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vfio-user: run vfio-user context

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Setup a handler to run vfio-user context. The context is driven by
messages to the file descriptor associated with it - get the fd for
the context and hook up the handler with it

Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: e934b0090529d448b6a7972b21dfc3d7421ce494.1655151679.git.jag.raman@oracle.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Jagannathan Raman 2022-06-13 16:26:28 -04:00 committed by Stefan Hajnoczi
parent a6e8d6d98e
commit 9fb3fba149
2 changed files with 148 additions and 1 deletions
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118
hw/remote/vfio-user-obj.c
View File

@ -27,6 +27,9 @@
*
* device - id of a device on the server, a required option. PCI devices
* alone are supported presently.
*
* notes - x-vfio-user-server could block IO and monitor during the
* initialization phase.
*/
#include "qemu/osdep.h"
@ -40,11 +43,14 @@
#include "hw/remote/machine.h"
#include "qapi/error.h"
#include "qapi/qapi-visit-sockets.h"
#include "qapi/qapi-events-misc.h"
#include "qemu/notify.h"
#include "qemu/thread.h"
#include "sysemu/sysemu.h"
#include "libvfio-user.h"
#include "hw/qdev-core.h"
#include "hw/pci/pci.h"
#include "qemu/timer.h"
#define TYPE_VFU_OBJECT "x-vfio-user-server"
OBJECT_DECLARE_TYPE(VfuObject, VfuObjectClass, VFU_OBJECT)
@ -86,6 +92,8 @@ struct VfuObject {
PCIDevice *pci_dev;
Error *unplug_blocker;
int vfu_poll_fd;
};
static void vfu_object_init_ctx(VfuObject *o, Error **errp);
@ -164,6 +172,78 @@ static void vfu_object_set_device(Object *obj, const char *str, Error **errp)
vfu_object_init_ctx(o, errp);
}
static void vfu_object_ctx_run(void *opaque)
{
VfuObject *o = opaque;
const char *vfu_id;
char *vfu_path, *pci_dev_path;
int ret = -1;
while (ret != 0) {
ret = vfu_run_ctx(o->vfu_ctx);
if (ret < 0) {
if (errno == EINTR) {
continue;
} else if (errno == ENOTCONN) {
vfu_id = object_get_canonical_path_component(OBJECT(o));
vfu_path = object_get_canonical_path(OBJECT(o));
g_assert(o->pci_dev);
pci_dev_path = object_get_canonical_path(OBJECT(o->pci_dev));
/* o->device is a required property and is non-NULL here */
g_assert(o->device);
qapi_event_send_vfu_client_hangup(vfu_id, vfu_path,
o->device, pci_dev_path);
qemu_set_fd_handler(o->vfu_poll_fd, NULL, NULL, NULL);
o->vfu_poll_fd = -1;
object_unparent(OBJECT(o));
g_free(vfu_path);
g_free(pci_dev_path);
break;
} else {
VFU_OBJECT_ERROR(o, "vfu: Failed to run device %s - %s",
o->device, strerror(errno));
break;
}
}
}
}
static void vfu_object_attach_ctx(void *opaque)
{
VfuObject *o = opaque;
GPollFD pfds[1];
int ret;
qemu_set_fd_handler(o->vfu_poll_fd, NULL, NULL, NULL);
pfds[0].fd = o->vfu_poll_fd;
pfds[0].events = G_IO_IN | G_IO_HUP | G_IO_ERR;
retry_attach:
ret = vfu_attach_ctx(o->vfu_ctx);
if (ret < 0 && (errno == EAGAIN || errno == EWOULDBLOCK)) {
/**
* vfu_object_attach_ctx can block QEMU's main loop
* during attach - the monitor and other IO
* could be unresponsive during this time.
*/
(void)qemu_poll_ns(pfds, 1, 500 * (int64_t)SCALE_MS);
goto retry_attach;
} else if (ret < 0) {
VFU_OBJECT_ERROR(o, "vfu: Failed to attach device %s to context - %s",
o->device, strerror(errno));
return;
}
o->vfu_poll_fd = vfu_get_poll_fd(o->vfu_ctx);
if (o->vfu_poll_fd < 0) {
VFU_OBJECT_ERROR(o, "vfu: Failed to get poll fd %s", o->device);
return;
}
qemu_set_fd_handler(o->vfu_poll_fd, vfu_object_ctx_run, NULL, o);
}
/*
* TYPE_VFU_OBJECT depends on the availability of the 'socket' and 'device'
* properties. It also depends on devices instantiated in QEMU. These
@ -184,6 +264,20 @@ static void vfu_object_machine_done(Notifier *notifier, void *data)
}
}
/**
* vfu_object_init_ctx: Create and initialize libvfio-user context. Add
* an unplug blocker for the associated PCI device. Setup a FD handler
* to process incoming messages in the context's socket.
*
* The socket and device properties are mandatory, and this function
* will not create the context without them - the setters for these
* properties should call this function when the property is set. The
* machine should also be ready when this function is invoked - it is
* because QEMU objects are initialized before devices, and the
* associated PCI device wouldn't be available at the object
* initialization time. Until these conditions are satisfied, this
* function would return early without performing any task.
*/
static void vfu_object_init_ctx(VfuObject *o, Error **errp)
{
ERRP_GUARD();
@ -202,7 +296,8 @@ static void vfu_object_init_ctx(VfuObject *o, Error **errp)
return;
}
o->vfu_ctx = vfu_create_ctx(VFU_TRANS_SOCK, o->socket->u.q_unix.path, 0,
o->vfu_ctx = vfu_create_ctx(VFU_TRANS_SOCK, o->socket->u.q_unix.path,
LIBVFIO_USER_FLAG_ATTACH_NB,
o, VFU_DEV_TYPE_PCI);
if (o->vfu_ctx == NULL) {
error_setg(errp, "vfu: Failed to create context - %s", strerror(errno));
@ -241,6 +336,21 @@ static void vfu_object_init_ctx(VfuObject *o, Error **errp)
TYPE_VFU_OBJECT, o->device);
qdev_add_unplug_blocker(DEVICE(o->pci_dev), o->unplug_blocker);
ret = vfu_realize_ctx(o->vfu_ctx);
if (ret < 0) {
error_setg(errp, "vfu: Failed to realize device %s- %s",
o->device, strerror(errno));
goto fail;
}
o->vfu_poll_fd = vfu_get_poll_fd(o->vfu_ctx);
if (o->vfu_poll_fd < 0) {
error_setg(errp, "vfu: Failed to get poll fd %s", o->device);
goto fail;
}
qemu_set_fd_handler(o->vfu_poll_fd, vfu_object_attach_ctx, NULL, o);
return;
fail:
@ -275,6 +385,7 @@ static void vfu_object_init(Object *obj)
qemu_add_machine_init_done_notifier(&o->machine_done);
}
o->vfu_poll_fd = -1;
}
static void vfu_object_finalize(Object *obj)
@ -288,6 +399,11 @@ static void vfu_object_finalize(Object *obj)
o->socket = NULL;
if (o->vfu_poll_fd != -1) {
qemu_set_fd_handler(o->vfu_poll_fd, NULL, NULL, NULL);
o->vfu_poll_fd = -1;
}
if (o->vfu_ctx) {
vfu_destroy_ctx(o->vfu_ctx);
o->vfu_ctx = NULL;

31
qapi/misc.json
View File

@ -553,3 +553,34 @@
##
{ 'event': 'RTC_CHANGE',
'data': { 'offset': 'int', 'qom-path': 'str' } }
##
# @VFU_CLIENT_HANGUP:
#
# Emitted when the client of a TYPE_VFIO_USER_SERVER closes the
# communication channel
#
# @vfu-id: ID of the TYPE_VFIO_USER_SERVER object. It is the last component
# of @vfu-qom-path referenced below
#
# @vfu-qom-path: path to the TYPE_VFIO_USER_SERVER object in the QOM tree
#
# @dev-id: ID of attached PCI device
#
# @dev-qom-path: path to attached PCI device in the QOM tree
#
# Since: 7.1
#
# Example:
#
# <- { "event": "VFU_CLIENT_HANGUP",
# "data": { "vfu-id": "vfu1",
# "vfu-qom-path": "/objects/vfu1",
# "dev-id": "sas1",
# "dev-qom-path": "/machine/peripheral/sas1" },
# "timestamp": { "seconds": 1265044230, "microseconds": 450486 } }
#
##
{ 'event': 'VFU_CLIENT_HANGUP',
'data': { 'vfu-id': 'str', 'vfu-qom-path': 'str',
'dev-id': 'str', 'dev-qom-path': 'str' } }