From mboxrd@z Thu Jan 1 00:00:00 1970 From: Suravee Suthikulpanit Subject: Re: [PATCH 1/1] iommu/amd: Fix PASID format in INVALIDATE_IOTLB_PAGES command Date: Tue, 4 Mar 2014 11:06:34 -0600 Message-ID: <5316081A.9020008@amd.com> References: <1393451371-17894-1-git-send-email-suravee.suthikulpanit@amd.com> <20140304141251.GB2799@8bytes.org> <5316051E.2030004@amd.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5316051E.2030004-5C7GfCeVMHo@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Joerg Roedel Cc: iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, Jay Cornwall , Linux Kernel Mailing List , "Naru, Kim" List-Id: iommu@lists.linux-foundation.org On 3/4/2014 10:53 AM, Suravee Suthikulpanit wrote: > On 3/4/2014 8:12 AM, Joerg Roedel wrote: >> On Wed, Feb 26, 2014 at 03:49:31PM -0600, >> suravee.suthikulpanit-5C7GfCeVMHo@public.gmane.org wrote: >>> From: Jay Cornwall >>> >>> This patch corrects the PASID format in the INVALIDATE_IOTLB_PAGES >>> command, which was caused by incorrect information in >>> the AMD IOMMU Architectural Specification v2.01 document. >>> >>> Incorrect format: >>> cmd->data[0][16:23] = PASID[7:0] >>> cmd->data[1][16:27] = PASID[19:8] >>> >>> Correct format: >>> cmd->data[0][16:23] = PASID[15:8] >>> cmd->data[1][16:23] = PASID[7:0] >>> >>> However, this does not affect the IOMMUv2 hardware implementation, >>> and has been corrected since version 2.02 of the specification >>> (available through AMD NDA). >>> >>> Signed-off-by: Jay Cornwall >>> Reviewed-by: Suravee Suthikulpanit >> >> Applied, thanks. >> >> Does this mean that PASIDs are only 16 bits wide now from the former 20 >> bits? >> >> >> > > Thank you Joerg. The specification also state that this command format > does not support the maximum size of the PASID field. However, other > commands seem to still support 20-bit PASID. > > Suravee Actually, just thinking about this again, even though we don't have systems with 20-bit PASID yet (only up-to 16-bit), but for future proof, we should add another logic to make sure that this logic won't try to use the 20-bit PASID with this version of the command. I'll send out another patch soon. Suravee