From owner-soc-status@freebsd.org Tue Jul 3 10:56:15 2018 Return-Path: Delivered-To: soc-status@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id A6A641035505 for ; Tue, 3 Jul 2018 10:56:15 +0000 (UTC) (envelope-from pratiy0100@gmail.com) Received: from mail-ed1-f45.google.com (mail-ed1-f45.google.com [209.85.208.45]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 30B067A7BA for ; Tue, 3 Jul 2018 10:56:15 +0000 (UTC) (envelope-from pratiy0100@gmail.com) Received: by mail-ed1-f45.google.com with SMTP id g12-v6so1290353edi.9 for ; Tue, 03 Jul 2018 03:56:15 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=BSm5LZxoHZIvQhscYlaExm/OMZdZv3lBbfJdwC7TJds=; b=sa5LIBwWxIRCGgxb+NYZqAjdSiL49NM1gtFg9oKc3G+o7SkC9wgrX+InX5oHHS0JVy X+tMsResN7LMgTfAr6sooplZncn7P6JbVH36Nq5YFmMxJaqev+M3SOH4iAsVMo5pVI6a V3NU0G4Swa9n/TCXEkAWQkhvCqUKuWFjCcbAL0zaLcUOByxmD0DAeEHQAl4k8PkcWfDo MDbgxpy+R+1bET9TLK0Eemxq1CJDOa6Cc5Frl5FeUzWiv8TxU4QwFb5m4uBdBxqjFfaQ bPJJ018VZ5Xz1vhomIafpCJ8i0fx7BrNh1jQpcHvw3E5TekBG6Zg6VRkntRXlseTkamt KK5w== X-Gm-Message-State: APt69E1gibv9ArLUUOl+6QQKau1kdZo4E36x/FmWFIJb2l1JuSRBYlRt OCPDXeX8zR3lp4lKdrriUuCWdjBA X-Google-Smtp-Source: AAOMgpeq03RQVtF9x3h5+/7Eijtw/GBGTFzEwqXrGK3suyCIcfDxN+QfCXZpjCHtb2p51kQkO7zKOw== X-Received: by 2002:a50:b178:: with SMTP id l53-v6mr6324015edd.306.1530597293295; Mon, 02 Jul 2018 22:54:53 -0700 (PDT) Received: from mail-ed1-f53.google.com (mail-ed1-f53.google.com. [209.85.208.53]) by smtp.gmail.com with ESMTPSA id p59-v6sm329048edp.54.2018.07.02.22.54.53 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 02 Jul 2018 22:54:53 -0700 (PDT) Received: by mail-ed1-f53.google.com with SMTP id a5-v6so711292edt.5 for ; Mon, 02 Jul 2018 22:54:53 -0700 (PDT) X-Received: by 2002:a50:b178:: with SMTP id l53-v6mr6323995edd.306.1530597292945; Mon, 02 Jul 2018 22:54:52 -0700 (PDT) MIME-Version: 1.0 From: Pratyush Yadav Date: Tue, 3 Jul 2018 11:24:16 +0530 X-Gmail-Original-Message-ID: Message-ID: Subject: [Week 7] Import the Xen grant-table bus_dma(9) handlers from OpenBSD To: soc-status@freebsd.org Content-Type: text/plain; charset="UTF-8" X-BeenThere: soc-status@freebsd.org X-Mailman-Version: 2.1.27 Precedence: list List-Id: Summer of Code Status Reports and Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 03 Jul 2018 10:56:15 -0000 Hi, At this point, the Xen-specific bus_dma(9) implementation is nearly complete, with some minor fixes and additions required. So this last week I went through the blkfront driver, so I can understand how it works before starting to convert it to use the xen busdma. That itself raised the question, how would a driver use the xen busdma implementation, instead of the default implementation? After some help from Roger, I modified xenpv.c to return the new implementation's tag when a driver calls its bus_get_dma_tag(). Functionality to "bootstrap" the dma tag was also added to busdma_xen. This week, I will try to convert the blkfront driver to use the Xen's busdma implementation. You can check the code here [0]. I maintain a blog on Blogger where I publish my progress every few days. Check it out if you want more details on what I'm doing [1]. [0] https://pratyushgsoc.blogspot.com/ [1] https://github.com/prati0100/freebsd/tree/master -- Regards, Pratyush Yadav