From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39991) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VEqeb-0004Pd-N5 for qemu-devel@nongnu.org; Wed, 28 Aug 2013 21:04:11 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VEqeV-0002SN-Fk for qemu-devel@nongnu.org; Wed, 28 Aug 2013 21:04:05 -0400 Received: from mail-pd0-f173.google.com ([209.85.192.173]:40952) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VEqeV-0002Ru-8a for qemu-devel@nongnu.org; Wed, 28 Aug 2013 21:03:59 -0400 Received: by mail-pd0-f173.google.com with SMTP id p10so6979503pdj.18 for ; Wed, 28 Aug 2013 18:03:57 -0700 (PDT) Message-ID: <521E9DF5.9080709@ozlabs.ru> Date: Thu, 29 Aug 2013 11:03:49 +1000 From: Alexey Kardashevskiy MIME-Version: 1.0 References: <1377170965-9905-1-git-send-email-aik@ozlabs.ru> <1377170965-9905-4-git-send-email-aik@ozlabs.ru> <1377703099.10408.71.camel@ul30vt.home> In-Reply-To: <1377703099.10408.71.camel@ul30vt.home> Content-Type: text/plain; charset=KOI8-R Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v3 3/3] vfio: Fix 128 bit handling List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alex Williamson Cc: Paolo Bonzini , qemu-devel@nongnu.org, Peter Maydell On 08/29/2013 01:18 AM, Alex Williamson wrote: > On Thu, 2013-08-22 at 21:29 +1000, Alexey Kardashevskiy wrote: >> Upcoming VFIO on SPAPR PPC64 support will initialize the IOMMU >> memory region with UINT64_MAX (2^64 bytes) size so int128_get64() >> will assert. >> >> The patch takes care of this check. The existing type1 IOMMU code >> is not expected to map all 64 bits of RAM so the patch does not >> touch that part. >> >> Signed-off-by: Alexey Kardashevskiy >> --- >> Changes: >> v2: >> * used new function int128_exts64() >> --- >> hw/misc/vfio.c | 11 ++++++++--- >> 1 file changed, 8 insertions(+), 3 deletions(-) >> >> diff --git a/hw/misc/vfio.c b/hw/misc/vfio.c >> index dfe3a80..3878fc7 100644 >> --- a/hw/misc/vfio.c >> +++ b/hw/misc/vfio.c >> @@ -1920,6 +1920,7 @@ static void vfio_listener_region_add(MemoryListener *listener, >> VFIOContainer *container = container_of(listener, VFIOContainer, >> iommu_data.listener); >> hwaddr iova, end; >> + Int128 llend; >> void *vaddr; >> int ret; >> >> @@ -1940,13 +1941,17 @@ static void vfio_listener_region_add(MemoryListener *listener, >> } >> >> iova = TARGET_PAGE_ALIGN(section->offset_within_address_space); >> - end = (section->offset_within_address_space + int128_get64(section->size)) & >> - TARGET_PAGE_MASK; >> + llend = int128_make64(section->offset_within_address_space); >> + llend = int128_add(llend, section->size); >> + llend = int128_and(llend, int128_exts64(TARGET_PAGE_MASK)); >> >> - if (iova >= end) { >> + if (int128_ge(int128_make64(iova), llend)) { >> return; >> } >> >> + end = (section->offset_within_address_space + int128_get64(section->size)) & >> + TARGET_PAGE_MASK; >> + > > I'm confused, we build an Int128 version of end above for the > comparison, why isn't this just: > > end = int128_get64(llend); section->size for IOMMU memory region I have on spapr-vfio is 2^64 so int128_get64() fails. > here? Thanks, > > Alex > >> vaddr = memory_region_get_ram_ptr(section->mr) + >> section->offset_within_region + >> (iova - section->offset_within_address_space); > > > -- Alexey