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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 4733AC5475B for ; Mon, 11 Mar 2024 22:07:14 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rjngI-0000Bn-Tt; Mon, 11 Mar 2024 17:59:38 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rjngG-0000Ah-Td for qemu-devel@nongnu.org; Mon, 11 Mar 2024 17:59:36 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rjngF-0003xu-BB for qemu-devel@nongnu.org; Mon, 11 Mar 2024 17:59:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1710194374; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=uwyy8rtdLNCpslvbHPqDS/nmA49F1iWnhudQzO3o784=; b=gA+usf2zp6Ce6nXSuSqmlsCV7c0ZTcmk/XHA7EzxPEDivskidnKEA3akfs29m1oV5ooTfW hRAL/yWHnRA84WdltaqphrI4bupzP8sfT8dLxtfPrdUX+koh//gCQP/bUs+C8SXGfBDXP6 bo+w4tDPWRaYDY21SxMedcpmvcRMMQ4= Received: from mail-qv1-f69.google.com (mail-qv1-f69.google.com [209.85.219.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-508-Ucrsj4nwMPSON_aTYjAsXg-1; Mon, 11 Mar 2024 17:59:32 -0400 X-MC-Unique: Ucrsj4nwMPSON_aTYjAsXg-1 Received: by mail-qv1-f69.google.com with SMTP id 6a1803df08f44-6818b8cb840so15026386d6.1 for ; Mon, 11 Mar 2024 14:59:32 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1710194372; x=1710799172; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=uwyy8rtdLNCpslvbHPqDS/nmA49F1iWnhudQzO3o784=; b=LqYqxJCkXdJOaE95wcOEq/DNGAGlPPHDIoL7yr/K0xQ8M9Hl621VNyihkuccCSAakG oz5N3jMm618kxtmJk24jDmHrOTsNOS++TpBObj7M2PsZGty3UR9O/EZoivkXwpbZElC9 BgyGMU2WU62fIbKmBd8Sy4M6JNPj3wRBE4LzOvRcqSBKpYLEVV95vsrilkJan8h8GFnF vdFbcJGxwqmal0MPZsXj1ghUoExRMwVscxg4Ql9gnCHNcaoTVwPXqPycaEJB7auE/USD 1BqHd5x2i4XTXOe9bqp/xpDRJIzAs/Ut+CytIugPYJJgrZmXwtZ/iPSH/uIycePUSc6T +ggQ== X-Gm-Message-State: AOJu0YyaqEjBMnBWl+vVBGFMMSreG9zwP++BpGFlawVQjjWdD47HUsL+ AAyetOVUhZozgq1P5pTlWVORYyoc41qe+o5Egd3EydYIzDC2khEu6jXukPN3JnHaeVC52Q+IQOh 6wQJsbQseIFOm6Rs8+eiaROUuRFuZF7W6IWizsYRFOW6ol7SaV+8xbMq8huLJmyX6vrNp6c5Yaq vvKlHn48sABbGxRRzo80f02+Z1dnlFR/inUg== X-Received: by 2002:a05:6214:b6a:b0:690:ca31:f070 with SMTP id ey10-20020a0562140b6a00b00690ca31f070mr5305036qvb.2.1710194372131; Mon, 11 Mar 2024 14:59:32 -0700 (PDT) X-Google-Smtp-Source: AGHT+IFPtYvRgKglwS5jyZdSISMmu08wk8u4NUN8bEuMHipzZ9gx06K2n7D4LOqq8FHuw65pqRpjDg== X-Received: by 2002:a05:6214:b6a:b0:690:ca31:f070 with SMTP id ey10-20020a0562140b6a00b00690ca31f070mr5305017qvb.2.1710194371727; Mon, 11 Mar 2024 14:59:31 -0700 (PDT) Received: from x1n.. (cpe688f2e2cb7c3-cm688f2e2cb7c0.cpe.net.cable.rogers.com. [99.254.121.117]) by smtp.gmail.com with ESMTPSA id d6-20020a0ce446000000b00690cec16254sm1541932qvm.68.2024.03.11.14.59.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 11 Mar 2024 14:59:31 -0700 (PDT) From: peterx@redhat.com To: qemu-devel@nongnu.org, Peter Maydell Cc: Paolo Bonzini , peterx@redhat.com, Fabiano Rosas , David Hildenbrand , Prasad Pandit , Avihai Horon Subject: [PULL 03/34] vfio/migration: Add a note about migration rate limiting Date: Mon, 11 Mar 2024 17:58:54 -0400 Message-ID: <20240311215925.40618-4-peterx@redhat.com> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240311215925.40618-1-peterx@redhat.com> References: <20240311215925.40618-1-peterx@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=170.10.133.124; envelope-from=peterx@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1.029, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Avihai Horon VFIO migration buffer size is currently limited to 1MB. Therefore, there is no need to check if migration rate exceeded, as in the worst case it will exceed by only 1MB. However, if the buffer size is later changed to a bigger value, vfio_save_iterate() should enforce migration rate (similar to migration RAM code). Add a note about this in vfio_save_iterate() to serve as a reminder. Suggested-by: Peter Xu Signed-off-by: Avihai Horon Reviewed-by: Fabiano Rosas Link: https://lore.kernel.org/r/20240304105339.20713-4-avihaih@nvidia.com Signed-off-by: Peter Xu --- hw/vfio/migration.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c index 0af783a589..f82dcabc49 100644 --- a/hw/vfio/migration.c +++ b/hw/vfio/migration.c @@ -505,6 +505,12 @@ static bool vfio_is_active_iterate(void *opaque) return vfio_device_state_is_precopy(vbasedev); } +/* + * Note about migration rate limiting: VFIO migration buffer size is currently + * limited to 1MB, so there is no need to check if migration rate exceeded (as + * in the worst case it will exceed by 1MB). However, if the buffer size is + * later changed to a bigger value, migration rate should be enforced here. + */ static int vfio_save_iterate(QEMUFile *f, void *opaque) { VFIODevice *vbasedev = opaque; -- 2.44.0