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From: Jaeyong Yoo <jaeyong.yoo@samsung.com>
To: "xen-devel@lists.xen.org" <xen-devel@lists.xen.org>
Subject: A simple question regarding hvm_context_save
Date: Fri, 31 May 2013 10:46:39 +0000 (GMT)	[thread overview]
Message-ID: <32587091.297611369997199444.JavaMail.weblogic@epv6ml06> (raw)

Hello,
I'm reading live migration related code and got a simple question 
in function hvm_context_save:

static int hvm_save_cpu_ctxt(struct domain *d, hvm_domain_context_t *h)
{
blah...
        /* We don't need to save state for a vcpu that is down; the restore 
         * code will leave it down if there is nothing saved. */
        if ( test_bit(_VPF_down, &v->pause_flags) )
            continue;
blah...

In the above, if the vcpu is paused, we don't need to store cpu registers
(since vcpu structure already stored them). But, as far as I know, before
we save the hvm context, we suspend the domain, which calls shutdown 
sched_op, and the vcpu is paused. 
Then, I guess testing pause_flags always returns down and we don't
need to store cpu ctxts. Do I miss something here?

best,
Jaeyong

             reply	other threads:[~2013-05-31 10:46 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-05-31 10:46 Jaeyong Yoo [this message]
2013-05-31 10:53 ` A simple question regarding hvm_context_save Ian Campbell
2013-05-31 10:55 ` Andrew Cooper

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