From owner-freebsd-xen@freebsd.org Thu Aug 4 10:28:02 2016 Return-Path: Delivered-To: freebsd-xen@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 80E18BAED45 for ; Thu, 4 Aug 2016 10:28:02 +0000 (UTC) (envelope-from akshay1994.leo@gmail.com) Received: from mail-io0-f195.google.com (mail-io0-f195.google.com [209.85.223.195]) (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 55F351880; Thu, 4 Aug 2016 10:28:02 +0000 (UTC) (envelope-from akshay1994.leo@gmail.com) Received: by mail-io0-f195.google.com with SMTP id y195so21051183iod.0; Thu, 04 Aug 2016 03:28:02 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=kfdrtO8y+PH2+ijSt98RBDYX5PMtpADKFxXUTXQaPe4=; b=SN652a0j4FncbRVQixbHPfg3FHorikTNqgc1aEb4Wfu/BvCuT3OPNhMsK8vIlOwnNk mg5Oyp1lkxOcwfWOGNm2vbW9BSQqNtRd3OPNSE/IY92tokSo6WE0yzfaovK0AmrwlTGl pwUj1ooYmwAJQv1e7VZPJAiPuk3xirw3QGNoZDR3Dg0H6T1QaOAu11KRWlOhG+GP+3pa /Lp9s6j5YkNHrHGX/+FlB3oU8OSZaYY28qjcJHEd1ZrPTAXK8roPnuv3DWC7es/+/6+V sumHSGJ0u7tMP/mUOQQhgcdbTLZL+iE3RmxNhSFfeJu7jjzfkEckMETPk5YxCIHlvrRK pojA== X-Gm-Message-State: AEkoouuy8DM9O4zgiZKEJCtGjayNumpIPHEs+9YTipb0GpU+eqNyHwPGCjav26S315vrpg== X-Received: by 10.107.36.75 with SMTP id k72mr73966102iok.155.1470306481054; Thu, 04 Aug 2016 03:28:01 -0700 (PDT) Received: from mail-io0-f174.google.com (mail-io0-f174.google.com. [209.85.223.174]) by smtp.gmail.com with ESMTPSA id c191sm1322890ith.15.2016.08.04.03.28.00 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 04 Aug 2016 03:28:00 -0700 (PDT) Received: by mail-io0-f174.google.com with SMTP id b62so267351189iod.3; Thu, 04 Aug 2016 03:28:00 -0700 (PDT) X-Received: by 10.107.36.75 with SMTP id k72mr73966061iok.155.1470306480510; Thu, 04 Aug 2016 03:28:00 -0700 (PDT) MIME-Version: 1.0 Received: by 10.107.20.85 with HTTP; Thu, 4 Aug 2016 03:27:40 -0700 (PDT) From: Akshay Jaggi Date: Thu, 4 Aug 2016 15:57:40 +0530 X-Gmail-Original-Message-ID: Message-ID: Subject: Event Channel notification issue - Gntdev device To: =?UTF-8?Q?Roger_Pau_Monn=C3=A9?= , freebsd-xen@freebsd.org Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.22 X-BeenThere: freebsd-xen@freebsd.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: Discussion of the freebsd port to xen - implementation and usage List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 04 Aug 2016 10:28:02 -0000 Hi, I've been working on unmap notifications for the grant table user space device (check progress: https://reviews.freebsd.org/D7293). I've added and tested unmap_clear_byte notification and unmap_send_event notification is left. I was implementing the unmap_send_notify on event-channel, but I am stuck. Basically, linux grabs a reference to the event-channel port, in case it is deallocated, so that it can still send a notify. I could not find such a reference-grabbing mechanism for event channel in FreeBSD. What should I do now? Should I add notify, adding the constraint that you cannot deallocate your reference to that port till the notify is sent (ie, after an unmap). Regards, Akshay