From owner-freebsd-xen@FreeBSD.ORG Fri Dec 16 21:11:07 2011 Return-Path: Delivered-To: xen@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 34D5A106564A for ; Fri, 16 Dec 2011 21:11:07 +0000 (UTC) (envelope-from seanbru@yahoo-inc.com) Received: from mrout1-b.corp.bf1.yahoo.com (mrout1-b.corp.bf1.yahoo.com [98.139.253.104]) by mx1.freebsd.org (Postfix) with ESMTP id E75CF8FC13 for ; Fri, 16 Dec 2011 21:11:06 +0000 (UTC) Received: from [127.0.0.1] (rideseveral.corp.yahoo.com [10.73.160.231]) by mrout1-b.corp.bf1.yahoo.com (8.14.4/8.14.4/y.out) with ESMTP id pBGL0Fd6044195; Fri, 16 Dec 2011 13:00:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=yahoo-inc.com; s=cobra; t=1324069215; bh=ZxyJvgsIJB8cvRhfIqos+t0kbtW6chBOC68tT781n7g=; h=Subject:From:To:Cc:In-Reply-To:References:Content-Type:Date: Message-ID:Mime-Version:Content-Transfer-Encoding; b=JBQro/jZRinLCGp7Sd1HeXur9lUtNQOIy51KSbiCVKvahNOSh0/ve2TZVGJhgbnQJ BuI5BUHL/oNFCACo9nTyXkFsQQtInwLxZa4vVw0yXoPEyYcl6zO4U8Kr+flpnPeWrF Q+hS9e3gW1J8Ic4AFhk/WOORauIFd/mxFvBTrDws= From: Sean Bruno To: Alan Cox In-Reply-To: <4EEB9CCE.6090701@rice.edu> References: <4EEB9CCE.6090701@rice.edu> Content-Type: text/plain; charset="UTF-8" Date: Fri, 16 Dec 2011 13:00:14 -0800 Message-ID: <1324069214.2669.6.camel@hitfishpass-lx.corp.yahoo.com> Mime-Version: 1.0 X-Mailer: Evolution 2.32.3 (2.32.3-1.fc14) Content-Transfer-Encoding: 7bit Cc: Alan Cox , "xen@freebsd.org" Subject: Re: PV i386 patch X-BeenThere: freebsd-xen@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussion of the freebsd port to xen - implementation and usage List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 16 Dec 2011 21:11:07 -0000 I'll test this out on the VMs in the fbsd cluster later. Sean On Fri, 2011-12-16 at 11:32 -0800, Alan Cox wrote: > Is anyone here actively working on fixing problems with SMP support > under PV i386? While doing some other maintenance on the > vm_page_alloc() callers in the source tree, I happened to take a look at > cpu_initialize_context() in mp_machdep.c. This function is involved in > bringing up the 2nd, 3rd, etc. CPUs on an SMP system. I spotted a > couple obvious errors. First, the size parameter given to kmem_*() > functions is expected to be in terms of bytes and not pages. Second, I > believe that PV i386 requires PAE to be used. If so, there are out of > range accesses to the array m[]. > > Index: i386/xen/mp_machdep.c > =================================================================== > --- i386/xen/mp_machdep.c (revision 228561) > +++ i386/xen/mp_machdep.c (working copy) > @@ -810,7 +810,7 @@ cpu_initialize_context(unsigned int cpu) > { > /* vcpu_guest_context_t is too large to allocate on the stack. > * Hence we allocate statically and protect it with a lock */ > - vm_page_t m[4]; > + vm_page_t m[NPGPTD + 2]; > static vcpu_guest_context_t ctxt; > vm_offset_t boot_stack; > vm_offset_t newPTD; > @@ -831,8 +831,8 @@ cpu_initialize_context(unsigned int cpu) > pmap_zero_page(m[i]); > > } > - boot_stack = kmem_alloc_nofault(kernel_map, 1); > - newPTD = kmem_alloc_nofault(kernel_map, NPGPTD); > + boot_stack = kmem_alloc_nofault(kernel_map, PAGE_SIZE); > + newPTD = kmem_alloc_nofault(kernel_map, NPGPTD * PAGE_SIZE); > ma[0] = VM_PAGE_TO_MACH(m[0])|PG_V; > > #ifdef PAE > @@ -854,7 +854,7 @@ cpu_initialize_context(unsigned int cpu) > nkpt*sizeof(vm_paddr_t)); > > pmap_qremove(newPTD, 4); > - kmem_free(kernel_map, newPTD, 4); > + kmem_free(kernel_map, newPTD, 4 * PAGE_SIZE); > /* > * map actual idle stack to boot_stack > */ > > _______________________________________________ > freebsd-xen@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-xen > To unsubscribe, send any mail to "freebsd-xen-unsubscribe@freebsd.org"