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From: "Marcin Gibuła" <m.gibula@beyond.pl>
To: qemu-devel@nongnu.org
Cc: liang.z.li@intel.com
Subject: Re: [Qemu-devel] about the patch kvmclock Ensure proper env->tsc value for kvmclock_current_nsec calculation
Date: Fri, 14 Aug 2015 16:10:17 +0200	[thread overview]
Message-ID: <55CDF6C9.80001@beyond.pl> (raw)
In-Reply-To: <F2CBF3009FA73547804AE4C663CAB28E5B94E2@shsmsx102.ccr.corp.intel.com>

> So, the problem is cause by stop_vm(RUN_STATE_PAUSED), in this case the env->tsc is not updated, which lead to the issue.
> Is that right?

I think so.

> If the cpu_clean_all_dirty() is needed just for the APIC status reason, I think we can do the cpu_synchronize_all_states() in do_vm_stop
> and after vm_state_notify() when the RUN_STATE_PAUSED is hit, at this point all the device models is stopped, there is no outdated APIC status.

Yes, cpu_clean_all_dirty() was needed because without it, the second 
call to cpu_synchronize_all_states() (which is done inside 
qemu_savevm_state_complete() and after kvmclock) does nothing.

> I want to write a patch to fix this issue in another way, could help to verify it in you environment, very appreciate if you could.

Sure, I'll test it. Both issues were quite easy to reproduce.

-- 
mg

  reply	other threads:[~2015-08-14 14:10 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-08-13  1:25 [Qemu-devel] about the patch kvmclock Ensure proper env->tsc value for kvmclock_current_nsec calculation Li, Liang Z
2015-08-13 22:16 ` Marcelo Tosatti
2015-08-14  1:23   ` Li, Liang Z
2015-08-14  7:31     ` Marcin Gibuła
2015-08-14  7:51       ` Li, Liang Z
2015-08-14  8:51         ` Marcin Gibuła
2015-08-14  9:18           ` Li, Liang Z
2015-08-14 14:10             ` Marcin Gibuła [this message]
2015-08-14 22:35             ` Marcelo Tosatti

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