From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 502BDC43613 for ; Mon, 24 Jun 2019 05:29:53 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0FEF42083D for ; Mon, 24 Jun 2019 05:29:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0FEF42083D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:48014 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hfHY7-0004QU-JD for qemu-devel@archiver.kernel.org; Mon, 24 Jun 2019 01:29:51 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:57940) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hfHXV-0003zQ-HI for qemu-devel@nongnu.org; Mon, 24 Jun 2019 01:29:15 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hfHXT-0005Vy-On for qemu-devel@nongnu.org; Mon, 24 Jun 2019 01:29:13 -0400 Received: from mga14.intel.com ([192.55.52.115]:11976) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hfHXR-00056f-Ng for qemu-devel@nongnu.org; Mon, 24 Jun 2019 01:29:11 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 23 Jun 2019 22:28:49 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.63,411,1557212400"; d="scan'208";a="187807374" Received: from joy-optiplex-7040.sh.intel.com (HELO joy-OptiPlex-7040) ([10.239.13.9]) by fmsmga002.fm.intel.com with ESMTP; 23 Jun 2019 22:28:48 -0700 Date: Mon, 24 Jun 2019 01:22:55 -0400 From: Yan Zhao To: Peter Xu Message-ID: <20190624052255.GA27894@joy-OptiPlex-7040> References: <1560934185-14152-1-git-send-email-yan.y.zhao@intel.com> <39c4c32b-e34a-8d8f-abbc-ab346ec5bed7@redhat.com> <20190620040230.GB9073@xz-x1> <6829b139-3eab-449e-04d6-07f1e381316d@redhat.com> <20190620125955.GB9657@xz-x1> <20190620130443.GC9657@xz-x1> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190620130443.GC9657@xz-x1> User-Agent: Mutt/1.9.4 (2018-02-28) X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 192.55.52.115 Subject: Re: [Qemu-devel] [PATCH] memory: do not do out of bound notification X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Yan Zhao Cc: Paolo Bonzini , "qemu-devel@nongnu.org" , Auger Eric Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, Jun 20, 2019 at 09:04:43PM +0800, Peter Xu wrote: > On Thu, Jun 20, 2019 at 08:59:55PM +0800, Peter Xu wrote: > > On Thu, Jun 20, 2019 at 10:35:29AM +0200, Paolo Bonzini wrote: > > > On 20/06/19 06:02, Peter Xu wrote: > > > > Seems workable, to be explicit - we can even cut it into chunks with > > > > different size to be efficient. > > > > > > Yes, this is not hard (completely untested): > > > > > > diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c > > > index 44b1231157..541538bc6c 100644 > > > --- a/hw/i386/intel_iommu.c > > > +++ b/hw/i386/intel_iommu.c > > > @@ -3388,39 +3388,34 @@ static void vtd_address_space_unmap(VTDAddressSpace *as, IOMMUNotifier *n) > > > } > > > > > > assert(start <= end); > > > - size = end - start; > > > + while (end > start) { > > > + size = end - start; > > > + /* Only keep the lowest bit of either size or start. */ > > > + size = MIN(size & -size, start & -start); > > > > I feel like this can be problematic. I'm imaging: > > > > start=0x1000_0000, size=0x1000_1000 > > > > This will get size=0x1000 but actually we can do size=0x1000_0000 as > > the first. > > > > > + /* Should not happen, but limit to address width too just in case */ > > > + size = MIN(size, 1ULL << s->aw_bits); > > > > > > - if (ctpop64(size) != 1) { > > > - /* > > > - * This size cannot format a correct mask. Let's enlarge it to > > > - * suite the minimum available mask. > > > - */ > > > - int n = 64 - clz64(size); > > > - if (n > s->aw_bits) { > > > - /* should not happen, but in case it happens, limit it */ > > > - n = s->aw_bits; > > > - } > > > - size = 1ULL << n; > > > - } > > > + assert((start & (size - 1)) == 0); > > > > > > - entry.target_as = &address_space_memory; > > > - /* Adjust iova for the size */ > > > - entry.iova = n->start & ~(size - 1); > > > - /* This field is meaningless for unmap */ > > > - entry.translated_addr = 0; > > > - entry.perm = IOMMU_NONE; > > > - entry.addr_mask = size - 1; > > > + entry.target_as = &address_space_memory; > > > + entry.iova = start; > > > + /* This field is meaningless for unmap */ > > > + entry.translated_addr = 0; > > > + entry.perm = IOMMU_NONE; > > > + entry.addr_mask = size - 1; > > > > (some of the fields can be moved out of loop because they are > > constants) > > > > > > > > - trace_vtd_as_unmap_whole(pci_bus_num(as->bus), > > > - VTD_PCI_SLOT(as->devfn), > > > - VTD_PCI_FUNC(as->devfn), > > > - entry.iova, size); > > > + trace_vtd_as_unmap_whole(pci_bus_num(as->bus), > > > + VTD_PCI_SLOT(as->devfn), > > > + VTD_PCI_FUNC(as->devfn), > > > + entry.iova, size); > > > > Can move this out because this is a trace only so we don't have > > restriction on mask? > > > > > > > > - map.iova = entry.iova; > > > - map.size = entry.addr_mask; > > > - iova_tree_remove(as->iova_tree, &map); > > > + map.iova = entry.iova; > > > + map.size = entry.addr_mask; > > > + iova_tree_remove(as->iova_tree, &map); > > > > Same here? > > > > > > > > - memory_region_notify_one(n, &entry); > > > + memory_region_notify_one(n, &entry); > > > + start += size; > > > + } > > > } > > > > > > static void vtd_address_space_unmap_all(IntelIOMMUState *s) > > > > > > > > > Yan, > > > > > > if something like this works for you, let me know and I will submit it > > > as a proper patch. > > > > > > Paolo > > > > Since during review I'm thinking how to generate a correct sequence of > > these masks... here's my try below with above issues fixed... :) > > > > I've tried compile but not tested. Yan can test it, or I can do it > > too tomorrow after I find some machines. > > > > Thanks, > > > > ------------------------------------------------------------ > > diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c > > index 44b1231157..cfbd225f0a 100644 > > --- a/hw/i386/intel_iommu.c > > +++ b/hw/i386/intel_iommu.c > > @@ -3363,11 +3363,32 @@ VTDAddressSpace *vtd_find_add_as(IntelIOMMUState *s, PCIBus *bus, int devfn) > > return vtd_dev_as; > > } > > > > +static uint64_t vtd_get_next_mask(uint64_t start, uint64_t size, int gaw) > > +{ > > + /* Tries to find smallest mask from start first */ > > + uint64_t rmask = start & -start, max_mask = 1ULL << gaw; > > + > > + assert(size && gaw > 0 && gaw < 64); > > + > > + /* Zero start, or too big */ > > + if (!rmask || rmask > max_mask) { > > + rmask = max_mask; > > + } > > + > > + /* If the start mask worked, then use it */ > > + if (rmask <= size) { > > + return rmask; > > + } > > + > > + /* Find the largest page mask from size */ > > + return 1ULL << (63 - clz64(size)); > > +} > > + > > /* Unmap the whole range in the notifier's scope. */ > > static void vtd_address_space_unmap(VTDAddressSpace *as, IOMMUNotifier *n) > > { > > IOMMUTLBEntry entry; > > - hwaddr size; > > + hwaddr size, remain; > > hwaddr start = n->start; > > hwaddr end = n->end; > > IntelIOMMUState *s = as->iommu_state; > > @@ -3388,39 +3409,28 @@ static void vtd_address_space_unmap(VTDAddressSpace *as, IOMMUNotifier *n) > > } > > > > assert(start <= end); > > - size = end - start; > > - > > - if (ctpop64(size) != 1) { > > - /* > > - * This size cannot format a correct mask. Let's enlarge it to > > - * suite the minimum available mask. > > - */ > > - int n = 64 - clz64(size); > > - if (n > s->aw_bits) { > > - /* should not happen, but in case it happens, limit it */ > > - n = s->aw_bits; > > - } > > - size = 1ULL << n; > > - } > > - > > + size = remain = end - start; > > entry.target_as = &address_space_memory; > > - /* Adjust iova for the size */ > > - entry.iova = n->start & ~(size - 1); > > + entry.perm = IOMMU_NONE; > > /* This field is meaningless for unmap */ > > entry.translated_addr = 0; > > - entry.perm = IOMMU_NONE; > > - entry.addr_mask = size - 1; > > + > > + while (remain) { > > + uint64_t mask = vtd_get_next_mask(start, remain, s->aw_bits); > > + > > + entry.iova = start; > > + entry.addr_mask = mask - 1; > > + memory_region_notify_one(n, &entry); > > Sorry, I at least missed these lines: > > start += mask; > remain -= mask; > > > + } > > > > trace_vtd_as_unmap_whole(pci_bus_num(as->bus), > > VTD_PCI_SLOT(as->devfn), > > VTD_PCI_FUNC(as->devfn), > > - entry.iova, size); > > + n->start, size); > > > > - map.iova = entry.iova; > > - map.size = entry.addr_mask; > > + map.iova = n->start; > > + map.size = size; > > iova_tree_remove(as->iova_tree, &map); > > - > > - memory_region_notify_one(n, &entry); > > } > > > > static void vtd_address_space_unmap_all(IntelIOMMUState *s) > > ------------------------------------------------------------ > > > > Regards, > > > > -- > > Peter Xu > > Regards, > > -- > Peter Xu hi Peter and Paolo, I tested with code and it's fine in my side. It's base on your version with some minor modifications, such as size is now (end - start + 1) now. Thanks Yan +static uint64_t vtd_get_next_mask(uint64_t start, uint64_t size, int gaw) +{ + /* Tries to find smallest mask from start first */ + uint64_t rmask = start & -start, max_mask = 1ULL << gaw; + assert(size && gaw > 0 && gaw < 64); + /* Zero start, or too big */ + if (!rmask || rmask > max_mask) { + rmask = max_mask; + } + /* If the start mask worked, then use it */ + if (rmask <= size) { + return rmask; + } + + /* Find the largest page mask from size */ + return 1ULL << (63 - clz64(size)); +} + /* Unmap the whole range in the notifier's scope. */ static void vtd_address_space_unmap(VTDAddressSpace *as, IOMMUNotifier *n) { IOMMUTLBEntry entry; - hwaddr size; + hwaddr size, remain; hwaddr start = n->start; hwaddr end = n->end; IntelIOMMUState *s = as->iommu_state; @@ -3380,48 +3398,46 @@ static void vtd_address_space_unmap(VTDAddressSpace *as, IOMMUNotifier *n) * VT-d spec), otherwise we need to consider overflow of 64 bits. */ - if (end > VTD_ADDRESS_SIZE(s->aw_bits)) { + if (end > VTD_ADDRESS_SIZE(s->aw_bits) - 1) { /* * Don't need to unmap regions that is bigger than the whole * VT-d supported address space size */ - end = VTD_ADDRESS_SIZE(s->aw_bits); + end = VTD_ADDRESS_SIZE(s->aw_bits) - 1; } assert(start <= end); - size = end - start; - if (ctpop64(size) != 1) { - /* - * This size cannot format a correct mask. Let's enlarge it to - * suite the minimum available mask. - */ - int n = 64 - clz64(size); - if (n > s->aw_bits) { - /* should not happen, but in case it happens, limit it */ - n = s->aw_bits; - } - size = 1ULL << n; - } + size = remain = end - start + 1; entry.target_as = &address_space_memory; - /* Adjust iova for the size */ - entry.iova = n->start & ~(size - 1); + + entry.perm = IOMMU_NONE; /* This field is meaningless for unmap */ entry.translated_addr = 0; - entry.perm = IOMMU_NONE; - entry.addr_mask = size - 1; + + while (remain >= VTD_PAGE_SIZE) { + uint64_t mask = vtd_get_next_mask(start, remain, s->aw_bits); + + entry.iova = start; + entry.addr_mask = mask - 1; + memory_region_notify_one(n, &entry); + start += mask; + remain -= mask; + } + + if (remain) { + warn_report("Unmapping unaligned range %lx-%lx", start, end); + } trace_vtd_as_unmap_whole(pci_bus_num(as->bus), VTD_PCI_SLOT(as->devfn), VTD_PCI_FUNC(as->devfn), - entry.iova, size); - - map.iova = entry.iova; - map.size = entry.addr_mask; + n->start, size); + map.iova = n->start; + map.size = size; iova_tree_remove(as->iova_tree, &map); - memory_region_notify_one(n, &entry); } static void vtd_address_space_unmap_all(IntelIOMMUState *s) -- 2.7.4