From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-f46.google.com (mail-ed1-f46.google.com [209.85.208.46]) by dpdk.org (Postfix) with ESMTP id 0CD9F7CB0 for ; Thu, 28 Jun 2018 11:56:51 +0200 (CEST) Received: by mail-ed1-f46.google.com with SMTP id v22-v6so4794711edq.4 for ; Thu, 28 Jun 2018 02:56:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netronome-com.20150623.gappssmtp.com; s=20150623; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=VVWfoFUhnaCs2NaSFRKad5nmlxSVq+hOedQ7/tkJyJ8=; b=HrwMHFf5yhUtLBKUkZsbkWDaZtGUwJ9fkc9fvLms42lmw3EjkNnYSiGqHi6cgoVUhX f30ZzKftHZcJsF2yd+VXMHPmdFGFS37OkmrH3K01hqXMW4kkZtdG7V7l+QfI9fLoQPRo lqmYb/p+xCmdEiNw/GLd3rOAeYll0mrZkiZsfcVCItfE2NI4leynQB8mN94gE94TNnNV rr27QzmBgmqXvaf6vdZc5YJsL6ASXXzywr7fgN+shWuwEV2aGX50K9k5SrOrNdGdKzky Lhu1PG8kMigUk+wMqycN8I+fX5PNKxGDLP0bEB9feGBFSEpgCNjau52GERKAAZfBwc4W LESQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=VVWfoFUhnaCs2NaSFRKad5nmlxSVq+hOedQ7/tkJyJ8=; b=Co8N0L6NDyxmJLZU0Ig/30tIrkZsSVPcWx8df6qEdKr3/t39zkjJEESZN3nMpTfrpD UfQscKlGuliQmXfBnQkfVgoiNUW6WYNTczRi36iCmykpug/R/bHpZRyd8SGJQXxmlww9 4XILe1KxdFhZOJhHEPGsFf3Swms4Pezizjee0JKduYBRfmnNlF0VdX7UYZ3UULQlovdN rwxy1+XZyUqkxz45TWOxBVVdF8Ge04WHXsO5ZisdhUhp7VyVQC9S+msFa7uXBWJfTCLH NNUM4k1KRDJ225lVrtlrYxHJCN6DEb+VfjqR7HrV17T6yQLdHHonVUU2hSJvA+tw5dV4 MWZg== X-Gm-Message-State: APt69E0fwhVMkBkxHnjaxO74NqH58CIh6J7iNC+2PlMiYV63nwdwMSfi y4R0IFFox+gbqn97ncZNC4qEHXA1YiTTQ3ctPIYGcw== X-Google-Smtp-Source: AAOMgpfrHA+vpPT7+p7dOyW3AuY8B9ssAY6rcoPXJgVstG+w00leUz1x89crKQnRcOLWj1ZxjBVDaG5QU6p8UtJq6gA= X-Received: by 2002:a50:86a1:: with SMTP id r30-v6mr8775475eda.138.1530179811653; Thu, 28 Jun 2018 02:56:51 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:a50:b194:0:0:0:0:0 with HTTP; Thu, 28 Jun 2018 02:56:51 -0700 (PDT) In-Reply-To: <35c86511-7bf7-4840-d7ba-8362ddefc8ec@intel.com> References: <1530034653-28299-1-git-send-email-alejandro.lucero@netronome.com> <552f939e-f28e-0648-1796-8f42269887a2@intel.com> <03046f23-2466-cbb7-ae2b-f2770d5c6b0f@intel.com> <35c86511-7bf7-4840-d7ba-8362ddefc8ec@intel.com> From: Alejandro Lucero Date: Thu, 28 Jun 2018 10:56:51 +0100 Message-ID: To: "Burakov, Anatoly" Cc: dev , stable@dpdk.org Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.15 Subject: Re: [dpdk-stable] [RFC] Add support for device dma mask X-BeenThere: stable@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches for DPDK stable branches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 28 Jun 2018 09:56:52 -0000 On Thu, Jun 28, 2018 at 9:54 AM, Burakov, Anatoly wrote: > On 27-Jun-18 5:52 PM, Alejandro Lucero wrote: > >> >> >> On Wed, Jun 27, 2018 at 2:24 PM, Burakov, Anatoly < >> anatoly.burakov@intel.com > wrote: >> >> On 27-Jun-18 11:13 AM, Alejandro Lucero wrote: >> >> >> >> On Wed, Jun 27, 2018 at 9:17 AM, Burakov, Anatoly >> >> > >> >> wrote: >> >> On 26-Jun-18 6:37 PM, Alejandro Lucero wrote: >> >> This RFC tries to handle devices with addressing >> limitations. >> NFP devices >> 4000/6000 can just handle addresses with 40 bits implying >> problems for handling >> physical address when machines have more than 1TB of >> memory. But >> because how >> iovas are configured, which can be equivalent to physical >> addresses or based on >> virtual addresses, this can be a more likely problem. >> >> I tried to solve this some time ago: >> >> https://www.mail-archive.com/dev@dpdk.org/msg45214.html >> >> > dev@dpdk.org/msg45214.html >> > >> >> It was delayed because there was some changes in >> progress with >> EAL device >> handling, and, being honest, I completely forgot about >> this >> until now, when >> I have had to work on supporting NFP devices with DPDK >> and >> non-root users. >> >> I was working on a patch for being applied on main DPDK >> branch >> upstream, but >> because changes to memory initialization during the >> last months, >> this can not >> be backported to stable versions, at least the part >> where the >> hugepages iovas >> are checked. >> >> I realize stable versions only allow bug fixing, and this >> patchset could >> arguably not be considered as so. But without this, it >> could be, >> although >> unlikely, a DPDK used in a machine with more than 1TB, >> and then >> NFP using >> the wrong DMA host addresses. >> >> Although virtual addresses used as iovas are more >> dangerous, for >> DPDK versions >> before 18.05 this is not worse than with physical >> addresses, >> because iovas, >> when physical addresses are not available, are based on a >> starting address set >> to 0x0. >> >> >> You might want to look at the following patch: >> >> http://patches.dpdk.org/patch/37149/ >> >> > > >> >> Since this patch, IOVA as VA mode uses VA addresses, and >> that has >> been backported to earlier releases. I don't think there's >> any case >> where we used zero-based addresses any more. >> >> >> But memsegs get the iova based on hugepages physaddr, and for VA >> mode that is based on 0x0 as starting point. >> >> And as far as I know, memsegs iovas are what end up being used >> for IOMMU mappings and what devices will use. >> >> >> For when physaddrs are available, IOVA as PA mode assigns IOVA >> addresses to PA, while IOVA as VA mode assigns IOVA addresses to VA >> (both 18.05+ and pre-18.05 as per above patch, which was applied to >> pre-18.05 stable releases). >> >> When physaddrs aren't available, IOVA as VA mode assigns IOVA >> addresses to VA, both 18.05+ and pre-18.05, as per above patch. >> >> >> This is right. >> >> If physaddrs aren't available and IOVA as PA mode is used, then i as >> far as i can remember, even though technically memsegs get their >> addresses set to 0x0 onwards, the actual addresses we get in >> memzones etc. are RTE_BAD_IOVA. >> >> >> This is not right. Not sure if this was the intention, but if PA mode and >> physaddrs not available, this code inside vfio_type1_dma_map: >> >> if(rte_eal_iova_mode() == RTE_IOVA_VA) >> >> dma_map.iova = dma_map.vaddr; >> >> else >> >> dma_map.iova = ms[i].iova; >> >> >> does the IOMMU mapping using the iovas and not the vaddr, with the iovas >> starting at 0x0. >> > > Yep, you're right, apologies. I confused this with no-huge option. So, what do you think about the patchset? Could it be this applied to stable versions? I'll send a patch for current 18.05 code which will have the dma mask and the hugepage check, along with changes for doing the mmaps below the dma mask limit. > > > -- > Thanks, > Anatoly >