[Qemu-devel] [Bug 732155] Re: system_reset doesn't work with qemu-kvm and latest SeaBIOS

[Matthew Bloch]

This patch to SeaBIOS seems to fix it, but I still think there's a bug
in kvm if it behaves differently with or without the "-no-kvm" flag.

** Tags added: bios kvm reset

** Patch added: "qemu-reset.patch"
   
https://bugs.launchpad.net/qemu/+bug/732155/+attachment/1906859/+files/qemu-reset.patch

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https://bugs.launchpad.net/bugs/732155

Title:
  system_reset doesn't work with qemu-kvm and latest SeaBIOS

Status in QEMU:
  New

Bug description:
  I've built qemu-kvm and seabios from the latest git sources, and found
  that the system_reset monitor command causes a freeze if I start qemu-
  system-x86_64 with the -no-kvm flag.  This is a serial log from an
  attempt at rebooting:

  $ ./x86_64-softmmu/qemu-system-x86_64 -monitor stdio -bios 
../seabios/out/bios.bin -serial /dev/stdout -no-kvm
  QEMU 0.14.50 monitor - type 'help' for more information
  (qemu) Changing serial settings was 0/0 now 3/0
  Start bios (version pre-0.6.3-20110309_171929-desk4)
  Ram Size=0x08000000 (0x0000000000000000 high)
  CPU Mhz=2202
  PCI: pci_bios_init_bus_rec bus = 0x0
  PIIX3/PIIX4 init: elcr=00 0c
  PCI: bus=0 devfn=0x00: vendor_id=0x8086 device_id=0x1237
  PCI: bus=0 devfn=0x08: vendor_id=0x8086 device_id=0x7000
  PCI: bus=0 devfn=0x09: vendor_id=0x8086 device_id=0x7010
  region 4: 0x0000c000
  PCI: bus=0 devfn=0x0b: vendor_id=0x8086 device_id=0x7113
  PCI: bus=0 devfn=0x10: vendor_id=0x1013 device_id=0x00b8
  region 0: 0xf0000000
  region 1: 0xf2000000
  region 6: 0xf2010000
  PCI: bus=0 devfn=0x18: vendor_id=0x10ec device_id=0x8139
  region 0: 0x0000c100
  region 1: 0xf2020000
  region 6: 0xf2030000
  Found 1 cpu(s) max supported 1 cpu(s)
  MP table addr=0x000fdb40 MPC table addr=0x000fdb50 size=224
  SMBIOS ptr=0x000fdb20 table=0x07fffef0
  ACPI tables: RSDP=0x000fdaf0 RSDT=0x07ffd6a0
  Scan for VGA option rom
  Running option rom at c000:0003
  Turning on vga text mode console
  SeaBIOS (version pre-0.6.3-20110309_171929-desk4)

  PS2 keyboard initialized
  Found 1 lpt ports
  Found 1 serial ports
  ATA controller 0 at 1f0/3f4/0 (irq 14 dev 9)
  ATA controller 1 at 170/374/0 (irq 15 dev 9)
  DVD/CD [ata1-0: QEMU DVD-ROM ATAPI-4 DVD/CD]
  Searching bootorder for: 
/address@hidden/address@hidden,1/address@hidden/address@hidden
  Scan for option roms
  Running option rom at c900:0003
  pnp call arg1=60
  pmm call arg1=0
  pmm call arg1=2
  pmm call arg1=0
  Searching bootorder for: /address@hidden/address@hidden
  Searching bootorder for: /address@hidden/vapic.bin
  Running option rom at c980:0003
  ebda moved from 9fc00 to 9f400
  Returned 53248 bytes of ZoneHigh
  e820 map has 6 items:
    0: 0000000000000000 - 000000000009f400 = 1
    1: 000000000009f400 - 00000000000a0000 = 2
    2: 00000000000f0000 - 0000000000100000 = 2
    3: 0000000000100000 - 0000000007ffd000 = 1
    4: 0000000007ffd000 - 0000000008000000 = 2
    5: 00000000fffc0000 - 0000000100000000 = 2
  enter handle_19:
    NULL
  Booting from DVD/CD...
  Device reports MEDIUM NOT PRESENT
  atapi_is_ready returned -1
  Boot failed: Could not read from CDROM (code 0003)
  enter handle_18:
    NULL
  Booting from ROM...
  Booting from c900:0336

  (qemu) 
  (qemu) system_reset
  (qemu) RESET REQUESTEDChanging serial settings was 0/0 now 3/0
  Start bios (version pre-0.6.3-20110309_171929-desk4)
  Attempting a hard reboot
  prep_reset
  apm_shutdown?
  i8042_reboot
  i8042: wait to write...
  i8042: outb
  RESET REQUESTED
  (qemu) 
  (qemu) 
  (qemu) 
  (qemu) info cpus
  * CPU #0: pc=0x00000000fffffff0 thread_id=18125 
  (qemu) system_reset
  (qemu) RESET REQUESTED
  (qemu) 
  (qemu) q

  I've tried fiddling a few build options in SeaBIOS but I'm not sure
  that's where the issue lies.  The RESET REQUESTED is me adding some
  extra debug to vl.c:1477 in the clause that tests for a reset request,
  and the i8042: lines are debug lines from seabios tracing the
  execution of the reset request.

  This may be a bug in SeaBIOS of course, since I can replicate the
  behaviour on my distro's qemu and kvm packages.  However it seems odd
  that qemu behaves differently with KVM turned on (i.e. system_reset
  works) than with it disabled.