From patchwork Mon May 9 15:02:47 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: "Dr. David Alan Gilbert" X-Patchwork-Id: 12843765 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 7A3D9C433F5 for ; Mon, 9 May 2022 15:14:03 +0000 (UTC) Received: from localhost ([::1]:41980 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1no55G-0007Tm-J2 for qemu-devel@archiver.kernel.org; Mon, 09 May 2022 11:14:02 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:34998) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1no4uq-00017h-6H for qemu-devel@nongnu.org; Mon, 09 May 2022 11:03:16 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:56443) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1no4un-0002ly-QH for qemu-devel@nongnu.org; Mon, 09 May 2022 11:03:15 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1652108593; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=V1Pe+Rqs8eJd3dmFMVVoBVkTHPMVTJfUBNY577RUCyg=; b=TIjsGUPGix5bzsK19ILFI5s9E6Dp6DoKo0BCu7lu0vASFSf72kTFZ46iC9BDIw/rzww6PH jisk1mIe9ZxGs/tevT0Tw1mYEobAj2V0HBf7QaT3RbqzmU+KSX7TTa7UugzxHOzqZY903U yEwtmy8tgktsA0NDBAYVONk9hJiVr5c= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-493-ArOXiRSDNTGWeQds9tdQ3Q-1; Mon, 09 May 2022 11:03:11 -0400 X-MC-Unique: ArOXiRSDNTGWeQds9tdQ3Q-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 534EF1C08966 for ; Mon, 9 May 2022 15:03:11 +0000 (UTC) Received: from dgilbert-t580.localhost (unknown [10.39.193.66]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6D5ADC07F43; Mon, 9 May 2022 15:03:10 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, quintela@redhat.com, peterx@redhat.com, leobras@redhat.com, berrange@redhat.com Subject: [PULL 10/16] QIOChannel: Add flags on io_writev and introduce io_flush callback Date: Mon, 9 May 2022 16:02:47 +0100 Message-Id: <20220509150253.218715-11-dgilbert@redhat.com> In-Reply-To: <20220509150253.218715-1-dgilbert@redhat.com> References: <20220509150253.218715-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.85 on 10.11.54.8 Received-SPF: pass client-ip=170.10.129.124; envelope-from=dgilbert@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -28 X-Spam_score: -2.9 X-Spam_bar: -- X-Spam_report: (-2.9 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, 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" From: Leonardo Bras Add flags to io_writev and introduce io_flush as optional callback to QIOChannelClass, allowing the implementation of zero copy writes by subclasses. How to use them: - Write data using qio_channel_writev*(...,QIO_CHANNEL_WRITE_FLAG_ZERO_COPY), - Wait write completion with qio_channel_flush(). Notes: As some zero copy write implementations work asynchronously, it's recommended to keep the write buffer untouched until the return of qio_channel_flush(), to avoid the risk of sending an updated buffer instead of the buffer state during write. As io_flush callback is optional, if a subclass does not implement it, then: - io_flush will return 0 without changing anything. Also, some functions like qio_channel_writev_full_all() were adapted to receive a flag parameter. That allows shared code between zero copy and non-zero copy writev, and also an easier implementation on new flags. Signed-off-by: Leonardo Bras Reviewed-by: Daniel P. Berrangé Reviewed-by: Peter Xu Reviewed-by: Juan Quintela Message-Id: <20220507015759.840466-2-leobras@redhat.com> Signed-off-by: Dr. David Alan Gilbert --- chardev/char-io.c | 2 +- hw/remote/mpqemu-link.c | 2 +- include/io/channel.h | 38 +++++++++++++++++++++- io/channel-buffer.c | 1 + io/channel-command.c | 1 + io/channel-file.c | 1 + io/channel-socket.c | 2 ++ io/channel-tls.c | 1 + io/channel-websock.c | 1 + io/channel.c | 49 +++++++++++++++++++++++------ migration/rdma.c | 1 + scsi/pr-manager-helper.c | 2 +- tests/unit/test-io-channel-socket.c | 1 + 13 files changed, 88 insertions(+), 14 deletions(-) diff --git a/chardev/char-io.c b/chardev/char-io.c index 8ced184160..4451128cba 100644 --- a/chardev/char-io.c +++ b/chardev/char-io.c @@ -122,7 +122,7 @@ int io_channel_send_full(QIOChannel *ioc, ret = qio_channel_writev_full( ioc, &iov, 1, - fds, nfds, NULL); + fds, nfds, 0, NULL); if (ret == QIO_CHANNEL_ERR_BLOCK) { if (offset) { return offset; diff --git a/hw/remote/mpqemu-link.c b/hw/remote/mpqemu-link.c index 2a4aa651ca..9bd98e8219 100644 --- a/hw/remote/mpqemu-link.c +++ b/hw/remote/mpqemu-link.c @@ -68,7 +68,7 @@ bool mpqemu_msg_send(MPQemuMsg *msg, QIOChannel *ioc, Error **errp) } if (!qio_channel_writev_full_all(ioc, send, G_N_ELEMENTS(send), - fds, nfds, errp)) { + fds, nfds, 0, errp)) { ret = true; } else { trace_mpqemu_send_io_error(msg->cmd, msg->size, nfds); diff --git a/include/io/channel.h b/include/io/channel.h index 88988979f8..c680ee7480 100644 --- a/include/io/channel.h +++ b/include/io/channel.h @@ -32,12 +32,15 @@ OBJECT_DECLARE_TYPE(QIOChannel, QIOChannelClass, #define QIO_CHANNEL_ERR_BLOCK -2 +#define QIO_CHANNEL_WRITE_FLAG_ZERO_COPY 0x1 + typedef enum QIOChannelFeature QIOChannelFeature; enum QIOChannelFeature { QIO_CHANNEL_FEATURE_FD_PASS, QIO_CHANNEL_FEATURE_SHUTDOWN, QIO_CHANNEL_FEATURE_LISTEN, + QIO_CHANNEL_FEATURE_WRITE_ZERO_COPY, }; @@ -104,6 +107,7 @@ struct QIOChannelClass { size_t niov, int *fds, size_t nfds, + int flags, Error **errp); ssize_t (*io_readv)(QIOChannel *ioc, const struct iovec *iov, @@ -136,6 +140,8 @@ struct QIOChannelClass { IOHandler *io_read, IOHandler *io_write, void *opaque); + int (*io_flush)(QIOChannel *ioc, + Error **errp); }; /* General I/O handling functions */ @@ -228,6 +234,7 @@ ssize_t qio_channel_readv_full(QIOChannel *ioc, * @niov: the length of the @iov array * @fds: an array of file handles to send * @nfds: number of file handles in @fds + * @flags: write flags (QIO_CHANNEL_WRITE_FLAG_*) * @errp: pointer to a NULL-initialized error object * * Write data to the IO channel, reading it from the @@ -260,6 +267,7 @@ ssize_t qio_channel_writev_full(QIOChannel *ioc, size_t niov, int *fds, size_t nfds, + int flags, Error **errp); /** @@ -837,6 +845,7 @@ int qio_channel_readv_full_all(QIOChannel *ioc, * @niov: the length of the @iov array * @fds: an array of file handles to send * @nfds: number of file handles in @fds + * @flags: write flags (QIO_CHANNEL_WRITE_FLAG_*) * @errp: pointer to a NULL-initialized error object * * @@ -846,6 +855,14 @@ int qio_channel_readv_full_all(QIOChannel *ioc, * to be written, yielding from the current coroutine * if required. * + * If QIO_CHANNEL_WRITE_FLAG_ZERO_COPY is passed in flags, + * instead of waiting for all requested data to be written, + * this function will wait until it's all queued for writing. + * In this case, if the buffer gets changed between queueing and + * sending, the updated buffer will be sent. If this is not a + * desired behavior, it's suggested to call qio_channel_flush() + * before reusing the buffer. + * * Returns: 0 if all bytes were written, or -1 on error */ @@ -853,6 +870,25 @@ int qio_channel_writev_full_all(QIOChannel *ioc, const struct iovec *iov, size_t niov, int *fds, size_t nfds, - Error **errp); + int flags, Error **errp); + +/** + * qio_channel_flush: + * @ioc: the channel object + * @errp: pointer to a NULL-initialized error object + * + * Will block until every packet queued with + * qio_channel_writev_full() + QIO_CHANNEL_WRITE_FLAG_ZERO_COPY + * is sent, or return in case of any error. + * + * If not implemented, acts as a no-op, and returns 0. + * + * Returns -1 if any error is found, + * 1 if every send failed to use zero copy. + * 0 otherwise. + */ + +int qio_channel_flush(QIOChannel *ioc, + Error **errp); #endif /* QIO_CHANNEL_H */ diff --git a/io/channel-buffer.c b/io/channel-buffer.c index baa4e2b089..bf52011be2 100644 --- a/io/channel-buffer.c +++ b/io/channel-buffer.c @@ -81,6 +81,7 @@ static ssize_t qio_channel_buffer_writev(QIOChannel *ioc, size_t niov, int *fds, size_t nfds, + int flags, Error **errp) { QIOChannelBuffer *bioc = QIO_CHANNEL_BUFFER(ioc); diff --git a/io/channel-command.c b/io/channel-command.c index 4a1f969aaa..9f2f4a1793 100644 --- a/io/channel-command.c +++ b/io/channel-command.c @@ -276,6 +276,7 @@ static ssize_t qio_channel_command_writev(QIOChannel *ioc, size_t niov, int *fds, size_t nfds, + int flags, Error **errp) { QIOChannelCommand *cioc = QIO_CHANNEL_COMMAND(ioc); diff --git a/io/channel-file.c b/io/channel-file.c index d146ace7db..b67687c2aa 100644 --- a/io/channel-file.c +++ b/io/channel-file.c @@ -114,6 +114,7 @@ static ssize_t qio_channel_file_writev(QIOChannel *ioc, size_t niov, int *fds, size_t nfds, + int flags, Error **errp) { QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc); diff --git a/io/channel-socket.c b/io/channel-socket.c index e531d7bd2a..05c425abb8 100644 --- a/io/channel-socket.c +++ b/io/channel-socket.c @@ -524,6 +524,7 @@ static ssize_t qio_channel_socket_writev(QIOChannel *ioc, size_t niov, int *fds, size_t nfds, + int flags, Error **errp) { QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc); @@ -619,6 +620,7 @@ static ssize_t qio_channel_socket_writev(QIOChannel *ioc, size_t niov, int *fds, size_t nfds, + int flags, Error **errp) { QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc); diff --git a/io/channel-tls.c b/io/channel-tls.c index 2ae1b92fc0..4ce890a538 100644 --- a/io/channel-tls.c +++ b/io/channel-tls.c @@ -301,6 +301,7 @@ static ssize_t qio_channel_tls_writev(QIOChannel *ioc, size_t niov, int *fds, size_t nfds, + int flags, Error **errp) { QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc); diff --git a/io/channel-websock.c b/io/channel-websock.c index 55145a6a8c..9619906ac3 100644 --- a/io/channel-websock.c +++ b/io/channel-websock.c @@ -1127,6 +1127,7 @@ static ssize_t qio_channel_websock_writev(QIOChannel *ioc, size_t niov, int *fds, size_t nfds, + int flags, Error **errp) { QIOChannelWebsock *wioc = QIO_CHANNEL_WEBSOCK(ioc); diff --git a/io/channel.c b/io/channel.c index e8b019dc36..0640941ac5 100644 --- a/io/channel.c +++ b/io/channel.c @@ -72,18 +72,32 @@ ssize_t qio_channel_writev_full(QIOChannel *ioc, size_t niov, int *fds, size_t nfds, + int flags, Error **errp) { QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc); - if ((fds || nfds) && - !qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_FD_PASS)) { + if (fds || nfds) { + if (!qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_FD_PASS)) { + error_setg_errno(errp, EINVAL, + "Channel does not support file descriptor passing"); + return -1; + } + if (flags & QIO_CHANNEL_WRITE_FLAG_ZERO_COPY) { + error_setg_errno(errp, EINVAL, + "Zero Copy does not support file descriptor passing"); + return -1; + } + } + + if ((flags & QIO_CHANNEL_WRITE_FLAG_ZERO_COPY) && + !qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_WRITE_ZERO_COPY)) { error_setg_errno(errp, EINVAL, - "Channel does not support file descriptor passing"); + "Requested Zero Copy feature is not available"); return -1; } - return klass->io_writev(ioc, iov, niov, fds, nfds, errp); + return klass->io_writev(ioc, iov, niov, fds, nfds, flags, errp); } @@ -217,14 +231,14 @@ int qio_channel_writev_all(QIOChannel *ioc, size_t niov, Error **errp) { - return qio_channel_writev_full_all(ioc, iov, niov, NULL, 0, errp); + return qio_channel_writev_full_all(ioc, iov, niov, NULL, 0, 0, errp); } int qio_channel_writev_full_all(QIOChannel *ioc, const struct iovec *iov, size_t niov, int *fds, size_t nfds, - Error **errp) + int flags, Error **errp) { int ret = -1; struct iovec *local_iov = g_new(struct iovec, niov); @@ -237,8 +251,10 @@ int qio_channel_writev_full_all(QIOChannel *ioc, while (nlocal_iov > 0) { ssize_t len; - len = qio_channel_writev_full(ioc, local_iov, nlocal_iov, fds, nfds, - errp); + + len = qio_channel_writev_full(ioc, local_iov, nlocal_iov, fds, + nfds, flags, errp); + if (len == QIO_CHANNEL_ERR_BLOCK) { if (qemu_in_coroutine()) { qio_channel_yield(ioc, G_IO_OUT); @@ -277,7 +293,7 @@ ssize_t qio_channel_writev(QIOChannel *ioc, size_t niov, Error **errp) { - return qio_channel_writev_full(ioc, iov, niov, NULL, 0, errp); + return qio_channel_writev_full(ioc, iov, niov, NULL, 0, 0, errp); } @@ -297,7 +313,7 @@ ssize_t qio_channel_write(QIOChannel *ioc, Error **errp) { struct iovec iov = { .iov_base = (char *)buf, .iov_len = buflen }; - return qio_channel_writev_full(ioc, &iov, 1, NULL, 0, errp); + return qio_channel_writev_full(ioc, &iov, 1, NULL, 0, 0, errp); } @@ -473,6 +489,19 @@ off_t qio_channel_io_seek(QIOChannel *ioc, return klass->io_seek(ioc, offset, whence, errp); } +int qio_channel_flush(QIOChannel *ioc, + Error **errp) +{ + QIOChannelClass *klass = QIO_CHANNEL_GET_CLASS(ioc); + + if (!klass->io_flush || + !qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_WRITE_ZERO_COPY)) { + return 0; + } + + return klass->io_flush(ioc, errp); +} + static void qio_channel_restart_read(void *opaque) { diff --git a/migration/rdma.c b/migration/rdma.c index ef1e65ec36..672d1958a9 100644 --- a/migration/rdma.c +++ b/migration/rdma.c @@ -2840,6 +2840,7 @@ static ssize_t qio_channel_rdma_writev(QIOChannel *ioc, size_t niov, int *fds, size_t nfds, + int flags, Error **errp) { QIOChannelRDMA *rioc = QIO_CHANNEL_RDMA(ioc); diff --git a/scsi/pr-manager-helper.c b/scsi/pr-manager-helper.c index 451c7631b7..3be52a98d5 100644 --- a/scsi/pr-manager-helper.c +++ b/scsi/pr-manager-helper.c @@ -77,7 +77,7 @@ static int pr_manager_helper_write(PRManagerHelper *pr_mgr, iov.iov_base = (void *)buf; iov.iov_len = sz; n_written = qio_channel_writev_full(QIO_CHANNEL(pr_mgr->ioc), &iov, 1, - nfds ? &fd : NULL, nfds, errp); + nfds ? &fd : NULL, nfds, 0, errp); if (n_written <= 0) { assert(n_written != QIO_CHANNEL_ERR_BLOCK); diff --git a/tests/unit/test-io-channel-socket.c b/tests/unit/test-io-channel-socket.c index c49eec1f03..6713886d02 100644 --- a/tests/unit/test-io-channel-socket.c +++ b/tests/unit/test-io-channel-socket.c @@ -444,6 +444,7 @@ static void test_io_channel_unix_fd_pass(void) G_N_ELEMENTS(iosend), fdsend, G_N_ELEMENTS(fdsend), + 0, &error_abort); qio_channel_readv_full(dst,