qemu-ga: Introduce guest-hibernate command

This is basically suspend to disk on a Linux guest.

Now, while testing this or even "echo disk > /sys/power/state" I get several funny results. Some times qemu just dies after printing that message:

Quoted 4 lines · Luiz Capitulino

This is basically suspend to disk on a Linux guest.

Now, while testing this or even "echo disk > /sys/power/state" I get several funny results. Some times qemu just dies after printing that message:

I think you should really be invoking 'pm-hibernate', because IIUC there are others tasks that need to be done, besides just telling the kernel to hibernate via sysfs.

This is basically suspend to disk on a Linux guest.

Signed-off-by Luiz Capitulino <[email protected]>

---

This is an RFC because I did it as simple as possible and I'm open to suggestions...

Now, while testing this or even "echo disk > /sys/power/state" I get several funny results. Some times qemu just dies after printing that message:

"Guest moved used index from 20151 to 1"

This is basically suspend to disk on a Linux guest.

Signed-off-by Luiz Capitulino<[email protected]>

---

This is an RFC because I did it as simple as possible and I'm open to suggestions...

Now, while testing this or even "echo disk> /sys/power/state" I get several funny results. Some times qemu just dies after printing that message:

"Guest moved used index from 20151 to 1"

Some times it doesn't die, but I'm unable to log into the guest: I type username& password but the terminal kind of locks (the shell doesn't run).

Some times it works...

  qapi-schema-guest.json     |   11 +++++++++++
  qga/guest-agent-commands.c |   19 +++++++++++++++++++
  2 files changed, 30 insertions(+), 0 deletions(-)

qapi-schema-guest.json +11 -0

index fde5971..2c5bbcf 100644
@@ -215,3 +215,14 @@
  ##
  { 'command': 'guest-fsfreeze-thaw',
    'returns': 'int' }
+
+##
+# @guest-hibernate
+#
+# Save RAM contents to disk and powerdown the guest.
+#
+# Notes: This command doesn't return on success.
+#
+# Since: 1.1
+##
+{ 'command': 'guest-hibernate' }

qga/guest-agent-commands.c +5 -0

index 6da9904..9dd4060 100644
@@ -550,6 +550,25 @@ int64_t qmp_guest_fsfreeze_thaw(Error **err)
  }
  #endif
 
+#define LINUX_SYS_STATE_FILE "/sys/power/state"
+
+void qmp_guest_hibernate(Error **err)
+{
+    int fd;

qga/guest-agent-commands.c +4 -0

+
+    close(fd);
+}
+
  /* register init/cleanup routines for stateful command groups */
  void ga_command_state_init(GAState *s, GACommandState *cs)
  {

Quoted 1 line · Luiz Capitulino

This is basically suspend to disk on a Linux guest.

Nice!

Quoted 7 lines

Signed-off-by Luiz Capitulino<[email protected]>

---

This is an RFC because I did it as simple as possible and I'm open to suggestions...

Quoted 7 lines

Now, while testing this or even "echo disk> /sys/power/state" I get several funny results. Some times qemu just dies after printing that message:

"Guest moved used index from 20151 to 1"

Some times it doesn't die, but I'm unable to log into the guest: I type username& password but the terminal kind of locks (the shell doesn't run).

Triggered this pretty easily on FC15 amd64:

qemu-system-x86_64: Guest moved used index from 13024 to 80

I'll see if I can get a trace of what's happening on my end.

Quoted 47 lines

Some times it works...

  qapi-schema-guest.json     |   11 +++++++++++
  qga/guest-agent-commands.c |   19 +++++++++++++++++++
  2 files changed, 30 insertions(+), 0 deletions(-)

qapi-schema-guest.json +11 -0

index fde5971..2c5bbcf 100644
@@ -215,3 +215,14 @@
  ##
  { 'command': 'guest-fsfreeze-thaw',
    'returns': 'int' }
+
+##
+# @guest-hibernate
+#
+# Save RAM contents to disk and powerdown the guest.
+#
+# Notes: This command doesn't return on success.
+#
+# Since: 1.1
+##
+{ 'command': 'guest-hibernate' }

qga/guest-agent-commands.c +13 -0

index 6da9904..9dd4060 100644
@@ -550,6 +550,25 @@ int64_t qmp_guest_fsfreeze_thaw(Error **err)
  }
  #endif
 
+#define LINUX_SYS_STATE_FILE "/sys/power/state"
+
+void qmp_guest_hibernate(Error **err)
+{
+    int fd;
+
+    fd = open(LINUX_SYS_STATE_FILE, O_WRONLY);
+    if (fd<  0) {
+        error_set(err, QERR_OPEN_FILE_FAILED, LINUX_SYS_STATE_FILE);
+        return;
+    }
+
+    if (write(fd, "disk", 4)<  0) {

qga/guest-agent-commands.c int64_t qmp_guest_fsfreeze_thaw(Error **err) · line 567

Quoted 2 lines

qga/guest-agent-commands.c +2 -0

+        error_set(err, QERR_UNDEFINED_ERROR);
+    }

There's basically no chance of this returning, so we should issue it asynchronously like we do with qmp_guest_shutdown(). Also agreed on Daniel's point that we should use pm-hibernate, but failing back to this should be okay...assuming the virtio issue isn't indicative of some fundamental problem with that approach...

Quoted 8 lines

qga/guest-agent-commands.c +4 -0

+
+    close(fd);
+}
+
  /* register init/cleanup routines for stateful command groups */
  void ga_command_state_init(GAState *s, GACommandState *cs)
  {

This is basically suspend to disk on a Linux guest.

Signed-off-by Luiz Capitulino<[email protected]>

---

This is an RFC because I did it as simple as possible and I'm open to suggestions...

Now, while testing this or even "echo disk> /sys/power/state" I get several funny results. Some times qemu just dies after printing that message:

"Guest moved used index from 20151 to 1"

Some times it doesn't die, but I'm unable to log into the guest: I type username& password but the terminal kind of locks (the shell doesn't run).

Some times it works...

  qapi-schema-guest.json     |   11 +++++++++++
  qga/guest-agent-commands.c |   19 +++++++++++++++++++
  2 files changed, 30 insertions(+), 0 deletions(-)

qapi-schema-guest.json +11 -0

index fde5971..2c5bbcf 100644
@@ -215,3 +215,14 @@
  ##
  { 'command': 'guest-fsfreeze-thaw',
    'returns': 'int' }
+
+##
+# @guest-hibernate
+#
+# Save RAM contents to disk and powerdown the guest.
+#
+# Notes: This command doesn't return on success.
+#
+# Since: 1.1
+##
+{ 'command': 'guest-hibernate' }

qga/guest-agent-commands.c +19 -0

index 6da9904..9dd4060 100644
@@ -550,6 +550,25 @@ int64_t qmp_guest_fsfreeze_thaw(Error **err)
  }
  #endif
 
+#define LINUX_SYS_STATE_FILE "/sys/power/state"
+
+void qmp_guest_hibernate(Error **err)
+{
+    int fd;
+
+    fd = open(LINUX_SYS_STATE_FILE, O_WRONLY);
+    if (fd<  0) {
+        error_set(err, QERR_OPEN_FILE_FAILED, LINUX_SYS_STATE_FILE);
+        return;
+    }
+
+    if (write(fd, "disk", 4)<  0) {
+        error_set(err, QERR_UNDEFINED_ERROR);
+    }
+
+    close(fd);
+}
+
  /* register init/cleanup routines for stateful command groups */
  void ga_command_state_init(GAState *s, GACommandState *cs)
  {

Quoted 11 lines · Luiz Capitulino

This is basically suspend to disk on a Linux guest.

Signed-off-by Luiz Capitulino<[email protected]>

---

This is an RFC because I did it as simple as possible and I'm open to suggestions...

Now, while testing this or even "echo disk> /sys/power/state" I get several funny results. Some times qemu just dies after printing that message:

Quoted 7 lines

"Guest moved used index from 20151 to 1"

Some times it doesn't die, but I'm unable to log into the guest: I type username& password but the terminal kind of locks (the shell doesn't run).

Some times it works...

Here's the tail-end of the trace...

virtio_queue_notify 237.880 vdev=0x7f11f4c8f5e0 n=0x0 vq=0x7f11f4cb4d40 virtqueue_pop 3.701 vq=0x7f11f4cb4d40 elem=0x7f11f5966118 in_num=0x2 out_num=0x1
virtio_blk_rw_complete 51.613 req=0x7f11f5966110 ret=0x0 virtio_blk_req_complete 1.327 req=0x7f11f5966110 status=0x0 virtqueue_fill 1.187 vq=0x7f11f4cb4d40 elem=0x7f11f5966118 len=0x1001 idx=0x0
virtqueue_flush 1.746 vq=0x7f11f4cb4d40 count=0x1 virtio_notify 1.537 vdev=0x7f11f4c8f5e0 vq=0x7f11f4cb4d40 virtio_queue_notify 374.978 vdev=0x7f11f4c8f5e0 n=0x0 vq=0x7f11f4cb4d40 virtqueue_pop 3.631 vq=0x7f11f4cb4d40 elem=0x7f11f5faec58 in_num=0x2 out_num=0x1
virtio_blk_rw_complete 49.029 req=0x7f11f5faec50 ret=0x0 virtio_blk_req_complete 1.327 req=0x7f11f5faec50 status=0x0 virtqueue_fill 1.327 vq=0x7f11f4cb4d40 elem=0x7f11f5faec58 len=0x1001 idx=0x0
virtqueue_flush 1.746 vq=0x7f11f4cb4d40 count=0x1 virtio_notify 1.397 vdev=0x7f11f4c8f5e0 vq=0x7f11f4cb4d40 virtio_queue_notify 245.073 vdev=0x7f11f4c8f5e0 n=0x0 vq=0x7f11f4cb4d40 virtqueue_pop 3.631 vq=0x7f11f4cb4d40 elem=0x7f11f5966118 in_num=0x2 out_num=0x1
virtio_blk_rw_complete 47.702 req=0x7f11f5966110 ret=0x0 virtio_blk_req_complete 1.257 req=0x7f11f5966110 status=0x0 virtqueue_fill 1.327 vq=0x7f11f4cb4d40 elem=0x7f11f5966118 len=0x1001 idx=0x0
virtqueue_flush 1.816 vq=0x7f11f4cb4d40 count=0x1 virtio_notify 1.327 vdev=0x7f11f4c8f5e0 vq=0x7f11f4cb4d40 virtio_queue_notify 450.616 vdev=0x7f11f4c8f5e0 n=0x0 vq=0x7f11f4cb4d40 virtqueue_pop 4.051 vq=0x7f11f4cb4d40 elem=0x7f11f5faec58 in_num=0x2 out_num=0x1
virtio_blk_rw_complete 67.885 req=0x7f11f5faec50 ret=0x0 virtio_blk_req_complete 1.327 req=0x7f11f5faec50 status=0x0 virtqueue_fill 1.327 vq=0x7f11f4cb4d40 elem=0x7f11f5faec58 len=0x1001 idx=0x0

...
virtio_queue_notify 374.978 vdev=0x7f11f4c8f5e0 n=0x0 vq=0x7f11f4cb4d40 virtqueue_pop 3.631 vq=0x7f11f4cb4d40 elem=0x7f11f5faec58 in_num=0x2 out_num=0x1
virtio_blk_rw_complete 49.029 req=0x7f11f5faec50 ret=0x0 virtio_blk_req_complete 1.327 req=0x7f11f5faec50 status=0x0 virtqueue_fill 1.327 vq=0x7f11f4cb4d40 elem=0x7f11f5faec58 len=0x1001 idx=0x0
virtqueue_flush 1.746 vq=0x7f11f4cb4d40 count=0x1 virtio_notify 1.397 vdev=0x7f11f4c8f5e0 vq=0x7f11f4cb4d40 virtio_queue_notify 245.073 vdev=0x7f11f4c8f5e0 n=0x0 vq=0x7f11f4cb4d40 virtqueue_pop 3.631 vq=0x7f11f4cb4d40 elem=0x7f11f5966118 in_num=0x2 out_num=0x1
virtio_blk_rw_complete 47.702 req=0x7f11f5966110 ret=0x0 virtio_blk_req_complete 1.257 req=0x7f11f5966110 status=0x0 virtqueue_fill 1.327 vq=0x7f11f4cb4d40 elem=0x7f11f5966118 len=0x1001 idx=0x0
virtqueue_flush 1.816 vq=0x7f11f4cb4d40 count=0x1 virtio_notify 1.327 vdev=0x7f11f4c8f5e0 vq=0x7f11f4cb4d40 virtio_queue_notify 450.616 vdev=0x7f11f4c8f5e0 n=0x0 vq=0x7f11f4cb4d40 virtqueue_pop 4.051 vq=0x7f11f4cb4d40 elem=0x7f11f5faec58 in_num=0x2 out_num=0x1
virtio_blk_rw_complete 67.885 req=0x7f11f5faec50 ret=0x0 virtio_blk_req_complete 1.327 req=0x7f11f5faec50 status=0x0 virtqueue_fill 1.327 vq=0x7f11f4cb4d40 elem=0x7f11f5faec58 len=0x1001 idx=0x0
virtqueue_flush 1.607 vq=0x7f11f4cb4d40 count=0x1 virtio_notify 1.257 vdev=0x7f11f4c8f5e0 vq=0x7f11f4cb4d40 virtio_queue_notify 196.813 vdev=0x7f11f4c8f5e0 n=0x0 vq=0x7f11f4cb4d40 virtqueue_pop 3.562 vq=0x7f11f4cb4d40 elem=0x7f11f5966118 in_num=0x2 out_num=0x1
virtio_blk_rw_complete 47.492 req=0x7f11f5966110 ret=0x0 virtio_blk_req_complete 1.327 req=0x7f11f5966110 status=0x0 virtqueue_fill 1.327 vq=0x7f11f4cb4d40 elem=0x7f11f5966118 len=0x1001 idx=0x0
virtqueue_flush 1.676 vq=0x7f11f4cb4d40 count=0x1 virtio_notify 1.397 vdev=0x7f11f4c8f5e0 vq=0x7f11f4cb4d40 virtio_queue_notify 882289.570 vdev=0x7f11f4c8f5e0 n=0x0 vq=0x7f11f4cb4d40

It doesn't seem to tell us much...but there's a bunch of successful reads before the final virtio_queue_notify, and that notify takes quite a bit longer than the previous ones. I can only speculate at this point, but I would guess this is when the guest has completed loading the saved memory from disk and it attempting to restore the previous state..

In the kernel there's a virtio_pci_suspend() PM callback that seems to get called around this time and restores the PCI config from virtio_pci_resume(). Could that be switching us to an older vring and throwing the QEMU side out of whack?

Quoted 55 lines

  qapi-schema-guest.json     |   11 +++++++++++
  qga/guest-agent-commands.c |   19 +++++++++++++++++++
  2 files changed, 30 insertions(+), 0 deletions(-)

qapi-schema-guest.json +11 -0

index fde5971..2c5bbcf 100644
@@ -215,3 +215,14 @@
  ##
  { 'command': 'guest-fsfreeze-thaw',
    'returns': 'int' }
+
+##
+# @guest-hibernate
+#
+# Save RAM contents to disk and powerdown the guest.
+#
+# Notes: This command doesn't return on success.
+#
+# Since: 1.1
+##
+{ 'command': 'guest-hibernate' }

qga/guest-agent-commands.c +19 -0

index 6da9904..9dd4060 100644
@@ -550,6 +550,25 @@ int64_t qmp_guest_fsfreeze_thaw(Error **err)
  }
  #endif
 
+#define LINUX_SYS_STATE_FILE "/sys/power/state"
+
+void qmp_guest_hibernate(Error **err)
+{
+    int fd;
+
+    fd = open(LINUX_SYS_STATE_FILE, O_WRONLY);
+    if (fd<  0) {
+        error_set(err, QERR_OPEN_FILE_FAILED, LINUX_SYS_STATE_FILE);
+        return;
+    }
+
+    if (write(fd, "disk", 4)<  0) {
+        error_set(err, QERR_UNDEFINED_ERROR);
+    }
+
+    close(fd);
+}
+
  /* register init/cleanup routines for stateful command groups */
  void ga_command_state_init(GAState *s, GACommandState *cs)
  {

Quoted 18 lines · On Thu, 08 Dec 2011 21:18:00 -0600 Michael Roth <[email protected]>…

Quoted 17 lines · Luiz Capitulino

This is basically suspend to disk on a Linux guest.

Signed-off-by Luiz Capitulino<[email protected]>

---

This is an RFC because I did it as simple as possible and I'm open to suggestions...

Now, while testing this or even "echo disk> /sys/power/state" I get several funny results. Some times qemu just dies after printing that message:

"Guest moved used index from 20151 to 1"

Some times it doesn't die, but I'm unable to log into the guest: I type username& password but the terminal kind of locks (the shell doesn't run).

Some times it works...

Quoted 6 lines

It doesn't seem to tell us much...but there's a bunch of successful reads before the final virtio_queue_notify, and that notify takes quite a bit longer than the previous ones. I can only speculate at this point, but I would guess this is when the guest has completed loading the saved memory from disk and it attempting to restore the previous state..

Quoted 4 lines

In the kernel there's a virtio_pci_suspend() PM callback that seems to get called around this time and restores the PCI config from virtio_pci_resume(). Could that be switching us to an older vring and throwing the QEMU side out of whack?

Not sure. But Amit has confirmed that it's a virtio bug and he's working on it. Right Amit?

This is basically suspend to disk on a Linux guest.

Signed-off-by Luiz Capitulino <[email protected]>

---

This is an RFC because I did it as simple as possible and I'm open to suggestions...

Now, while testing this or even "echo disk > /sys/power/state" I get several funny results. Some times qemu just dies after printing that message:

"Guest moved used index from 20151 to 1"

Some times it doesn't die, but I'm unable to log into the guest: I type username & password but the terminal kind of locks (the shell doesn't run).

This is basically suspend to disk on a Linux guest.

Signed-off-by Luiz Capitulino<[email protected]>

---

This is an RFC because I did it as simple as possible and I'm open to suggestions...

Now, while testing this or even "echo disk> /sys/power/state" I get several

funny results. Some times qemu just dies after printing that message:

"Guest moved used index from 20151 to 1"

Some times it doesn't die, but I'm unable to log into the guest: I type username& password but the terminal kind of locks (the shell doesn't run).

Some times it works...

  qapi-schema-guest.json     |   11 +++++++++++
  qga/guest-agent-commands.c |   19 +++++++++++++++++++
  2 files changed, 30 insertions(+), 0 deletions(-)

qapi-schema-guest.json +11 -0

index fde5971..2c5bbcf 100644
@@ -215,3 +215,14 @@
  ##
  { 'command': 'guest-fsfreeze-thaw',
    'returns': 'int' }
+
+##
+# @guest-hibernate
+#
+# Save RAM contents to disk and powerdown the guest.
+#
+# Notes: This command doesn't return on success.
+#
+# Since: 1.1
+##
+{ 'command': 'guest-hibernate' }

qga/guest-agent-commands.c +19 -0

index 6da9904..9dd4060 100644
@@ -550,6 +550,25 @@ int64_t qmp_guest_fsfreeze_thaw(Error **err)
  }
  #endif
 
+#define LINUX_SYS_STATE_FILE "/sys/power/state"
+
+void qmp_guest_hibernate(Error **err)
+{
+    int fd;
+
+    fd = open(LINUX_SYS_STATE_FILE, O_WRONLY);
+    if (fd<  0) {
+        error_set(err, QERR_OPEN_FILE_FAILED, LINUX_SYS_STATE_FILE);
+        return;
+    }
+
+    if (write(fd, "disk", 4)<  0) {
+        error_set(err, QERR_UNDEFINED_ERROR);
+    }
+
+    close(fd);
+}
+
  /* register init/cleanup routines for stateful command groups */
  void ga_command_state_init(GAState *s, GACommandState *cs)
  {

Quoted 8 lines · Luiz Capitulino

This is basically suspend to disk on a Linux guest.

Signed-off-by Luiz Capitulino<[email protected]>

---

This is an RFC because I did it as simple as possible and I'm open to suggestions...

Quoted 1 line

Now, while testing this or even "echo disk> /sys/power/state" I get several

Beyond the previous comments about virtio s4 that Amit solved and pm-hibernate I think it will be nice to add suspend to ram (s3) option too. Currently qemu wakes up immediately after s3 but it can be fixed and it can pause the guest and wait to a keyboard event or monitor command.

Quoted 63 lines

funny results. Some times qemu just dies after printing that message:

"Guest moved used index from 20151 to 1"

Some times it doesn't die, but I'm unable to log into the guest: I type username& password but the terminal kind of locks (the shell doesn't run).

Some times it works...

  qapi-schema-guest.json     |   11 +++++++++++
  qga/guest-agent-commands.c |   19 +++++++++++++++++++
  2 files changed, 30 insertions(+), 0 deletions(-)

qapi-schema-guest.json +11 -0

index fde5971..2c5bbcf 100644
@@ -215,3 +215,14 @@
  ##
  { 'command': 'guest-fsfreeze-thaw',
    'returns': 'int' }
+
+##
+# @guest-hibernate
+#
+# Save RAM contents to disk and powerdown the guest.
+#
+# Notes: This command doesn't return on success.
+#
+# Since: 1.1
+##
+{ 'command': 'guest-hibernate' }

qga/guest-agent-commands.c +19 -0

index 6da9904..9dd4060 100644
@@ -550,6 +550,25 @@ int64_t qmp_guest_fsfreeze_thaw(Error **err)
  }
  #endif
 
+#define LINUX_SYS_STATE_FILE "/sys/power/state"
+
+void qmp_guest_hibernate(Error **err)
+{
+    int fd;
+
+    fd = open(LINUX_SYS_STATE_FILE, O_WRONLY);
+    if (fd<  0) {
+        error_set(err, QERR_OPEN_FILE_FAILED, LINUX_SYS_STATE_FILE);
+        return;
+    }
+
+    if (write(fd, "disk", 4)<  0) {
+        error_set(err, QERR_UNDEFINED_ERROR);
+    }
+
+    close(fd);
+}
+
  /* register init/cleanup routines for stateful command groups */
  void ga_command_state_init(GAState *s, GACommandState *cs)
  {