Re: [Qemu-devel] [RFC V2 10/10] cpus: reclaim allocated vCPU objects

[Bharata B Rao]

On Fri, Sep 12, 2014 at 3:23 PM, Gu Zheng <address@hidden> wrote:
> Hi Bharata,
> On 09/12/2014 04:09 PM, Bharata B Rao wrote:
>
>> On Fri, Sep 12, 2014 at 6:54 AM, Gu Zheng <address@hidden> wrote:
>>> Is guest os enabled acpi cpu hotplug? What's the guest's cpu info?
>>> Please try latest QEMU, and any feedback is welcome.
>>>
>>
>> Tried with latest QEMU git + your patchset and Fedora 20 guest, but
>> QEMU monitor still shows the removed CPU.
>>
>> Guest kernel messages during hotplug:
>>
>> address@hidden cpu]# echo 1 > cpu8/online
>> [   72.936069] smpboot: Booting Node 0 Processor 8 APIC 0x8
>> [    0.003000] kvm-clock: cpu 8, msr 0:7ffc9201, secondary cpu clock
>> [   72.950003] TSC synchronization [CPU#0 -> CPU#8]:
>> [   72.950003] Measured 199886723309 cycles TSC warp between CPUs,
>> turning off TSC clock.
>> [   72.950003] tsc: Marking TSC unstable due to check_tsc_sync_source failed
>> [   72.972976] KVM setup async PF for cpu 8
>> [   72.973648] kvm-stealtime: cpu 8, msr 7d30df00
>> [   72.974415] Will online and init hotplugged CPU: 8
>> [   72.975307] microcode: CPU8 sig=0x663, pf=0x1, revision=0x1
>>
>> Guest kernel messages during hotunplug:
>>
>> address@hidden cpu]# [   95.482172] Unregister pv shared memory for cpu 8
>> [   95.487169] smpboot: CPU 8 is now offline
>> [   95.488667] ACPI: Device does not support D3cold
>>
>>
>> Guest cpuinfo (showing for the last CPU only after adding and removing CPU 8)
>>
>> processor    : 7
>> vendor_id    : GenuineIntel
>> cpu family    : 6
>> model        : 6
>> model name    : QEMU Virtual CPU version 2.1.50
>> stepping    : 3
>> microcode    : 0x1
>> cpu MHz        : 2899.998
>> cache size    : 4096 KB
>> fpu        : yes
>> fpu_exception    : yes
>> cpuid level    : 4
>> wp        : yes
>> flags        : fpu de pse tsc msr pae mce cx8 apic sep mtrr pge mca
>> cmov pse36 clflush mmx fxsr sse sse2 syscall nx lm rep_good nopl pni
>> cx16 x2apic popcnt hypervisor lahf_lm
>> bogomips    : 5799.99
>> clflush size    : 64
>> cache_alignment    : 64
>> address sizes    : 40 bits physical, 48 bits virtual
>> power management:
>
> Guest ejected CPU 8 successfully.
> I confirmed it with the same environment as yours, it works well.
> Could you please offer your QEMU config and the guest start cmd?
> It may help me to investigate the issue.

Let me also debug this a bit in my environment, but here are the
details you asked for.

# ./x86_64-softmmu/qemu-system-x86_64 --nographic --enable-kvm -m 2G
-smp 8,maxcpus=32 -device virtio-blk-pci,drive=rootdisk -drive
file=/home/bharata/F20.img,if=none,cache=none,format=qcow2,id=rootdisk
-monitor telnet:localhost:1234,server,nowait

# cat config-host.h
/* Automatically generated by create_config - do not modify */
#define CONFIG_QEMU_CONFDIR "/usr/local/etc/qemu"
#define CONFIG_QEMU_DATADIR "/usr/local/share/qemu"
#define CONFIG_QEMU_DOCDIR "/usr/local/share/doc/qemu"
#define CONFIG_QEMU_MODDIR "/usr/local/lib/qemu"
#define CONFIG_QEMU_LOCALSTATEDIR "/usr/local/var"
#define CONFIG_QEMU_HELPERDIR "/usr/local/libexec"
#define CONFIG_QEMU_LOCALEDIR "/usr/local/share/locale"
#define HOST_X86_64 1
#define CONFIG_DEBUG_TCG 1
#define CONFIG_POSIX 1
#define CONFIG_LINUX 1
#define CONFIG_SLIRP 1
#define CONFIG_SMBD_COMMAND "/usr/sbin/smbd"
#define CONFIG_L2TPV3 1
#define CONFIG_AUDIO_DRIVERS \
    &oss_audio_driver,\

#define CONFIG_OSS 1
#define CONFIG_BDRV_RW_WHITELIST\
    NULL
#define CONFIG_BDRV_RO_WHITELIST\
    NULL
#define CONFIG_VNC 1
#define CONFIG_FNMATCH 1
#define QEMU_VERSION "2.1.50"
#define QEMU_PKGVERSION ""
#define CONFIG_UTIMENSAT 1
#define CONFIG_PIPE2 1
#define CONFIG_ACCEPT4 1
#define CONFIG_SPLICE 1
#define CONFIG_EVENTFD 1
#define CONFIG_FALLOCATE 1
#define CONFIG_FALLOCATE_PUNCH_HOLE 1
#define CONFIG_SYNC_FILE_RANGE 1
#define CONFIG_FIEMAP 1
#define CONFIG_DUP3 1
#define CONFIG_PPOLL 1
#define CONFIG_PRCTL_PR_SET_TIMERSLACK 1
#define CONFIG_EPOLL 1
#define CONFIG_EPOLL_CREATE1 1
#define CONFIG_EPOLL_PWAIT 1
#define CONFIG_SENDFILE 1
#define CONFIG_TIMERFD 1
#define CONFIG_INOTIFY 1
#define CONFIG_INOTIFY1 1
#define CONFIG_BYTESWAP_H 1
#define CONFIG_ATTR 1
#define CONFIG_VHOST_SCSI 1
#define CONFIG_VHOST_NET_USED 1
#define CONFIG_IOVEC 1
#define CONFIG_PREADV 1
#define CONFIG_SIGNALFD 1
#define CONFIG_FDATASYNC 1
#define CONFIG_MADVISE 1
#define CONFIG_POSIX_MADVISE 1
#define CONFIG_SIGEV_THREAD_ID 1
#define CONFIG_QOM_CAST_DEBUG 1
#define CONFIG_COROUTINE_BACKEND ucontext
#define CONFIG_COROUTINE_POOL 1
#define CONFIG_LINUX_MAGIC_H 1
#define CONFIG_HAS_ENVIRON 1
#define CONFIG_CPUID_H 1
#define CONFIG_INT128 1
#define CONFIG_TPM $(CONFIG_SOFTMMU)
#define CONFIG_TPM_PASSTHROUGH 1
#define CONFIG_TRACE_NOP 1
#define CONFIG_TRACE_FILE trace
#define CONFIG_THREAD_SETNAME_BYTHREAD 1
#define CONFIG_PTHREAD_SETNAME_NP 1
#define HOST_DSOSUF ".so

And I am on commit ID 0dfa7e30126364c434a4

Regards,
Bharata.