* [Qemu-devel] [PATCH V2 1/3] virtio-9p: Add support for 9p migration.
2013-04-11 14:41 [Qemu-devel] [PATCH V2 0/3] Virtio-9p live migration patchset Benoît Canet
@ 2013-04-11 14:41 ` Benoît Canet
2013-04-11 14:41 ` [Qemu-devel] [PATCH V2 2/3] virtio-9p: Wait for 9p operations to complete before migration and savevm Benoît Canet
` (2 subsequent siblings)
3 siblings, 0 replies; 6+ messages in thread
From: Benoît Canet @ 2013-04-11 14:41 UTC (permalink / raw)
To: qemu-devel
Cc: peter.maydell, pbonzini, Benoît Canet, aneesh.kumar,
quintela
This patch use the old migration framework because of lack
of support for migrating linked list in the new generic framework.
This patch is a rebase of Aneesh Kumar's patch.
Signed-off-by: Benoit Canet <benoit@irqsave.net>
---
hw/9pfs/virtio-9p-device.c | 152 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 152 insertions(+)
diff --git a/hw/9pfs/virtio-9p-device.c b/hw/9pfs/virtio-9p-device.c
index d321c80..2af4858 100644
--- a/hw/9pfs/virtio-9p-device.c
+++ b/hw/9pfs/virtio-9p-device.c
@@ -20,6 +20,149 @@
#include "virtio-9p-xattr.h"
#include "virtio-9p-coth.h"
+static void virtio_9p_save_path(QEMUFile *f, V9fsPath *path)
+{
+ qemu_put_be16(f, path->size);
+ qemu_put_buffer(f, (const uint8_t *) path->data, path->size);
+}
+
+static void virtio_9p_save_string(QEMUFile *f, V9fsString *s)
+{
+ qemu_put_be16(f, s->size);
+ qemu_put_buffer(f, (const uint8_t *) s->data, s->size);
+}
+
+static void virtio_9p_save_xattr(QEMUFile *f, V9fsXattr *xattr)
+{
+ qemu_put_be64(f, xattr->copied_len);
+ qemu_put_be64(f, xattr->len);
+ qemu_put_buffer(f, (const uint8_t *) xattr->value, xattr->len);
+ virtio_9p_save_string(f, &xattr->name);
+ qemu_put_be32(f, xattr->flags);
+}
+
+static void virtio_9p_save_fid(QEMUFile *f, V9fsFidState *fid)
+{
+ /* First close the fid and mark it for reopen if migration fail */
+ if (fid->fid_type == P9_FID_FILE) {
+ close(fid->fs.fd);
+ fid->fs.fd = -1;
+ } else if (fid->fid_type == P9_FID_DIR) {
+ closedir(fid->fs.dir);
+ fid->fs.dir = NULL;
+ }
+
+ qemu_put_be32(f, fid->fid_type);
+ if (fid->fid_type == P9_FID_XATTR) {
+ /* we don't save fs_reclaim */
+ virtio_9p_save_xattr(f, &fid->fs.xattr);
+ }
+ qemu_put_be32(f, fid->fid);
+ virtio_9p_save_path(f, &fid->path);
+ qemu_put_be32(f, fid->flags);
+ qemu_put_be32(f, fid->open_flags);
+ qemu_put_be32(f, fid->uid);
+ qemu_put_be32(f, fid->ref);
+ qemu_put_be32(f, fid->clunked);
+}
+
+static void virtio_9p_save(QEMUFile *f, void *opaque)
+{
+ int fidcount = 0;
+ V9fsState *s = opaque;
+ V9fsFidState *fid;
+
+ virtio_save(&s->vdev, f);
+
+ for (fid = s->fid_list; fid; fid = fid->next) {
+ fidcount++;
+ }
+ /* Write the total number of fid structure */
+ qemu_put_be32(f, fidcount);
+
+ for (fid = s->fid_list; fid; fid = fid->next) {
+ virtio_9p_save_fid(f, fid);
+ }
+
+ qemu_put_be32(f, s->proto_version);
+ qemu_put_be32(f, s->msize);
+}
+
+static void virtio_9p_load_path(QEMUFile *f, V9fsPath *path)
+{
+ path->size = qemu_get_be16(f);
+ path->data = g_malloc0(path->size);
+ qemu_get_buffer(f, (uint8_t *) path->data, path->size);
+}
+
+static void virtio_9p_load_string(QEMUFile *f, V9fsString *s)
+{
+ s->size = qemu_get_be16(f);
+ s->data = g_malloc0(s->size);
+ qemu_get_buffer(f, (uint8_t *) s->data, s->size);
+}
+
+static void virtio_9p_load_xattr(QEMUFile *f, V9fsXattr *xattr)
+{
+ xattr->copied_len = qemu_get_be64(f);
+ xattr->len = qemu_get_be64(f);
+ qemu_get_buffer(f, (uint8_t *) xattr->value, xattr->len);
+ virtio_9p_load_string(f, &xattr->name);
+ xattr->flags = qemu_get_be32(f);
+}
+
+static V9fsFidState *virtio_9p_load_fid(QEMUFile *f)
+{
+ V9fsFidState *fid;
+ fid = g_new0(V9fsFidState, 1);
+
+ fid->fid_type = qemu_get_be32(f);
+ if (fid->fid_type == P9_FID_XATTR) {
+ virtio_9p_load_xattr(f, &fid->fs.xattr);
+ }
+ fid->fid = qemu_get_be32(f);
+ virtio_9p_load_path(f, &fid->path);
+ fid->flags = qemu_get_be32(f);
+ fid->open_flags = qemu_get_be32(f);
+ fid->uid = qemu_get_be32(f);
+ fid->ref = qemu_get_be32(f);
+ fid->clunked = qemu_get_be32(f);
+
+ /* If it's a file fid mark the file descriptors as closed.
+ * DIR is null thanks to g_new0.
+ * When doing get_fid v9fs_reopen_fid will reopen the file or the directory.
+ */
+ if (fid->fid_type == P9_FID_FILE) {
+ fid->fs.fd = -1;
+ }
+ return fid;
+}
+
+static int virtio_9p_load(QEMUFile *f, void *opaque, int version_id)
+{
+ int fidcount;
+ V9fsState *s = opaque;
+ V9fsFidState **fid;
+
+ if (version_id != 1) {
+ return -EINVAL;
+ }
+ virtio_load(&s->vdev, f);
+ fidcount = qemu_get_be32(f);
+
+ fid = &s->fid_list;
+ while (fidcount) {
+ *fid = virtio_9p_load_fid(f);
+ fid = &((*fid)->next);
+ fidcount--;
+ }
+
+ s->proto_version = qemu_get_be32(f);
+ s->msize = qemu_get_be32(f);
+
+ return 0;
+}
+
static uint32_t virtio_9p_get_features(VirtIODevice *vdev, uint32_t features)
{
features |= 1 << VIRTIO_9P_MOUNT_TAG;
@@ -53,6 +196,7 @@ VirtIODevice *virtio_9p_init(DeviceState *dev, V9fsConf *conf)
struct stat stat;
FsDriverEntry *fse;
V9fsPath path;
+ static int virtio_9p_id;
s = (V9fsState *)virtio_common_init("virtio-9p",
VIRTIO_ID_9P,
@@ -102,6 +246,14 @@ VirtIODevice *virtio_9p_init(DeviceState *dev, V9fsConf *conf)
s->config_size = sizeof(struct virtio_9p_config) + len;
s->vdev.get_config = virtio_9p_get_config;
s->fid_list = NULL;
+
+ /* Original patch says that instance id must be derived of tag
+ * name. Hash functions do have collisions so why would it be better
+ * than an increment ?
+ */
+ register_savevm(dev, "virtio-9p", virtio_9p_id++, 1,
+ virtio_9p_save, virtio_9p_load, s);
+
qemu_co_rwlock_init(&s->rename_lock);
if (s->ops->init(&s->ctx) < 0) {
--
1.7.10.4
^ permalink raw reply related [flat|nested] 6+ messages in thread* [Qemu-devel] [PATCH V2 2/3] virtio-9p: Wait for 9p operations to complete before migration and savevm.
2013-04-11 14:41 [Qemu-devel] [PATCH V2 0/3] Virtio-9p live migration patchset Benoît Canet
2013-04-11 14:41 ` [Qemu-devel] [PATCH V2 1/3] virtio-9p: Add support for 9p migration Benoît Canet
@ 2013-04-11 14:41 ` Benoît Canet
2013-04-11 14:52 ` Paolo Bonzini
2013-04-11 14:41 ` [Qemu-devel] [PATCH V2 3/3] virtio-9p: Remove migration blockers Benoît Canet
2013-04-29 13:13 ` [Qemu-devel] [PATCH V2 0/3] Virtio-9p live migration patchset Benoît Canet
3 siblings, 1 reply; 6+ messages in thread
From: Benoît Canet @ 2013-04-11 14:41 UTC (permalink / raw)
To: qemu-devel
Cc: peter.maydell, pbonzini, Benoît Canet, aneesh.kumar,
quintela
The completion status is put in the virtio ring buffer which
will be send to the guest on resume by the viring vmstate code
This patch is a rewrite from the one written by Aneesh Kumar.
Signed-off-by: Benoit Canet <benoit@irqsave.net>
---
hw/9pfs/virtio-9p-device.c | 2 ++
hw/9pfs/virtio-9p.c | 75 ++++++++++++++++++++++++++++++++++++++++++++
hw/9pfs/virtio-9p.h | 2 ++
3 files changed, 79 insertions(+)
diff --git a/hw/9pfs/virtio-9p-device.c b/hw/9pfs/virtio-9p-device.c
index 2af4858..feaccd3 100644
--- a/hw/9pfs/virtio-9p-device.c
+++ b/hw/9pfs/virtio-9p-device.c
@@ -198,6 +198,8 @@ VirtIODevice *virtio_9p_init(DeviceState *dev, V9fsConf *conf)
V9fsPath path;
static int virtio_9p_id;
+ v9fs_init_vmstate_io_drain();
+
s = (V9fsState *)virtio_common_init("virtio-9p",
VIRTIO_ID_9P,
sizeof(struct virtio_9p_config)+
diff --git a/hw/9pfs/virtio-9p.c b/hw/9pfs/virtio-9p.c
index 5cc4c92..66322ee 100644
--- a/hw/9pfs/virtio-9p.c
+++ b/hw/9pfs/virtio-9p.c
@@ -25,6 +25,11 @@ int open_fd_hw;
int total_open_fd;
static int open_fd_rc;
+static int32_t pending_initialized;
+static int32_t pending_requests;
+static QemuCond pending_cond;
+static QemuMutex pending_mutex;
+
enum {
Oread = 0x00,
Owrite = 0x01,
@@ -37,6 +42,71 @@ enum {
Oappend = 0x80,
};
+static void v9fs_vm_change_state_handler(void *opaque, int running,
+ RunState state)
+{
+ if (!pending_initialized) {
+ return;
+ }
+
+ if (running) {
+ return;
+ }
+
+ if (state != RUN_STATE_FINISH_MIGRATE && state != RUN_STATE_SAVE_VM) {
+ return;
+ }
+
+ qemu_mutex_lock(&pending_mutex);
+ while (pending_requests) {
+ /* At this point ticks and vcpus will be stopped so we can safely
+ * release the BQL so pending 9p callbacks will be executed and the
+ * condition signaled.
+ */
+ qemu_mutex_unlock_iothread();
+ qemu_cond_wait(&pending_cond, &pending_mutex);
+ qemu_mutex_lock_iothread();
+ }
+ qemu_mutex_unlock(&pending_mutex);
+}
+
+void v9fs_init_vmstate_io_drain(void)
+{
+ if (pending_initialized) {
+ return;
+ }
+
+ pending_initialized = 1;
+ qemu_mutex_init(&pending_mutex);
+ qemu_cond_init(&pending_cond);
+ qemu_add_vm_change_state_handler(v9fs_vm_change_state_handler, NULL);
+}
+
+static void v9fs_inc_pending_requests(void)
+{
+ if (!pending_initialized) {
+ return;
+ }
+
+ qemu_mutex_lock(&pending_mutex);
+ pending_requests++;
+ qemu_mutex_unlock(&pending_mutex);
+}
+
+static void v9fs_dec_pending_requests(void)
+{
+ if (!pending_initialized) {
+ return;
+ }
+
+ qemu_mutex_lock(&pending_mutex);
+ pending_requests--;
+ if (!pending_requests) {
+ qemu_cond_signal(&pending_cond);
+ }
+ qemu_mutex_unlock(&pending_mutex);
+}
+
static int omode_to_uflags(int8_t mode)
{
int ret = 0;
@@ -637,6 +707,8 @@ static void complete_pdu(V9fsState *s, V9fsPDU *pdu, ssize_t len)
qemu_co_queue_next(&pdu->complete);
free_pdu(s, pdu);
+
+ v9fs_dec_pending_requests();
}
static mode_t v9mode_to_mode(uint32_t mode, V9fsString *extension)
@@ -3240,6 +3312,9 @@ static void submit_pdu(V9fsState *s, V9fsPDU *pdu)
if (is_ro_export(&s->ctx) && !is_read_only_op(pdu)) {
handler = v9fs_fs_ro;
}
+
+ v9fs_inc_pending_requests();
+
co = qemu_coroutine_create(handler);
qemu_coroutine_enter(co, pdu);
}
diff --git a/hw/9pfs/virtio-9p.h b/hw/9pfs/virtio-9p.h
index 52b1c69..604502a 100644
--- a/hw/9pfs/virtio-9p.h
+++ b/hw/9pfs/virtio-9p.h
@@ -401,4 +401,6 @@ extern int v9fs_name_to_path(V9fsState *s, V9fsPath *dirpath,
#define pdu_unmarshal(pdu, offset, fmt, args...) \
v9fs_unmarshal(pdu->elem.out_sg, pdu->elem.out_num, offset, 1, fmt, ##args)
+void v9fs_init_vmstate_io_drain(void);
+
#endif
--
1.7.10.4
^ permalink raw reply related [flat|nested] 6+ messages in thread* [Qemu-devel] [PATCH V2 3/3] virtio-9p: Remove migration blockers.
2013-04-11 14:41 [Qemu-devel] [PATCH V2 0/3] Virtio-9p live migration patchset Benoît Canet
2013-04-11 14:41 ` [Qemu-devel] [PATCH V2 1/3] virtio-9p: Add support for 9p migration Benoît Canet
2013-04-11 14:41 ` [Qemu-devel] [PATCH V2 2/3] virtio-9p: Wait for 9p operations to complete before migration and savevm Benoît Canet
@ 2013-04-11 14:41 ` Benoît Canet
2013-04-29 13:13 ` [Qemu-devel] [PATCH V2 0/3] Virtio-9p live migration patchset Benoît Canet
3 siblings, 0 replies; 6+ messages in thread
From: Benoît Canet @ 2013-04-11 14:41 UTC (permalink / raw)
To: qemu-devel
Cc: peter.maydell, pbonzini, Benoît Canet, aneesh.kumar,
quintela
Signed-off-by: Benoit Canet <benoit@irqsave.net>
---
hw/9pfs/virtio-9p.c | 23 -----------------------
hw/9pfs/virtio-9p.h | 2 --
2 files changed, 25 deletions(-)
diff --git a/hw/9pfs/virtio-9p.c b/hw/9pfs/virtio-9p.c
index 66322ee..d81087b 100644
--- a/hw/9pfs/virtio-9p.c
+++ b/hw/9pfs/virtio-9p.c
@@ -404,19 +404,6 @@ static int put_fid(V9fsPDU *pdu, V9fsFidState *fidp)
* Don't free the fid if it is in reclaim list
*/
if (!fidp->ref && fidp->clunked) {
- if (fidp->fid == pdu->s->root_fid) {
- /*
- * if the clunked fid is root fid then we
- * have unmounted the fs on the client side.
- * delete the migration blocker. Ideally, this
- * should be hooked to transport close notification
- */
- if (pdu->s->migration_blocker) {
- migrate_del_blocker(pdu->s->migration_blocker);
- error_free(pdu->s->migration_blocker);
- pdu->s->migration_blocker = NULL;
- }
- }
return free_fid(pdu, fidp);
}
return 0;
@@ -1053,16 +1040,6 @@ static void v9fs_attach(void *opaque)
err += offset;
trace_v9fs_attach_return(pdu->tag, pdu->id,
qid.type, qid.version, qid.path);
- /*
- * disable migration if we haven't done already.
- * attach could get called multiple times for the same export.
- */
- if (!s->migration_blocker) {
- s->root_fid = fid;
- error_set(&s->migration_blocker, QERR_VIRTFS_FEATURE_BLOCKS_MIGRATION,
- s->ctx.fs_root ? s->ctx.fs_root : "NULL", s->tag);
- migrate_add_blocker(s->migration_blocker);
- }
out:
put_fid(pdu, fidp);
out_nofid:
diff --git a/hw/9pfs/virtio-9p.h b/hw/9pfs/virtio-9p.h
index 604502a..acd6703 100644
--- a/hw/9pfs/virtio-9p.h
+++ b/hw/9pfs/virtio-9p.h
@@ -223,8 +223,6 @@ typedef struct V9fsState
* on rename.
*/
CoRwlock rename_lock;
- int32_t root_fid;
- Error *migration_blocker;
} V9fsState;
typedef struct V9fsStatState {
--
1.7.10.4
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [Qemu-devel] [PATCH V2 0/3] Virtio-9p live migration patchset
2013-04-11 14:41 [Qemu-devel] [PATCH V2 0/3] Virtio-9p live migration patchset Benoît Canet
` (2 preceding siblings ...)
2013-04-11 14:41 ` [Qemu-devel] [PATCH V2 3/3] virtio-9p: Remove migration blockers Benoît Canet
@ 2013-04-29 13:13 ` Benoît Canet
3 siblings, 0 replies; 6+ messages in thread
From: Benoît Canet @ 2013-04-29 13:13 UTC (permalink / raw)
To: qemu-devel; +Cc: peter.maydell, pbonzini, aneesh.kumar, quintela
quintela: ping.
I really need your review to get this patchset in shape for merging.
Regards
Benoît
> Le Thursday 11 Apr 2013 à 16:41:05 (+0200), Benoît Canet a écrit :
> This patchset is a rework of the 9p live migration patchs made a few years ago
> by Aneesh.
> As the new vmstate API doesn't support linked list so the old API is used.
>
> v2:
> Drop pre migration flush hook code (Paolo)
> Use vmstate change notifier (Paolo)
> Use static variables instead of a struct in patch 2 (Paolo, Peter)
> Drop spurious root_id related code (Peter)
> Rename functions in patch two (Benoît)
>
> Benoît Canet (3):
> virtio-9p: Add support for 9p migration.
> virtio-9p: Wait for 9p operations to complete before migration and
> savevm.
> virtio-9p: Remove migration blockers.
>
> hw/9pfs/virtio-9p-device.c | 154 ++++++++++++++++++++++++++++++++++++++++++++
> hw/9pfs/virtio-9p.c | 98 +++++++++++++++++++++-------
> hw/9pfs/virtio-9p.h | 4 +-
> 3 files changed, 231 insertions(+), 25 deletions(-)
>
> --
> 1.7.10.4
>
^ permalink raw reply [flat|nested] 6+ messages in thread