All of lore.kernel.org
 help / color / mirror / Atom feed
From: bugzilla-daemon@bugzilla.kernel.org
To: kvm@vger.kernel.org
Subject: [Bug 210213] New: vCPUs >= 64 can't be online and hotplugged in some scenarios
Date: Mon, 16 Nov 2020 03:27:36 +0000	[thread overview]
Message-ID: <bug-210213-28872@https.bugzilla.kernel.org/> (raw)

https://bugzilla.kernel.org/show_bug.cgi?id=210213

            Bug ID: 210213
           Summary: vCPUs >= 64 can't be online and hotplugged in some
                    scenarios
           Product: Virtualization
           Version: unspecified
    Kernel Version: 5.10-rc4
          Hardware: x86-64
                OS: Linux
              Tree: Mainline
            Status: NEW
          Severity: normal
          Priority: P1
         Component: kvm
          Assignee: virtualization_kvm@kernel-bugs.osdl.org
          Reporter: zelin.deng@linux.alibaba.com
        Regression: No

Created attachment 293685
  --> https://bugzilla.kernel.org/attachment.cgi?id=293685&action=edit
Here is a workaround to fix this issue

In VM, if no-kvmclock-vsyscall is set, lscpu shows online 0-63 vcpus are online
vcpus >= 64 are offline and if we attempting to hotplug them, they will return
-ENOMEM.
This issue also happened in VM which are on TSC unstable host.
 bash-14295 [040] .... 64209.953702: cpuhp_enter: cpu: 0064 target: 199 step: 
64 (kvmclock_setup_percpu)
            bash-14295 [040] .... 64209.953702: cpuhp_exit:  cpu: 0064  state: 
64 step:  64 ret: -12
----------------------------

[root@iZwz9208df47apaoyvbmm3Z processor]# cat /sys/kernel/debug/tracing/trace
# tracer: nop
#
# entries-in-buffer/entries-written: 166/166   #P:49
#
#                              _-----=> irqs-off
#                             / _----=> need-resched
#                            | / _---=> hardirq/softirq
#                            || / _--=> preempt-depth
#                            ||| /     delay
#           TASK-PID   CPU#  ||||    TIMESTAMP  FUNCTION
#              | |       |   ||||       |         |
            bash-14295 [040] .... 64209.953675: cpuhp_enter: cpu: 0064 target:
199 step:   1 (smpboot_create_threads)
            bash-14295 [040] .... 64209.953676: cpuhp_exit:  cpu: 0064  state: 
 1 step:   1 ret: 0
            bash-14295 [040] .... 64209.953676: cpuhp_enter: cpu: 0064 target:
199 step:   2 (perf_event_init_cpu)
            bash-14295 [040] .... 64209.953677: cpuhp_exit:  cpu: 0064  state: 
 2 step:   2 ret: 0
            bash-14295 [040] .... 64209.953678: cpuhp_enter: cpu: 0064 target:
199 step:  35 (workqueue_prepare_cpu)
            bash-14295 [040] .... 64209.953678: cpuhp_exit:  cpu: 0064  state: 
35 step:  35 ret: 0
            bash-14295 [040] .... 64209.953678: cpuhp_enter: cpu: 0064 target:
199 step:  37 (hrtimers_prepare_cpu)
            bash-14295 [040] .... 64209.953679: cpuhp_exit:  cpu: 0064  state: 
37 step:  37 ret: 0
            bash-14295 [040] .... 64209.953679: cpuhp_enter: cpu: 0064 target:
199 step:  40 (smpcfd_prepare_cpu)
            bash-14295 [040] .... 64209.953692: cpuhp_exit:  cpu: 0064  state: 
40 step:  40 ret: 0
            bash-14295 [040] .... 64209.953693: cpuhp_enter: cpu: 0064 target:
199 step:  41 (relay_prepare_cpu)
            bash-14295 [040] .... 64209.953693: cpuhp_exit:  cpu: 0064  state: 
41 step:  41 ret: 0
            bash-14295 [040] .... 64209.953693: cpuhp_enter: cpu: 0064 target:
199 step:  44 (rcutree_prepare_cpu)
            bash-14295 [040] .... 64209.953694: cpuhp_exit:  cpu: 0064  state: 
44 step:  44 ret: 0
            bash-14295 [040] .... 64209.953694: cpuhp_enter: cpu: 0064 target:
199 step:  53 (topology_add_dev)
            bash-14295 [040] .... 64209.953699: cpuhp_exit:  cpu: 0064  state: 
53 step:  53 ret: 0
            bash-14295 [040] .... 64209.953700: cpuhp_multi_enter: cpu: 0064
target: 199 step:  56 (trace_rb_cpu_prepare)
            bash-14295 [040] .... 64209.953700: cpuhp_exit:  cpu: 0064  state: 
56 step:  56 ret: 0
            bash-14295 [040] .... 64209.953700: cpuhp_multi_enter: cpu: 0064
target: 199 step:  56 (trace_rb_cpu_prepare)
            bash-14295 [040] .... 64209.953700: cpuhp_exit:  cpu: 0064  state: 
56 step:  56 ret: 0
            bash-14295 [040] .... 64209.953701: cpuhp_multi_enter: cpu: 0064
target: 199 step:  56 (trace_rb_cpu_prepare)
            bash-14295 [040] .... 64209.953701: cpuhp_exit:  cpu: 0064  state: 
56 step:  56 ret: 0
            bash-14295 [040] .... 64209.953701: cpuhp_enter: cpu: 0064 target:
199 step:  62 (timers_prepare_cpu)
            bash-14295 [040] .... 64209.953701: cpuhp_exit:  cpu: 0064  state: 
62 step:  62 ret: 0
            bash-14295 [040] .... 64209.953702: cpuhp_enter: cpu: 0064 target:
199 step:  64 (kvmclock_setup_percpu)
            bash-14295 [040] .... 64209.953702: cpuhp_exit:  cpu: 0064  state: 
64 step:  64 ret: -12

-- 
You are receiving this mail because:
You are watching the assignee of the bug.

                 reply	other threads:[~2020-11-16  3:27 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=bug-210213-28872@https.bugzilla.kernel.org/ \
    --to=bugzilla-daemon@bugzilla.kernel.org \
    --cc=kvm@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.