diff options
author | Jens Freimann <jfreimann@redhat.com> | 2019-10-29 12:48:55 +0100 |
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committer | Michael S. Tsirkin <mst@redhat.com> | 2019-10-29 18:55:26 -0400 |
commit | f3a8505656935cde32e28c1c6317f725084da1e0 (patch) | |
tree | c86d50bd3de257e80dd8dbc1c44318f256ee8fdc /qdev-monitor.c | |
parent | 16884391c750d0c5e863f55ad7aaaa146fc5181e (diff) | |
download | qemu-f3a8505656935cde32e28c1c6317f725084da1e0.zip qemu-f3a8505656935cde32e28c1c6317f725084da1e0.tar.gz qemu-f3a8505656935cde32e28c1c6317f725084da1e0.tar.bz2 |
qdev/qbus: add hidden device support
This adds support for hiding a device to the qbus and qdev APIs. The
first user of this will be the virtio-net failover feature but the API
introduced with this patch could be used to implement other features as
well, for example hiding pci devices when a pci bus is powered off.
qdev_device_add() is modified to check for a failover_pair_id
argument in the option string. A DeviceListener callback
should_be_hidden() is added. It can be used by a standby device to
inform qdev that this device should not be added now. The standby device
handler can store the device options to plug the device in at a later
point in time.
One reason for hiding the device is that we don't want to expose both
devices to the guest kernel until the respective virtio feature bit
VIRTIO_NET_F_STANDBY was negotiated and we know that the devices will be
handled correctly by the guest.
More information on the kernel feature this is using:
https://www.kernel.org/doc/html/latest/networking/net_failover.html
An example where the primary device is a vfio-pci device and the standby
device is a virtio-net device:
A device is hidden when it has an "failover_pair_id" option, e.g.
-device virtio-net-pci,...,failover=on,...
-device vfio-pci,...,failover_pair_id=net1,...
Signed-off-by: Jens Freimann <jfreimann@redhat.com>
Message-Id: <20191029114905.6856-2-jfreimann@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'qdev-monitor.c')
-rw-r--r-- | qdev-monitor.c | 41 |
1 files changed, 37 insertions, 4 deletions
diff --git a/qdev-monitor.c b/qdev-monitor.c index 148df9c..ffa08c6 100644 --- a/qdev-monitor.c +++ b/qdev-monitor.c @@ -32,9 +32,11 @@ #include "qemu/help_option.h" #include "qemu/option.h" #include "qemu/qemu-print.h" +#include "qemu/option_int.h" #include "sysemu/block-backend.h" #include "sysemu/sysemu.h" #include "migration/misc.h" +#include "migration/migration.h" /* * Aliases were a bad idea from the start. Let's keep them @@ -562,13 +564,36 @@ void qdev_set_id(DeviceState *dev, const char *id) } } +static int is_failover_device(void *opaque, const char *name, const char *value, + Error **errp) +{ + if (strcmp(name, "failover_pair_id") == 0) { + QemuOpts *opts = (QemuOpts *)opaque; + + if (qdev_should_hide_device(opts)) { + return 1; + } + } + + return 0; +} + +static bool should_hide_device(QemuOpts *opts) +{ + if (qemu_opt_foreach(opts, is_failover_device, opts, NULL) == 0) { + return false; + } + return true; +} + DeviceState *qdev_device_add(QemuOpts *opts, Error **errp) { DeviceClass *dc; const char *driver, *path; - DeviceState *dev; + DeviceState *dev = NULL; BusState *bus = NULL; Error *err = NULL; + bool hide; driver = qemu_opt_get(opts, "driver"); if (!driver) { @@ -602,11 +627,17 @@ DeviceState *qdev_device_add(QemuOpts *opts, Error **errp) return NULL; } } - if (qdev_hotplug && bus && !qbus_is_hotpluggable(bus)) { + hide = should_hide_device(opts); + + if ((hide || qdev_hotplug) && bus && !qbus_is_hotpluggable(bus)) { error_setg(errp, QERR_BUS_NO_HOTPLUG, bus->name); return NULL; } + if (hide) { + return NULL; + } + if (!migration_is_idle()) { error_setg(errp, "device_add not allowed while migrating"); return NULL; @@ -648,8 +679,10 @@ DeviceState *qdev_device_add(QemuOpts *opts, Error **errp) err_del_dev: error_propagate(errp, err); - object_unparent(OBJECT(dev)); - object_unref(OBJECT(dev)); + if (dev) { + object_unparent(OBJECT(dev)); + object_unref(OBJECT(dev)); + } return NULL; } |