From de4f7c3b6dbba3eb8450cd7714ae93787009cd17 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Tue, 27 Aug 2024 15:27:50 -0400 Subject: [PATCH 3/7] qdev-monitor: avoid QemuOpts in QMP device_add MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Stefan Hajnoczi RH-MergeRequest: 312: qdev-monitor: avoid QemuOpts in QMP device_add RH-Jira: RHEL-43412 RH-Acked-by: Kevin Wolf RH-Acked-by: Hanna Czenczek RH-Commit: [3/4] 7c45f3791491cd66ec2476ef0aa515b5bffba456 (stefanha/centos-stream-qemu-kvm) The QMP device_add monitor command converts the QDict arguments to QemuOpts and then back again to QDict. This process only supports scalar types. Device properties like virtio-blk-pci's iothread-vq-mapping (an array of objects) are silently dropped by qemu_opts_from_qdict() during the QemuOpts conversion even though QAPI is capable of validating them. As a result, hotplugging virtio-blk-pci devices with the iothread-vq-mapping property does not work as expected (the property is ignored). Get rid of the QemuOpts conversion in qmp_device_add() and call qdev_device_add_from_qdict() with from_json=true. Using the QMP command's QDict arguments directly allows non-scalar properties. The HMP is also adjusted since qmp_device_add()'s now expects properly typed JSON arguments and cannot be used from HMP anymore. Move the code that was previously in qmp_device_add() (with QemuOpts conversion and from_json=false) into hmp_device_add() so that its behavior is unchanged. This patch changes the behavior of QMP device_add but not HMP device_add. QMP clients that sent incorrectly typed device_add QMP commands no longer work. This is a breaking change but clients should be using the correct types already. See the netdev_add QAPIfication in commit db2a380c8457 for similar reasoning and object-add in commit 9151e59a8b6e. Unlike those commits, we continue to rely on 'gen': false for the time being. Markus helped me figure this out and even provided a draft patch. The code ended up very close to what he suggested. Suggested-by: Markus Armbruster Cc: Daniel P. Berrangé Signed-off-by: Stefan Hajnoczi Message-ID: <20240827192751.948633-2-stefanha@redhat.com> Reviewed-by: Daniel P. Berrangé Reviewed-by: Kevin Wolf Signed-off-by: Kevin Wolf (cherry picked from commit be93fd53723cbdca675bd9ed112dae5cabbe1e91) Signed-off-by: Stefan Hajnoczi --- system/qdev-monitor.c | 42 ++++++++++++++++++++++++++++-------------- 1 file changed, 28 insertions(+), 14 deletions(-) diff --git a/system/qdev-monitor.c b/system/qdev-monitor.c index 6af6ef7d66..8b27cc42b0 100644 --- a/system/qdev-monitor.c +++ b/system/qdev-monitor.c @@ -849,18 +849,9 @@ void hmp_info_qdm(Monitor *mon, const QDict *qdict) void qmp_device_add(QDict *qdict, QObject **ret_data, Error **errp) { - QemuOpts *opts; DeviceState *dev; - opts = qemu_opts_from_qdict(qemu_find_opts("device"), qdict, errp); - if (!opts) { - return; - } - if (!monitor_cur_is_qmp() && qdev_device_help(opts)) { - qemu_opts_del(opts); - return; - } - dev = qdev_device_add(opts, errp); + dev = qdev_device_add_from_qdict(qdict, true, errp); if (!dev) { /* * Drain all pending RCU callbacks. This is done because @@ -872,9 +863,6 @@ void qmp_device_add(QDict *qdict, QObject **ret_data, Error **errp) * to the user */ drain_call_rcu(); - - qemu_opts_del(opts); - return; } object_unref(OBJECT(dev)); } @@ -967,8 +955,34 @@ void qmp_device_del(const char *id, Error **errp) void hmp_device_add(Monitor *mon, const QDict *qdict) { Error *err = NULL; + QemuOpts *opts; + DeviceState *dev; - qmp_device_add((QDict *)qdict, NULL, &err); + opts = qemu_opts_from_qdict(qemu_find_opts("device"), qdict, &err); + if (!opts) { + goto out; + } + if (qdev_device_help(opts)) { + qemu_opts_del(opts); + return; + } + dev = qdev_device_add(opts, &err); + if (!dev) { + /* + * Drain all pending RCU callbacks. This is done because + * some bus related operations can delay a device removal + * (in this case this can happen if device is added and then + * removed due to a configuration error) + * to a RCU callback, but user might expect that this interface + * will finish its job completely once qmp command returns result + * to the user + */ + drain_call_rcu(); + + qemu_opts_del(opts); + } + object_unref(dev); +out: hmp_handle_error(mon, err); } -- 2.39.3