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From: Paolo Bonzini <pbonzini@redhat.com>
To: Vadim Rozenfeld <vrozenfe@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>,
	kvm@vger.kernel.org, gleb@redhat.com, pl@dlh.net
Subject: Re: [RFC PATCH v2 1/2] add support for Hyper-V reference time counter
Date: Wed, 22 May 2013 23:55:34 +0200	[thread overview]
Message-ID: <519D3ED6.8010804@redhat.com> (raw)
In-Reply-To: <745195650.5763962.1369207977883.JavaMail.root@redhat.com>

Il 22/05/2013 09:32, Vadim Rozenfeld ha scritto:
>> > @@ -1827,6 +1829,29 @@ static int set_msr_hyperv_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data)
>> >  		if (__copy_to_user((void __user *)addr, instructions, 4))
>> >  			return 1;
>> >  		kvm->arch.hv_hypercall = data;
>> > +		local_irq_disable();
>> > +		kvm->arch.hv_ref_count = get_kernel_ns();
>> > +		local_irq_enable();
>> > +		break;
> local_irq_disable/local_irq_enable not needed.
> 
> 
> What is the reasoning behind reading this time value at msr write time?
> [VR] Windows writs this MSR only once, during HAL initialization.
> So, I decided to treat this call as a partition crate event.
> 

But is it expected by Windows that the reference count starts counting
up from 0 at partition creation time?  If you could just use
(get_kernel_ns() + kvm->arch.kvmclock_offset) / 100, it would also be
simpler for migration purposes.

Paolo

  reply	other threads:[~2013-05-22 21:55 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-05-19  7:06 [RFC PATCH v2 0/2] Hyper-V timers Vadim Rozenfeld
2013-05-19  7:06 ` [RFC PATCH v2 1/2] add support for Hyper-V reference time counter Vadim Rozenfeld
2013-05-19 13:47   ` Gleb Natapov
2013-05-19 14:37   ` Paolo Bonzini
2013-05-22  0:46   ` Marcelo Tosatti
2013-05-22  3:28     ` Gleb Natapov
2013-05-22  3:32       ` Marcelo Tosatti
2013-05-22  3:38         ` Gleb Natapov
2013-05-22 14:31           ` Marcelo Tosatti
2013-05-22  7:32     ` Vadim Rozenfeld
2013-05-22 21:55       ` Paolo Bonzini [this message]
2013-05-23  6:17         ` Peter Lieven
2013-05-23  9:54           ` Paolo Bonzini
2013-05-23 10:45             ` Peter Lieven
2013-05-23 12:25           ` Vadim Rozenfeld
2013-05-23 13:18             ` Paolo Bonzini
2013-05-23 13:20               ` Peter Lieven
2013-05-23 13:23                 ` Paolo Bonzini
2013-05-23 13:30                   ` Peter Lieven
2013-05-23 13:40                     ` Paolo Bonzini
2013-05-19  7:06 ` [RFC PATCH v2 2/2] add support for Hyper-V invariant TSC Vadim Rozenfeld
2013-05-22  0:50   ` Marcelo Tosatti
2013-05-22  7:22     ` Vadim Rozenfeld
2013-05-22 21:23       ` Marcelo Tosatti
2013-05-23  6:18         ` Peter Lieven
2013-05-23  9:13           ` Gleb Natapov
2013-05-23 13:35             ` Marcelo Tosatti
2013-05-23 15:14               ` Gleb Natapov
2013-05-24  9:57               ` Vadim Rozenfeld
2013-05-23 12:33           ` Vadim Rozenfeld
2013-05-23 12:44             ` Peter Lieven
2013-05-23 12:45               ` Gleb Natapov
2013-05-23 12:54               ` Vadim Rozenfeld
2013-05-23  9:12         ` Gleb Natapov
2013-05-23 13:53           ` Marcelo Tosatti
2013-05-23 15:31             ` Gleb Natapov
2013-05-24 10:11               ` Vadim Rozenfeld
2013-05-24 19:41                 ` Marcelo Tosatti
2013-05-27 12:33                   ` Vadim Rozenfeld
2013-05-23 12:21         ` Vadim Rozenfeld
2013-05-23 13:47           ` Marcelo Tosatti
2013-05-24 10:01             ` Vadim Rozenfeld
2013-05-23 16:44   ` Paolo Bonzini
2013-05-24 10:16     ` Vadim Rozenfeld

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