From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [RFC v2 5/6] xen/arm: Implement hypercall for dirty page tracing Date: Wed, 23 Apr 2014 12:59:36 +0100 Message-ID: <5357AB28.60808@linaro.org> References: <1397595918-30419-1-git-send-email-w1.huang@samsung.com> <1397595918-30419-13-git-send-email-w1.huang@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1397595918-30419-13-git-send-email-w1.huang@samsung.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Wei Huang Cc: ian.campbell@citrix.com, stefano.stabellini@eu.citrix.com, andrew.cooper3@citrix.com, jaeyong.yoo@samsung.com, xen-devel@lists.xen.org, yjhyun.yoo@samsung.com List-Id: xen-devel@lists.xenproject.org Hi Wei, On 04/15/2014 10:05 PM, Wei Huang wrote: > diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c > index 3f04a77..d2531ed 100644 > --- a/xen/arch/arm/domain.c > +++ b/xen/arch/arm/domain.c > @@ -207,6 +207,12 @@ static void ctxt_switch_to(struct vcpu *n) > > isb(); > > + /* Dirty-page tracing > + * NB: How do we consider SMP case? > + */ > + if ( n->domain->arch.dirty.mode ) > + restore_vlpt(n->domain); > + I though a bit more of this piece of code. Your VLPT implementation uses xen_second which is shared between every vCPU. Therefore restoring VLPT is pointless here. In another hand, I didn't see anything which prevent you to migrate 2 domain at the same time. You will likely crash one of (if not both) the guests. Regards, -- Julien Grall