From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49353) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cxFBS-0007BS-9r for qemu-devel@nongnu.org; Sun, 09 Apr 2017 11:55:23 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cxFBR-0006ku-GD for qemu-devel@nongnu.org; Sun, 09 Apr 2017 11:55:22 -0400 Received: from mail-ua0-x235.google.com ([2607:f8b0:400c:c08::235]:33216) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1cxFBR-0006kd-BZ for qemu-devel@nongnu.org; Sun, 09 Apr 2017 11:55:21 -0400 Received: by mail-ua0-x235.google.com with SMTP id q26so13808130uaa.0 for ; Sun, 09 Apr 2017 08:55:21 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: From: hrg Date: Sun, 9 Apr 2017 23:55:20 +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: stefano.stabellini@eu.citrix.com, anthony.perard@citrix.com, xen-devel@lists.xensource.com, qemu-devel@nongnu.org, jun.nakajima@intel.com, agraf@suse.de Cc: xen-devel@lists.xenproject.org, xen-devel@lists.xen.org, "Herongguang (Stephen)" , wangxinxin.wang@huawei.com 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 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: Sun, 9 Apr 2017 23:55:20 +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: stefano.stabellini@eu.citrix.com, anthony.perard@citrix.com, xen-devel@lists.xensource.com, qemu-devel@nongnu.org, jun.nakajima@intel.com, agraf@suse.de Cc: xen-devel@lists.xenproject.org, wangxinxin.wang@huawei.com, "Herongguang (Stephen)" , xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org T24gU3VuLCBBcHIgOSwgMjAxNyBhdCAxMTo1MiBQTSwgaHJnIDxocmdzdGVwaGVuQGdtYWlsLmNv bT4gd3JvdGU6Cj4gSGksCj4KPiBJbiB4ZW5fbWFwX2NhY2hlX3VubG9ja2VkKCksIG1hcCB0byBn dWVzdCBtZW1vcnkgbWF5YmUgaW4gZW50cnktPm5leHQKPiBpbnN0ZWFkIG9mIGZpcnN0IGxldmVs IGVudHJ5IChpZiBtYXAgdG8gcm9tIG90aGVyIHRoYW4gZ3Vlc3QgbWVtb3J5Cj4gY29tZXMgZmly c3QpLCB3aGlsZSBpbiB4ZW5faW52YWxpZGF0ZV9tYXBfY2FjaGUoKSwgd2hlbiBWTSBiYWxsb29u ZWQKPiBvdXQgbWVtb3J5LCBxZW11IGRpZCBub3QgaW52YWxpZGF0ZSBjYWNoZSBlbnRyaWVzIGlu IGxpbmtlZAo+IGxpc3QoZW50cnktPm5leHQpLCBzbyB3aGVuIFZNIGJhbGxvb24gYmFjayBpbiBt ZW1vcnksIGdmbnMgcHJvYmFibHkKPiBtYXBwZWQgdG8gZGlmZmVyZW50IG1mbnMsIHRodXMgaWYg Z3Vlc3QgYXNrcyBkZXZpY2UgdG8gRE1BIHRvIHRoZXNlCj4gR1BBLCBxZW11IG1heSBETUEgdG8g c3RhbGUgTUZOcy4KPgo+IFNvIEkgdGhpbmsgaW4geGVuX2ludmFsaWRhdGVfbWFwX2NhY2hlKCkg bGlua2VkIGxpc3RzIHNob3VsZCBhbHNvIGJlCj4gY2hlY2tlZCBhbmQgaW52YWxpZGF0ZWQuCj4K PiBXaGF04oCZcyB5b3VyIG9waW5pb24/IElzIHRoaXMgYSBidWc/IElzIG15IGFuYWx5emUgY29y cmVjdD8KCkFkZGVkIEp1biBOYWthamltYSBhbmQgQWxleGFuZGVyIEdyYWYKCl9fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fClhlbi1kZXZlbCBtYWlsaW5nIGxp c3QKWGVuLWRldmVsQGxpc3RzLnhlbi5vcmcKaHR0cHM6Ly9saXN0cy54ZW4ub3JnL3hlbi1kZXZl bAo=