From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: ** X-Spam-Status: No, score=2.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,HTML_MESSAGE,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8A7CEC47247 for ; Thu, 30 Apr 2020 17:14:00 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4F7B52064A for ; Thu, 30 Apr 2020 17:14:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=anisinha-ca.20150623.gappssmtp.com header.i=@anisinha-ca.20150623.gappssmtp.com header.b="eIvM22Xt" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4F7B52064A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=anisinha.ca Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:59722 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jUCl5-0007As-83 for qemu-devel@archiver.kernel.org; Thu, 30 Apr 2020 13:13:59 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:55536) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jUCk1-0006dz-7w for qemu-devel@nongnu.org; Thu, 30 Apr 2020 13:13:17 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.90_1) (envelope-from ) id 1jUCjq-0005Sh-Od for qemu-devel@nongnu.org; Thu, 30 Apr 2020 13:12:52 -0400 Received: from mail-wm1-x342.google.com ([2a00:1450:4864:20::342]:39323) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jUCjq-0005RE-6u for qemu-devel@nongnu.org; Thu, 30 Apr 2020 13:12:42 -0400 Received: by mail-wm1-x342.google.com with SMTP id y24so2845486wma.4 for ; Thu, 30 Apr 2020 10:12:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=anisinha-ca.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=dyCi02HU4lMw6Td9Z3vxrZdwP6ujsprSmHgD5oNTtyY=; b=eIvM22XtuP4qiHr+ZUt16YUfJZLh71OCm8fC5KSjMH/2dms0noCPX2tYdVHe+E7dZc NfWp7yfhSxnbi11I1J97sCziPX0FdbHBpLugYD3WM8UlW8Tvgsf/Wl+lcTY83RoSYh4H alnBncjtw8ENJb1ItI5dnzEfO/fx/ndM82B3BF8hfbqF7SyWEQdeYxa9ZhqDpY6m9wDi qEBoAweakiGWMDlUSBJ7MddPyM4HfPIdeJFQMEDAxk+oYYOxjR21WI1bJ0ufYJre/vkP 7j2SFBgrRgUZZIAbFfK0hcOcEFi2yueYDqTIb9azCXg67EV7ookpL2uHDdaWgjGdJaX8 M4Hw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=dyCi02HU4lMw6Td9Z3vxrZdwP6ujsprSmHgD5oNTtyY=; b=t6q/VR2mnb7ps8IejrLaonUAWo7n8n8tCDBVCx5zaKbmRizw7LztaGlnU8cMOwck/B xHIqQ3R7Pn3MvCwTwdVHozChoREszizk8GaIgkV2oBZltPBx4LnqtoKa9MEXYc+UGcv9 EjdW93pnE9ujqbtbuV9zhHpuL1TI6h93J3+cxV545v3grlE9+oAbJk9X3f1IaoW6ycnM BPyPcLNeaPVzdUYselBlkBZiwMCW8Wc0Z8EYxnH7pnJpUI7+YQj9pQBUcVxmkVTIGWT5 wBfvXn4FtS65nIQIq+ouBeoSx5/KGqS4Xa1kXNfpDIe4n18LMdE+W9v/je/Q3CZ3UM2C sBKA== X-Gm-Message-State: AGi0PuZ7MxvVj4yF3i9LIvjBA+2gfRzBia6fNN/JqtIWsyPOmVdeWjuX 9+UfR+4AM8hmMwJRG0zR0yEbyo5k0LzQYT2EeizTQg== X-Google-Smtp-Source: APiQypLd+I1/by+2meugdJr+4X6TbCpaTy0cmrvlhnq0QHXKHmJmiChN4p4WLXxHcL33WAs2POc5XVpX5ignNwumcuk= X-Received: by 2002:a7b:c959:: with SMTP id i25mr4036875wml.20.1588266759048; Thu, 30 Apr 2020 10:12:39 -0700 (PDT) MIME-Version: 1.0 References: <20200428121837-mutt-send-email-mst@kernel.org> <20200428164428-mutt-send-email-mst@kernel.org> <20200429011228-mutt-send-email-mst@kernel.org> <544B4749-9A1C-44BB-BD89-C37A7E8D86F4@nutanix.com> <20200429025200-mutt-send-email-mst@kernel.org> <20200429025535-mutt-send-email-mst@kernel.org> <20200429033657-mutt-send-email-mst@kernel.org> In-Reply-To: From: Ani Sinha Date: Thu, 30 Apr 2020 22:42:27 +0530 Message-ID: Subject: Re: [PATCH V2] Add a new PIIX option to control PCI hot unplugging of devices on non-root buses To: Ani Sinha Content-Type: multipart/alternative; boundary="000000000000fb636a05a4852bb8" Received-SPF: none client-ip=2a00:1450:4864:20::342; envelope-from=ani@anisinha.ca; helo=mail-wm1-x342.google.com X-detected-operating-system: by eggs.gnu.org: Error: [-] PROGRAM ABORT : Malformed IPv6 address (bad octet value). Location : parse_addr6(), p0f-client.c:67 X-Received-From: 2a00:1450:4864:20::342 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Eduardo Habkost , "Michael S. Tsirkin" , "qemu-devel@nongnu.org" , Aleksandar Markovic , Paolo Bonzini , Igor Mammedov , =?UTF-8?Q?Philippe_Mathieu=2DDaud=C3=A9?= , Aurelien Jarno , Richard Henderson Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --000000000000fb636a05a4852bb8 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable . Accidental? So maybe what you need is actually something else then - avoid *removing* the device when it's powered down. You don=E2=80=99t get it. It is not hypervisor admins who are unplugging it= . It is the end users. Even RedHat customers want this feature. See following resources: https://www.redhat.com/archives/libvir-list/2020-February/msg00110.html https://bugzilla.redhat.com/show_bug.cgi?id=3D1802592 https://bugzilla.redhat.com/show_bug.cgi?id=3D1790899 My approach is much more fine grained than just disable everything approach that we have for q35. For i440fx we can do better than that By the way, here's another glaring feature disparity between i440fx and q35 which we perhaps did not debate with as much fervour and push back as we debated here. When we implemented per slot hotplug disable for PCIE, we ignored to implement the same per slot capability for conventional PCI. Why was feature disparity across two machine types wasn't so much of an issue then? --=20 MST --000000000000fb636a05a4852bb8 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable

.

Acc= idental? So maybe what you need is actually something else then -
avoid *removing* the device w= hen it's powered down.

Yo= u don=E2=80=99t get it. It is not hypervisor admins who are unplugging it. = It is the end users. Even RedHat customers want this feature. See following= resources:
https://www.redhat.= com/archives/libvir-list/2020-February/msg00110.html
https://bugzilla.redhat.com/show_bug.cgi?id=3D1802592
= https://bugzilla.redhat.com/show_bug.cgi?id=3D1790899

My approach is much more fine grained than j= ust disable everything approach that we have for q35. For i440fx we can do = better than that

By the way, here's another glaring feature disparity between i440fx a= nd q35 which we perhaps did not debate with as much fervour and push back a= s we debated here. When we implemented per slot hotplug disable for PCIE, w= e ignored to implement the same per slot capability for conventional PCI. W= hy was feature disparity across two machine types wasn't so much of an = issue then?=C2=A0



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