From mboxrd@z Thu Jan 1 00:00:00 1970 From: Olaf Hering Subject: Re: [PATCH] xenpaging: check p2mt in p2m_mem_paging functions Date: Thu, 13 Oct 2011 14:14:02 +0200 Message-ID: <20111013121402.GA20431@aepfle.de> References: <20111013112755.GE44937@ocelot.phlegethon.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Return-path: Content-Disposition: inline In-Reply-To: <20111013112755.GE44937@ocelot.phlegethon.org> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Tim Deegan Cc: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org On Thu, Oct 13, Tim Deegan wrote: > Hi, > > At 14:42 +0200 on 11 Oct (1318344151), Olaf Hering wrote: > > @@ -897,9 +903,16 @@ void p2m_mem_paging_resume(struct domain > > { > > p2m_lock(p2m); > > mfn = p2m->get_entry(p2m, rsp.gfn, &p2mt, &a, p2m_query, NULL); > > - set_p2m_entry(p2m, rsp.gfn, mfn, 0, p2m_ram_rw, a); > > - set_gpfn_from_mfn(mfn_x(mfn), rsp.gfn); > > - audit_p2m(p2m, 1); > > + /* Allow only pages which were prepared properly or pages which were nominated but not evicted */ > > + if ( mfn_valid(mfn) && ( p2mt == p2m_ram_paging_in || p2mt == p2m_ram_paging_in_start ) ) > > Wouldn't a nominated-but-not-evicted page have type p2m_ram_paging_out? Yes, but in the page-in path it will be p2m_ram_paging_in_start with a valid mfn. > > + { > > + set_p2m_entry(p2m, rsp.gfn, mfn, 0, p2m_ram_rw, a); > > + set_gpfn_from_mfn(mfn_x(mfn), rsp.gfn); > > + audit_p2m(p2m, 1); > > + /* May be called more than once if the gfn was populate from different vcpus */ > > + } else if ( p2mt != p2m_ram_rw ) { > > + printk("resume: %d %lx %x %lx\n", d->domain_id, rsp.gfn, p2mt, mfn_x(mfn)); > > This should be a gdprintk of some kind, probably XENLOG_WARNING unless > it happens a lot. Its just debug, perhaps that gfn was already use for something else while the pager processed multiple page-in requests from different vcpus. Do you want me to resend this patch? Olaf