From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxime Coquelin Subject: Re: [PATCH v2] bus/pci: forbid VA as IOVA mode if IOMMU address width too small Date: Thu, 11 Jan 2018 21:19:38 +0100 Message-ID: <5c168150-7dcc-c110-a3d6-968738d781f7@redhat.com> References: <20180109131801.26520-1-maxime.coquelin@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: dev@dpdk.org, stable@dpdk.org, santosh.shukla@caviumnetworks.com, anatoly.burakov@intel.com, thomas@monjalon.net, stephen@networkplumber.org, peterx@redhat.com To: jianfeng.tan@intel.com Return-path: In-Reply-To: <20180109131801.26520-1-maxime.coquelin@redhat.com> Content-Language: en-US List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Hi Jianfeng, On 01/09/2018 02:18 PM, Maxime Coquelin wrote: > Intel VT-d supports different address widths for the IOVAs, from > 39 bits to 56 bits. > > While recent processors support at least 48 bits, VT-d emulation > currently only supports 39 bits. It makes DMA mapping to fail in this > case when using VA as IOVA mode, as user-space virtual addresses uses > up to 47 bits (see kernel's Documentation/x86/x86_64/mm.txt). > > This patch parses VT-d CAP register value available in sysfs, and > forbid VA as IOVA mode if the GAW is 39 bits or unknown. > > Fixes: f37dfab21c98 ("drivers/net: enable IOVA mode for Intel PMDs") > > Cc: stable@dpdk.org > Signed-off-by: Maxime Coquelin > --- > > Changes in v2: > ============== > - Rework pci_one_device_iommu_support_va #ifdefery (Stephen) > - Don't inline introduced functions (Stephen) > > drivers/bus/pci/linux/pci.c | 108 ++++++++++++++++++++++++++++++++++++++++---- > 1 file changed, 99 insertions(+), 9 deletions(-) > Could you please try the patch and confirm it does not break your --no-huge usecase? Are you fine with the fix? Thanks, Maxime