kvm-78 - kernel panic after using system_reset except when using -no-kvm-irqchip

This happens every other use of system_reset -- ie. resetting the system
using system_reset while in this panic'd state results in correct
functionality. Following the suggestion and booting the guest with noapic results in other IRQ-related errors.

The guest kernel is CentOS 5 2.6.18-53.el5 on x86_64. The host is running 2.6.27.5.

Kernel command line: ro root=/dev/VolGroup01/LogVol00 Initializing CPU#0
PID hash table entries: 4096 (order: 12, 32768 bytes)
Console: colour VGA+ 80x25
Dentry cache hash table entries: 131072 (order: 8, 1048576 bytes) Inode-cache hash table entries: 65536 (order: 7, 524288 bytes) Checking aperture...
Memory: 746368k/76936k available (2434k kernel code, 21180k reserved, 1235k data, 192k init)
Calibrating delay using timer specific routine.. 4793.50 BogoMIPS (lpj=2396750)
Security Framework v1.0.0 initialized

SELinux:  Initializing.
selinux_register_security:  Registering secondary module capability

Capability LSM initialized as secondary
Mount-cache hash table entries: 256
CPU: L1 I cache: 32K, L1 D cache: 32K
CPU: L2 cache: 2048K
SMP alternatives: switching to UP code
ACPI: Core revision 20060707
irq 25, desc: ffffffff803afc80, depth: 1, count: 0, unhandled: 0 ->handle_irq(): ffffffff800b54e3, handle_bad_irq+0x0/0x1f6 ->chip(): ffffffff802ea700, 0xffffffff802ea700 ->action(): 0000000000000000
IRQ_DISABLED set
unexpected IRQ trap at vector 19
..MP-BIOS bug: 8254 timer not connected to IO-APIC timer doesn't work through the IO-APIC - disabling NMI Watchdog!

Kernel panic - not syncing: IO-APIC + timer doesn't work! Try using the

'noapic' kernel parameter

Quoted 10 lines · Charles Duffy

irq 25, desc: ffffffff803afc80, depth: 1, count: 0, unhandled: 0 ->handle_irq(): ffffffff800b54e3, handle_bad_irq+0x0/0x1f6 ->chip(): ffffffff802ea700, 0xffffffff802ea700 ->action(): 0000000000000000
IRQ_DISABLED set
unexpected IRQ trap at vector 19
..MP-BIOS bug: 8254 timer not connected to IO-APIC timer doesn't work through the IO-APIC - disabling NMI Watchdog!

Kernel panic - not syncing: IO-APIC + timer doesn't work! Try using the

'noapic' kernel parameter

Still too early for me, so I didn't get yet if you can trigger this guest panic reliably or only sporadically (like I can). In the former case I would be very interested in the how!

So far my theory on this is that the guest happens to loose too many PIC timer ticks during the test window where it checks the PIC IRQ routing (it does so with 10 ticks, out of which at least 4 must be delivered). The theory also says that this is hard to avoid, maybe just less likely with Gleb's timer drift compensation patches.

Jan

PS: Booting with noapic leaves many real boxes useless as well.

Quoted 12 lines · Jan Kiszka

Quoted 10 lines · Charles Duffy

irq 25, desc: ffffffff803afc80, depth: 1, count: 0, unhandled: 0 ->handle_irq(): ffffffff800b54e3, handle_bad_irq+0x0/0x1f6 ->chip(): ffffffff802ea700, 0xffffffff802ea700 ->action(): 0000000000000000
IRQ_DISABLED set
unexpected IRQ trap at vector 19
..MP-BIOS bug: 8254 timer not connected to IO-APIC timer doesn't work through the IO-APIC - disabling NMI Watchdog!

Kernel panic - not syncing: IO-APIC + timer doesn't work! Try using the

'noapic' kernel parameter

Quoted 3 lines

Still too early for me, so I didn't get yet if you can trigger this guest panic reliably or only sporadically (like I can). In the former case I would be very interested in the how!

Reproduced 100% of the time when using system_reset at the qemu monitor console coming from a non-panic'd state. (Thus, it happens only every other time doing a series of boots and system_reset monitor commands).

Quoted 15 lines · Charles Duffy

Quoted 14 lines · Jan Kiszka

Quoted 10 lines · Charles Duffy

irq 25, desc: ffffffff803afc80, depth: 1, count: 0, unhandled: 0 ->handle_irq(): ffffffff800b54e3, handle_bad_irq+0x0/0x1f6 ->chip(): ffffffff802ea700, 0xffffffff802ea700 ->action(): 0000000000000000
IRQ_DISABLED set
unexpected IRQ trap at vector 19
..MP-BIOS bug: 8254 timer not connected to IO-APIC timer doesn't work through the IO-APIC - disabling NMI Watchdog!

Kernel panic - not syncing: IO-APIC + timer doesn't work! Try using the

'noapic' kernel parameter

Still too early for me, so I didn't get yet if you can trigger this guest panic reliably or only sporadically (like I can). In the former case I would be very interested in the how!

Quoted 3 lines

Reproduced 100% of the time when using system_reset at the qemu monitor console coming from a non-panic'd state. (Thus, it happens only every other time doing a series of boots and system_reset monitor commands).

Mmmh, /that/ sounds like some (re-)initialization issue of the virtualized hardware. OK, once that kernel boots again on latest kvm.git (currently broken due to a different issue), I will try to reproduce it.