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GET /api/patches/812801/?format=api
{ "id": 812801, "url": "http://patchwork.ozlabs.org/api/patches/812801/?format=api", "web_url": "http://patchwork.ozlabs.org/project/qemu-devel/patch/20170912112855.24269-2-berrange@redhat.com/", "project": { "id": 14, "url": "http://patchwork.ozlabs.org/api/projects/14/?format=api", "name": "QEMU Development", "link_name": "qemu-devel", "list_id": "qemu-devel.nongnu.org", "list_email": "qemu-devel@nongnu.org", "web_url": "", "scm_url": "", "webscm_url": "", "list_archive_url": "", "list_archive_url_format": "", "commit_url_format": "" }, "msgid": "<20170912112855.24269-2-berrange@redhat.com>", "list_archive_url": null, "date": "2017-09-12T11:28:49", "name": "[v3,1/7] block: use 1 MB bounce buffers for crypto instead of 16KB", "commit_ref": null, "pull_url": null, "state": "new", "archived": false, "hash": "a6da3ff8e4dcc49522e38df4cce9e369af0c0171", "submitter": { "id": 2694, "url": "http://patchwork.ozlabs.org/api/people/2694/?format=api", "name": "Daniel P. Berrangé", "email": "berrange@redhat.com" }, "delegate": null, "mbox": "http://patchwork.ozlabs.org/project/qemu-devel/patch/20170912112855.24269-2-berrange@redhat.com/mbox/", "series": [ { "id": 2673, "url": "http://patchwork.ozlabs.org/api/series/2673/?format=api", "web_url": "http://patchwork.ozlabs.org/project/qemu-devel/list/?series=2673", "date": "2017-09-12T11:28:48", "name": "Misc improvements to crypto block driver", "version": 3, "mbox": "http://patchwork.ozlabs.org/series/2673/mbox/" } ], "comments": "http://patchwork.ozlabs.org/api/patches/812801/comments/", "check": "pending", "checks": "http://patchwork.ozlabs.org/api/patches/812801/checks/", "tags": {}, "related": [], "headers": { "Return-Path": "<qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org>", "X-Original-To": "incoming@patchwork.ozlabs.org", "Delivered-To": "patchwork-incoming@bilbo.ozlabs.org", "Authentication-Results": [ "ozlabs.org;\n\tspf=pass (mailfrom) smtp.mailfrom=nongnu.org\n\t(client-ip=2001:4830:134:3::11; helo=lists.gnu.org;\n\tenvelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org;\n\treceiver=<UNKNOWN>)", "ext-mx05.extmail.prod.ext.phx2.redhat.com;\n\tdmarc=none (p=none dis=none) header.from=redhat.com", "ext-mx05.extmail.prod.ext.phx2.redhat.com;\n\tspf=fail smtp.mailfrom=berrange@redhat.com" ], "Received": [ "from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11])\n\t(using TLSv1 with cipher AES256-SHA (256/256 bits))\n\t(No client certificate requested)\n\tby ozlabs.org (Postfix) with ESMTPS id 3xs2j51z5yz9s7B\n\tfor <incoming@patchwork.ozlabs.org>;\n\tTue, 12 Sep 2017 21:32:57 +1000 (AEST)", "from localhost ([::1]:35024 helo=lists.gnu.org)\n\tby lists.gnu.org with esmtp (Exim 4.71) (envelope-from\n\t<qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org>)\n\tid 1drjR1-0005nV-Cq\n\tfor incoming@patchwork.ozlabs.org; Tue, 12 Sep 2017 07:32:55 -0400", "from eggs.gnu.org ([2001:4830:134:3::10]:53811)\n\tby lists.gnu.org with esmtp (Exim 4.71)\n\t(envelope-from <berrange@redhat.com>) id 1drjNQ-0002zU-Ly\n\tfor qemu-devel@nongnu.org; Tue, 12 Sep 2017 07:29:14 -0400", "from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)\n\t(envelope-from <berrange@redhat.com>) id 1drjNP-0004RQ-Ii\n\tfor qemu-devel@nongnu.org; Tue, 12 Sep 2017 07:29:12 -0400", "from mx1.redhat.com ([209.132.183.28]:57820)\n\tby eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32)\n\t(Exim 4.71) (envelope-from <berrange@redhat.com>)\n\tid 1drjNJ-0004KP-Qk; Tue, 12 Sep 2017 07:29:05 -0400", "from smtp.corp.redhat.com\n\t(int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11])\n\t(using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits))\n\t(No client certificate requested)\n\tby mx1.redhat.com (Postfix) with ESMTPS id EA2A413AAD;\n\tTue, 12 Sep 2017 11:29:04 +0000 (UTC)", "from localhost.localdomain.com (unknown [10.42.22.189])\n\tby smtp.corp.redhat.com (Postfix) with ESMTP id B9B5B6E1FC;\n\tTue, 12 Sep 2017 11:29:03 +0000 (UTC)" ], "DMARC-Filter": "OpenDMARC Filter v1.3.2 mx1.redhat.com EA2A413AAD", "From": "\"Daniel P. Berrange\" <berrange@redhat.com>", "To": "qemu-devel@nongnu.org", "Date": "Tue, 12 Sep 2017 12:28:49 +0100", "Message-Id": "<20170912112855.24269-2-berrange@redhat.com>", "In-Reply-To": "<20170912112855.24269-1-berrange@redhat.com>", "References": "<20170912112855.24269-1-berrange@redhat.com>", "X-Scanned-By": "MIMEDefang 2.79 on 10.5.11.11", "X-Greylist": "Sender IP whitelisted, not delayed by milter-greylist-4.5.16\n\t(mx1.redhat.com [10.5.110.29]);\n\tTue, 12 Sep 2017 11:29:05 +0000 (UTC)", "X-detected-operating-system": "by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic]\n\t[fuzzy]", "X-Received-From": "209.132.183.28", "Subject": "[Qemu-devel] [PATCH v3 1/7] block: use 1 MB bounce buffers for\n\tcrypto instead of 16KB", "X-BeenThere": "qemu-devel@nongnu.org", "X-Mailman-Version": "2.1.21", "Precedence": "list", "List-Id": "<qemu-devel.nongnu.org>", "List-Unsubscribe": "<https://lists.nongnu.org/mailman/options/qemu-devel>,\n\t<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>", "List-Archive": "<http://lists.nongnu.org/archive/html/qemu-devel/>", "List-Post": "<mailto:qemu-devel@nongnu.org>", "List-Help": "<mailto:qemu-devel-request@nongnu.org?subject=help>", "List-Subscribe": "<https://lists.nongnu.org/mailman/listinfo/qemu-devel>,\n\t<mailto:qemu-devel-request@nongnu.org?subject=subscribe>", "Cc": "Kevin Wolf <kwolf@redhat.com>, qemu-block@nongnu.org,\n\tStefan Hajnoczi <stefanha@gmail.com>, Max Reitz <mreitz@redhat.com>", "Errors-To": "qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org", "Sender": "\"Qemu-devel\"\n\t<qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org>" }, "content": "Using 16KB bounce buffers creates a significant performance\npenalty for I/O to encrypted volumes on storage which high\nI/O latency (rotating rust & network drives), because it\ntriggers lots of fairly small I/O operations.\n\nOn tests with rotating rust, and cache=none|directsync,\nwrite speed increased from 2MiB/s to 32MiB/s, on a par\nwith that achieved by the in-kernel luks driver. With\nother cache modes the in-kernel driver is still notably\nfaster because it is able to report completion of the\nI/O request before any encryption is done, while the\nin-QEMU driver must encrypt the data before completion.\n\nReviewed-by: Eric Blake <eblake@redhat.com>\nReviewed-by: Stefan Hajnoczi <stefanha@redhat.com>\nSigned-off-by: Daniel P. Berrange <berrange@redhat.com>\n---\n block/crypto.c | 12 +++++-------\n 1 file changed, 5 insertions(+), 7 deletions(-)", "diff": "diff --git a/block/crypto.c b/block/crypto.c\nindex 58ef6f2f52..cc8afe0e0d 100644\n--- a/block/crypto.c\n+++ b/block/crypto.c\n@@ -379,7 +379,7 @@ static void block_crypto_close(BlockDriverState *bs)\n }\n \n \n-#define BLOCK_CRYPTO_MAX_SECTORS 32\n+#define BLOCK_CRYPTO_MAX_SECTORS 2048\n \n static coroutine_fn int\n block_crypto_co_readv(BlockDriverState *bs, int64_t sector_num,\n@@ -396,9 +396,8 @@ block_crypto_co_readv(BlockDriverState *bs, int64_t sector_num,\n \n qemu_iovec_init(&hd_qiov, qiov->niov);\n \n- /* Bounce buffer so we have a linear mem region for\n- * entire sector. XXX optimize so we avoid bounce\n- * buffer in case that qiov->niov == 1\n+ /* Bounce buffer because we don't wish to expose cipher text\n+ * in qiov which points to guest memory.\n */\n cipher_data =\n qemu_try_blockalign(bs->file->bs, MIN(BLOCK_CRYPTO_MAX_SECTORS * 512,\n@@ -464,9 +463,8 @@ block_crypto_co_writev(BlockDriverState *bs, int64_t sector_num,\n \n qemu_iovec_init(&hd_qiov, qiov->niov);\n \n- /* Bounce buffer so we have a linear mem region for\n- * entire sector. XXX optimize so we avoid bounce\n- * buffer in case that qiov->niov == 1\n+ /* Bounce buffer because we're not permitted to touch\n+ * contents of qiov - it points to guest memory.\n */\n cipher_data =\n qemu_try_blockalign(bs->file->bs, MIN(BLOCK_CRYPTO_MAX_SECTORS * 512,\n", "prefixes": [ "v3", "1/7" ] }