> >> >> 1: movl $BUILD_SMM_ADDR + 0x8000, %esp
> >> >> calll _cfunc32flat_handle_smi - BUILD_BIOS_ADDR
> >> >> @@ -216,8 +217,10 @@ entry_smi:
> >> >> DECLFUNC entry_smp
> >> >> entry_smp:
> >> >> // Transition to 32bit mode.
> >> >> + cli
> >> >> + cld
> >> >> movl $2f + BUILD_BIOS_ADDR, %edx
> >> >> - jmp transition32
> >> >> + jmp transition32_nmi_off
> >> >> .code32
> >> >> // Acquire lock and take ownership of shared stack
> >> >> 1: rep ; nop
> >> > --
> >> > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
> > --
> > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK