From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41743) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1W3WNv-0001J5-DO for qemu-devel@nongnu.org; Wed, 15 Jan 2014 14:44:25 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1W3WNp-0007Y8-Et for qemu-devel@nongnu.org; Wed, 15 Jan 2014 14:44:19 -0500 Received: from mx1.redhat.com ([209.132.183.28]:22770) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1W3WNp-0007Y0-6J for qemu-devel@nongnu.org; Wed, 15 Jan 2014 14:44:13 -0500 From: Alex Williamson Date: Wed, 15 Jan 2014 12:44:08 -0700 Message-ID: <20140115194348.21785.76357.stgit@bling.home> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] [PATCH] vfio: Filter out bogus mappings List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: alex.williamson@redhat.com Cc: aik@ozlabs.ru, bsd@redhat.com, qemu-devel@nongnu.org, mst@redhat.com Since 57271d63 we now see spurious mappings with the upper bits set if 64bit PCI BARs are sized while enabled. The guest writes a mask of 0xffffffff to the lower BAR to size it, then restores it, then writes the same mask to the upper BAR resulting in a spurious BAR mapping into the last 4G of the 64bit address space. Most architectures do not support or make use of the full 64bits address space for PCI BARs, so we filter out mappings with the high bit set. Long term, we probably need to think about vfio telling us the address width limitations of the IOMMU. Signed-off-by: Alex Williamson --- hw/misc/vfio.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/hw/misc/vfio.c b/hw/misc/vfio.c index 30b1a78..c8f63a6 100644 --- a/hw/misc/vfio.c +++ b/hw/misc/vfio.c @@ -2156,7 +2156,9 @@ static int vfio_dma_map(VFIOContainer *container, hwaddr iova, static bool vfio_listener_skipped_section(MemoryRegionSection *section) { - return !memory_region_is_ram(section->mr); + return !memory_region_is_ram(section->mr) || + section->offset_within_address_space > + ~section->offset_within_address_space; } static void vfio_listener_region_add(MemoryListener *listener,