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.ufimts...@oracle.com>
Signed-off-by: John G Johnson <john.g.john...@oracle.com>
Signed-off-by: Jagannathan Raman <jag.ra...@oracle.com>
Reviewed-by: Stefan Hajnoczi <stefa...@redhat.com>
---
qapi/misc.json | 31 ++++++++++
hw/remote/vfio-user-obj.c | 118 +++++++++++++++++++++++++++++++++++++-
2 files changed, 148 insertions(+), 1 deletion(-)
diff --git a/qapi/misc.json b/qapi/misc.json
index 45344483cd..27ef5a2b20 100644
--- a/qapi/misc.json
+++ b/qapi/misc.json
@@ -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' } }
diff --git a/hw/remote/vfio-user-obj.c b/hw/remote/vfio-user-obj.c
index 3ca6aa2b45..178bd6f8ed 100644
--- a/hw/remote/vfio-user-obj.c
+++ b/hw/remote/vfio-user-obj.c
@@ -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;
--
2.20.1
