On 03/08/2016 11:43, Xulei (Stone) wrote:
> Hi, all:
> Recently I use a shell script to continuously reset a vm to see what may happen.
> After one day, the vm is stuck. Looking from the following seabios log and
> kvm trace log, it seems like losing a SMI or SeaBIOS can not handle a SMI.
> This problem is reproducible on my machine (SeaBIOS 1.9.1, Qemu 2.6.0,
> Kmod 4.4.11).
Thanks for the report!
The more interesting part of the trace would be around the pio_write at
0xb2. Also please try kernel commit c43203cab1e, which just went into 4.8.
Paolo
> ==================my shell script===
> #!/bin/bash
> while((1))
> do
> virsh reset VMNAME
> sleep 1
> done
>
> ==================kvm trace log===
> CPU 0/KVM-13843 [020] d... 1025056.813494: kvm_entry: vcpu 0
> CPU 0/KVM-13843 [020] .... 1025056.813495: kvm_exit: reason IO_INSTRUCTION rip 0xef10e info b30048 0
> CPU 0/KVM-13843 [020] .... 1025056.813495: kvm_emulate_insn: 0:ef10e:e4 b3 (prot32)
> CPU 0/KVM-13843 [020] .... 1025056.813496: kvm_userspace_exit: reason KVM_EXIT_IO (2)
> CPU 0/KVM-13843 [020] .... 1025056.813496: kvm_fpu: unload
> CPU 0/KVM-13843 [020] .... 1025056.813497: kvm_pio: pio_read at 0xb3 size 1 count 1 val 0x1
> CPU 0/KVM-13843 [020] .... 1025056.813497: kvm_fpu: load
> CPU 0/KVM-13843 [020] d... 1025056.813497: kvm_entry: vcpu 0
> CPU 0/KVM-13843 [020] .... 1025056.813498: kvm_exit: reason IO_INSTRUCTION rip 0xef10e info b30048 0
> CPU 0/KVM-13843 [020] .... 1025056.813498: kvm_emulate_insn: 0:ef10e:e4 b3 (prot32)
> CPU 0/KVM-13843 [020] .... 1025056.813499: kvm_userspace_exit: reason KVM_EXIT_IO (2)
> CPU 0/KVM-13843 [020] .... 1025056.813499: kvm_fpu: unload
> CPU 0/KVM-13843 [020] .... 1025056.813500: kvm_pio: pio_read at 0xb3 size 1 count 1 val 0x1
> CPU 0/KVM-13843 [020] .... 1025056.813500: kvm_fpu: load
>
> ==================my seabios log===
> --- a/roms/seabios/src/fw/smm.c
> +++ b/roms/seabios/src/fw/smm.c
> @@ -65,7 +65,8 @@ handle_smi(u16 cs)
> u8 cmd = inb(PORT_SMI_CMD);
> struct smm_layout *smm = MAKE_FLATPTR(cs, 0);
> u32 rev = smm->cpu.i32.smm_rev & SMM_REV_MASK;
> - dprintf(DEBUG_HDL_smi, "handle_smi cmd=%x smbase=%p\n", cmd, smm);
> + if(cmd == 0x00) {
> + dprintf(1, "handle_smi cmd=%x smbase=%p\n", cmd, smm);
> + }
>
> if (smm == (void*)BUILD_SMM_INIT_ADDR) {
> // relocate SMBASE to 0xa0000
> @@ -147,14 +148,14 @@ smm_relocate_and_restore(void)
> {
> /* init APM status port */
> outb(0x01, PORT_SMI_STATUS);
> + dprintf(1,"before SMI====\n");
>
> /* raise an SMI interrupt */
> outb(0x00, PORT_SMI_CMD);
> + dprintf(1,"after SMI=====\n");
>
> /* wait until SMM code executed */
> while (inb(PORT_SMI_STATUS) != 0x00)
> ;
> + dprintf(1,"smm code executes complete====\n");
>
> And the log output like this:
> 2016-08-03 16:23:15PCI: Using 00:02.0 for primary VGA
> 2016-08-03 16:23:15smm_device_setup start
> 2016-08-03 16:23:15init smm
> 2016-08-03 16:23:15before SMI====
> 2016-08-03 16:23:15after SMI===== <----always stuck here, unless i destroy it
>
> As above, it is obviously that if bios doesn't handle_smi, PORT_SMI_STATUS is
> always 0x01. smm_relocate_and_restore() will always in the while loop.
>
> Why does bios handle_smi at this point, is this a kvm bug? or SeaBIOS bug?
>
> --------------
> Xulei (Stone)
>
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