From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46831) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f8RcD-0006LW-6k for qemu-devel@nongnu.org; Tue, 17 Apr 2018 10:29:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1f8RcA-0007WV-GM for qemu-devel@nongnu.org; Tue, 17 Apr 2018 10:29:49 -0400 Received: from smtp03.citrix.com ([162.221.156.55]:12677) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1f8RcA-0007UM-7h for qemu-devel@nongnu.org; Tue, 17 Apr 2018 10:29:46 -0400 References: <1523049683-11782-1-git-send-email-igor.druzhinin@citrix.com> <20180417141518.GM2208@perard> From: Igor Druzhinin Message-ID: Date: Tue, 17 Apr 2018 15:29:42 +0100 MIME-Version: 1.0 In-Reply-To: <20180417141518.GM2208@perard> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] xen/pt: use address_space_memory object for memory region hooks List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anthony PERARD Cc: xen-devel@lists.xenproject.org, qemu-devel@nongnu.org, sstabellini@kernel.org, ross.lagerwall@citrix.com On 17/04/18 15:15, Anthony PERARD wrote: > On Fri, Apr 06, 2018 at 10:21:23PM +0100, Igor Druzhinin wrote: >> Commit 99605175c (xen-pt: Fix PCI devices re-attach failed) introduced >> a subtle bug. As soon as the guest switches off Bus Mastering on the >> device it immediately causes all the BARs be unmapped due to the DMA >> address space of the device being changed. This is undesired behavior >> because the guest may try to communicate with the device after that >> which triggers the following errors in the logs: >> >> [00:05.0] xen_pt_bar_read: Error: Should not read BAR through QEMU. @0x0000000000000200 >> [00:05.0] xen_pt_bar_write: Error: Should not write BAR through QEMU. @0x0000000000000200 >> >> The issue that the original patch tried to workaround (uneven number of >> region_add/del calls on device attach/detach) was fixed in later QEMU >> versions. > > Do you know when the issue was fixed? > I think it's this commit: commit d25836cafd7508090d211e97acfc0abc5ae88daa Author: Peter Xu Date: Mon Jan 22 14:02:44 2018 +0800 memory: do explicit cleanup when remove listeners Igor