>>> On 23.11.16 at 10:48, <paul.durr...@citrix.com> wrote: >> From: Jan Beulich [mailto:jbeul...@suse.com] >> Sent: 23 November 2016 09:24 >> >> We should not consume the second slot if it didn't get written yet. >> Normal writers - i.e. Xen - would not update write_pointer between the >> two writes, but the page may get fiddled with by the guest itself, and >> we're better off entering an infinite loop in that case. >> > > Xen would never put QEMU in this situation and the guest can't actually > modify the page whilst it's in use, since activation of the IOREQ server > removes the page from the guest's p2m so the premise of the patch is not > correct.
Is that the case even for pre-ioreq-server Xen versions? The issue here was reported together with what became XSA-197, and it's not been assigned its own XSA just because there are other ways for a guest to place high load on its qemu process (and there are ways to deal with such high load situations). Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
