From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56655) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cxFoq-000564-PQ for qemu-devel@nongnu.org; Sun, 09 Apr 2017 12:36:05 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cxFop-0003oD-UF for qemu-devel@nongnu.org; Sun, 09 Apr 2017 12:36:04 -0400 Received: from mail-ua0-x242.google.com ([2607:f8b0:400c:c08::242]:35596) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1cxFop-0003ns-RH for qemu-devel@nongnu.org; Sun, 09 Apr 2017 12:36:03 -0400 Received: by mail-ua0-x242.google.com with SMTP id m20so2663718uab.2 for ; Sun, 09 Apr 2017 09:36:03 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: From: hrg Date: Mon, 10 Apr 2017 00:36:02 +0800 Message-ID: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [RFC/BUG] xen-mapcache: buggy invalidate map cache? List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: anthony.perard@citrix.com, xen-devel@lists.xensource.com, qemu-devel@nongnu.org, jun.nakajima@intel.com, agraf@suse.de, sstabellini@kernel.org Cc: xen-devel@lists.xenproject.org, xen-devel@lists.xen.org, "Herongguang (Stephen)" , wangxinxin.wang@huawei.com On Sun, Apr 9, 2017 at 11:55 PM, hrg wrote: > On Sun, Apr 9, 2017 at 11:52 PM, hrg wrote: >> Hi, >> >> In xen_map_cache_unlocked(), map to guest memory maybe in entry->next >> instead of first level entry (if map to rom other than guest memory >> comes first), while in xen_invalidate_map_cache(), when VM ballooned >> out memory, qemu did not invalidate cache entries in linked >> list(entry->next), so when VM balloon back in memory, gfns probably >> mapped to different mfns, thus if guest asks device to DMA to these >> GPA, qemu may DMA to stale MFNs. >> >> So I think in xen_invalidate_map_cache() linked lists should also be >> checked and invalidated. >> >> What=E2=80=99s your opinion? Is this a bug? Is my analyze correct? > > Added Jun Nakajima and Alexander Graf And correct Stefano Stabellini's email address. From mboxrd@z Thu Jan 1 00:00:00 1970 From: hrg Subject: Re: [Qemu-devel] [RFC/BUG] xen-mapcache: buggy invalidate map cache? Date: Mon, 10 Apr 2017 00:36:02 +0800 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" To: anthony.perard@citrix.com, xen-devel@lists.xensource.com, qemu-devel@nongnu.org, jun.nakajima@intel.com, agraf@suse.de, sstabellini@kernel.org Cc: xen-devel@lists.xenproject.org, wangxinxin.wang@huawei.com, "Herongguang (Stephen)" , xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org T24gU3VuLCBBcHIgOSwgMjAxNyBhdCAxMTo1NSBQTSwgaHJnIDxocmdzdGVwaGVuQGdtYWlsLmNv bT4gd3JvdGU6Cj4gT24gU3VuLCBBcHIgOSwgMjAxNyBhdCAxMTo1MiBQTSwgaHJnIDxocmdzdGVw aGVuQGdtYWlsLmNvbT4gd3JvdGU6Cj4+IEhpLAo+Pgo+PiBJbiB4ZW5fbWFwX2NhY2hlX3VubG9j a2VkKCksIG1hcCB0byBndWVzdCBtZW1vcnkgbWF5YmUgaW4gZW50cnktPm5leHQKPj4gaW5zdGVh ZCBvZiBmaXJzdCBsZXZlbCBlbnRyeSAoaWYgbWFwIHRvIHJvbSBvdGhlciB0aGFuIGd1ZXN0IG1l bW9yeQo+PiBjb21lcyBmaXJzdCksIHdoaWxlIGluIHhlbl9pbnZhbGlkYXRlX21hcF9jYWNoZSgp LCB3aGVuIFZNIGJhbGxvb25lZAo+PiBvdXQgbWVtb3J5LCBxZW11IGRpZCBub3QgaW52YWxpZGF0 ZSBjYWNoZSBlbnRyaWVzIGluIGxpbmtlZAo+PiBsaXN0KGVudHJ5LT5uZXh0KSwgc28gd2hlbiBW TSBiYWxsb29uIGJhY2sgaW4gbWVtb3J5LCBnZm5zIHByb2JhYmx5Cj4+IG1hcHBlZCB0byBkaWZm ZXJlbnQgbWZucywgdGh1cyBpZiBndWVzdCBhc2tzIGRldmljZSB0byBETUEgdG8gdGhlc2UKPj4g R1BBLCBxZW11IG1heSBETUEgdG8gc3RhbGUgTUZOcy4KPj4KPj4gU28gSSB0aGluayBpbiB4ZW5f aW52YWxpZGF0ZV9tYXBfY2FjaGUoKSBsaW5rZWQgbGlzdHMgc2hvdWxkIGFsc28gYmUKPj4gY2hl Y2tlZCBhbmQgaW52YWxpZGF0ZWQuCj4+Cj4+IFdoYXTigJlzIHlvdXIgb3Bpbmlvbj8gSXMgdGhp cyBhIGJ1Zz8gSXMgbXkgYW5hbHl6ZSBjb3JyZWN0Pwo+Cj4gQWRkZWQgSnVuIE5ha2FqaW1hIGFu ZCBBbGV4YW5kZXIgR3JhZgpBbmQgY29ycmVjdCBTdGVmYW5vIFN0YWJlbGxpbmkncyBlbWFpbCBh ZGRyZXNzLgoKX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18K WGVuLWRldmVsIG1haWxpbmcgbGlzdApYZW4tZGV2ZWxAbGlzdHMueGVuLm9yZwpodHRwczovL2xp c3RzLnhlbi5vcmcveGVuLWRldmVsCg==