* [Qemu-devel] [PULL 01/57] Add postcopy documentation
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
@ 2015-11-10 14:24 ` Juan Quintela
2015-11-10 14:24 ` [Qemu-devel] [PULL 02/57] Provide runtime Target page information Juan Quintela
` (56 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:24 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
docs/migration.txt | 191 +++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 191 insertions(+)
diff --git a/docs/migration.txt b/docs/migration.txt
index f6df4be..fda8d61 100644
--- a/docs/migration.txt
+++ b/docs/migration.txt
@@ -291,3 +291,194 @@ save/send this state when we are in the middle of a pio operation
(that is what ide_drive_pio_state_needed() checks). If DRQ_STAT is
not enabled, the values on that fields are garbage and don't need to
be sent.
+
+= Return path =
+
+In most migration scenarios there is only a single data path that runs
+from the source VM to the destination, typically along a single fd (although
+possibly with another fd or similar for some fast way of throwing pages across).
+
+However, some uses need two way communication; in particular the Postcopy
+destination needs to be able to request pages on demand from the source.
+
+For these scenarios there is a 'return path' from the destination to the source;
+qemu_file_get_return_path(QEMUFile* fwdpath) gives the QEMUFile* for the return
+path.
+
+ Source side
+ Forward path - written by migration thread
+ Return path - opened by main thread, read by return-path thread
+
+ Destination side
+ Forward path - read by main thread
+ Return path - opened by main thread, written by main thread AND postcopy
+ thread (protected by rp_mutex)
+
+= Postcopy =
+'Postcopy' migration is a way to deal with migrations that refuse to converge
+(or take too long to converge) its plus side is that there is an upper bound on
+the amount of migration traffic and time it takes, the down side is that during
+the postcopy phase, a failure of *either* side or the network connection causes
+the guest to be lost.
+
+In postcopy the destination CPUs are started before all the memory has been
+transferred, and accesses to pages that are yet to be transferred cause
+a fault that's translated by QEMU into a request to the source QEMU.
+
+Postcopy can be combined with precopy (i.e. normal migration) so that if precopy
+doesn't finish in a given time the switch is made to postcopy.
+
+=== Enabling postcopy ===
+
+To enable postcopy, issue this command on the monitor prior to the
+start of migration:
+
+migrate_set_capability x-postcopy-ram on
+
+The normal commands are then used to start a migration, which is still
+started in precopy mode. Issuing:
+
+migrate_start_postcopy
+
+will now cause the transition from precopy to postcopy.
+It can be issued immediately after migration is started or any
+time later on. Issuing it after the end of a migration is harmless.
+
+Note: During the postcopy phase, the bandwidth limits set using
+migrate_set_speed is ignored (to avoid delaying requested pages that
+the destination is waiting for).
+
+=== Postcopy device transfer ===
+
+Loading of device data may cause the device emulation to access guest RAM
+that may trigger faults that have to be resolved by the source, as such
+the migration stream has to be able to respond with page data *during* the
+device load, and hence the device data has to be read from the stream completely
+before the device load begins to free the stream up. This is achieved by
+'packaging' the device data into a blob that's read in one go.
+
+Source behaviour
+
+Until postcopy is entered the migration stream is identical to normal
+precopy, except for the addition of a 'postcopy advise' command at
+the beginning, to tell the destination that postcopy might happen.
+When postcopy starts the source sends the page discard data and then
+forms the 'package' containing:
+
+ Command: 'postcopy listen'
+ The device state
+ A series of sections, identical to the precopy streams device state stream
+ containing everything except postcopiable devices (i.e. RAM)
+ Command: 'postcopy run'
+
+The 'package' is sent as the data part of a Command: 'CMD_PACKAGED', and the
+contents are formatted in the same way as the main migration stream.
+
+During postcopy the source scans the list of dirty pages and sends them
+to the destination without being requested (in much the same way as precopy),
+however when a page request is received from the destination, the dirty page
+scanning restarts from the requested location. This causes requested pages
+to be sent quickly, and also causes pages directly after the requested page
+to be sent quickly in the hope that those pages are likely to be used
+by the destination soon.
+
+Destination behaviour
+
+Initially the destination looks the same as precopy, with a single thread
+reading the migration stream; the 'postcopy advise' and 'discard' commands
+are processed to change the way RAM is managed, but don't affect the stream
+processing.
+
+------------------------------------------------------------------------------
+ 1 2 3 4 5 6 7
+main -----DISCARD-CMD_PACKAGED ( LISTEN DEVICE DEVICE DEVICE RUN )
+thread | |
+ | (page request)
+ | \___
+ v \
+listen thread: --- page -- page -- page -- page -- page --
+
+ a b c
+------------------------------------------------------------------------------
+
+On receipt of CMD_PACKAGED (1)
+ All the data associated with the package - the ( ... ) section in the
+diagram - is read into memory (into a QEMUSizedBuffer), and the main thread
+recurses into qemu_loadvm_state_main to process the contents of the package (2)
+which contains commands (3,6) and devices (4...)
+
+On receipt of 'postcopy listen' - 3 -(i.e. the 1st command in the package)
+a new thread (a) is started that takes over servicing the migration stream,
+while the main thread carries on loading the package. It loads normal
+background page data (b) but if during a device load a fault happens (5) the
+returned page (c) is loaded by the listen thread allowing the main threads
+device load to carry on.
+
+The last thing in the CMD_PACKAGED is a 'RUN' command (6) letting the destination
+CPUs start running.
+At the end of the CMD_PACKAGED (7) the main thread returns to normal running behaviour
+and is no longer used by migration, while the listen thread carries
+on servicing page data until the end of migration.
+
+=== Postcopy states ===
+
+Postcopy moves through a series of states (see postcopy_state) from
+ADVISE->DISCARD->LISTEN->RUNNING->END
+
+ Advise: Set at the start of migration if postcopy is enabled, even
+ if it hasn't had the start command; here the destination
+ checks that its OS has the support needed for postcopy, and performs
+ setup to ensure the RAM mappings are suitable for later postcopy.
+ The destination will fail early in migration at this point if the
+ required OS support is not present.
+ (Triggered by reception of POSTCOPY_ADVISE command)
+
+ Discard: Entered on receipt of the first 'discard' command; prior to
+ the first Discard being performed, hugepages are switched off
+ (using madvise) to ensure that no new huge pages are created
+ during the postcopy phase, and to cause any huge pages that
+ have discards on them to be broken.
+
+ Listen: The first command in the package, POSTCOPY_LISTEN, switches
+ the destination state to Listen, and starts a new thread
+ (the 'listen thread') which takes over the job of receiving
+ pages off the migration stream, while the main thread carries
+ on processing the blob. With this thread able to process page
+ reception, the destination now 'sensitises' the RAM to detect
+ any access to missing pages (on Linux using the 'userfault'
+ system).
+
+ Running: POSTCOPY_RUN causes the destination to synchronise all
+ state and start the CPUs and IO devices running. The main
+ thread now finishes processing the migration package and
+ now carries on as it would for normal precopy migration
+ (although it can't do the cleanup it would do as it
+ finishes a normal migration).
+
+ End: The listen thread can now quit, and perform the cleanup of migration
+ state, the migration is now complete.
+
+=== Source side page maps ===
+
+The source side keeps two bitmaps during postcopy; 'the migration bitmap'
+and 'unsent map'. The 'migration bitmap' is basically the same as in
+the precopy case, and holds a bit to indicate that page is 'dirty' -
+i.e. needs sending. During the precopy phase this is updated as the CPU
+dirties pages, however during postcopy the CPUs are stopped and nothing
+should dirty anything any more.
+
+The 'unsent map' is used for the transition to postcopy. It is a bitmap that
+has a bit cleared whenever a page is sent to the destination, however during
+the transition to postcopy mode it is combined with the migration bitmap
+to form a set of pages that:
+ a) Have been sent but then redirtied (which must be discarded)
+ b) Have not yet been sent - which also must be discarded to cause any
+ transparent huge pages built during precopy to be broken.
+
+Note that the contents of the unsentmap are sacrificed during the calculation
+of the discard set and thus aren't valid once in postcopy. The dirtymap
+is still valid and is used to ensure that no page is sent more than once. Any
+request for a page that has already been sent is ignored. Duplicate requests
+such as this can happen as a page is sent at about the same time the
+destination accesses it.
+
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 02/57] Provide runtime Target page information
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
2015-11-10 14:24 ` [Qemu-devel] [PULL 01/57] Add postcopy documentation Juan Quintela
@ 2015-11-10 14:24 ` Juan Quintela
2015-11-10 14:24 ` [Qemu-devel] [PULL 03/57] Move configuration section writing Juan Quintela
` (55 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:24 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
The migration code generally is built target-independent, however
there are a few places where knowing the target page size would
avoid artificially moving stuff into migration/ram.c.
Provide 'qemu_target_page_bits()' that returns TARGET_PAGE_BITS
to other bits of code so that they can stay target-independent.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
exec.c | 10 ++++++++++
include/sysemu/sysemu.h | 1 +
2 files changed, 11 insertions(+)
diff --git a/exec.c b/exec.c
index a028961..4ced1a6 100644
--- a/exec.c
+++ b/exec.c
@@ -3502,6 +3502,16 @@ int cpu_memory_rw_debug(CPUState *cpu, target_ulong addr,
}
return 0;
}
+
+/*
+ * Allows code that needs to deal with migration bitmaps etc to still be built
+ * target independent.
+ */
+size_t qemu_target_page_bits(void)
+{
+ return TARGET_PAGE_BITS;
+}
+
#endif
/*
diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index 5cb0f05..8dc2add 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -70,6 +70,7 @@ void qemu_system_killed(int signal, pid_t pid);
void qemu_devices_reset(void);
void qemu_system_reset(bool report);
void qemu_system_guest_panicked(void);
+size_t qemu_target_page_bits(void);
void qemu_add_exit_notifier(Notifier *notify);
void qemu_remove_exit_notifier(Notifier *notify);
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 03/57] Move configuration section writing
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
2015-11-10 14:24 ` [Qemu-devel] [PULL 01/57] Add postcopy documentation Juan Quintela
2015-11-10 14:24 ` [Qemu-devel] [PULL 02/57] Provide runtime Target page information Juan Quintela
@ 2015-11-10 14:24 ` Juan Quintela
2015-11-10 14:24 ` [Qemu-devel] [PULL 04/57] Move page_size_init earlier Juan Quintela
` (54 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:24 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
The vmstate_configuration is currently written
in 'qemu_savevm_state_begin', move it to
'qemu_savevm_state_header' since it's got a hard
requirement that it must be the 1st thing after
the header.
(In postcopy some 'command' sections get sent
early before the saving of the main sections
and hence before qemu_savevm_state_begin).
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
migration/savevm.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/migration/savevm.c b/migration/savevm.c
index e05158d..638aa1f 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -713,6 +713,12 @@ void qemu_savevm_state_header(QEMUFile *f)
trace_savevm_state_header();
qemu_put_be32(f, QEMU_VM_FILE_MAGIC);
qemu_put_be32(f, QEMU_VM_FILE_VERSION);
+
+ if (!savevm_state.skip_configuration) {
+ qemu_put_byte(f, QEMU_VM_CONFIGURATION);
+ vmstate_save_state(f, &vmstate_configuration, &savevm_state, 0);
+ }
+
}
void qemu_savevm_state_begin(QEMUFile *f,
@@ -729,11 +735,6 @@ void qemu_savevm_state_begin(QEMUFile *f,
se->ops->set_params(params, se->opaque);
}
- if (!savevm_state.skip_configuration) {
- qemu_put_byte(f, QEMU_VM_CONFIGURATION);
- vmstate_save_state(f, &vmstate_configuration, &savevm_state, 0);
- }
-
QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
if (!se->ops || !se->ops->save_live_setup) {
continue;
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 04/57] Move page_size_init earlier
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (2 preceding siblings ...)
2015-11-10 14:24 ` [Qemu-devel] [PULL 03/57] Move configuration section writing Juan Quintela
@ 2015-11-10 14:24 ` Juan Quintela
2015-11-10 14:24 ` [Qemu-devel] [PULL 05/57] qemu_ram_block_from_host Juan Quintela
` (53 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:24 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
The HOST_PAGE_ALIGN macros don't work until the page size variables
have been set up; later in postcopy I use those macros in the RAM
code, and it can be triggered using -object.
Fix this by initialising page_size_init() earlier - it's currently
initialised inside the accelerators, move it up into vl.c.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/exec/exec-all.h | 1 -
include/qemu-common.h | 1 +
kvm-all.c | 1 -
qtest.c | 1 -
vl.c | 1 +
5 files changed, 2 insertions(+), 3 deletions(-)
diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
index b07de10..d900b0d 100644
--- a/include/exec/exec-all.h
+++ b/include/exec/exec-all.h
@@ -72,7 +72,6 @@ void restore_state_to_opc(CPUArchState *env, struct TranslationBlock *tb,
void cpu_gen_init(void);
bool cpu_restore_state(CPUState *cpu, uintptr_t searched_pc);
-void page_size_init(void);
void QEMU_NORETURN cpu_resume_from_signal(CPUState *cpu, void *puc);
void QEMU_NORETURN cpu_io_recompile(CPUState *cpu, uintptr_t retaddr);
diff --git a/include/qemu-common.h b/include/qemu-common.h
index 2f74540..405364f 100644
--- a/include/qemu-common.h
+++ b/include/qemu-common.h
@@ -499,5 +499,6 @@ size_t buffer_find_nonzero_offset(const void *buf, size_t len);
int parse_debug_env(const char *name, int max, int initial);
const char *qemu_ether_ntoa(const MACAddr *mac);
+void page_size_init(void);
#endif
diff --git a/kvm-all.c b/kvm-all.c
index 1bc1273..de3c8c4 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -1461,7 +1461,6 @@ static int kvm_init(MachineState *ms)
* page size for the system though.
*/
assert(TARGET_PAGE_SIZE <= getpagesize());
- page_size_init();
s->sigmask_len = 8;
diff --git a/qtest.c b/qtest.c
index 8e10340..05cefd2 100644
--- a/qtest.c
+++ b/qtest.c
@@ -657,7 +657,6 @@ void qtest_init(const char *qtest_chrdev, const char *qtest_log, Error **errp)
inbuf = g_string_new("");
qtest_chr = chr;
- page_size_init();
}
bool qtest_driver(void)
diff --git a/vl.c b/vl.c
index 21e8876..7d993a5 100644
--- a/vl.c
+++ b/vl.c
@@ -4285,6 +4285,7 @@ int main(int argc, char **argv, char **envp)
exit(1);
}
+ page_size_init();
socket_init();
if (qemu_opts_foreach(qemu_find_opts("object"),
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 05/57] qemu_ram_block_from_host
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (3 preceding siblings ...)
2015-11-10 14:24 ` [Qemu-devel] [PULL 04/57] Move page_size_init earlier Juan Quintela
@ 2015-11-10 14:24 ` Juan Quintela
2015-11-10 14:24 ` [Qemu-devel] [PULL 06/57] qemu_ram_block_by_name Juan Quintela
` (52 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:24 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Postcopy sends RAMBlock names and offsets over the wire (since it can't
rely on the order of ramaddr being the same), and it starts out with
HVA fault addresses from the kernel.
qemu_ram_block_from_host translates a HVA into a RAMBlock, an offset
in the RAMBlock and the global ram_addr_t value.
Rewrite qemu_ram_addr_from_host to use qemu_ram_block_from_host.
Provide qemu_ram_get_idstr since its the actual name text sent on the
wire.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
exec.c | 54 +++++++++++++++++++++++++++++++++++++++--------
include/exec/cpu-common.h | 3 +++
include/exec/ram_addr.h | 2 --
include/qemu/typedefs.h | 1 +
4 files changed, 49 insertions(+), 11 deletions(-)
diff --git a/exec.c b/exec.c
index 4ced1a6..53d3848 100644
--- a/exec.c
+++ b/exec.c
@@ -1377,6 +1377,11 @@ static RAMBlock *find_ram_block(ram_addr_t addr)
return NULL;
}
+const char *qemu_ram_get_idstr(RAMBlock *rb)
+{
+ return rb->idstr;
+}
+
/* Called with iothread lock held. */
void qemu_ram_set_idstr(ram_addr_t addr, const char *name, DeviceState *dev)
{
@@ -1877,8 +1882,16 @@ static void *qemu_ram_ptr_length(ram_addr_t addr, hwaddr *size)
}
}
-/* Some of the softmmu routines need to translate from a host pointer
- * (typically a TLB entry) back to a ram offset.
+/*
+ * Translates a host ptr back to a RAMBlock, a ram_addr and an offset
+ * in that RAMBlock.
+ *
+ * ptr: Host pointer to look up
+ * round_offset: If true round the result offset down to a page boundary
+ * *ram_addr: set to result ram_addr
+ * *offset: set to result offset within the RAMBlock
+ *
+ * Returns: RAMBlock (or NULL if not found)
*
* By the time this function returns, the returned pointer is not protected
* by RCU anymore. If the caller is not within an RCU critical section and
@@ -1886,18 +1899,22 @@ static void *qemu_ram_ptr_length(ram_addr_t addr, hwaddr *size)
* pointer, such as a reference to the region that includes the incoming
* ram_addr_t.
*/
-MemoryRegion *qemu_ram_addr_from_host(void *ptr, ram_addr_t *ram_addr)
+RAMBlock *qemu_ram_block_from_host(void *ptr, bool round_offset,
+ ram_addr_t *ram_addr,
+ ram_addr_t *offset)
{
RAMBlock *block;
uint8_t *host = ptr;
- MemoryRegion *mr;
if (xen_enabled()) {
rcu_read_lock();
*ram_addr = xen_ram_addr_from_mapcache(ptr);
- mr = qemu_get_ram_block(*ram_addr)->mr;
+ block = qemu_get_ram_block(*ram_addr);
+ if (block) {
+ *offset = (host - block->host);
+ }
rcu_read_unlock();
- return mr;
+ return block;
}
rcu_read_lock();
@@ -1920,10 +1937,29 @@ MemoryRegion *qemu_ram_addr_from_host(void *ptr, ram_addr_t *ram_addr)
return NULL;
found:
- *ram_addr = block->offset + (host - block->host);
- mr = block->mr;
+ *offset = (host - block->host);
+ if (round_offset) {
+ *offset &= TARGET_PAGE_MASK;
+ }
+ *ram_addr = block->offset + *offset;
rcu_read_unlock();
- return mr;
+ return block;
+}
+
+/* Some of the softmmu routines need to translate from a host pointer
+ (typically a TLB entry) back to a ram offset. */
+MemoryRegion *qemu_ram_addr_from_host(void *ptr, ram_addr_t *ram_addr)
+{
+ RAMBlock *block;
+ ram_addr_t offset; /* Not used */
+
+ block = qemu_ram_block_from_host(ptr, false, ram_addr, &offset);
+
+ if (!block) {
+ return NULL;
+ }
+
+ return block->mr;
}
static void notdirty_mem_write(void *opaque, hwaddr ram_addr,
diff --git a/include/exec/cpu-common.h b/include/exec/cpu-common.h
index 9fb1d54..94d1f8a 100644
--- a/include/exec/cpu-common.h
+++ b/include/exec/cpu-common.h
@@ -64,8 +64,11 @@ typedef uint32_t CPUReadMemoryFunc(void *opaque, hwaddr addr);
void qemu_ram_remap(ram_addr_t addr, ram_addr_t length);
/* This should not be used by devices. */
MemoryRegion *qemu_ram_addr_from_host(void *ptr, ram_addr_t *ram_addr);
+RAMBlock *qemu_ram_block_from_host(void *ptr, bool round_offset,
+ ram_addr_t *ram_addr, ram_addr_t *offset);
void qemu_ram_set_idstr(ram_addr_t addr, const char *name, DeviceState *dev);
void qemu_ram_unset_idstr(ram_addr_t addr);
+const char *qemu_ram_get_idstr(RAMBlock *rb);
void cpu_physical_memory_rw(hwaddr addr, uint8_t *buf,
int len, int is_write);
diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
index 3360ac5..7115154 100644
--- a/include/exec/ram_addr.h
+++ b/include/exec/ram_addr.h
@@ -22,8 +22,6 @@
#ifndef CONFIG_USER_ONLY
#include "hw/xen/xen.h"
-typedef struct RAMBlock RAMBlock;
-
struct RAMBlock {
struct rcu_head rcu;
struct MemoryRegion *mr;
diff --git a/include/qemu/typedefs.h b/include/qemu/typedefs.h
index 2cdce18..4338767 100644
--- a/include/qemu/typedefs.h
+++ b/include/qemu/typedefs.h
@@ -79,6 +79,7 @@ typedef struct QEMUSizedBuffer QEMUSizedBuffer;
typedef struct QEMUTimerListGroup QEMUTimerListGroup;
typedef struct QEMUTimer QEMUTimer;
typedef struct Range Range;
+typedef struct RAMBlock RAMBlock;
typedef struct SerialState SerialState;
typedef struct SHPCDevice SHPCDevice;
typedef struct SMBusDevice SMBusDevice;
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 06/57] qemu_ram_block_by_name
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (4 preceding siblings ...)
2015-11-10 14:24 ` [Qemu-devel] [PULL 05/57] qemu_ram_block_from_host Juan Quintela
@ 2015-11-10 14:24 ` Juan Quintela
2015-11-10 14:24 ` [Qemu-devel] [PULL 07/57] Rename mis->file to from_src_file Juan Quintela
` (51 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:24 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Add a function to find a RAMBlock by name; use it in two
of the places that already open code that loop; we've
got another use later in postcopy.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
exec.c | 20 ++++++++++++++++++++
include/exec/cpu-common.h | 1 +
migration/ram.c | 35 +++++++++++++++--------------------
3 files changed, 36 insertions(+), 20 deletions(-)
diff --git a/exec.c b/exec.c
index 53d3848..36886ee 100644
--- a/exec.c
+++ b/exec.c
@@ -1946,6 +1946,26 @@ found:
return block;
}
+/*
+ * Finds the named RAMBlock
+ *
+ * name: The name of RAMBlock to find
+ *
+ * Returns: RAMBlock (or NULL if not found)
+ */
+RAMBlock *qemu_ram_block_by_name(const char *name)
+{
+ RAMBlock *block;
+
+ QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+ if (!strcmp(name, block->idstr)) {
+ return block;
+ }
+ }
+
+ return NULL;
+}
+
/* Some of the softmmu routines need to translate from a host pointer
(typically a TLB entry) back to a ram offset. */
MemoryRegion *qemu_ram_addr_from_host(void *ptr, ram_addr_t *ram_addr)
diff --git a/include/exec/cpu-common.h b/include/exec/cpu-common.h
index 94d1f8a..85aa403 100644
--- a/include/exec/cpu-common.h
+++ b/include/exec/cpu-common.h
@@ -64,6 +64,7 @@ typedef uint32_t CPUReadMemoryFunc(void *opaque, hwaddr addr);
void qemu_ram_remap(ram_addr_t addr, ram_addr_t length);
/* This should not be used by devices. */
MemoryRegion *qemu_ram_addr_from_host(void *ptr, ram_addr_t *ram_addr);
+RAMBlock *qemu_ram_block_by_name(const char *name);
RAMBlock *qemu_ram_block_from_host(void *ptr, bool round_offset,
ram_addr_t *ram_addr, ram_addr_t *offset);
void qemu_ram_set_idstr(ram_addr_t addr, const char *name, DeviceState *dev);
diff --git a/migration/ram.c b/migration/ram.c
index df3df9e..d654a73 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1420,14 +1420,12 @@ static inline void *host_from_stream_offset(QEMUFile *f,
qemu_get_buffer(f, (uint8_t *)id, len);
id[len] = 0;
- QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
- if (!strncmp(id, block->idstr, sizeof(id)) &&
- block->max_length > offset) {
- return block->host + offset;
- }
+ block = qemu_ram_block_by_name(id);
+ if (block && block->max_length > offset) {
+ return block->host + offset;
}
- error_report("Can't find block %s!", id);
+ error_report("Can't find block %s", id);
return NULL;
}
@@ -1576,23 +1574,20 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
id[len] = 0;
length = qemu_get_be64(f);
- QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
- if (!strncmp(id, block->idstr, sizeof(id))) {
- if (length != block->used_length) {
- Error *local_err = NULL;
+ block = qemu_ram_block_by_name(id);
+ if (block) {
+ if (length != block->used_length) {
+ Error *local_err = NULL;
- ret = qemu_ram_resize(block->offset, length, &local_err);
- if (local_err) {
- error_report_err(local_err);
- }
+ ret = qemu_ram_resize(block->offset, length,
+ &local_err);
+ if (local_err) {
+ error_report_err(local_err);
}
- ram_control_load_hook(f, RAM_CONTROL_BLOCK_REG,
- block->idstr);
- break;
}
- }
-
- if (!block) {
+ ram_control_load_hook(f, RAM_CONTROL_BLOCK_REG,
+ block->idstr);
+ } else {
error_report("Unknown ramblock \"%s\", cannot "
"accept migration", id);
ret = -EINVAL;
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 07/57] Rename mis->file to from_src_file
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (5 preceding siblings ...)
2015-11-10 14:24 ` [Qemu-devel] [PULL 06/57] qemu_ram_block_by_name Juan Quintela
@ 2015-11-10 14:24 ` Juan Quintela
2015-11-10 14:24 ` [Qemu-devel] [PULL 08/57] Add qemu_get_buffer_in_place to avoid copies some of the time Juan Quintela
` (50 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:24 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
'file' becomes confusing when you have flows in each direction;
rename to make it clear.
This leaves just the main forward direction ms->file, which is used
in a lot of places and is probably not worth renaming given the churn.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/migration/migration.h | 2 +-
migration/migration.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 8334621..83fba23 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -48,7 +48,7 @@ typedef QLIST_HEAD(, LoadStateEntry) LoadStateEntry_Head;
/* State for the incoming migration */
struct MigrationIncomingState {
- QEMUFile *file;
+ QEMUFile *from_src_file;
/* See savevm.c */
LoadStateEntry_Head loadvm_handlers;
diff --git a/migration/migration.c b/migration/migration.c
index f99d3ea..6fef544 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -95,7 +95,7 @@ MigrationIncomingState *migration_incoming_get_current(void)
MigrationIncomingState *migration_incoming_state_new(QEMUFile* f)
{
mis_current = g_new0(MigrationIncomingState, 1);
- mis_current->file = f;
+ mis_current->from_src_file = f;
QLIST_INIT(&mis_current->loadvm_handlers);
return mis_current;
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 08/57] Add qemu_get_buffer_in_place to avoid copies some of the time
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (6 preceding siblings ...)
2015-11-10 14:24 ` [Qemu-devel] [PULL 07/57] Rename mis->file to from_src_file Juan Quintela
@ 2015-11-10 14:24 ` Juan Quintela
2015-11-10 14:24 ` [Qemu-devel] [PULL 09/57] Add wrapper for setting blocking status on a QEMUFile Juan Quintela
` (49 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:24 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
qemu_get_buffer always copies the data it reads to a users buffer,
however in many cases the file buffer inside qemu_file could be given
back to the caller, avoiding the copy. This isn't always possible
depending on the size and alignment of the data.
Thus 'qemu_get_buffer_in_place' either copies the data to a supplied
buffer or updates a pointer to the internal buffer if convenient.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/migration/qemu-file.h | 2 ++
migration/qemu-file.c | 37 +++++++++++++++++++++++++++++++++++++
2 files changed, 39 insertions(+)
diff --git a/include/migration/qemu-file.h b/include/migration/qemu-file.h
index 29a338d..86bb972 100644
--- a/include/migration/qemu-file.h
+++ b/include/migration/qemu-file.h
@@ -163,9 +163,11 @@ void qemu_put_be32(QEMUFile *f, unsigned int v);
void qemu_put_be64(QEMUFile *f, uint64_t v);
size_t qemu_peek_buffer(QEMUFile *f, uint8_t **buf, size_t size, size_t offset);
size_t qemu_get_buffer(QEMUFile *f, uint8_t *buf, size_t size);
+size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size);
ssize_t qemu_put_compression_data(QEMUFile *f, const uint8_t *p, size_t size,
int level);
int qemu_put_qemu_file(QEMUFile *f_des, QEMUFile *f_src);
+
/*
* Note that you can only peek continuous bytes from where the current pointer
* is; you aren't guaranteed to be able to peak to +n bytes unless you've
diff --git a/migration/qemu-file.c b/migration/qemu-file.c
index df49023..e41a677 100644
--- a/migration/qemu-file.c
+++ b/migration/qemu-file.c
@@ -434,6 +434,43 @@ size_t qemu_get_buffer(QEMUFile *f, uint8_t *buf, size_t size)
}
/*
+ * Read 'size' bytes of data from the file.
+ * 'size' can be larger than the internal buffer.
+ *
+ * The data:
+ * may be held on an internal buffer (in which case *buf is updated
+ * to point to it) that is valid until the next qemu_file operation.
+ * OR
+ * will be copied to the *buf that was passed in.
+ *
+ * The code tries to avoid the copy if possible.
+ *
+ * It will return size bytes unless there was an error, in which case it will
+ * return as many as it managed to read (assuming blocking fd's which
+ * all current QEMUFile are)
+ *
+ * Note: Since **buf may get changed, the caller should take care to
+ * keep a pointer to the original buffer if it needs to deallocate it.
+ */
+size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size)
+{
+ if (size < IO_BUF_SIZE) {
+ size_t res;
+ uint8_t *src;
+
+ res = qemu_peek_buffer(f, &src, size, 0);
+
+ if (res == size) {
+ qemu_file_skip(f, res);
+ *buf = src;
+ return res;
+ }
+ }
+
+ return qemu_get_buffer(f, *buf, size);
+}
+
+/*
* Peeks a single byte from the buffer; this isn't guaranteed to work if
* offset leaves a gap after the previous read/peeked data.
*/
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 09/57] Add wrapper for setting blocking status on a QEMUFile
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (7 preceding siblings ...)
2015-11-10 14:24 ` [Qemu-devel] [PULL 08/57] Add qemu_get_buffer_in_place to avoid copies some of the time Juan Quintela
@ 2015-11-10 14:24 ` Juan Quintela
2015-11-10 14:24 ` [Qemu-devel] [PULL 10/57] Add QEMU_MADV_NOHUGEPAGE Juan Quintela
` (48 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:24 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Add a wrapper to change the blocking status on a QEMUFile
rather than having to use qemu_set_block(qemu_get_fd(f));
it seems best to avoid exposing the fd since not all QEMUFile's
really have one. With this wrapper we could move the implementation
down to be different on different transports.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/migration/qemu-file.h | 1 +
migration/qemu-file.c | 15 +++++++++++++++
2 files changed, 16 insertions(+)
diff --git a/include/migration/qemu-file.h b/include/migration/qemu-file.h
index 86bb972..66e741f 100644
--- a/include/migration/qemu-file.h
+++ b/include/migration/qemu-file.h
@@ -197,6 +197,7 @@ int qemu_file_get_error(QEMUFile *f);
void qemu_file_set_error(QEMUFile *f, int ret);
int qemu_file_shutdown(QEMUFile *f);
void qemu_fflush(QEMUFile *f);
+void qemu_file_set_blocking(QEMUFile *f, bool block);
static inline void qemu_put_be64s(QEMUFile *f, const uint64_t *pv)
{
diff --git a/migration/qemu-file.c b/migration/qemu-file.c
index e41a677..9ec2267 100644
--- a/migration/qemu-file.c
+++ b/migration/qemu-file.c
@@ -648,3 +648,18 @@ size_t qemu_get_counted_string(QEMUFile *f, char buf[256])
return res == len ? res : 0;
}
+
+/*
+ * Set the blocking state of the QEMUFile.
+ * Note: On some transports the OS only keeps a single blocking state for
+ * both directions, and thus changing the blocking on the main
+ * QEMUFile can also affect the return path.
+ */
+void qemu_file_set_blocking(QEMUFile *f, bool block)
+{
+ if (block) {
+ qemu_set_block(qemu_get_fd(f));
+ } else {
+ qemu_set_nonblock(qemu_get_fd(f));
+ }
+}
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 10/57] Add QEMU_MADV_NOHUGEPAGE
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (8 preceding siblings ...)
2015-11-10 14:24 ` [Qemu-devel] [PULL 09/57] Add wrapper for setting blocking status on a QEMUFile Juan Quintela
@ 2015-11-10 14:24 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 11/57] ram_debug_dump_bitmap: Dump a migration bitmap as text Juan Quintela
` (47 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:24 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Add QEMU_MADV_NOHUGEPAGE as an OS-independent version of
MADV_NOHUGEPAGE.
We include sys/mman.h before making the test to ensure
that we pick up the system defines.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/qemu/osdep.h | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
index ab2d5d9..861d84b 100644
--- a/include/qemu/osdep.h
+++ b/include/qemu/osdep.h
@@ -139,6 +139,8 @@ void qemu_anon_ram_free(void *ptr, size_t size);
#if defined(CONFIG_MADVISE)
+#include <sys/mman.h>
+
#define QEMU_MADV_WILLNEED MADV_WILLNEED
#define QEMU_MADV_DONTNEED MADV_DONTNEED
#ifdef MADV_DONTFORK
@@ -171,6 +173,11 @@ void qemu_anon_ram_free(void *ptr, size_t size);
#else
#define QEMU_MADV_HUGEPAGE QEMU_MADV_INVALID
#endif
+#ifdef MADV_NOHUGEPAGE
+#define QEMU_MADV_NOHUGEPAGE MADV_NOHUGEPAGE
+#else
+#define QEMU_MADV_NOHUGEPAGE QEMU_MADV_INVALID
+#endif
#elif defined(CONFIG_POSIX_MADVISE)
@@ -182,6 +189,7 @@ void qemu_anon_ram_free(void *ptr, size_t size);
#define QEMU_MADV_DODUMP QEMU_MADV_INVALID
#define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID
#define QEMU_MADV_HUGEPAGE QEMU_MADV_INVALID
+#define QEMU_MADV_NOHUGEPAGE QEMU_MADV_INVALID
#else /* no-op */
@@ -193,6 +201,7 @@ void qemu_anon_ram_free(void *ptr, size_t size);
#define QEMU_MADV_DODUMP QEMU_MADV_INVALID
#define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID
#define QEMU_MADV_HUGEPAGE QEMU_MADV_INVALID
+#define QEMU_MADV_NOHUGEPAGE QEMU_MADV_INVALID
#endif
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 11/57] ram_debug_dump_bitmap: Dump a migration bitmap as text
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (9 preceding siblings ...)
2015-11-10 14:24 ` [Qemu-devel] [PULL 10/57] Add QEMU_MADV_NOHUGEPAGE Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 12/57] ram_load: Factor out host_from_stream_offset call and check Juan Quintela
` (46 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Useful for debugging the migration bitmap and other bitmaps
of the same format (including the sentmap in postcopy).
The bitmap is printed to stderr.
Lines that are all the expected value are excluded so the output
can be quite compact for many bitmaps.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/migration/migration.h | 1 +
migration/ram.c | 39 +++++++++++++++++++++++++++++++++++++++
2 files changed, 40 insertions(+)
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 83fba23..51bc348 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -145,6 +145,7 @@ uint64_t xbzrle_mig_pages_cache_miss(void);
double xbzrle_mig_cache_miss_rate(void);
void ram_handle_compressed(void *host, uint8_t ch, uint64_t size);
+void ram_debug_dump_bitmap(unsigned long *todump, bool expected);
/**
* @migrate_add_blocker - prevent migration from proceeding
diff --git a/migration/ram.c b/migration/ram.c
index d654a73..86bf657 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1160,6 +1160,45 @@ void migration_bitmap_extend(ram_addr_t old, ram_addr_t new)
}
}
+/*
+ * 'expected' is the value you expect the bitmap mostly to be full
+ * of; it won't bother printing lines that are all this value.
+ * If 'todump' is null the migration bitmap is dumped.
+ */
+void ram_debug_dump_bitmap(unsigned long *todump, bool expected)
+{
+ int64_t ram_pages = last_ram_offset() >> TARGET_PAGE_BITS;
+
+ int64_t cur;
+ int64_t linelen = 128;
+ char linebuf[129];
+
+ if (!todump) {
+ todump = atomic_rcu_read(&migration_bitmap_rcu)->bmap;
+ }
+
+ for (cur = 0; cur < ram_pages; cur += linelen) {
+ int64_t curb;
+ bool found = false;
+ /*
+ * Last line; catch the case where the line length
+ * is longer than remaining ram
+ */
+ if (cur + linelen > ram_pages) {
+ linelen = ram_pages - cur;
+ }
+ for (curb = 0; curb < linelen; curb++) {
+ bool thisbit = test_bit(cur + curb, todump);
+ linebuf[curb] = thisbit ? '1' : '.';
+ found = found || (thisbit != expected);
+ }
+ if (found) {
+ linebuf[curb] = '\0';
+ fprintf(stderr, "0x%08" PRIx64 " : %s\n", cur, linebuf);
+ }
+ }
+}
+
/* Each of ram_save_setup, ram_save_iterate and ram_save_complete has
* long-running RCU critical section. When rcu-reclaims in the code
* start to become numerous it will be necessary to reduce the
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 12/57] ram_load: Factor out host_from_stream_offset call and check
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (10 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 11/57] ram_debug_dump_bitmap: Dump a migration bitmap as text Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 13/57] migrate_init: Call from savevm Juan Quintela
` (45 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
The main RAM load loop has a call to host_from_stream_offset for
each page type that actually loads data with the same test;
factor it out before the switch.
The host = NULL is to silence a bogus gcc warning of
an unitialised in the RAM_SAVE_COMPRESS_PAGE case, it
doesn't seem to realise that host is always initialised by the if at
the top in the cases the switch takes.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
migration/ram.c | 41 +++++++++++++++--------------------------
1 file changed, 15 insertions(+), 26 deletions(-)
diff --git a/migration/ram.c b/migration/ram.c
index 86bf657..298332c 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1592,13 +1592,23 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
rcu_read_lock();
while (!ret && !(flags & RAM_SAVE_FLAG_EOS)) {
ram_addr_t addr, total_ram_bytes;
- void *host;
+ void *host = NULL;
uint8_t ch;
addr = qemu_get_be64(f);
flags = addr & ~TARGET_PAGE_MASK;
addr &= TARGET_PAGE_MASK;
+ if (flags & (RAM_SAVE_FLAG_COMPRESS | RAM_SAVE_FLAG_PAGE |
+ RAM_SAVE_FLAG_COMPRESS_PAGE | RAM_SAVE_FLAG_XBZRLE)) {
+ host = host_from_stream_offset(f, addr, flags);
+ if (!host) {
+ error_report("Illegal RAM offset " RAM_ADDR_FMT, addr);
+ ret = -EINVAL;
+ break;
+ }
+ }
+
switch (flags & ~RAM_SAVE_FLAG_CONTINUE) {
case RAM_SAVE_FLAG_MEM_SIZE:
/* Synchronize RAM block list */
@@ -1635,33 +1645,17 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
total_ram_bytes -= length;
}
break;
+
case RAM_SAVE_FLAG_COMPRESS:
- host = host_from_stream_offset(f, addr, flags);
- if (!host) {
- error_report("Illegal RAM offset " RAM_ADDR_FMT, addr);
- ret = -EINVAL;
- break;
- }
ch = qemu_get_byte(f);
ram_handle_compressed(host, ch, TARGET_PAGE_SIZE);
break;
+
case RAM_SAVE_FLAG_PAGE:
- host = host_from_stream_offset(f, addr, flags);
- if (!host) {
- error_report("Illegal RAM offset " RAM_ADDR_FMT, addr);
- ret = -EINVAL;
- break;
- }
qemu_get_buffer(f, host, TARGET_PAGE_SIZE);
break;
+
case RAM_SAVE_FLAG_COMPRESS_PAGE:
- host = host_from_stream_offset(f, addr, flags);
- if (!host) {
- error_report("Invalid RAM offset " RAM_ADDR_FMT, addr);
- ret = -EINVAL;
- break;
- }
-
len = qemu_get_be32(f);
if (len < 0 || len > compressBound(TARGET_PAGE_SIZE)) {
error_report("Invalid compressed data length: %d", len);
@@ -1671,13 +1665,8 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
qemu_get_buffer(f, compressed_data_buf, len);
decompress_data_with_multi_threads(compressed_data_buf, host, len);
break;
+
case RAM_SAVE_FLAG_XBZRLE:
- host = host_from_stream_offset(f, addr, flags);
- if (!host) {
- error_report("Illegal RAM offset " RAM_ADDR_FMT, addr);
- ret = -EINVAL;
- break;
- }
if (load_xbzrle(f, addr, host) < 0) {
error_report("Failed to decompress XBZRLE page at "
RAM_ADDR_FMT, addr);
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 13/57] migrate_init: Call from savevm
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (11 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 12/57] ram_load: Factor out host_from_stream_offset call and check Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 14/57] Rename save_live_complete to save_live_complete_precopy Juan Quintela
` (44 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Suspend to file is very much like a migrate, and it makes life
easier if we have the Migration state available, so initialise it
in the savevm.c code for suspending.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewd-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/migration/migration.h | 4 +---
include/qemu/typedefs.h | 1 +
migration/migration.c | 2 +-
migration/savevm.c | 2 ++
4 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 51bc348..82cc3a6 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -42,10 +42,7 @@ struct MigrationParams {
bool shared;
};
-typedef struct MigrationState MigrationState;
-
typedef QLIST_HEAD(, LoadStateEntry) LoadStateEntry_Head;
-
/* State for the incoming migration */
struct MigrationIncomingState {
QEMUFile *from_src_file;
@@ -116,6 +113,7 @@ int migrate_fd_close(MigrationState *s);
void add_migration_state_change_notifier(Notifier *notify);
void remove_migration_state_change_notifier(Notifier *notify);
+MigrationState *migrate_init(const MigrationParams *params);
bool migration_in_setup(MigrationState *);
bool migration_has_finished(MigrationState *);
bool migration_has_failed(MigrationState *);
diff --git a/include/qemu/typedefs.h b/include/qemu/typedefs.h
index 4338767..f7e0ed0 100644
--- a/include/qemu/typedefs.h
+++ b/include/qemu/typedefs.h
@@ -44,6 +44,7 @@ typedef struct MemoryRegion MemoryRegion;
typedef struct MemoryRegionSection MemoryRegionSection;
typedef struct MigrationIncomingState MigrationIncomingState;
typedef struct MigrationParams MigrationParams;
+typedef struct MigrationState MigrationState;
typedef struct Monitor Monitor;
typedef struct MouseTransformInfo MouseTransformInfo;
typedef struct MSIMessage MSIMessage;
diff --git a/migration/migration.c b/migration/migration.c
index 6fef544..82efbeb 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -682,7 +682,7 @@ bool migration_has_failed(MigrationState *s)
s->state == MIGRATION_STATUS_FAILED);
}
-static MigrationState *migrate_init(const MigrationParams *params)
+MigrationState *migrate_init(const MigrationParams *params)
{
MigrationState *s = migrate_get_current();
int64_t bandwidth_limit = s->bandwidth_limit;
diff --git a/migration/savevm.c b/migration/savevm.c
index 638aa1f..9dc57d3 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -922,6 +922,8 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp)
.blk = 0,
.shared = 0
};
+ MigrationState *ms = migrate_init(¶ms);
+ ms->file = f;
if (qemu_savevm_state_blocked(errp)) {
return -EINVAL;
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 14/57] Rename save_live_complete to save_live_complete_precopy
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (12 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 13/57] migrate_init: Call from savevm Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 15/57] Add Linux userfaultfd.h header Juan Quintela
` (43 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
In postcopy we're going to need to perform the complete phase
for postcopiable devices at a different point, start out by
renaming all of the 'complete's to make the difference obvious.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
hw/ppc/spapr.c | 2 +-
include/migration/vmstate.h | 2 +-
include/sysemu/sysemu.h | 2 +-
migration/block.c | 2 +-
migration/migration.c | 2 +-
migration/ram.c | 2 +-
migration/savevm.c | 10 +++++-----
trace-events | 2 +-
8 files changed, 12 insertions(+), 12 deletions(-)
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 0ed8527..37d071e 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -1588,7 +1588,7 @@ static int htab_load(QEMUFile *f, void *opaque, int version_id)
static SaveVMHandlers savevm_htab_handlers = {
.save_live_setup = htab_save_setup,
.save_live_iterate = htab_save_iterate,
- .save_live_complete = htab_save_complete,
+ .save_live_complete_precopy = htab_save_complete,
.load_state = htab_load,
};
diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h
index d173b56..9986ccc 100644
--- a/include/migration/vmstate.h
+++ b/include/migration/vmstate.h
@@ -40,7 +40,7 @@ typedef struct SaveVMHandlers {
SaveStateHandler *save_state;
void (*cleanup)(void *opaque);
- int (*save_live_complete)(QEMUFile *f, void *opaque);
+ int (*save_live_complete_precopy)(QEMUFile *f, void *opaque);
/* This runs both outside and inside the iothread lock. */
bool (*is_active)(void *opaque);
diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index 8dc2add..470445f 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -89,8 +89,8 @@ void qemu_savevm_state_begin(QEMUFile *f,
const MigrationParams *params);
void qemu_savevm_state_header(QEMUFile *f);
int qemu_savevm_state_iterate(QEMUFile *f);
-void qemu_savevm_state_complete(QEMUFile *f);
void qemu_savevm_state_cleanup(void);
+void qemu_savevm_state_complete_precopy(QEMUFile *f);
uint64_t qemu_savevm_state_pending(QEMUFile *f, uint64_t max_size);
int qemu_loadvm_state(QEMUFile *f);
diff --git a/migration/block.c b/migration/block.c
index cf9d9f8..4fb9b7c 100644
--- a/migration/block.c
+++ b/migration/block.c
@@ -876,7 +876,7 @@ static SaveVMHandlers savevm_block_handlers = {
.set_params = block_set_params,
.save_live_setup = block_save_setup,
.save_live_iterate = block_save_iterate,
- .save_live_complete = block_save_complete,
+ .save_live_complete_precopy = block_save_complete,
.save_live_pending = block_save_pending,
.load_state = block_load,
.cleanup = block_migration_cleanup,
diff --git a/migration/migration.c b/migration/migration.c
index 82efbeb..bb7dcb9 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -994,7 +994,7 @@ static void migration_completion(MigrationState *s, bool *old_vm_running,
ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
if (ret >= 0) {
qemu_file_set_rate_limit(s->file, INT64_MAX);
- qemu_savevm_state_complete(s->file);
+ qemu_savevm_state_complete_precopy(s->file);
}
}
qemu_mutex_unlock_iothread();
diff --git a/migration/ram.c b/migration/ram.c
index 298332c..4fa44a7 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1700,7 +1700,7 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
static SaveVMHandlers savevm_ram_handlers = {
.save_live_setup = ram_save_setup,
.save_live_iterate = ram_save_iterate,
- .save_live_complete = ram_save_complete,
+ .save_live_complete_precopy = ram_save_complete,
.save_live_pending = ram_save_pending,
.load_state = ram_load,
.cleanup = ram_migration_cleanup,
diff --git a/migration/savevm.c b/migration/savevm.c
index 9dc57d3..fed41e6 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -807,19 +807,19 @@ static bool should_send_vmdesc(void)
return !machine->suppress_vmdesc;
}
-void qemu_savevm_state_complete(QEMUFile *f)
+void qemu_savevm_state_complete_precopy(QEMUFile *f)
{
QJSON *vmdesc;
int vmdesc_len;
SaveStateEntry *se;
int ret;
- trace_savevm_state_complete();
+ trace_savevm_state_complete_precopy();
cpu_synchronize_all_states();
QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
- if (!se->ops || !se->ops->save_live_complete) {
+ if (!se->ops || !se->ops->save_live_complete_precopy) {
continue;
}
if (se->ops && se->ops->is_active) {
@@ -831,7 +831,7 @@ void qemu_savevm_state_complete(QEMUFile *f)
save_section_header(f, se, QEMU_VM_SECTION_END);
- ret = se->ops->save_live_complete(f, se->opaque);
+ ret = se->ops->save_live_complete_precopy(f, se->opaque);
trace_savevm_section_end(se->idstr, se->section_id, ret);
save_section_footer(f, se);
if (ret < 0) {
@@ -942,7 +942,7 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp)
ret = qemu_file_get_error(f);
if (ret == 0) {
- qemu_savevm_state_complete(f);
+ qemu_savevm_state_complete_precopy(f);
ret = qemu_file_get_error(f);
}
if (ret != 0) {
diff --git a/trace-events b/trace-events
index ea2d32e..277a4aa 100644
--- a/trace-events
+++ b/trace-events
@@ -1210,8 +1210,8 @@ savevm_section_skip(const char *id, unsigned int section_id) "%s, section_id %u"
savevm_state_begin(void) ""
savevm_state_header(void) ""
savevm_state_iterate(void) ""
-savevm_state_complete(void) ""
savevm_state_cleanup(void) ""
+savevm_state_complete_precopy(void) ""
vmstate_save(const char *idstr, const char *vmsd_name) "%s, %s"
vmstate_load(const char *idstr, const char *vmsd_name) "%s, %s"
qemu_announce_self_iter(const char *mac) "%s"
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 15/57] Add Linux userfaultfd.h header
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (13 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 14/57] Rename save_live_complete to save_live_complete_precopy Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 16/57] Return path: Open a return path on QEMUFile for sockets Juan Quintela
` (42 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Postcopy uses the userfaultfd.h feature in the Linux kernel; include
the header.
(In early versions of the patch series we had this, and then we dropped
this by only including it if the kernel headers defined the syscall
number; however 1842bdfd added the syscall definition to our
headers, which means we can't tell if the kernel has it or not)
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
| 167 ++++++++++++++++++++++++++++++++++++++
1 file changed, 167 insertions(+)
create mode 100644 linux-headers/linux/userfaultfd.h
--git a/linux-headers/linux/userfaultfd.h b/linux-headers/linux/userfaultfd.h
new file mode 100644
index 0000000..9057d7a
--- /dev/null
+++ b/linux-headers/linux/userfaultfd.h
@@ -0,0 +1,167 @@
+/*
+ * include/linux/userfaultfd.h
+ *
+ * Copyright (C) 2007 Davide Libenzi <davidel@xmailserver.org>
+ * Copyright (C) 2015 Red Hat, Inc.
+ *
+ */
+
+#ifndef _LINUX_USERFAULTFD_H
+#define _LINUX_USERFAULTFD_H
+
+#include <linux/types.h>
+
+#define UFFD_API ((__u64)0xAA)
+/*
+ * After implementing the respective features it will become:
+ * #define UFFD_API_FEATURES (UFFD_FEATURE_PAGEFAULT_FLAG_WP | \
+ * UFFD_FEATURE_EVENT_FORK)
+ */
+#define UFFD_API_FEATURES (0)
+#define UFFD_API_IOCTLS \
+ ((__u64)1 << _UFFDIO_REGISTER | \
+ (__u64)1 << _UFFDIO_UNREGISTER | \
+ (__u64)1 << _UFFDIO_API)
+#define UFFD_API_RANGE_IOCTLS \
+ ((__u64)1 << _UFFDIO_WAKE | \
+ (__u64)1 << _UFFDIO_COPY | \
+ (__u64)1 << _UFFDIO_ZEROPAGE)
+
+/*
+ * Valid ioctl command number range with this API is from 0x00 to
+ * 0x3F. UFFDIO_API is the fixed number, everything else can be
+ * changed by implementing a different UFFD_API. If sticking to the
+ * same UFFD_API more ioctl can be added and userland will be aware of
+ * which ioctl the running kernel implements through the ioctl command
+ * bitmask written by the UFFDIO_API.
+ */
+#define _UFFDIO_REGISTER (0x00)
+#define _UFFDIO_UNREGISTER (0x01)
+#define _UFFDIO_WAKE (0x02)
+#define _UFFDIO_COPY (0x03)
+#define _UFFDIO_ZEROPAGE (0x04)
+#define _UFFDIO_API (0x3F)
+
+/* userfaultfd ioctl ids */
+#define UFFDIO 0xAA
+#define UFFDIO_API _IOWR(UFFDIO, _UFFDIO_API, \
+ struct uffdio_api)
+#define UFFDIO_REGISTER _IOWR(UFFDIO, _UFFDIO_REGISTER, \
+ struct uffdio_register)
+#define UFFDIO_UNREGISTER _IOR(UFFDIO, _UFFDIO_UNREGISTER, \
+ struct uffdio_range)
+#define UFFDIO_WAKE _IOR(UFFDIO, _UFFDIO_WAKE, \
+ struct uffdio_range)
+#define UFFDIO_COPY _IOWR(UFFDIO, _UFFDIO_COPY, \
+ struct uffdio_copy)
+#define UFFDIO_ZEROPAGE _IOWR(UFFDIO, _UFFDIO_ZEROPAGE, \
+ struct uffdio_zeropage)
+
+/* read() structure */
+struct uffd_msg {
+ __u8 event;
+
+ __u8 reserved1;
+ __u16 reserved2;
+ __u32 reserved3;
+
+ union {
+ struct {
+ __u64 flags;
+ __u64 address;
+ } pagefault;
+
+ struct {
+ /* unused reserved fields */
+ __u64 reserved1;
+ __u64 reserved2;
+ __u64 reserved3;
+ } reserved;
+ } arg;
+} __packed;
+
+/*
+ * Start at 0x12 and not at 0 to be more strict against bugs.
+ */
+#define UFFD_EVENT_PAGEFAULT 0x12
+#if 0 /* not available yet */
+#define UFFD_EVENT_FORK 0x13
+#endif
+
+/* flags for UFFD_EVENT_PAGEFAULT */
+#define UFFD_PAGEFAULT_FLAG_WRITE (1<<0) /* If this was a write fault */
+#define UFFD_PAGEFAULT_FLAG_WP (1<<1) /* If reason is VM_UFFD_WP */
+
+struct uffdio_api {
+ /* userland asks for an API number and the features to enable */
+ __u64 api;
+ /*
+ * Kernel answers below with the all available features for
+ * the API, this notifies userland of which events and/or
+ * which flags for each event are enabled in the current
+ * kernel.
+ *
+ * Note: UFFD_EVENT_PAGEFAULT and UFFD_PAGEFAULT_FLAG_WRITE
+ * are to be considered implicitly always enabled in all kernels as
+ * long as the uffdio_api.api requested matches UFFD_API.
+ */
+#if 0 /* not available yet */
+#define UFFD_FEATURE_PAGEFAULT_FLAG_WP (1<<0)
+#define UFFD_FEATURE_EVENT_FORK (1<<1)
+#endif
+ __u64 features;
+
+ __u64 ioctls;
+};
+
+struct uffdio_range {
+ __u64 start;
+ __u64 len;
+};
+
+struct uffdio_register {
+ struct uffdio_range range;
+#define UFFDIO_REGISTER_MODE_MISSING ((__u64)1<<0)
+#define UFFDIO_REGISTER_MODE_WP ((__u64)1<<1)
+ __u64 mode;
+
+ /*
+ * kernel answers which ioctl commands are available for the
+ * range, keep at the end as the last 8 bytes aren't read.
+ */
+ __u64 ioctls;
+};
+
+struct uffdio_copy {
+ __u64 dst;
+ __u64 src;
+ __u64 len;
+ /*
+ * There will be a wrprotection flag later that allows to map
+ * pages wrprotected on the fly. And such a flag will be
+ * available if the wrprotection ioctl are implemented for the
+ * range according to the uffdio_register.ioctls.
+ */
+#define UFFDIO_COPY_MODE_DONTWAKE ((__u64)1<<0)
+ __u64 mode;
+
+ /*
+ * "copy" is written by the ioctl and must be at the end: the
+ * copy_from_user will not read the last 8 bytes.
+ */
+ __s64 copy;
+};
+
+struct uffdio_zeropage {
+ struct uffdio_range range;
+#define UFFDIO_ZEROPAGE_MODE_DONTWAKE ((__u64)1<<0)
+ __u64 mode;
+
+ /*
+ * "zeropage" is written by the ioctl and must be at the end:
+ * the copy_from_user will not read the last 8 bytes.
+ */
+ __s64 zeropage;
+};
+
+#endif /* _LINUX_USERFAULTFD_H */
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 16/57] Return path: Open a return path on QEMUFile for sockets
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (14 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 15/57] Add Linux userfaultfd.h header Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 17/57] Return path: socket_writev_buffer: Block even on non-blocking fd's Juan Quintela
` (41 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Postcopy needs a method to send messages from the destination back to
the source, this is the 'return path'.
Wire it up for 'socket' QEMUFile's.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/migration/qemu-file.h | 7 +++++
migration/qemu-file-unix.c | 69 +++++++++++++++++++++++++++++++++++++------
migration/qemu-file.c | 12 ++++++++
3 files changed, 79 insertions(+), 9 deletions(-)
diff --git a/include/migration/qemu-file.h b/include/migration/qemu-file.h
index 66e741f..b5d08d2 100644
--- a/include/migration/qemu-file.h
+++ b/include/migration/qemu-file.h
@@ -89,6 +89,11 @@ typedef size_t (QEMURamSaveFunc)(QEMUFile *f, void *opaque,
uint64_t *bytes_sent);
/*
+ * Return a QEMUFile for comms in the opposite direction
+ */
+typedef QEMUFile *(QEMURetPathFunc)(void *opaque);
+
+/*
* Stop any read or write (depending on flags) on the underlying
* transport on the QEMUFile.
* Existing blocking reads/writes must be woken
@@ -106,6 +111,7 @@ typedef struct QEMUFileOps {
QEMURamHookFunc *after_ram_iterate;
QEMURamHookFunc *hook_ram_load;
QEMURamSaveFunc *save_page;
+ QEMURetPathFunc *get_return_path;
QEMUFileShutdownFunc *shut_down;
} QEMUFileOps;
@@ -196,6 +202,7 @@ int64_t qemu_file_get_rate_limit(QEMUFile *f);
int qemu_file_get_error(QEMUFile *f);
void qemu_file_set_error(QEMUFile *f, int ret);
int qemu_file_shutdown(QEMUFile *f);
+QEMUFile *qemu_file_get_return_path(QEMUFile *f);
void qemu_fflush(QEMUFile *f);
void qemu_file_set_blocking(QEMUFile *f, bool block);
diff --git a/migration/qemu-file-unix.c b/migration/qemu-file-unix.c
index 809bf07..bcb744b 100644
--- a/migration/qemu-file-unix.c
+++ b/migration/qemu-file-unix.c
@@ -97,6 +97,56 @@ static int socket_shutdown(void *opaque, bool rd, bool wr)
}
}
+static int socket_return_close(void *opaque)
+{
+ QEMUFileSocket *s = opaque;
+ /*
+ * Note: We don't close the socket, that should be done by the forward
+ * path.
+ */
+ g_free(s);
+ return 0;
+}
+
+static const QEMUFileOps socket_return_read_ops = {
+ .get_fd = socket_get_fd,
+ .get_buffer = socket_get_buffer,
+ .close = socket_return_close,
+ .shut_down = socket_shutdown,
+};
+
+static const QEMUFileOps socket_return_write_ops = {
+ .get_fd = socket_get_fd,
+ .writev_buffer = socket_writev_buffer,
+ .close = socket_return_close,
+ .shut_down = socket_shutdown,
+};
+
+/*
+ * Give a QEMUFile* off the same socket but data in the opposite
+ * direction.
+ */
+static QEMUFile *socket_get_return_path(void *opaque)
+{
+ QEMUFileSocket *forward = opaque;
+ QEMUFileSocket *reverse;
+
+ if (qemu_file_get_error(forward->file)) {
+ /* If the forward file is in error, don't try and open a return */
+ return NULL;
+ }
+
+ reverse = g_malloc0(sizeof(QEMUFileSocket));
+ reverse->fd = forward->fd;
+ /* I don't think there's a better way to tell which direction 'this' is */
+ if (forward->file->ops->get_buffer != NULL) {
+ /* being called from the read side, so we need to be able to write */
+ return qemu_fopen_ops(reverse, &socket_return_write_ops);
+ } else {
+ return qemu_fopen_ops(reverse, &socket_return_read_ops);
+ }
+}
+
static ssize_t unix_writev_buffer(void *opaque, struct iovec *iov, int iovcnt,
int64_t pos)
{
@@ -206,18 +256,19 @@ QEMUFile *qemu_fdopen(int fd, const char *mode)
}
static const QEMUFileOps socket_read_ops = {
- .get_fd = socket_get_fd,
- .get_buffer = socket_get_buffer,
- .close = socket_close,
- .shut_down = socket_shutdown
-
+ .get_fd = socket_get_fd,
+ .get_buffer = socket_get_buffer,
+ .close = socket_close,
+ .shut_down = socket_shutdown,
+ .get_return_path = socket_get_return_path
};
static const QEMUFileOps socket_write_ops = {
- .get_fd = socket_get_fd,
- .writev_buffer = socket_writev_buffer,
- .close = socket_close,
- .shut_down = socket_shutdown
+ .get_fd = socket_get_fd,
+ .writev_buffer = socket_writev_buffer,
+ .close = socket_close,
+ .shut_down = socket_shutdown,
+ .get_return_path = socket_get_return_path
};
QEMUFile *qemu_fopen_socket(int fd, const char *mode)
diff --git a/migration/qemu-file.c b/migration/qemu-file.c
index 9ec2267..0bbd257 100644
--- a/migration/qemu-file.c
+++ b/migration/qemu-file.c
@@ -44,6 +44,18 @@ int qemu_file_shutdown(QEMUFile *f)
return f->ops->shut_down(f->opaque, true, true);
}
+/*
+ * Result: QEMUFile* for a 'return path' for comms in the opposite direction
+ * NULL if not available
+ */
+QEMUFile *qemu_file_get_return_path(QEMUFile *f)
+{
+ if (!f->ops->get_return_path) {
+ return NULL;
+ }
+ return f->ops->get_return_path(f->opaque);
+}
+
bool qemu_file_mode_is_not_valid(const char *mode)
{
if (mode == NULL ||
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 17/57] Return path: socket_writev_buffer: Block even on non-blocking fd's
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (15 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 16/57] Return path: Open a return path on QEMUFile for sockets Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 18/57] Migration commands Juan Quintela
` (40 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
The destination sets the fd to non-blocking on incoming migrations;
this also affects the return path from the destination, and thus we
need to make sure we can safely write to the return path.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
migration/qemu-file-unix.c | 42 +++++++++++++++++++++++++++++++++++++-----
1 file changed, 37 insertions(+), 5 deletions(-)
diff --git a/migration/qemu-file-unix.c b/migration/qemu-file-unix.c
index bcb744b..c503b02 100644
--- a/migration/qemu-file-unix.c
+++ b/migration/qemu-file-unix.c
@@ -22,6 +22,7 @@
* THE SOFTWARE.
*/
#include "qemu-common.h"
+#include "qemu/error-report.h"
#include "qemu/iov.h"
#include "qemu/sockets.h"
#include "qemu/coroutine.h"
@@ -39,12 +40,43 @@ static ssize_t socket_writev_buffer(void *opaque, struct iovec *iov, int iovcnt,
QEMUFileSocket *s = opaque;
ssize_t len;
ssize_t size = iov_size(iov, iovcnt);
+ ssize_t offset = 0;
+ int err;
- len = iov_send(s->fd, iov, iovcnt, 0, size);
- if (len < size) {
- len = -socket_error();
- }
- return len;
+ while (size > 0) {
+ len = iov_send(s->fd, iov, iovcnt, offset, size);
+
+ if (len > 0) {
+ size -= len;
+ offset += len;
+ }
+
+ if (size > 0) {
+ err = socket_error();
+
+ if (err != EAGAIN && err != EWOULDBLOCK) {
+ error_report("socket_writev_buffer: Got err=%d for (%zu/%zu)",
+ err, (size_t)size, (size_t)len);
+ /*
+ * If I've already sent some but only just got the error, I
+ * could return the amount validly sent so far and wait for the
+ * next call to report the error, but I'd rather flag the error
+ * immediately.
+ */
+ return -err;
+ }
+
+ /* Emulate blocking */
+ GPollFD pfd;
+
+ pfd.fd = s->fd;
+ pfd.events = G_IO_OUT | G_IO_ERR;
+ pfd.revents = 0;
+ g_poll(&pfd, 1 /* 1 fd */, -1 /* no timeout */);
+ }
+ }
+
+ return offset;
}
static int socket_get_fd(void *opaque)
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 18/57] Migration commands
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (16 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 17/57] Return path: socket_writev_buffer: Block even on non-blocking fd's Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 19/57] Return path: Control commands Juan Quintela
` (39 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Create QEMU_VM_COMMAND section type for sending commands from
source to destination. These commands are not intended to convey
guest state but to control the migration process.
For use in postcopy.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/migration/migration.h | 1 +
include/sysemu/sysemu.h | 8 +++++
migration/savevm.c | 71 +++++++++++++++++++++++++++++++++++++++++++
trace-events | 2 ++
4 files changed, 82 insertions(+)
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 82cc3a6..0bb4383 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -35,6 +35,7 @@
#define QEMU_VM_SUBSECTION 0x05
#define QEMU_VM_VMDESCRIPTION 0x06
#define QEMU_VM_CONFIGURATION 0x07
+#define QEMU_VM_COMMAND 0x08
#define QEMU_VM_SECTION_FOOTER 0x7e
struct MigrationParams {
diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index 470445f..0a8790e 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -84,6 +84,12 @@ void hmp_info_snapshots(Monitor *mon, const QDict *qdict);
void qemu_announce_self(void);
+/* Subcommands for QEMU_VM_COMMAND */
+enum qemu_vm_cmd {
+ MIG_CMD_INVALID = 0, /* Must be 0 */
+ MIG_CMD_MAX
+};
+
bool qemu_savevm_state_blocked(Error **errp);
void qemu_savevm_state_begin(QEMUFile *f,
const MigrationParams *params);
@@ -92,6 +98,8 @@ int qemu_savevm_state_iterate(QEMUFile *f);
void qemu_savevm_state_cleanup(void);
void qemu_savevm_state_complete_precopy(QEMUFile *f);
uint64_t qemu_savevm_state_pending(QEMUFile *f, uint64_t max_size);
+void qemu_savevm_command_send(QEMUFile *f, enum qemu_vm_cmd command,
+ uint16_t len, uint8_t *data);
int qemu_loadvm_state(QEMUFile *f);
typedef enum DisplayType
diff --git a/migration/savevm.c b/migration/savevm.c
index fed41e6..a6829e1 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -59,6 +59,14 @@
static bool skip_section_footers;
+static struct mig_cmd_args {
+ ssize_t len; /* -1 = variable */
+ const char *name;
+} mig_cmd_args[] = {
+ [MIG_CMD_INVALID] = { .len = -1, .name = "INVALID" },
+ [MIG_CMD_MAX] = { .len = -1, .name = "MAX" },
+};
+
static int announce_self_create(uint8_t *buf,
uint8_t *mac_addr)
{
@@ -694,6 +702,28 @@ static void save_section_footer(QEMUFile *f, SaveStateEntry *se)
}
}
+/**
+ * qemu_savevm_command_send: Send a 'QEMU_VM_COMMAND' type element with the
+ * command and associated data.
+ *
+ * @f: File to send command on
+ * @command: Command type to send
+ * @len: Length of associated data
+ * @data: Data associated with command.
+ */
+void qemu_savevm_command_send(QEMUFile *f,
+ enum qemu_vm_cmd command,
+ uint16_t len,
+ uint8_t *data)
+{
+ trace_savevm_command_send(command, len);
+ qemu_put_byte(f, QEMU_VM_COMMAND);
+ qemu_put_be16(f, (uint16_t)command);
+ qemu_put_be16(f, len);
+ qemu_put_buffer(f, data, len);
+ qemu_fflush(f);
+}
+
bool qemu_savevm_state_blocked(Error **errp)
{
SaveStateEntry *se;
@@ -1004,6 +1034,41 @@ static SaveStateEntry *find_se(const char *idstr, int instance_id)
return NULL;
}
+/**
+ * loadvm_process_command: Process an incoming 'QEMU_VM_COMMAND'
+ *
+ * Returns: 0 on success, negative on error (in which case it will issue an
+ * error message).
+ * @f: The stream to read the command data from.
+ */
+static int loadvm_process_command(QEMUFile *f)
+{
+ uint16_t cmd;
+ uint16_t len;
+
+ cmd = qemu_get_be16(f);
+ len = qemu_get_be16(f);
+
+ trace_loadvm_process_command(cmd, len);
+ if (cmd >= MIG_CMD_MAX || cmd == MIG_CMD_INVALID) {
+ error_report("MIG_CMD 0x%x unknown (len 0x%x)", cmd, len);
+ return -EINVAL;
+ }
+
+ if (mig_cmd_args[cmd].len != -1 && mig_cmd_args[cmd].len != len) {
+ error_report("%s received with bad length - expecting %zu, got %d",
+ mig_cmd_args[cmd].name,
+ (size_t)mig_cmd_args[cmd].len, len);
+ return -ERANGE;
+ }
+
+ switch (cmd) {
+ /* Filling added in next patch */
+ }
+
+ return 0;
+}
+
struct LoadStateEntry {
QLIST_ENTRY(LoadStateEntry) entry;
SaveStateEntry *se;
@@ -1183,6 +1248,12 @@ int qemu_loadvm_state(QEMUFile *f)
goto out;
}
break;
+ case QEMU_VM_COMMAND:
+ ret = loadvm_process_command(f);
+ if (ret < 0) {
+ goto out;
+ }
+ break;
default:
error_report("Unknown savevm section type %d", section_type);
ret = -EINVAL;
diff --git a/trace-events b/trace-events
index 277a4aa..f077c23 100644
--- a/trace-events
+++ b/trace-events
@@ -1204,6 +1204,8 @@ virtio_gpu_fence_resp(uint64_t fence) "fence 0x%" PRIx64
qemu_loadvm_state_section(unsigned int section_type) "%d"
qemu_loadvm_state_section_partend(uint32_t section_id) "%u"
qemu_loadvm_state_section_startfull(uint32_t section_id, const char *idstr, uint32_t instance_id, uint32_t version_id) "%u(%s) %u %u"
+loadvm_process_command(uint16_t com, uint16_t len) "com=0x%x len=%d"
+savevm_command_send(uint16_t command, uint16_t len) "com=0x%x len=%d"
savevm_section_start(const char *id, unsigned int section_id) "%s, section_id %u"
savevm_section_end(const char *id, unsigned int section_id, int ret) "%s, section_id %u -> %d"
savevm_section_skip(const char *id, unsigned int section_id) "%s, section_id %u"
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 19/57] Return path: Control commands
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (17 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 18/57] Migration commands Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 20/57] Return path: Send responses from destination to source Juan Quintela
` (38 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Add two src->dest commands:
* OPEN_RETURN_PATH - To request that the destination open the return path
* PING - Request an acknowledge from the destination
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/migration/migration.h | 2 ++
include/sysemu/sysemu.h | 4 ++++
migration/savevm.c | 43 ++++++++++++++++++++++++++++++++++++++++++-
trace-events | 3 +++
4 files changed, 51 insertions(+), 1 deletion(-)
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 0bb4383..98a6d07 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -48,6 +48,8 @@ typedef QLIST_HEAD(, LoadStateEntry) LoadStateEntry_Head;
struct MigrationIncomingState {
QEMUFile *from_src_file;
+ QEMUFile *to_src_file;
+
/* See savevm.c */
LoadStateEntry_Head loadvm_handlers;
};
diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index 0a8790e..70473f4 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -87,6 +87,8 @@ void qemu_announce_self(void);
/* Subcommands for QEMU_VM_COMMAND */
enum qemu_vm_cmd {
MIG_CMD_INVALID = 0, /* Must be 0 */
+ MIG_CMD_OPEN_RETURN_PATH, /* Tell the dest to open the Return path */
+ MIG_CMD_PING, /* Request a PONG on the RP */
MIG_CMD_MAX
};
@@ -100,6 +102,8 @@ void qemu_savevm_state_complete_precopy(QEMUFile *f);
uint64_t qemu_savevm_state_pending(QEMUFile *f, uint64_t max_size);
void qemu_savevm_command_send(QEMUFile *f, enum qemu_vm_cmd command,
uint16_t len, uint8_t *data);
+void qemu_savevm_send_ping(QEMUFile *f, uint32_t value);
+void qemu_savevm_send_open_return_path(QEMUFile *f);
int qemu_loadvm_state(QEMUFile *f);
typedef enum DisplayType
diff --git a/migration/savevm.c b/migration/savevm.c
index a6829e1..d47c55b 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -64,6 +64,8 @@ static struct mig_cmd_args {
const char *name;
} mig_cmd_args[] = {
[MIG_CMD_INVALID] = { .len = -1, .name = "INVALID" },
+ [MIG_CMD_OPEN_RETURN_PATH] = { .len = 0, .name = "OPEN_RETURN_PATH" },
+ [MIG_CMD_PING] = { .len = sizeof(uint32_t), .name = "PING" },
[MIG_CMD_MAX] = { .len = -1, .name = "MAX" },
};
@@ -724,6 +726,21 @@ void qemu_savevm_command_send(QEMUFile *f,
qemu_fflush(f);
}
+void qemu_savevm_send_ping(QEMUFile *f, uint32_t value)
+{
+ uint32_t buf;
+
+ trace_savevm_send_ping(value);
+ buf = cpu_to_be32(value);
+ qemu_savevm_command_send(f, MIG_CMD_PING, sizeof(value), (uint8_t *)&buf);
+}
+
+void qemu_savevm_send_open_return_path(QEMUFile *f)
+{
+ trace_savevm_send_open_return_path();
+ qemu_savevm_command_send(f, MIG_CMD_OPEN_RETURN_PATH, 0, NULL);
+}
+
bool qemu_savevm_state_blocked(Error **errp)
{
SaveStateEntry *se;
@@ -1043,8 +1060,10 @@ static SaveStateEntry *find_se(const char *idstr, int instance_id)
*/
static int loadvm_process_command(QEMUFile *f)
{
+ MigrationIncomingState *mis = migration_incoming_get_current();
uint16_t cmd;
uint16_t len;
+ uint32_t tmp32;
cmd = qemu_get_be16(f);
len = qemu_get_be16(f);
@@ -1063,7 +1082,29 @@ static int loadvm_process_command(QEMUFile *f)
}
switch (cmd) {
- /* Filling added in next patch */
+ case MIG_CMD_OPEN_RETURN_PATH:
+ if (mis->to_src_file) {
+ error_report("CMD_OPEN_RETURN_PATH called when RP already open");
+ /* Not really a problem, so don't give up */
+ return 0;
+ }
+ mis->to_src_file = qemu_file_get_return_path(f);
+ if (!mis->to_src_file) {
+ error_report("CMD_OPEN_RETURN_PATH failed");
+ return -1;
+ }
+ break;
+
+ case MIG_CMD_PING:
+ tmp32 = qemu_get_be32(f);
+ trace_loadvm_process_command_ping(tmp32);
+ if (!mis->to_src_file) {
+ error_report("CMD_PING (0x%x) received with no return path",
+ tmp32);
+ return -1;
+ }
+ /* migrate_send_rp_pong(mis, tmp32); TODO: gets added later */
+ break;
}
return 0;
diff --git a/trace-events b/trace-events
index f077c23..500f1e3 100644
--- a/trace-events
+++ b/trace-events
@@ -1205,10 +1205,13 @@ qemu_loadvm_state_section(unsigned int section_type) "%d"
qemu_loadvm_state_section_partend(uint32_t section_id) "%u"
qemu_loadvm_state_section_startfull(uint32_t section_id, const char *idstr, uint32_t instance_id, uint32_t version_id) "%u(%s) %u %u"
loadvm_process_command(uint16_t com, uint16_t len) "com=0x%x len=%d"
+loadvm_process_command_ping(uint32_t val) "%x"
savevm_command_send(uint16_t command, uint16_t len) "com=0x%x len=%d"
savevm_section_start(const char *id, unsigned int section_id) "%s, section_id %u"
savevm_section_end(const char *id, unsigned int section_id, int ret) "%s, section_id %u -> %d"
savevm_section_skip(const char *id, unsigned int section_id) "%s, section_id %u"
+savevm_send_open_return_path(void) ""
+savevm_send_ping(uint32_t val) "%x"
savevm_state_begin(void) ""
savevm_state_header(void) ""
savevm_state_iterate(void) ""
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 20/57] Return path: Send responses from destination to source
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (18 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 19/57] Return path: Control commands Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 21/57] migration_is_setup_or_active Juan Quintela
` (37 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Add migrate_send_rp_message to send a message from destination to source along the return path.
(It uses a mutex to let it be called from multiple threads)
Add migrate_send_rp_shut to send a 'shut' message to indicate
the destination is finished with the RP.
Add migrate_send_rp_ack to send a 'PONG' message in response to a PING
Use it in the MSG_RP_PING handler
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/migration/migration.h | 19 ++++++++++++++++++
migration/migration.c | 45 +++++++++++++++++++++++++++++++++++++++++++
migration/savevm.c | 2 +-
trace-events | 1 +
4 files changed, 66 insertions(+), 1 deletion(-)
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 98a6d07..3ce3fda 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -43,12 +43,22 @@ struct MigrationParams {
bool shared;
};
+/* Messages sent on the return path from destination to source */
+enum mig_rp_message_type {
+ MIG_RP_MSG_INVALID = 0, /* Must be 0 */
+ MIG_RP_MSG_SHUT, /* sibling will not send any more RP messages */
+ MIG_RP_MSG_PONG, /* Response to a PING; data (seq: be32 ) */
+
+ MIG_RP_MSG_MAX
+};
+
typedef QLIST_HEAD(, LoadStateEntry) LoadStateEntry_Head;
/* State for the incoming migration */
struct MigrationIncomingState {
QEMUFile *from_src_file;
QEMUFile *to_src_file;
+ QemuMutex rp_mutex; /* We send replies from multiple threads */
/* See savevm.c */
LoadStateEntry_Head loadvm_handlers;
@@ -181,6 +191,15 @@ int migrate_compress_threads(void);
int migrate_decompress_threads(void);
bool migrate_use_events(void);
+/* Sending on the return path - generic and then for each message type */
+void migrate_send_rp_message(MigrationIncomingState *mis,
+ enum mig_rp_message_type message_type,
+ uint16_t len, void *data);
+void migrate_send_rp_shut(MigrationIncomingState *mis,
+ uint32_t value);
+void migrate_send_rp_pong(MigrationIncomingState *mis,
+ uint32_t value);
+
void ram_control_before_iterate(QEMUFile *f, uint64_t flags);
void ram_control_after_iterate(QEMUFile *f, uint64_t flags);
void ram_control_load_hook(QEMUFile *f, uint64_t flags, void *data);
diff --git a/migration/migration.c b/migration/migration.c
index bb7dcb9..8380e2f 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -97,6 +97,7 @@ MigrationIncomingState *migration_incoming_state_new(QEMUFile* f)
mis_current = g_new0(MigrationIncomingState, 1);
mis_current->from_src_file = f;
QLIST_INIT(&mis_current->loadvm_handlers);
+ qemu_mutex_init(&mis_current->rp_mutex);
return mis_current;
}
@@ -344,6 +345,50 @@ void process_incoming_migration(QEMUFile *f)
qemu_coroutine_enter(co, f);
}
+/*
+ * Send a message on the return channel back to the source
+ * of the migration.
+ */
+void migrate_send_rp_message(MigrationIncomingState *mis,
+ enum mig_rp_message_type message_type,
+ uint16_t len, void *data)
+{
+ trace_migrate_send_rp_message((int)message_type, len);
+ qemu_mutex_lock(&mis->rp_mutex);
+ qemu_put_be16(mis->to_src_file, (unsigned int)message_type);
+ qemu_put_be16(mis->to_src_file, len);
+ qemu_put_buffer(mis->to_src_file, data, len);
+ qemu_fflush(mis->to_src_file);
+ qemu_mutex_unlock(&mis->rp_mutex);
+}
+
+/*
+ * Send a 'SHUT' message on the return channel with the given value
+ * to indicate that we've finished with the RP. Non-0 value indicates
+ * error.
+ */
+void migrate_send_rp_shut(MigrationIncomingState *mis,
+ uint32_t value)
+{
+ uint32_t buf;
+
+ buf = cpu_to_be32(value);
+ migrate_send_rp_message(mis, MIG_RP_MSG_SHUT, sizeof(buf), &buf);
+}
+
+/*
+ * Send a 'PONG' message on the return channel with the given value
+ * (normally in response to a 'PING')
+ */
+void migrate_send_rp_pong(MigrationIncomingState *mis,
+ uint32_t value)
+{
+ uint32_t buf;
+
+ buf = cpu_to_be32(value);
+ migrate_send_rp_message(mis, MIG_RP_MSG_PONG, sizeof(buf), &buf);
+}
+
/* amount of nanoseconds we are willing to wait for migration to be down.
* the choice of nanoseconds is because it is the maximum resolution that
* get_clock() can achieve. It is an internal measure. All user-visible
diff --git a/migration/savevm.c b/migration/savevm.c
index d47c55b..1ffe7b0 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1103,7 +1103,7 @@ static int loadvm_process_command(QEMUFile *f)
tmp32);
return -1;
}
- /* migrate_send_rp_pong(mis, tmp32); TODO: gets added later */
+ migrate_send_rp_pong(mis, tmp32);
break;
}
diff --git a/trace-events b/trace-events
index 500f1e3..ca5909b 100644
--- a/trace-events
+++ b/trace-events
@@ -1431,6 +1431,7 @@ migrate_fd_cleanup(void) ""
migrate_fd_error(void) ""
migrate_fd_cancel(void) ""
migrate_pending(uint64_t size, uint64_t max) "pending size %" PRIu64 " max %" PRIu64
+migrate_send_rp_message(int msg_type, uint16_t len) "%d: len %d"
migrate_transferred(uint64_t tranferred, uint64_t time_spent, double bandwidth, uint64_t size) "transferred %" PRIu64 " time_spent %" PRIu64 " bandwidth %g max_size %" PRId64
migrate_state_too_big(void) ""
migrate_global_state_post_load(const char *state) "loaded state: %s"
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 21/57] migration_is_setup_or_active
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (19 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 20/57] Return path: Send responses from destination to source Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 22/57] Return path: Source handling of return path Juan Quintela
` (36 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Add 'migration_is_setup_or_active' utility function to check state.
(It gets postcopy added to it's list later on in the series)
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
migration/migration.c | 26 ++++++++++++++++++++------
1 file changed, 20 insertions(+), 6 deletions(-)
diff --git a/migration/migration.c b/migration/migration.c
index 8380e2f..4317bab 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -444,6 +444,23 @@ MigrationParameters *qmp_query_migrate_parameters(Error **errp)
return params;
}
+/*
+ * Return true if we're already in the middle of a migration
+ * (i.e. any of the active or setup states)
+ */
+static bool migration_is_setup_or_active(int state)
+{
+ switch (state) {
+ case MIGRATION_STATUS_ACTIVE:
+ case MIGRATION_STATUS_SETUP:
+ return true;
+
+ default:
+ return false;
+
+ }
+}
+
static void get_xbzrle_cache_stats(MigrationInfo *info)
{
if (migrate_use_xbzrle()) {
@@ -551,8 +568,7 @@ void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params,
MigrationState *s = migrate_get_current();
MigrationCapabilityStatusList *cap;
- if (s->state == MIGRATION_STATUS_ACTIVE ||
- s->state == MIGRATION_STATUS_SETUP) {
+ if (migration_is_setup_or_active(s->state)) {
error_setg(errp, QERR_MIGRATION_ACTIVE);
return;
}
@@ -682,8 +698,7 @@ static void migrate_fd_cancel(MigrationState *s)
do {
old_state = s->state;
- if (old_state != MIGRATION_STATUS_SETUP &&
- old_state != MIGRATION_STATUS_ACTIVE) {
+ if (!migration_is_setup_or_active(old_state)) {
break;
}
migrate_set_state(s, old_state, MIGRATION_STATUS_CANCELLING);
@@ -815,8 +830,7 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk,
params.blk = has_blk && blk;
params.shared = has_inc && inc;
- if (s->state == MIGRATION_STATUS_ACTIVE ||
- s->state == MIGRATION_STATUS_SETUP ||
+ if (migration_is_setup_or_active(s->state) ||
s->state == MIGRATION_STATUS_CANCELLING) {
error_setg(errp, QERR_MIGRATION_ACTIVE);
return;
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 22/57] Return path: Source handling of return path
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (20 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 21/57] migration_is_setup_or_active Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 23/57] Rework loadvm path for subloops Juan Quintela
` (35 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Open a return path, and handle messages that are received upon it.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/migration/migration.h | 8 +++
migration/migration.c | 159 +++++++++++++++++++++++++++++++++++++++++-
trace-events | 10 +++
3 files changed, 175 insertions(+), 2 deletions(-)
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 3ce3fda..571466b 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -80,6 +80,14 @@ struct MigrationState
int state;
MigrationParams params;
+
+ /* State related to return path */
+ struct {
+ QEMUFile *from_dst_file;
+ QemuThread rp_thread;
+ bool error;
+ } rp_state;
+
double mbps;
int64_t total_time;
int64_t downtime;
diff --git a/migration/migration.c b/migration/migration.c
index 4317bab..295deb8 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -696,6 +696,11 @@ static void migrate_fd_cancel(MigrationState *s)
QEMUFile *f = migrate_get_current()->file;
trace_migrate_fd_cancel();
+ if (s->rp_state.from_dst_file) {
+ /* shutdown the rp socket, so causing the rp thread to shutdown */
+ qemu_file_shutdown(s->rp_state.from_dst_file);
+ }
+
do {
old_state = s->state;
if (!migration_is_setup_or_active(old_state)) {
@@ -1030,6 +1035,154 @@ int64_t migrate_xbzrle_cache_size(void)
return s->xbzrle_cache_size;
}
+/* migration thread support */
+/*
+ * Something bad happened to the RP stream, mark an error
+ * The caller shall print or trace something to indicate why
+ */
+static void mark_source_rp_bad(MigrationState *s)
+{
+ s->rp_state.error = true;
+}
+
+static struct rp_cmd_args {
+ ssize_t len; /* -1 = variable */
+ const char *name;
+} rp_cmd_args[] = {
+ [MIG_RP_MSG_INVALID] = { .len = -1, .name = "INVALID" },
+ [MIG_RP_MSG_SHUT] = { .len = 4, .name = "SHUT" },
+ [MIG_RP_MSG_PONG] = { .len = 4, .name = "PONG" },
+ [MIG_RP_MSG_MAX] = { .len = -1, .name = "MAX" },
+};
+
+/*
+ * Handles messages sent on the return path towards the source VM
+ *
+ */
+static void *source_return_path_thread(void *opaque)
+{
+ MigrationState *ms = opaque;
+ QEMUFile *rp = ms->rp_state.from_dst_file;
+ uint16_t header_len, header_type;
+ const int max_len = 512;
+ uint8_t buf[max_len];
+ uint32_t tmp32, sibling_error;
+ int res;
+
+ trace_source_return_path_thread_entry();
+ while (!ms->rp_state.error && !qemu_file_get_error(rp) &&
+ migration_is_setup_or_active(ms->state)) {
+ trace_source_return_path_thread_loop_top();
+ header_type = qemu_get_be16(rp);
+ header_len = qemu_get_be16(rp);
+
+ if (header_type >= MIG_RP_MSG_MAX ||
+ header_type == MIG_RP_MSG_INVALID) {
+ error_report("RP: Received invalid message 0x%04x length 0x%04x",
+ header_type, header_len);
+ mark_source_rp_bad(ms);
+ goto out;
+ }
+
+ if ((rp_cmd_args[header_type].len != -1 &&
+ header_len != rp_cmd_args[header_type].len) ||
+ header_len > max_len) {
+ error_report("RP: Received '%s' message (0x%04x) with"
+ "incorrect length %d expecting %zu",
+ rp_cmd_args[header_type].name, header_type, header_len,
+ (size_t)rp_cmd_args[header_type].len);
+ mark_source_rp_bad(ms);
+ goto out;
+ }
+
+ /* We know we've got a valid header by this point */
+ res = qemu_get_buffer(rp, buf, header_len);
+ if (res != header_len) {
+ error_report("RP: Failed reading data for message 0x%04x"
+ " read %d expected %d",
+ header_type, res, header_len);
+ mark_source_rp_bad(ms);
+ goto out;
+ }
+
+ /* OK, we have the message and the data */
+ switch (header_type) {
+ case MIG_RP_MSG_SHUT:
+ sibling_error = be32_to_cpup((uint32_t *)buf);
+ trace_source_return_path_thread_shut(sibling_error);
+ if (sibling_error) {
+ error_report("RP: Sibling indicated error %d", sibling_error);
+ mark_source_rp_bad(ms);
+ }
+ /*
+ * We'll let the main thread deal with closing the RP
+ * we could do a shutdown(2) on it, but we're the only user
+ * anyway, so there's nothing gained.
+ */
+ goto out;
+
+ case MIG_RP_MSG_PONG:
+ tmp32 = be32_to_cpup((uint32_t *)buf);
+ trace_source_return_path_thread_pong(tmp32);
+ break;
+
+ default:
+ break;
+ }
+ }
+ if (rp && qemu_file_get_error(rp)) {
+ trace_source_return_path_thread_bad_end();
+ mark_source_rp_bad(ms);
+ }
+
+ trace_source_return_path_thread_end();
+out:
+ ms->rp_state.from_dst_file = NULL;
+ qemu_fclose(rp);
+ return NULL;
+}
+
+__attribute__ (( unused )) /* Until later in patch series */
+static int open_return_path_on_source(MigrationState *ms)
+{
+
+ ms->rp_state.from_dst_file = qemu_file_get_return_path(ms->file);
+ if (!ms->rp_state.from_dst_file) {
+ return -1;
+ }
+
+ trace_open_return_path_on_source();
+ qemu_thread_create(&ms->rp_state.rp_thread, "return path",
+ source_return_path_thread, ms, QEMU_THREAD_JOINABLE);
+
+ trace_open_return_path_on_source_continue();
+
+ return 0;
+}
+
+__attribute__ (( unused )) /* Until later in patch series */
+/* Returns 0 if the RP was ok, otherwise there was an error on the RP */
+static int await_return_path_close_on_source(MigrationState *ms)
+{
+ /*
+ * If this is a normal exit then the destination will send a SHUT and the
+ * rp_thread will exit, however if there's an error we need to cause
+ * it to exit.
+ */
+ if (qemu_file_get_error(ms->file) && ms->rp_state.from_dst_file) {
+ /*
+ * shutdown(2), if we have it, will cause it to unblock if it's stuck
+ * waiting for the destination.
+ */
+ qemu_file_shutdown(ms->rp_state.from_dst_file);
+ mark_source_rp_bad(ms);
+ }
+ trace_await_return_path_close_on_source_joining();
+ qemu_thread_join(&ms->rp_state.rp_thread);
+ trace_await_return_path_close_on_source_close();
+ return ms->rp_state.error;
+}
+
/**
* migration_completion: Used by migration_thread when there's not much left.
* The caller 'breaks' the loop when this returns.
@@ -1074,8 +1227,10 @@ fail:
migrate_set_state(s, MIGRATION_STATUS_ACTIVE, MIGRATION_STATUS_FAILED);
}
-/* migration thread support */
-
+/*
+ * Master migration thread on the source VM.
+ * It drives the migration and pumps the data down the outgoing channel.
+ */
static void *migration_thread(void *opaque)
{
MigrationState *s = opaque;
diff --git a/trace-events b/trace-events
index ca5909b..d61fcf9 100644
--- a/trace-events
+++ b/trace-events
@@ -1426,12 +1426,22 @@ flic_no_device_api(int err) "flic: no Device Contral API support %d"
flic_reset_failed(int err) "flic: reset failed %d"
# migration.c
+await_return_path_close_on_source_close(void) ""
+await_return_path_close_on_source_joining(void) ""
migrate_set_state(int new_state) "new state %d"
migrate_fd_cleanup(void) ""
migrate_fd_error(void) ""
migrate_fd_cancel(void) ""
migrate_pending(uint64_t size, uint64_t max) "pending size %" PRIu64 " max %" PRIu64
migrate_send_rp_message(int msg_type, uint16_t len) "%d: len %d"
+open_return_path_on_source(void) ""
+open_return_path_on_source_continue(void) ""
+source_return_path_thread_bad_end(void) ""
+source_return_path_thread_end(void) ""
+source_return_path_thread_entry(void) ""
+source_return_path_thread_loop_top(void) ""
+source_return_path_thread_pong(uint32_t val) "%x"
+source_return_path_thread_shut(uint32_t val) "%x"
migrate_transferred(uint64_t tranferred, uint64_t time_spent, double bandwidth, uint64_t size) "transferred %" PRIu64 " time_spent %" PRIu64 " bandwidth %g max_size %" PRId64
migrate_state_too_big(void) ""
migrate_global_state_post_load(const char *state) "loaded state: %s"
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 23/57] Rework loadvm path for subloops
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (21 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 22/57] Return path: Source handling of return path Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 24/57] Add migration-capability boolean for postcopy-ram Juan Quintela
` (34 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Postcopy needs to have two migration streams loading concurrently;
one from memory (with the device state) and the other from the fd
with the memory transactions.
Split the core of qemu_loadvm_state out so we can use it for both.
Allow the inner loadvm loop to quit and cause the parent loops to
exit as well.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/migration/migration.h | 6 ++
migration/migration.c | 2 +
migration/savevm.c | 141 ++++++++++++++++++++++--------------------
trace-events | 4 ++
4 files changed, 86 insertions(+), 67 deletions(-)
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 571466b..3dc95f4 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -57,6 +57,12 @@ typedef QLIST_HEAD(, LoadStateEntry) LoadStateEntry_Head;
struct MigrationIncomingState {
QEMUFile *from_src_file;
+ /*
+ * Free at the start of the main state load, set as the main thread finishes
+ * loading state.
+ */
+ QemuEvent main_thread_load_event;
+
QEMUFile *to_src_file;
QemuMutex rp_mutex; /* We send replies from multiple threads */
diff --git a/migration/migration.c b/migration/migration.c
index 295deb8..e4f91a9 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -98,12 +98,14 @@ MigrationIncomingState *migration_incoming_state_new(QEMUFile* f)
mis_current->from_src_file = f;
QLIST_INIT(&mis_current->loadvm_handlers);
qemu_mutex_init(&mis_current->rp_mutex);
+ qemu_event_init(&mis_current->main_thread_load_event, false);
return mis_current;
}
void migration_incoming_state_destroy(void)
{
+ qemu_event_destroy(&mis_current->main_thread_load_event);
loadvm_free_handlers(mis_current);
g_free(mis_current);
mis_current = NULL;
diff --git a/migration/savevm.c b/migration/savevm.c
index 1ffe7b0..6b04f46 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1051,11 +1051,18 @@ static SaveStateEntry *find_se(const char *idstr, int instance_id)
return NULL;
}
+enum LoadVMExitCodes {
+ /* Allow a command to quit all layers of nested loadvm loops */
+ LOADVM_QUIT = 1,
+};
+
+static int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis);
/**
* loadvm_process_command: Process an incoming 'QEMU_VM_COMMAND'
*
- * Returns: 0 on success, negative on error (in which case it will issue an
- * error message).
+ * Returns: 0 on just a normal return
+ * LOADVM_QUIT All good, but exit the loop
+ * <0 error (in which case it will issue an error message).
* @f: The stream to read the command data from.
*/
static int loadvm_process_command(QEMUFile *f)
@@ -1162,47 +1169,10 @@ void loadvm_free_handlers(MigrationIncomingState *mis)
}
}
-int qemu_loadvm_state(QEMUFile *f)
+static int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis)
{
- MigrationIncomingState *mis = migration_incoming_get_current();
- Error *local_err = NULL;
uint8_t section_type;
- unsigned int v;
int ret;
- int file_error_after_eof = -1;
-
- if (qemu_savevm_state_blocked(&local_err)) {
- error_report_err(local_err);
- return -EINVAL;
- }
-
- v = qemu_get_be32(f);
- if (v != QEMU_VM_FILE_MAGIC) {
- error_report("Not a migration stream");
- return -EINVAL;
- }
-
- v = qemu_get_be32(f);
- if (v == QEMU_VM_FILE_VERSION_COMPAT) {
- error_report("SaveVM v2 format is obsolete and don't work anymore");
- return -ENOTSUP;
- }
- if (v != QEMU_VM_FILE_VERSION) {
- error_report("Unsupported migration stream version");
- return -ENOTSUP;
- }
-
- if (!savevm_state.skip_configuration) {
- if (qemu_get_byte(f) != QEMU_VM_CONFIGURATION) {
- error_report("Configuration section missing");
- return -EINVAL;
- }
- ret = vmstate_load_state(f, &vmstate_configuration, &savevm_state, 0);
-
- if (ret) {
- return ret;
- }
- }
while ((section_type = qemu_get_byte(f)) != QEMU_VM_EOF) {
uint32_t instance_id, version_id, section_id;
@@ -1231,16 +1201,14 @@ int qemu_loadvm_state(QEMUFile *f)
if (se == NULL) {
error_report("Unknown savevm section or instance '%s' %d",
idstr, instance_id);
- ret = -EINVAL;
- goto out;
+ return -EINVAL;
}
/* Validate version */
if (version_id > se->version_id) {
error_report("savevm: unsupported version %d for '%s' v%d",
version_id, idstr, se->version_id);
- ret = -EINVAL;
- goto out;
+ return -EINVAL;
}
/* Add entry */
@@ -1255,11 +1223,10 @@ int qemu_loadvm_state(QEMUFile *f)
if (ret < 0) {
error_report("error while loading state for instance 0x%x of"
" device '%s'", instance_id, idstr);
- goto out;
+ return ret;
}
if (!check_section_footer(f, le)) {
- ret = -EINVAL;
- goto out;
+ return -EINVAL;
}
break;
case QEMU_VM_SECTION_PART:
@@ -1274,35 +1241,83 @@ int qemu_loadvm_state(QEMUFile *f)
}
if (le == NULL) {
error_report("Unknown savevm section %d", section_id);
- ret = -EINVAL;
- goto out;
+ return -EINVAL;
}
ret = vmstate_load(f, le->se, le->version_id);
if (ret < 0) {
error_report("error while loading state section id %d(%s)",
section_id, le->se->idstr);
- goto out;
+ return ret;
}
if (!check_section_footer(f, le)) {
- ret = -EINVAL;
- goto out;
+ return -EINVAL;
}
break;
case QEMU_VM_COMMAND:
ret = loadvm_process_command(f);
- if (ret < 0) {
- goto out;
+ trace_qemu_loadvm_state_section_command(ret);
+ if ((ret < 0) || (ret & LOADVM_QUIT)) {
+ return ret;
}
break;
default:
error_report("Unknown savevm section type %d", section_type);
- ret = -EINVAL;
- goto out;
+ return -EINVAL;
}
}
- file_error_after_eof = qemu_file_get_error(f);
+ return 0;
+}
+
+int qemu_loadvm_state(QEMUFile *f)
+{
+ MigrationIncomingState *mis = migration_incoming_get_current();
+ Error *local_err = NULL;
+ unsigned int v;
+ int ret;
+
+ if (qemu_savevm_state_blocked(&local_err)) {
+ error_report_err(local_err);
+ return -EINVAL;
+ }
+
+ v = qemu_get_be32(f);
+ if (v != QEMU_VM_FILE_MAGIC) {
+ error_report("Not a migration stream");
+ return -EINVAL;
+ }
+
+ v = qemu_get_be32(f);
+ if (v == QEMU_VM_FILE_VERSION_COMPAT) {
+ error_report("SaveVM v2 format is obsolete and don't work anymore");
+ return -ENOTSUP;
+ }
+ if (v != QEMU_VM_FILE_VERSION) {
+ error_report("Unsupported migration stream version");
+ return -ENOTSUP;
+ }
+
+ if (!savevm_state.skip_configuration) {
+ if (qemu_get_byte(f) != QEMU_VM_CONFIGURATION) {
+ error_report("Configuration section missing");
+ return -EINVAL;
+ }
+ ret = vmstate_load_state(f, &vmstate_configuration, &savevm_state, 0);
+
+ if (ret) {
+ return ret;
+ }
+ }
+
+ ret = qemu_loadvm_state_main(f, mis);
+ qemu_event_set(&mis->main_thread_load_event);
+
+ trace_qemu_loadvm_state_post_main(ret);
+
+ if (ret == 0) {
+ ret = qemu_file_get_error(f);
+ }
/*
* Try to read in the VMDESC section as well, so that dumping tools that
@@ -1314,10 +1329,10 @@ int qemu_loadvm_state(QEMUFile *f)
* We also mustn't read data that isn't there; some transports (RDMA)
* will stall waiting for that data when the source has already closed.
*/
- if (should_send_vmdesc()) {
+ if (ret == 0 && should_send_vmdesc()) {
uint8_t *buf;
uint32_t size;
- section_type = qemu_get_byte(f);
+ uint8_t section_type = qemu_get_byte(f);
if (section_type != QEMU_VM_VMDESCRIPTION) {
error_report("Expected vmdescription section, but got %d",
@@ -1341,14 +1356,6 @@ int qemu_loadvm_state(QEMUFile *f)
cpu_synchronize_all_post_init();
- ret = 0;
-
-out:
- if (ret == 0) {
- /* We may not have a VMDESC section, so ignore relative errors */
- ret = file_error_after_eof;
- }
-
return ret;
}
diff --git a/trace-events b/trace-events
index d61fcf9..fbb099d 100644
--- a/trace-events
+++ b/trace-events
@@ -1202,7 +1202,11 @@ virtio_gpu_fence_resp(uint64_t fence) "fence 0x%" PRIx64
# migration/savevm.c
qemu_loadvm_state_section(unsigned int section_type) "%d"
+qemu_loadvm_state_section_command(int ret) "%d"
qemu_loadvm_state_section_partend(uint32_t section_id) "%u"
+qemu_loadvm_state_main(void) ""
+qemu_loadvm_state_main_quit_parent(void) ""
+qemu_loadvm_state_post_main(int ret) "%d"
qemu_loadvm_state_section_startfull(uint32_t section_id, const char *idstr, uint32_t instance_id, uint32_t version_id) "%u(%s) %u %u"
loadvm_process_command(uint16_t com, uint16_t len) "com=0x%x len=%d"
loadvm_process_command_ping(uint32_t val) "%x"
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 24/57] Add migration-capability boolean for postcopy-ram.
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (22 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 23/57] Rework loadvm path for subloops Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 25/57] Add wrappers and handlers for sending/receiving the postcopy-ram migration messages Juan Quintela
` (33 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
The 'postcopy ram' capability allows postcopy migration of RAM;
note that the migration starts off in precopy mode until
postcopy mode is triggered (see the migrate_start_postcopy
patch later in the series).
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/migration/migration.h | 1 +
migration/migration.c | 23 +++++++++++++++++++++++
qapi-schema.json | 6 +++++-
3 files changed, 29 insertions(+), 1 deletion(-)
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 3dc95f4..4ed7931 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -186,6 +186,7 @@ void migrate_add_blocker(Error *reason);
*/
void migrate_del_blocker(Error *reason);
+bool migrate_postcopy_ram(void);
bool migrate_zero_blocks(void);
bool migrate_auto_converge(void);
diff --git a/migration/migration.c b/migration/migration.c
index e4f91a9..f849f89 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -578,6 +578,20 @@ void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params,
for (cap = params; cap; cap = cap->next) {
s->enabled_capabilities[cap->value->capability] = cap->value->state;
}
+
+ if (migrate_postcopy_ram()) {
+ if (migrate_use_compression()) {
+ /* The decompression threads asynchronously write into RAM
+ * rather than use the atomic copies needed to avoid
+ * userfaulting. It should be possible to fix the decompression
+ * threads for compatibility in future.
+ */
+ error_report("Postcopy is not currently compatible with "
+ "compression");
+ s->enabled_capabilities[MIGRATION_CAPABILITY_X_POSTCOPY_RAM] =
+ false;
+ }
+ }
}
void qmp_migrate_set_parameters(bool has_compress_level,
@@ -956,6 +970,15 @@ void qmp_migrate_set_downtime(double value, Error **errp)
max_downtime = (uint64_t)value;
}
+bool migrate_postcopy_ram(void)
+{
+ MigrationState *s;
+
+ s = migrate_get_current();
+
+ return s->enabled_capabilities[MIGRATION_CAPABILITY_X_POSTCOPY_RAM];
+}
+
bool migrate_auto_converge(void)
{
MigrationState *s;
diff --git a/qapi-schema.json b/qapi-schema.json
index e18f14c..8638d42 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -540,11 +540,15 @@
# @auto-converge: If enabled, QEMU will automatically throttle down the guest
# to speed up convergence of RAM migration. (since 1.6)
#
+# @x-postcopy-ram: Start executing on the migration target before all of RAM has
+# been migrated, pulling the remaining pages along as needed. NOTE: If
+# the migration fails during postcopy the VM will fail. (since 2.5)
+#
# Since: 1.2
##
{ 'enum': 'MigrationCapability',
'data': ['xbzrle', 'rdma-pin-all', 'auto-converge', 'zero-blocks',
- 'compress', 'events'] }
+ 'compress', 'events', 'x-postcopy-ram'] }
##
# @MigrationCapabilityStatus
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 25/57] Add wrappers and handlers for sending/receiving the postcopy-ram migration messages.
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (23 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 24/57] Add migration-capability boolean for postcopy-ram Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-14 19:11 ` Stefan Weil
2015-11-10 14:25 ` [Qemu-devel] [PULL 26/57] MIG_CMD_PACKAGED: Send a packaged chunk of migration stream Juan Quintela
` (32 subsequent siblings)
57 siblings, 1 reply; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
The state of the postcopy process is managed via a series of messages;
* Add wrappers and handlers for sending/receiving these messages
* Add state variable that track the current state of postcopy
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/migration/migration.h | 27 +++++
include/sysemu/sysemu.h | 19 ++++
migration/migration.c | 20 ++++
migration/savevm.c | 254 ++++++++++++++++++++++++++++++++++++++++++
trace-events | 10 ++
5 files changed, 330 insertions(+)
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 4ed7931..2e9fa3c 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -53,6 +53,29 @@ enum mig_rp_message_type {
};
typedef QLIST_HEAD(, LoadStateEntry) LoadStateEntry_Head;
+
+/* The current postcopy state is read/set by postcopy_state_get/set
+ * which update it atomically.
+ * The state is updated as postcopy messages are received, and
+ * in general only one thread should be writing to the state at any one
+ * time, initially the main thread and then the listen thread;
+ * Corner cases are where either thread finishes early and/or errors.
+ * The state is checked as messages are received to ensure that
+ * the source is sending us messages in the correct order.
+ * The state is also used by the RAM reception code to know if it
+ * has to place pages atomically, and the cleanup code at the end of
+ * the main thread to know if it has to delay cleanup until the end
+ * of postcopy.
+ */
+typedef enum {
+ POSTCOPY_INCOMING_NONE = 0, /* Initial state - no postcopy */
+ POSTCOPY_INCOMING_ADVISE,
+ POSTCOPY_INCOMING_DISCARD,
+ POSTCOPY_INCOMING_LISTENING,
+ POSTCOPY_INCOMING_RUNNING,
+ POSTCOPY_INCOMING_END
+} PostcopyState;
+
/* State for the incoming migration */
struct MigrationIncomingState {
QEMUFile *from_src_file;
@@ -240,4 +263,8 @@ void global_state_set_optional(void);
void savevm_skip_configuration(void);
int global_state_store(void);
void global_state_store_running(void);
+
+PostcopyState postcopy_state_get(void);
+/* Set the state and return the old state */
+PostcopyState postcopy_state_set(PostcopyState new_state);
#endif
diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index 70473f4..6225e00 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -89,6 +89,16 @@ enum qemu_vm_cmd {
MIG_CMD_INVALID = 0, /* Must be 0 */
MIG_CMD_OPEN_RETURN_PATH, /* Tell the dest to open the Return path */
MIG_CMD_PING, /* Request a PONG on the RP */
+
+ MIG_CMD_POSTCOPY_ADVISE, /* Prior to any page transfers, just
+ warn we might want to do PC */
+ MIG_CMD_POSTCOPY_LISTEN, /* Start listening for incoming
+ pages as it's running. */
+ MIG_CMD_POSTCOPY_RUN, /* Start execution */
+
+ MIG_CMD_POSTCOPY_RAM_DISCARD, /* A list of pages to discard that
+ were previously sent during
+ precopy but are dirty. */
MIG_CMD_MAX
};
@@ -104,6 +114,15 @@ void qemu_savevm_command_send(QEMUFile *f, enum qemu_vm_cmd command,
uint16_t len, uint8_t *data);
void qemu_savevm_send_ping(QEMUFile *f, uint32_t value);
void qemu_savevm_send_open_return_path(QEMUFile *f);
+void qemu_savevm_send_postcopy_advise(QEMUFile *f);
+void qemu_savevm_send_postcopy_listen(QEMUFile *f);
+void qemu_savevm_send_postcopy_run(QEMUFile *f);
+
+void qemu_savevm_send_postcopy_ram_discard(QEMUFile *f, const char *name,
+ uint16_t len,
+ uint64_t *start_list,
+ uint64_t *length_list);
+
int qemu_loadvm_state(QEMUFile *f);
typedef enum DisplayType
diff --git a/migration/migration.c b/migration/migration.c
index f849f89..7097e5b 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -57,6 +57,13 @@ static NotifierList migration_state_notifiers =
static bool deferred_incoming;
+/*
+ * Current state of incoming postcopy; note this is not part of
+ * MigrationIncomingState since it's state is used during cleanup
+ * at the end as MIS is being freed.
+ */
+static PostcopyState incoming_postcopy_state;
+
/* When we add fault tolerance, we could have several
migrations at once. For now we don't need to add
dynamic creation of migration */
@@ -284,6 +291,7 @@ static void process_incoming_migration_co(void *opaque)
int ret;
migration_incoming_state_new(f);
+ postcopy_state_set(POSTCOPY_INCOMING_NONE);
migrate_generate_event(MIGRATION_STATUS_ACTIVE);
ret = qemu_loadvm_state(f);
@@ -1367,3 +1375,15 @@ void migrate_fd_connect(MigrationState *s)
qemu_thread_create(&s->thread, "migration", migration_thread, s,
QEMU_THREAD_JOINABLE);
}
+
+PostcopyState postcopy_state_get(void)
+{
+ return atomic_mb_read(&incoming_postcopy_state);
+}
+
+/* Set the state and return the old state */
+PostcopyState postcopy_state_set(PostcopyState new_state)
+{
+ return atomic_xchg(&incoming_postcopy_state, new_state);
+}
+
diff --git a/migration/savevm.c b/migration/savevm.c
index 6b04f46..1ce022a 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -45,6 +45,7 @@
#include "exec/memory.h"
#include "qmp-commands.h"
#include "trace.h"
+#include "qemu/bitops.h"
#include "qemu/iov.h"
#include "block/snapshot.h"
#include "block/qapi.h"
@@ -57,6 +58,8 @@
#define ARP_PTYPE_IP 0x0800
#define ARP_OP_REQUEST_REV 0x3
+const unsigned int postcopy_ram_discard_version = 0;
+
static bool skip_section_footers;
static struct mig_cmd_args {
@@ -66,6 +69,11 @@ static struct mig_cmd_args {
[MIG_CMD_INVALID] = { .len = -1, .name = "INVALID" },
[MIG_CMD_OPEN_RETURN_PATH] = { .len = 0, .name = "OPEN_RETURN_PATH" },
[MIG_CMD_PING] = { .len = sizeof(uint32_t), .name = "PING" },
+ [MIG_CMD_POSTCOPY_ADVISE] = { .len = 16, .name = "POSTCOPY_ADVISE" },
+ [MIG_CMD_POSTCOPY_LISTEN] = { .len = 0, .name = "POSTCOPY_LISTEN" },
+ [MIG_CMD_POSTCOPY_RUN] = { .len = 0, .name = "POSTCOPY_RUN" },
+ [MIG_CMD_POSTCOPY_RAM_DISCARD] = {
+ .len = -1, .name = "POSTCOPY_RAM_DISCARD" },
[MIG_CMD_MAX] = { .len = -1, .name = "MAX" },
};
@@ -741,6 +749,77 @@ void qemu_savevm_send_open_return_path(QEMUFile *f)
qemu_savevm_command_send(f, MIG_CMD_OPEN_RETURN_PATH, 0, NULL);
}
+/* Send prior to any postcopy transfer */
+void qemu_savevm_send_postcopy_advise(QEMUFile *f)
+{
+ uint64_t tmp[2];
+ tmp[0] = cpu_to_be64(getpagesize());
+ tmp[1] = cpu_to_be64(1ul << qemu_target_page_bits());
+
+ trace_qemu_savevm_send_postcopy_advise();
+ qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_ADVISE, 16, (uint8_t *)tmp);
+}
+
+/* Sent prior to starting the destination running in postcopy, discard pages
+ * that have already been sent but redirtied on the source.
+ * CMD_POSTCOPY_RAM_DISCARD consist of:
+ * byte version (0)
+ * byte Length of name field (not including 0)
+ * n x byte RAM block name
+ * byte 0 terminator (just for safety)
+ * n x Byte ranges within the named RAMBlock
+ * be64 Start of the range
+ * be64 Length
+ *
+ * name: RAMBlock name that these entries are part of
+ * len: Number of page entries
+ * start_list: 'len' addresses
+ * length_list: 'len' addresses
+ *
+ */
+void qemu_savevm_send_postcopy_ram_discard(QEMUFile *f, const char *name,
+ uint16_t len,
+ uint64_t *start_list,
+ uint64_t *length_list)
+{
+ uint8_t *buf;
+ uint16_t tmplen;
+ uint16_t t;
+ size_t name_len = strlen(name);
+
+ trace_qemu_savevm_send_postcopy_ram_discard(name, len);
+ assert(name_len < 256);
+ buf = g_malloc0(1 + 1 + name_len + 1 + (8 + 8) * len);
+ buf[0] = postcopy_ram_discard_version;
+ buf[1] = name_len;
+ memcpy(buf + 2, name, name_len);
+ tmplen = 2 + name_len;
+ buf[tmplen++] = '\0';
+
+ for (t = 0; t < len; t++) {
+ cpu_to_be64w((uint64_t *)(buf + tmplen), start_list[t]);
+ tmplen += 8;
+ cpu_to_be64w((uint64_t *)(buf + tmplen), length_list[t]);
+ tmplen += 8;
+ }
+ qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_RAM_DISCARD, tmplen, buf);
+ g_free(buf);
+}
+
+/* Get the destination into a state where it can receive postcopy data. */
+void qemu_savevm_send_postcopy_listen(QEMUFile *f)
+{
+ trace_savevm_send_postcopy_listen();
+ qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_LISTEN, 0, NULL);
+}
+
+/* Kick the destination into running */
+void qemu_savevm_send_postcopy_run(QEMUFile *f)
+{
+ trace_savevm_send_postcopy_run();
+ qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_RUN, 0, NULL);
+}
+
bool qemu_savevm_state_blocked(Error **errp)
{
SaveStateEntry *se;
@@ -1057,6 +1136,169 @@ enum LoadVMExitCodes {
};
static int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis);
+
+/* ------ incoming postcopy messages ------ */
+/* 'advise' arrives before any transfers just to tell us that a postcopy
+ * *might* happen - it might be skipped if precopy transferred everything
+ * quickly.
+ */
+static int loadvm_postcopy_handle_advise(MigrationIncomingState *mis)
+{
+ PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_ADVISE);
+ uint64_t remote_hps, remote_tps;
+
+ trace_loadvm_postcopy_handle_advise();
+ if (ps != POSTCOPY_INCOMING_NONE) {
+ error_report("CMD_POSTCOPY_ADVISE in wrong postcopy state (%d)", ps);
+ return -1;
+ }
+
+ remote_hps = qemu_get_be64(mis->from_src_file);
+ if (remote_hps != getpagesize()) {
+ /*
+ * Some combinations of mismatch are probably possible but it gets
+ * a bit more complicated. In particular we need to place whole
+ * host pages on the dest at once, and we need to ensure that we
+ * handle dirtying to make sure we never end up sending part of
+ * a hostpage on it's own.
+ */
+ error_report("Postcopy needs matching host page sizes (s=%d d=%d)",
+ (int)remote_hps, getpagesize());
+ return -1;
+ }
+
+ remote_tps = qemu_get_be64(mis->from_src_file);
+ if (remote_tps != (1ul << qemu_target_page_bits())) {
+ /*
+ * Again, some differences could be dealt with, but for now keep it
+ * simple.
+ */
+ error_report("Postcopy needs matching target page sizes (s=%d d=%d)",
+ (int)remote_tps, 1 << qemu_target_page_bits());
+ return -1;
+ }
+
+ return 0;
+}
+
+/* After postcopy we will be told to throw some pages away since they're
+ * dirty and will have to be demand fetched. Must happen before CPU is
+ * started.
+ * There can be 0..many of these messages, each encoding multiple pages.
+ */
+static int loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis,
+ uint16_t len)
+{
+ int tmp;
+ char ramid[256];
+ PostcopyState ps = postcopy_state_get();
+
+ trace_loadvm_postcopy_ram_handle_discard();
+
+ switch (ps) {
+ case POSTCOPY_INCOMING_ADVISE:
+ /* 1st discard */
+ tmp = 0; /* TODO: later patch postcopy_ram_prepare_discard(mis); */
+ if (tmp) {
+ return tmp;
+ }
+ break;
+
+ case POSTCOPY_INCOMING_DISCARD:
+ /* Expected state */
+ break;
+
+ default:
+ error_report("CMD_POSTCOPY_RAM_DISCARD in wrong postcopy state (%d)",
+ ps);
+ return -1;
+ }
+ /* We're expecting a
+ * Version (0)
+ * a RAM ID string (length byte, name, 0 term)
+ * then at least 1 16 byte chunk
+ */
+ if (len < (1 + 1 + 1 + 1 + 2 * 8)) {
+ error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len);
+ return -1;
+ }
+
+ tmp = qemu_get_byte(mis->from_src_file);
+ if (tmp != postcopy_ram_discard_version) {
+ error_report("CMD_POSTCOPY_RAM_DISCARD invalid version (%d)", tmp);
+ return -1;
+ }
+
+ if (!qemu_get_counted_string(mis->from_src_file, ramid)) {
+ error_report("CMD_POSTCOPY_RAM_DISCARD Failed to read RAMBlock ID");
+ return -1;
+ }
+ tmp = qemu_get_byte(mis->from_src_file);
+ if (tmp != 0) {
+ error_report("CMD_POSTCOPY_RAM_DISCARD missing nil (%d)", tmp);
+ return -1;
+ }
+
+ len -= 3 + strlen(ramid);
+ if (len % 16) {
+ error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len);
+ return -1;
+ }
+ trace_loadvm_postcopy_ram_handle_discard_header(ramid, len);
+ while (len) {
+ /* TODO - ram_discard_range gets added in a later patch
+ uint64_t start_addr, block_length;
+ start_addr = qemu_get_be64(mis->from_src_file);
+ block_length = qemu_get_be64(mis->from_src_file);
+
+ len -= 16;
+ int ret = ram_discard_range(mis, ramid, start_addr,
+ block_length);
+ if (ret) {
+ return ret;
+ }
+ */
+ }
+ trace_loadvm_postcopy_ram_handle_discard_end();
+
+ return 0;
+}
+
+/* After this message we must be able to immediately receive postcopy data */
+static int loadvm_postcopy_handle_listen(MigrationIncomingState *mis)
+{
+ PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_LISTENING);
+ trace_loadvm_postcopy_handle_listen();
+ if (ps != POSTCOPY_INCOMING_ADVISE && ps != POSTCOPY_INCOMING_DISCARD) {
+ error_report("CMD_POSTCOPY_LISTEN in wrong postcopy state (%d)", ps);
+ return -1;
+ }
+
+ /* TODO start up the postcopy listening thread */
+ return 0;
+}
+
+/* After all discards we can start running and asking for pages */
+static int loadvm_postcopy_handle_run(MigrationIncomingState *mis)
+{
+ PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_RUNNING);
+ trace_loadvm_postcopy_handle_run();
+ if (ps != POSTCOPY_INCOMING_LISTENING) {
+ error_report("CMD_POSTCOPY_RUN in wrong postcopy state (%d)", ps);
+ return -1;
+ }
+
+ if (autostart) {
+ /* Hold onto your hats, starting the CPU */
+ vm_start();
+ } else {
+ /* leave it paused and let management decide when to start the CPU */
+ runstate_set(RUN_STATE_PAUSED);
+ }
+
+ return 0;
+}
+
/**
* loadvm_process_command: Process an incoming 'QEMU_VM_COMMAND'
*
@@ -1112,6 +1354,18 @@ static int loadvm_process_command(QEMUFile *f)
}
migrate_send_rp_pong(mis, tmp32);
break;
+
+ case MIG_CMD_POSTCOPY_ADVISE:
+ return loadvm_postcopy_handle_advise(mis);
+
+ case MIG_CMD_POSTCOPY_LISTEN:
+ return loadvm_postcopy_handle_listen(mis);
+
+ case MIG_CMD_POSTCOPY_RUN:
+ return loadvm_postcopy_handle_run(mis);
+
+ case MIG_CMD_POSTCOPY_RAM_DISCARD:
+ return loadvm_postcopy_ram_handle_discard(mis, len);
}
return 0;
diff --git a/trace-events b/trace-events
index fbb099d..5359235 100644
--- a/trace-events
+++ b/trace-events
@@ -1208,14 +1208,24 @@ qemu_loadvm_state_main(void) ""
qemu_loadvm_state_main_quit_parent(void) ""
qemu_loadvm_state_post_main(int ret) "%d"
qemu_loadvm_state_section_startfull(uint32_t section_id, const char *idstr, uint32_t instance_id, uint32_t version_id) "%u(%s) %u %u"
+loadvm_postcopy_handle_advise(void) ""
+loadvm_postcopy_handle_listen(void) ""
+loadvm_postcopy_handle_run(void) ""
+loadvm_postcopy_ram_handle_discard(void) ""
+loadvm_postcopy_ram_handle_discard_end(void) ""
+loadvm_postcopy_ram_handle_discard_header(const char *ramid, uint16_t len) "%s: %ud"
loadvm_process_command(uint16_t com, uint16_t len) "com=0x%x len=%d"
loadvm_process_command_ping(uint32_t val) "%x"
+qemu_savevm_send_postcopy_advise(void) ""
+qemu_savevm_send_postcopy_ram_discard(const char *id, uint16_t len) "%s: %ud"
savevm_command_send(uint16_t command, uint16_t len) "com=0x%x len=%d"
savevm_section_start(const char *id, unsigned int section_id) "%s, section_id %u"
savevm_section_end(const char *id, unsigned int section_id, int ret) "%s, section_id %u -> %d"
savevm_section_skip(const char *id, unsigned int section_id) "%s, section_id %u"
savevm_send_open_return_path(void) ""
savevm_send_ping(uint32_t val) "%x"
+savevm_send_postcopy_listen(void) ""
+savevm_send_postcopy_run(void) ""
savevm_state_begin(void) ""
savevm_state_header(void) ""
savevm_state_iterate(void) ""
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* Re: [Qemu-devel] [PULL 25/57] Add wrappers and handlers for sending/receiving the postcopy-ram migration messages.
2015-11-10 14:25 ` [Qemu-devel] [PULL 25/57] Add wrappers and handlers for sending/receiving the postcopy-ram migration messages Juan Quintela
@ 2015-11-14 19:11 ` Stefan Weil
2015-11-16 10:07 ` Dr. David Alan Gilbert
0 siblings, 1 reply; 81+ messages in thread
From: Stefan Weil @ 2015-11-14 19:11 UTC (permalink / raw)
To: Juan Quintela, qemu-devel; +Cc: amit.shah, Paolo Bonzini, dgilbert
Am 10.11.2015 um 15:25 schrieb Juan Quintela:
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
>
> The state of the postcopy process is managed via a series of messages;
> * Add wrappers and handlers for sending/receiving these messages
> * Add state variable that track the current state of postcopy
>
> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> Reviewed-by: Amit Shah <amit.shah@redhat.com>
> Reviewed-by: Juan Quintela <quintela@redhat.com>
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> ---
> include/migration/migration.h | 27 +++++
> include/sysemu/sysemu.h | 19 ++++
> migration/migration.c | 20 ++++
> migration/savevm.c | 254 ++++++++++++++++++++++++++++++++++++++++++
> trace-events | 10 ++
> 5 files changed, 330 insertions(+)
>
[...]
> diff --git a/migration/savevm.c b/migration/savevm.c
[...]
> + if (remote_hps != getpagesize()) {
> + /*
> + * Some combinations of mismatch are probably possible but it gets
> + * a bit more complicated. In particular we need to place whole
> + * host pages on the dest at once, and we need to ensure that we
> + * handle dirtying to make sure we never end up sending part of
> + * a hostpage on it's own.
> + */
> + error_report("Postcopy needs matching host page sizes (s=%d d=%d)",
> + (int)remote_hps, getpagesize());
This statement introduces a new warning when compiling for
Windows where getpagesize() returns a size_t. I'll send a patch
to change that definition to return an int value.
Is there a special reason why a type cast was used here
instead of using PRIu64? See also the format string below.
Regards
Stefan
> + return -1;
> + }
> +
> + remote_tps = qemu_get_be64(mis->from_src_file);
> + if (remote_tps != (1ul << qemu_target_page_bits())) {
> + /*
> + * Again, some differences could be dealt with, but for now keep it
> + * simple.
> + */
> + error_report("Postcopy needs matching target page sizes (s=%d d=%d)",
> + (int)remote_tps, 1 << qemu_target_page_bits());
>
^ permalink raw reply [flat|nested] 81+ messages in thread* Re: [Qemu-devel] [PULL 25/57] Add wrappers and handlers for sending/receiving the postcopy-ram migration messages.
2015-11-14 19:11 ` Stefan Weil
@ 2015-11-16 10:07 ` Dr. David Alan Gilbert
2015-11-16 13:14 ` Stefan Weil
0 siblings, 1 reply; 81+ messages in thread
From: Dr. David Alan Gilbert @ 2015-11-16 10:07 UTC (permalink / raw)
To: Stefan Weil; +Cc: amit.shah, Paolo Bonzini, qemu-devel, Juan Quintela
* Stefan Weil (sw@weilnetz.de) wrote:
> Am 10.11.2015 um 15:25 schrieb Juan Quintela:
> > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> >
> > The state of the postcopy process is managed via a series of messages;
> > * Add wrappers and handlers for sending/receiving these messages
> > * Add state variable that track the current state of postcopy
> >
> > Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> > Reviewed-by: Amit Shah <amit.shah@redhat.com>
> > Reviewed-by: Juan Quintela <quintela@redhat.com>
> > Signed-off-by: Juan Quintela <quintela@redhat.com>
> > ---
> > include/migration/migration.h | 27 +++++
> > include/sysemu/sysemu.h | 19 ++++
> > migration/migration.c | 20 ++++
> > migration/savevm.c | 254 ++++++++++++++++++++++++++++++++++++++++++
> > trace-events | 10 ++
> > 5 files changed, 330 insertions(+)
> >
> [...]
> > diff --git a/migration/savevm.c b/migration/savevm.c
> [...]
> > + if (remote_hps != getpagesize()) {
> > + /*
> > + * Some combinations of mismatch are probably possible but it gets
> > + * a bit more complicated. In particular we need to place whole
> > + * host pages on the dest at once, and we need to ensure that we
> > + * handle dirtying to make sure we never end up sending part of
> > + * a hostpage on it's own.
> > + */
> > + error_report("Postcopy needs matching host page sizes (s=%d d=%d)",
> > + (int)remote_hps, getpagesize());
>
> This statement introduces a new warning when compiling for
> Windows where getpagesize() returns a size_t. I'll send a patch
> to change that definition to return an int value.
Interesting; which compiler are you using; I don't think any of us testing with
ming hit that.
> Is there a special reason why a type cast was used here
> instead of using PRIu64? See also the format string below.
No not really; to be honest those should probably have been something smaller
than 64bit anyway, normal page size being that big would be odd.
Dave
> Regards
> Stefan
>
>
> > + return -1;
> > + }
> > +
> > + remote_tps = qemu_get_be64(mis->from_src_file);
> > + if (remote_tps != (1ul << qemu_target_page_bits())) {
> > + /*
> > + * Again, some differences could be dealt with, but for now keep it
> > + * simple.
> > + */
> > + error_report("Postcopy needs matching target page sizes (s=%d d=%d)",
> > + (int)remote_tps, 1 << qemu_target_page_bits());
> >
>
>
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
^ permalink raw reply [flat|nested] 81+ messages in thread* Re: [Qemu-devel] [PULL 25/57] Add wrappers and handlers for sending/receiving the postcopy-ram migration messages.
2015-11-16 10:07 ` Dr. David Alan Gilbert
@ 2015-11-16 13:14 ` Stefan Weil
2015-11-16 14:20 ` Dr. David Alan Gilbert
0 siblings, 1 reply; 81+ messages in thread
From: Stefan Weil @ 2015-11-16 13:14 UTC (permalink / raw)
To: Dr. David Alan Gilbert
Cc: amit.shah, Paolo Bonzini, qemu-devel, Juan Quintela
Am 16.11.2015 um 11:07 schrieb Dr. David Alan Gilbert:
> * Stefan Weil (sw@weilnetz.de) wrote:
>> Am 10.11.2015 um 15:25 schrieb Juan Quintela:
>>> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
>>>
>>> The state of the postcopy process is managed via a series of messages;
>>> * Add wrappers and handlers for sending/receiving these messages
>>> * Add state variable that track the current state of postcopy
>>>
>>> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
>>> Reviewed-by: Amit Shah <amit.shah@redhat.com>
>>> Reviewed-by: Juan Quintela <quintela@redhat.com>
>>> Signed-off-by: Juan Quintela <quintela@redhat.com>
>>> ---
>>> include/migration/migration.h | 27 +++++
>>> include/sysemu/sysemu.h | 19 ++++
>>> migration/migration.c | 20 ++++
>>> migration/savevm.c | 254 ++++++++++++++++++++++++++++++++++++++++++
>>> trace-events | 10 ++
>>> 5 files changed, 330 insertions(+)
>>>
>> [...]
>>> diff --git a/migration/savevm.c b/migration/savevm.c
>> [...]
>>> + if (remote_hps != getpagesize()) {
>>> + /*
>>> + * Some combinations of mismatch are probably possible but it gets
>>> + * a bit more complicated. In particular we need to place whole
>>> + * host pages on the dest at once, and we need to ensure that we
>>> + * handle dirtying to make sure we never end up sending part of
>>> + * a hostpage on it's own.
>>> + */
>>> + error_report("Postcopy needs matching host page sizes (s=%d d=%d)",
>>> + (int)remote_hps, getpagesize());
>>
>> This statement introduces a new warning when compiling for
>> Windows where getpagesize() returns a size_t. I'll send a patch
>> to change that definition to return an int value.
>
> Interesting; which compiler are you using; I don't think any of us testing with
> ming hit that.
I use Debian GNU Linux jessie with package gcc-mingw-w64-x86-64.
CC i386-softmmu/migration/savevm.o
migration/savevm.c: In function ‘loadvm_postcopy_handle_advise’:
migration/savevm.c:1284:22: warning: format ‘%d’ expects argument of
type ‘int’, but argument 3 has type ‘size_t’ [-Wformat=]
(int)remote_hps, getpagesize());
^
$ x86_64-w64-mingw32-gcc --version
x86_64-w64-mingw32-gcc (GCC) 4.9.1
Copyright (C) 2014 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
^ permalink raw reply [flat|nested] 81+ messages in thread* Re: [Qemu-devel] [PULL 25/57] Add wrappers and handlers for sending/receiving the postcopy-ram migration messages.
2015-11-16 13:14 ` Stefan Weil
@ 2015-11-16 14:20 ` Dr. David Alan Gilbert
0 siblings, 0 replies; 81+ messages in thread
From: Dr. David Alan Gilbert @ 2015-11-16 14:20 UTC (permalink / raw)
To: Stefan Weil; +Cc: amit.shah, Paolo Bonzini, qemu-devel, Juan Quintela
* Stefan Weil (sw@weilnetz.de) wrote:
> Am 16.11.2015 um 11:07 schrieb Dr. David Alan Gilbert:
> > * Stefan Weil (sw@weilnetz.de) wrote:
> >> Am 10.11.2015 um 15:25 schrieb Juan Quintela:
> >>> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> >>>
> >>> The state of the postcopy process is managed via a series of messages;
> >>> * Add wrappers and handlers for sending/receiving these messages
> >>> * Add state variable that track the current state of postcopy
> >>>
> >>> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> >>> Reviewed-by: Amit Shah <amit.shah@redhat.com>
> >>> Reviewed-by: Juan Quintela <quintela@redhat.com>
> >>> Signed-off-by: Juan Quintela <quintela@redhat.com>
> >>> ---
> >>> include/migration/migration.h | 27 +++++
> >>> include/sysemu/sysemu.h | 19 ++++
> >>> migration/migration.c | 20 ++++
> >>> migration/savevm.c | 254 ++++++++++++++++++++++++++++++++++++++++++
> >>> trace-events | 10 ++
> >>> 5 files changed, 330 insertions(+)
> >>>
> >> [...]
> >>> diff --git a/migration/savevm.c b/migration/savevm.c
> >> [...]
> >>> + if (remote_hps != getpagesize()) {
> >>> + /*
> >>> + * Some combinations of mismatch are probably possible but it gets
> >>> + * a bit more complicated. In particular we need to place whole
> >>> + * host pages on the dest at once, and we need to ensure that we
> >>> + * handle dirtying to make sure we never end up sending part of
> >>> + * a hostpage on it's own.
> >>> + */
> >>> + error_report("Postcopy needs matching host page sizes (s=%d d=%d)",
> >>> + (int)remote_hps, getpagesize());
> >>
> >> This statement introduces a new warning when compiling for
> >> Windows where getpagesize() returns a size_t. I'll send a patch
> >> to change that definition to return an int value.
> >
> > Interesting; which compiler are you using; I don't think any of us testing with
> > ming hit that.
>
> I use Debian GNU Linux jessie with package gcc-mingw-w64-x86-64.
>
> CC i386-softmmu/migration/savevm.o
> migration/savevm.c: In function ‘loadvm_postcopy_handle_advise’:
> migration/savevm.c:1284:22: warning: format ‘%d’ expects argument of
> type ‘int’, but argument 3 has type ‘size_t’ [-Wformat=]
> (int)remote_hps, getpagesize());
> ^
> $ x86_64-w64-mingw32-gcc --version
> x86_64-w64-mingw32-gcc (GCC) 4.9.1
> Copyright (C) 2014 Free Software Foundation, Inc.
> This is free software; see the source for copying conditions. There is NO
> warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Ah OK, I see that but only when I build with a 64bit mingw.
Dave
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
^ permalink raw reply [flat|nested] 81+ messages in thread
* [Qemu-devel] [PULL 26/57] MIG_CMD_PACKAGED: Send a packaged chunk of migration stream
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (24 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 25/57] Add wrappers and handlers for sending/receiving the postcopy-ram migration messages Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 27/57] Modify save_live_pending for postcopy Juan Quintela
` (31 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
MIG_CMD_PACKAGED is a migration command that wraps a chunk of migration
stream inside a package whose length can be determined purely by reading
its header. The destination guarantees that the whole MIG_CMD_PACKAGED
is read off the stream prior to parsing the contents.
This is used by postcopy to load device state (from the package)
while leaving the main stream free to receive memory pages.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/sysemu/sysemu.h | 4 ++
migration/savevm.c | 104 +++++++++++++++++++++++++++++++++++++++++++++---
trace-events | 4 ++
3 files changed, 107 insertions(+), 5 deletions(-)
diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index 6225e00..c27b926 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -99,9 +99,12 @@ enum qemu_vm_cmd {
MIG_CMD_POSTCOPY_RAM_DISCARD, /* A list of pages to discard that
were previously sent during
precopy but are dirty. */
+ MIG_CMD_PACKAGED, /* Send a wrapped stream within this stream */
MIG_CMD_MAX
};
+#define MAX_VM_CMD_PACKAGED_SIZE (1ul << 24)
+
bool qemu_savevm_state_blocked(Error **errp);
void qemu_savevm_state_begin(QEMUFile *f,
const MigrationParams *params);
@@ -114,6 +117,7 @@ void qemu_savevm_command_send(QEMUFile *f, enum qemu_vm_cmd command,
uint16_t len, uint8_t *data);
void qemu_savevm_send_ping(QEMUFile *f, uint32_t value);
void qemu_savevm_send_open_return_path(QEMUFile *f);
+int qemu_savevm_send_packaged(QEMUFile *f, const QEMUSizedBuffer *qsb);
void qemu_savevm_send_postcopy_advise(QEMUFile *f);
void qemu_savevm_send_postcopy_listen(QEMUFile *f);
void qemu_savevm_send_postcopy_run(QEMUFile *f);
diff --git a/migration/savevm.c b/migration/savevm.c
index 1ce022a..f499dfa 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -74,6 +74,7 @@ static struct mig_cmd_args {
[MIG_CMD_POSTCOPY_RUN] = { .len = 0, .name = "POSTCOPY_RUN" },
[MIG_CMD_POSTCOPY_RAM_DISCARD] = {
.len = -1, .name = "POSTCOPY_RAM_DISCARD" },
+ [MIG_CMD_PACKAGED] = { .len = 4, .name = "PACKAGED" },
[MIG_CMD_MAX] = { .len = -1, .name = "MAX" },
};
@@ -749,6 +750,48 @@ void qemu_savevm_send_open_return_path(QEMUFile *f)
qemu_savevm_command_send(f, MIG_CMD_OPEN_RETURN_PATH, 0, NULL);
}
+/* We have a buffer of data to send; we don't want that all to be loaded
+ * by the command itself, so the command contains just the length of the
+ * extra buffer that we then send straight after it.
+ * TODO: Must be a better way to organise that
+ *
+ * Returns:
+ * 0 on success
+ * -ve on error
+ */
+int qemu_savevm_send_packaged(QEMUFile *f, const QEMUSizedBuffer *qsb)
+{
+ size_t cur_iov;
+ size_t len = qsb_get_length(qsb);
+ uint32_t tmp;
+
+ if (len > MAX_VM_CMD_PACKAGED_SIZE) {
+ error_report("%s: Unreasonably large packaged state: %zu",
+ __func__, len);
+ return -1;
+ }
+
+ tmp = cpu_to_be32(len);
+
+ trace_qemu_savevm_send_packaged();
+ qemu_savevm_command_send(f, MIG_CMD_PACKAGED, 4, (uint8_t *)&tmp);
+
+ /* all the data follows (concatinating the iov's) */
+ for (cur_iov = 0; cur_iov < qsb->n_iov; cur_iov++) {
+ /* The iov entries are partially filled */
+ size_t towrite = MIN(qsb->iov[cur_iov].iov_len, len);
+ len -= towrite;
+
+ if (!towrite) {
+ break;
+ }
+
+ qemu_put_buffer(f, qsb->iov[cur_iov].iov_base, towrite);
+ }
+
+ return 0;
+}
+
/* Send prior to any postcopy transfer */
void qemu_savevm_send_postcopy_advise(QEMUFile *f)
{
@@ -1300,12 +1343,60 @@ static int loadvm_postcopy_handle_run(MigrationIncomingState *mis)
}
/**
- * loadvm_process_command: Process an incoming 'QEMU_VM_COMMAND'
+ * Immediately following this command is a blob of data containing an embedded
+ * chunk of migration stream; read it and load it.
*
- * Returns: 0 on just a normal return
- * LOADVM_QUIT All good, but exit the loop
- * <0 error (in which case it will issue an error message).
- * @f: The stream to read the command data from.
+ * @mis: Incoming state
+ * @length: Length of packaged data to read
+ *
+ * Returns: Negative values on error
+ *
+ */
+static int loadvm_handle_cmd_packaged(MigrationIncomingState *mis)
+{
+ int ret;
+ uint8_t *buffer;
+ uint32_t length;
+ QEMUSizedBuffer *qsb;
+
+ length = qemu_get_be32(mis->from_src_file);
+ trace_loadvm_handle_cmd_packaged(length);
+
+ if (length > MAX_VM_CMD_PACKAGED_SIZE) {
+ error_report("Unreasonably large packaged state: %u", length);
+ return -1;
+ }
+ buffer = g_malloc0(length);
+ ret = qemu_get_buffer(mis->from_src_file, buffer, (int)length);
+ if (ret != length) {
+ g_free(buffer);
+ error_report("CMD_PACKAGED: Buffer receive fail ret=%d length=%d\n",
+ ret, length);
+ return (ret < 0) ? ret : -EAGAIN;
+ }
+ trace_loadvm_handle_cmd_packaged_received(ret);
+
+ /* Setup a dummy QEMUFile that actually reads from the buffer */
+ qsb = qsb_create(buffer, length);
+ g_free(buffer); /* Because qsb_create copies */
+ if (!qsb) {
+ error_report("Unable to create qsb");
+ }
+ QEMUFile *packf = qemu_bufopen("r", qsb);
+
+ ret = qemu_loadvm_state_main(packf, mis);
+ trace_loadvm_handle_cmd_packaged_main(ret);
+ qemu_fclose(packf);
+ qsb_free(qsb);
+
+ return ret;
+}
+
+/*
+ * Process an incoming 'QEMU_VM_COMMAND'
+ * 0 just a normal return
+ * LOADVM_QUIT All good, but exit the loop
+ * <0 Error
*/
static int loadvm_process_command(QEMUFile *f)
{
@@ -1355,6 +1446,9 @@ static int loadvm_process_command(QEMUFile *f)
migrate_send_rp_pong(mis, tmp32);
break;
+ case MIG_CMD_PACKAGED:
+ return loadvm_handle_cmd_packaged(mis);
+
case MIG_CMD_POSTCOPY_ADVISE:
return loadvm_postcopy_handle_advise(mis);
diff --git a/trace-events b/trace-events
index 5359235..b908c19 100644
--- a/trace-events
+++ b/trace-events
@@ -1208,6 +1208,10 @@ qemu_loadvm_state_main(void) ""
qemu_loadvm_state_main_quit_parent(void) ""
qemu_loadvm_state_post_main(int ret) "%d"
qemu_loadvm_state_section_startfull(uint32_t section_id, const char *idstr, uint32_t instance_id, uint32_t version_id) "%u(%s) %u %u"
+qemu_savevm_send_packaged(void) ""
+loadvm_handle_cmd_packaged(unsigned int length) "%u"
+loadvm_handle_cmd_packaged_main(int ret) "%d"
+loadvm_handle_cmd_packaged_received(int ret) "%d"
loadvm_postcopy_handle_advise(void) ""
loadvm_postcopy_handle_listen(void) ""
loadvm_postcopy_handle_run(void) ""
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 27/57] Modify save_live_pending for postcopy
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (25 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 26/57] MIG_CMD_PACKAGED: Send a packaged chunk of migration stream Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 28/57] postcopy: OS support test Juan Quintela
` (30 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Modify save_live_pending to return separate postcopiable and
non-postcopiable counts.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/migration/vmstate.h | 5 +++--
include/sysemu/sysemu.h | 4 +++-
migration/block.c | 7 +++++--
migration/migration.c | 9 +++++++--
migration/ram.c | 8 ++++++--
migration/savevm.c | 17 +++++++++++++----
trace-events | 2 +-
7 files changed, 38 insertions(+), 14 deletions(-)
diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h
index 9986ccc..7f16a38 100644
--- a/include/migration/vmstate.h
+++ b/include/migration/vmstate.h
@@ -54,8 +54,9 @@ typedef struct SaveVMHandlers {
/* This runs outside the iothread lock! */
int (*save_live_setup)(QEMUFile *f, void *opaque);
- uint64_t (*save_live_pending)(QEMUFile *f, void *opaque, uint64_t max_size);
-
+ void (*save_live_pending)(QEMUFile *f, void *opaque, uint64_t max_size,
+ uint64_t *non_postcopiable_pending,
+ uint64_t *postcopiable_pending);
LoadStateHandler *load_state;
} SaveVMHandlers;
diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index c27b926..70835d0 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -112,7 +112,9 @@ void qemu_savevm_state_header(QEMUFile *f);
int qemu_savevm_state_iterate(QEMUFile *f);
void qemu_savevm_state_cleanup(void);
void qemu_savevm_state_complete_precopy(QEMUFile *f);
-uint64_t qemu_savevm_state_pending(QEMUFile *f, uint64_t max_size);
+void qemu_savevm_state_pending(QEMUFile *f, uint64_t max_size,
+ uint64_t *res_non_postcopiable,
+ uint64_t *res_postcopiable);
void qemu_savevm_command_send(QEMUFile *f, enum qemu_vm_cmd command,
uint16_t len, uint8_t *data);
void qemu_savevm_send_ping(QEMUFile *f, uint32_t value);
diff --git a/migration/block.c b/migration/block.c
index 4fb9b7c..310e2b3 100644
--- a/migration/block.c
+++ b/migration/block.c
@@ -748,7 +748,9 @@ static int block_save_complete(QEMUFile *f, void *opaque)
return 0;
}
-static uint64_t block_save_pending(QEMUFile *f, void *opaque, uint64_t max_size)
+static void block_save_pending(QEMUFile *f, void *opaque, uint64_t max_size,
+ uint64_t *non_postcopiable_pending,
+ uint64_t *postcopiable_pending)
{
/* Estimate pending number of bytes to send */
uint64_t pending;
@@ -767,7 +769,8 @@ static uint64_t block_save_pending(QEMUFile *f, void *opaque, uint64_t max_size)
qemu_mutex_unlock_iothread();
DPRINTF("Enter save live pending %" PRIu64 "\n", pending);
- return pending;
+ /* We don't do postcopy */
+ *non_postcopiable_pending += pending;
}
static int block_load(QEMUFile *f, void *opaque, int version_id)
diff --git a/migration/migration.c b/migration/migration.c
index 7097e5b..bb4c92e 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1288,8 +1288,13 @@ static void *migration_thread(void *opaque)
uint64_t pending_size;
if (!qemu_file_rate_limit(s->file)) {
- pending_size = qemu_savevm_state_pending(s->file, max_size);
- trace_migrate_pending(pending_size, max_size);
+ uint64_t pend_post, pend_nonpost;
+
+ qemu_savevm_state_pending(s->file, max_size, &pend_nonpost,
+ &pend_post);
+ pending_size = pend_nonpost + pend_post;
+ trace_migrate_pending(pending_size, max_size,
+ pend_post, pend_nonpost);
if (pending_size && pending_size >= max_size) {
qemu_savevm_state_iterate(s->file);
} else {
diff --git a/migration/ram.c b/migration/ram.c
index 4fa44a7..0e53325 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1383,7 +1383,9 @@ static int ram_save_complete(QEMUFile *f, void *opaque)
return 0;
}
-static uint64_t ram_save_pending(QEMUFile *f, void *opaque, uint64_t max_size)
+static void ram_save_pending(QEMUFile *f, void *opaque, uint64_t max_size,
+ uint64_t *non_postcopiable_pending,
+ uint64_t *postcopiable_pending)
{
uint64_t remaining_size;
@@ -1397,7 +1399,9 @@ static uint64_t ram_save_pending(QEMUFile *f, void *opaque, uint64_t max_size)
qemu_mutex_unlock_iothread();
remaining_size = ram_save_remaining() * TARGET_PAGE_SIZE;
}
- return remaining_size;
+
+ /* We can do postcopy, and all the data is postcopiable */
+ *postcopiable_pending += remaining_size;
}
static int load_xbzrle(QEMUFile *f, ram_addr_t addr, void *host)
diff --git a/migration/savevm.c b/migration/savevm.c
index f499dfa..7467dc0 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1053,10 +1053,19 @@ void qemu_savevm_state_complete_precopy(QEMUFile *f)
qemu_fflush(f);
}
-uint64_t qemu_savevm_state_pending(QEMUFile *f, uint64_t max_size)
+/* Give an estimate of the amount left to be transferred,
+ * the result is split into the amount for units that can and
+ * for units that can't do postcopy.
+ */
+void qemu_savevm_state_pending(QEMUFile *f, uint64_t max_size,
+ uint64_t *res_non_postcopiable,
+ uint64_t *res_postcopiable)
{
SaveStateEntry *se;
- uint64_t ret = 0;
+
+ *res_non_postcopiable = 0;
+ *res_postcopiable = 0;
+
QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
if (!se->ops || !se->ops->save_live_pending) {
@@ -1067,9 +1076,9 @@ uint64_t qemu_savevm_state_pending(QEMUFile *f, uint64_t max_size)
continue;
}
}
- ret += se->ops->save_live_pending(f, se->opaque, max_size);
+ se->ops->save_live_pending(f, se->opaque, max_size,
+ res_non_postcopiable, res_postcopiable);
}
- return ret;
}
void qemu_savevm_state_cleanup(void)
diff --git a/trace-events b/trace-events
index b908c19..d319cf8 100644
--- a/trace-events
+++ b/trace-events
@@ -1450,7 +1450,7 @@ migrate_set_state(int new_state) "new state %d"
migrate_fd_cleanup(void) ""
migrate_fd_error(void) ""
migrate_fd_cancel(void) ""
-migrate_pending(uint64_t size, uint64_t max) "pending size %" PRIu64 " max %" PRIu64
+migrate_pending(uint64_t size, uint64_t max, uint64_t post, uint64_t nonpost) "pending size %" PRIu64 " max %" PRIu64 " (post=%" PRIu64 " nonpost=%" PRIu64 ")"
migrate_send_rp_message(int msg_type, uint16_t len) "%d: len %d"
open_return_path_on_source(void) ""
open_return_path_on_source_continue(void) ""
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 28/57] postcopy: OS support test
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (26 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 27/57] Modify save_live_pending for postcopy Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 29/57] migrate_start_postcopy: Command to trigger transition to postcopy Juan Quintela
` (29 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Provide a check to see if the OS we're running on has all the bits
needed for postcopy.
Creates postcopy-ram.c which will get most of the other helpers we need.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/migration/postcopy-ram.h | 19 +++++
migration/Makefile.objs | 2 +-
migration/postcopy-ram.c | 157 +++++++++++++++++++++++++++++++++++++++
migration/savevm.c | 5 ++
4 files changed, 182 insertions(+), 1 deletion(-)
create mode 100644 include/migration/postcopy-ram.h
create mode 100644 migration/postcopy-ram.c
diff --git a/include/migration/postcopy-ram.h b/include/migration/postcopy-ram.h
new file mode 100644
index 0000000..d81934f
--- /dev/null
+++ b/include/migration/postcopy-ram.h
@@ -0,0 +1,19 @@
+/*
+ * Postcopy migration for RAM
+ *
+ * Copyright 2013 Red Hat, Inc. and/or its affiliates
+ *
+ * Authors:
+ * Dave Gilbert <dgilbert@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+#ifndef QEMU_POSTCOPY_RAM_H
+#define QEMU_POSTCOPY_RAM_H
+
+/* Return true if the host supports everything we need to do postcopy-ram */
+bool postcopy_ram_supported_by_host(void);
+
+#endif
diff --git a/migration/Makefile.objs b/migration/Makefile.objs
index d929e96..0cac6d7 100644
--- a/migration/Makefile.objs
+++ b/migration/Makefile.objs
@@ -1,7 +1,7 @@
common-obj-y += migration.o tcp.o
common-obj-y += vmstate.o
common-obj-y += qemu-file.o qemu-file-buf.o qemu-file-unix.o qemu-file-stdio.o
-common-obj-y += xbzrle.o
+common-obj-y += xbzrle.o postcopy-ram.o
common-obj-$(CONFIG_RDMA) += rdma.o
common-obj-$(CONFIG_POSIX) += exec.o unix.o fd.o
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
new file mode 100644
index 0000000..cdd0168
--- /dev/null
+++ b/migration/postcopy-ram.c
@@ -0,0 +1,157 @@
+/*
+ * Postcopy migration for RAM
+ *
+ * Copyright 2013-2015 Red Hat, Inc. and/or its affiliates
+ *
+ * Authors:
+ * Dave Gilbert <dgilbert@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+/*
+ * Postcopy is a migration technique where the execution flips from the
+ * source to the destination before all the data has been copied.
+ */
+
+#include <glib.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include "qemu-common.h"
+#include "migration/migration.h"
+#include "migration/postcopy-ram.h"
+#include "sysemu/sysemu.h"
+#include "qemu/error-report.h"
+#include "trace.h"
+
+/* Postcopy needs to detect accesses to pages that haven't yet been copied
+ * across, and efficiently map new pages in, the techniques for doing this
+ * are target OS specific.
+ */
+#if defined(__linux__)
+
+#include <sys/mman.h>
+#include <sys/ioctl.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <asm/types.h> /* for __u64 */
+#endif
+
+#if defined(__linux__) && defined(__NR_userfaultfd)
+#include <linux/userfaultfd.h>
+
+static bool ufd_version_check(int ufd)
+{
+ struct uffdio_api api_struct;
+ uint64_t ioctl_mask;
+
+ api_struct.api = UFFD_API;
+ api_struct.features = 0;
+ if (ioctl(ufd, UFFDIO_API, &api_struct)) {
+ error_report("postcopy_ram_supported_by_host: UFFDIO_API failed: %s",
+ strerror(errno));
+ return false;
+ }
+
+ ioctl_mask = (__u64)1 << _UFFDIO_REGISTER |
+ (__u64)1 << _UFFDIO_UNREGISTER;
+ if ((api_struct.ioctls & ioctl_mask) != ioctl_mask) {
+ error_report("Missing userfault features: %" PRIx64,
+ (uint64_t)(~api_struct.ioctls & ioctl_mask));
+ return false;
+ }
+
+ return true;
+}
+
+bool postcopy_ram_supported_by_host(void)
+{
+ long pagesize = getpagesize();
+ int ufd = -1;
+ bool ret = false; /* Error unless we change it */
+ void *testarea = NULL;
+ struct uffdio_register reg_struct;
+ struct uffdio_range range_struct;
+ uint64_t feature_mask;
+
+ if ((1ul << qemu_target_page_bits()) > pagesize) {
+ error_report("Target page size bigger than host page size");
+ goto out;
+ }
+
+ ufd = syscall(__NR_userfaultfd, O_CLOEXEC);
+ if (ufd == -1) {
+ error_report("%s: userfaultfd not available: %s", __func__,
+ strerror(errno));
+ goto out;
+ }
+
+ /* Version and features check */
+ if (!ufd_version_check(ufd)) {
+ goto out;
+ }
+
+ /*
+ * We need to check that the ops we need are supported on anon memory
+ * To do that we need to register a chunk and see the flags that
+ * are returned.
+ */
+ testarea = mmap(NULL, pagesize, PROT_READ | PROT_WRITE, MAP_PRIVATE |
+ MAP_ANONYMOUS, -1, 0);
+ if (testarea == MAP_FAILED) {
+ error_report("%s: Failed to map test area: %s", __func__,
+ strerror(errno));
+ goto out;
+ }
+ g_assert(((size_t)testarea & (pagesize-1)) == 0);
+
+ reg_struct.range.start = (uintptr_t)testarea;
+ reg_struct.range.len = pagesize;
+ reg_struct.mode = UFFDIO_REGISTER_MODE_MISSING;
+
+ if (ioctl(ufd, UFFDIO_REGISTER, ®_struct)) {
+ error_report("%s userfault register: %s", __func__, strerror(errno));
+ goto out;
+ }
+
+ range_struct.start = (uintptr_t)testarea;
+ range_struct.len = pagesize;
+ if (ioctl(ufd, UFFDIO_UNREGISTER, &range_struct)) {
+ error_report("%s userfault unregister: %s", __func__, strerror(errno));
+ goto out;
+ }
+
+ feature_mask = (__u64)1 << _UFFDIO_WAKE |
+ (__u64)1 << _UFFDIO_COPY |
+ (__u64)1 << _UFFDIO_ZEROPAGE;
+ if ((reg_struct.ioctls & feature_mask) != feature_mask) {
+ error_report("Missing userfault map features: %" PRIx64,
+ (uint64_t)(~reg_struct.ioctls & feature_mask));
+ goto out;
+ }
+
+ /* Success! */
+ ret = true;
+out:
+ if (testarea) {
+ munmap(testarea, pagesize);
+ }
+ if (ufd != -1) {
+ close(ufd);
+ }
+ return ret;
+}
+
+#else
+/* No target OS support, stubs just fail */
+bool postcopy_ram_supported_by_host(void)
+{
+ error_report("%s: No OS support", __func__);
+ return false;
+}
+
+#endif
+
diff --git a/migration/savevm.c b/migration/savevm.c
index 7467dc0..0e48a91 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -37,6 +37,7 @@
#include "qemu/timer.h"
#include "audio/audio.h"
#include "migration/migration.h"
+#include "migration/postcopy-ram.h"
#include "qapi/qmp/qerror.h"
#include "qemu/error-report.h"
#include "qemu/sockets.h"
@@ -1205,6 +1206,10 @@ static int loadvm_postcopy_handle_advise(MigrationIncomingState *mis)
return -1;
}
+ if (!postcopy_ram_supported_by_host()) {
+ return -1;
+ }
+
remote_hps = qemu_get_be64(mis->from_src_file);
if (remote_hps != getpagesize()) {
/*
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 29/57] migrate_start_postcopy: Command to trigger transition to postcopy
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (27 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 28/57] postcopy: OS support test Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 30/57] migration_completion: Take current state Juan Quintela
` (28 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Once postcopy is enabled (with migrate_set_capability), the migration
will still start on precopy mode. To cause a transition into postcopy
the:
migrate_start_postcopy
command must be issued. Postcopy will start sometime after this
(when it's next checked in the migration loop).
Issuing the command before migration has started will error,
and issuing after it has finished is ignored.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
hmp-commands.hx | 15 +++++++++++++++
hmp.c | 7 +++++++
hmp.h | 1 +
include/migration/migration.h | 3 +++
migration/migration.c | 22 ++++++++++++++++++++++
qapi-schema.json | 8 ++++++++
qmp-commands.hx | 19 +++++++++++++++++++
7 files changed, 75 insertions(+)
diff --git a/hmp-commands.hx b/hmp-commands.hx
index 3a4ae39..8939b98 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -1008,6 +1008,21 @@ Set the parameter @var{parameter} for migration.
ETEXI
{
+ .name = "migrate_start_postcopy",
+ .args_type = "",
+ .params = "",
+ .help = "Switch migration to postcopy mode",
+ .mhandler.cmd = hmp_migrate_start_postcopy,
+ },
+
+STEXI
+@item migrate_start_postcopy
+@findex migrate_start_postcopy
+Switch in-progress migration to postcopy mode. Ignored after the end of
+migration (or once already in postcopy).
+ETEXI
+
+ {
.name = "client_migrate_info",
.args_type = "protocol:s,hostname:s,port:i?,tls-port:i?,cert-subject:s?",
.params = "protocol hostname port tls-port cert-subject",
diff --git a/hmp.c b/hmp.c
index a15d00c..e1f854a 100644
--- a/hmp.c
+++ b/hmp.c
@@ -1293,6 +1293,13 @@ void hmp_client_migrate_info(Monitor *mon, const QDict *qdict)
hmp_handle_error(mon, &err);
}
+void hmp_migrate_start_postcopy(Monitor *mon, const QDict *qdict)
+{
+ Error *err = NULL;
+ qmp_migrate_start_postcopy(&err);
+ hmp_handle_error(mon, &err);
+}
+
void hmp_set_password(Monitor *mon, const QDict *qdict)
{
const char *protocol = qdict_get_str(qdict, "protocol");
diff --git a/hmp.h b/hmp.h
index 81656c3..a8c5b5a 100644
--- a/hmp.h
+++ b/hmp.h
@@ -69,6 +69,7 @@ void hmp_migrate_set_capability(Monitor *mon, const QDict *qdict);
void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict);
void hmp_migrate_set_cache_size(Monitor *mon, const QDict *qdict);
void hmp_client_migrate_info(Monitor *mon, const QDict *qdict);
+void hmp_migrate_start_postcopy(Monitor *mon, const QDict *qdict);
void hmp_set_password(Monitor *mon, const QDict *qdict);
void hmp_expire_password(Monitor *mon, const QDict *qdict);
void hmp_eject(Monitor *mon, const QDict *qdict);
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 2e9fa3c..2176666 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -127,6 +127,9 @@ struct MigrationState
int64_t xbzrle_cache_size;
int64_t setup_time;
int64_t dirty_sync_count;
+
+ /* Flag set once the migration has been asked to enter postcopy */
+ bool start_postcopy;
};
void process_incoming_migration(QEMUFile *f);
diff --git a/migration/migration.c b/migration/migration.c
index bb4c92e..9c46472 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -668,6 +668,28 @@ void qmp_migrate_set_parameters(bool has_compress_level,
}
}
+void qmp_migrate_start_postcopy(Error **errp)
+{
+ MigrationState *s = migrate_get_current();
+
+ if (!migrate_postcopy_ram()) {
+ error_setg(errp, "Enable postcopy with migration_set_capability before"
+ " the start of migration");
+ return;
+ }
+
+ if (s->state == MIGRATION_STATUS_NONE) {
+ error_setg(errp, "Postcopy must be started after migration has been"
+ " started");
+ return;
+ }
+ /*
+ * we don't error if migration has finished since that would be racy
+ * with issuing this command.
+ */
+ atomic_set(&s->start_postcopy, true);
+}
+
/* shared migration helpers */
static void migrate_set_state(MigrationState *s, int old_state, int new_state)
diff --git a/qapi-schema.json b/qapi-schema.json
index 8638d42..d25df93 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -702,6 +702,14 @@
'*tls-port': 'int', '*cert-subject': 'str' } }
##
+# @migrate-start-postcopy
+#
+# Switch migration to postcopy mode
+#
+# Since: 2.5
+{ 'command': 'migrate-start-postcopy' }
+
+##
# @MouseInfo:
#
# Information about a mouse device.
diff --git a/qmp-commands.hx b/qmp-commands.hx
index d7cf0ff..7f85d40 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -718,6 +718,25 @@ Example:
EQMP
{
+ .name = "migrate-start-postcopy",
+ .args_type = "",
+ .mhandler.cmd_new = qmp_marshal_migrate_start_postcopy,
+ },
+
+SQMP
+migrate-start-postcopy
+----------------------
+
+Switch an in-progress migration to postcopy mode. Ignored after the end of
+migration (or once already in postcopy).
+
+Example:
+-> { "execute": "migrate-start-postcopy" }
+<- { "return": {} }
+
+EQMP
+
+ {
.name = "query-migrate-cache-size",
.args_type = "",
.mhandler.cmd_new = qmp_marshal_query_migrate_cache_size,
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 30/57] migration_completion: Take current state
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (28 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 29/57] migrate_start_postcopy: Command to trigger transition to postcopy Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 31/57] MIGRATION_STATUS_POSTCOPY_ACTIVE: Add new migration state Juan Quintela
` (27 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Soon we'll be in either ACTIVE or POSTCOPY_ACTIVE when we
complete migration, and we need to know which we expect to be
in to change state safely.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
migration/migration.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/migration/migration.c b/migration/migration.c
index 9c46472..85e68bc 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1243,10 +1243,12 @@ static int await_return_path_close_on_source(MigrationState *ms)
* The caller 'breaks' the loop when this returns.
*
* @s: Current migration state
+ * @current_active_state: The migration state we expect to be in
* @*old_vm_running: Pointer to old_vm_running flag
* @*start_time: Pointer to time to update
*/
-static void migration_completion(MigrationState *s, bool *old_vm_running,
+static void migration_completion(MigrationState *s, int current_active_state,
+ bool *old_vm_running,
int64_t *start_time)
{
int ret;
@@ -1275,11 +1277,11 @@ static void migration_completion(MigrationState *s, bool *old_vm_running,
goto fail;
}
- migrate_set_state(s, MIGRATION_STATUS_ACTIVE, MIGRATION_STATUS_COMPLETED);
+ migrate_set_state(s, current_active_state, MIGRATION_STATUS_COMPLETED);
return;
fail:
- migrate_set_state(s, MIGRATION_STATUS_ACTIVE, MIGRATION_STATUS_FAILED);
+ migrate_set_state(s, current_active_state, MIGRATION_STATUS_FAILED);
}
/*
@@ -1321,7 +1323,8 @@ static void *migration_thread(void *opaque)
qemu_savevm_state_iterate(s->file);
} else {
trace_migration_thread_low_pending(pending_size);
- migration_completion(s, &old_vm_running, &start_time);
+ migration_completion(s, MIGRATION_STATUS_ACTIVE,
+ &old_vm_running, &start_time);
break;
}
}
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 31/57] MIGRATION_STATUS_POSTCOPY_ACTIVE: Add new migration state
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (29 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 30/57] migration_completion: Take current state Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 32/57] Avoid sending vmdescription during postcopy Juan Quintela
` (26 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
'MIGRATION_STATUS_POSTCOPY_ACTIVE' is entered after migrate_start_postcopy
'migration_in_postcopy' is provided for other sections to know if
they're in postcopy.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/migration/migration.h | 2 ++
migration/migration.c | 47 +++++++++++++++++++++++++++++++++++++++++--
qapi-schema.json | 4 +++-
trace-events | 1 +
4 files changed, 51 insertions(+), 3 deletions(-)
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 2176666..219032d 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -170,6 +170,8 @@ MigrationState *migrate_init(const MigrationParams *params);
bool migration_in_setup(MigrationState *);
bool migration_has_finished(MigrationState *);
bool migration_has_failed(MigrationState *);
+/* True if outgoing migration has entered postcopy phase */
+bool migration_in_postcopy(MigrationState *);
MigrationState *migrate_get_current(void);
void migrate_compress_threads_create(void);
diff --git a/migration/migration.c b/migration/migration.c
index 85e68bc..2acd0e6 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -462,6 +462,7 @@ static bool migration_is_setup_or_active(int state)
{
switch (state) {
case MIGRATION_STATUS_ACTIVE:
+ case MIGRATION_STATUS_POSTCOPY_ACTIVE:
case MIGRATION_STATUS_SETUP:
return true;
@@ -537,6 +538,39 @@ MigrationInfo *qmp_query_migrate(Error **errp)
get_xbzrle_cache_stats(info);
break;
+ case MIGRATION_STATUS_POSTCOPY_ACTIVE:
+ /* Mostly the same as active; TODO add some postcopy stats */
+ info->has_status = true;
+ info->has_total_time = true;
+ info->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME)
+ - s->total_time;
+ info->has_expected_downtime = true;
+ info->expected_downtime = s->expected_downtime;
+ info->has_setup_time = true;
+ info->setup_time = s->setup_time;
+
+ info->has_ram = true;
+ info->ram = g_malloc0(sizeof(*info->ram));
+ info->ram->transferred = ram_bytes_transferred();
+ info->ram->remaining = ram_bytes_remaining();
+ info->ram->total = ram_bytes_total();
+ info->ram->duplicate = dup_mig_pages_transferred();
+ info->ram->skipped = skipped_mig_pages_transferred();
+ info->ram->normal = norm_mig_pages_transferred();
+ info->ram->normal_bytes = norm_mig_bytes_transferred();
+ info->ram->dirty_pages_rate = s->dirty_pages_rate;
+ info->ram->mbps = s->mbps;
+
+ if (blk_mig_active()) {
+ info->has_disk = true;
+ info->disk = g_malloc0(sizeof(*info->disk));
+ info->disk->transferred = blk_mig_bytes_transferred();
+ info->disk->remaining = blk_mig_bytes_remaining();
+ info->disk->total = blk_mig_bytes_total();
+ }
+
+ get_xbzrle_cache_stats(info);
+ break;
case MIGRATION_STATUS_COMPLETED:
get_xbzrle_cache_stats(info);
@@ -718,7 +752,8 @@ static void migrate_fd_cleanup(void *opaque)
s->file = NULL;
}
- assert(s->state != MIGRATION_STATUS_ACTIVE);
+ assert((s->state != MIGRATION_STATUS_ACTIVE) &&
+ (s->state != MIGRATION_STATUS_POSTCOPY_ACTIVE));
if (s->state == MIGRATION_STATUS_CANCELLING) {
migrate_set_state(s, MIGRATION_STATUS_CANCELLING,
@@ -793,6 +828,11 @@ bool migration_has_failed(MigrationState *s)
s->state == MIGRATION_STATUS_FAILED);
}
+bool migration_in_postcopy(MigrationState *s)
+{
+ return (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE);
+}
+
MigrationState *migrate_init(const MigrationParams *params)
{
MigrationState *s = migrate_get_current();
@@ -1307,7 +1347,10 @@ static void *migration_thread(void *opaque)
s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start;
migrate_set_state(s, MIGRATION_STATUS_SETUP, MIGRATION_STATUS_ACTIVE);
- while (s->state == MIGRATION_STATUS_ACTIVE) {
+ trace_migration_thread_setup_complete();
+
+ while (s->state == MIGRATION_STATUS_ACTIVE ||
+ s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) {
int64_t current_time;
uint64_t pending_size;
diff --git a/qapi-schema.json b/qapi-schema.json
index d25df93..8c3a42a 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -430,6 +430,8 @@
#
# @active: in the process of doing migration.
#
+# @postcopy-active: like active, but now in postcopy mode. (since 2.5)
+#
# @completed: migration is finished.
#
# @failed: some error occurred during migration process.
@@ -439,7 +441,7 @@
##
{ 'enum': 'MigrationStatus',
'data': [ 'none', 'setup', 'cancelling', 'cancelled',
- 'active', 'completed', 'failed' ] }
+ 'active', 'postcopy-active', 'completed', 'failed' ] }
##
# @MigrationInfo
diff --git a/trace-events b/trace-events
index d319cf8..a51ce22 100644
--- a/trace-events
+++ b/trace-events
@@ -1452,6 +1452,7 @@ migrate_fd_error(void) ""
migrate_fd_cancel(void) ""
migrate_pending(uint64_t size, uint64_t max, uint64_t post, uint64_t nonpost) "pending size %" PRIu64 " max %" PRIu64 " (post=%" PRIu64 " nonpost=%" PRIu64 ")"
migrate_send_rp_message(int msg_type, uint16_t len) "%d: len %d"
+migration_thread_setup_complete(void) ""
open_return_path_on_source(void) ""
open_return_path_on_source_continue(void) ""
source_return_path_thread_bad_end(void) ""
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 32/57] Avoid sending vmdescription during postcopy
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (30 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 31/57] MIGRATION_STATUS_POSTCOPY_ACTIVE: Add new migration state Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 33/57] Add qemu_savevm_state_complete_postcopy Juan Quintela
` (25 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
VMDescription is normally sent at the end, after all
of the devices; however that's not the end for postcopy,
so just don't send it when in postcopy.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
migration/savevm.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/migration/savevm.c b/migration/savevm.c
index 0e48a91..be61eb1 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -974,7 +974,8 @@ int qemu_savevm_state_iterate(QEMUFile *f)
static bool should_send_vmdesc(void)
{
MachineState *machine = MACHINE(qdev_get_machine());
- return !machine->suppress_vmdesc;
+ bool in_postcopy = migration_in_postcopy(migrate_get_current());
+ return !machine->suppress_vmdesc && !in_postcopy;
}
void qemu_savevm_state_complete_precopy(QEMUFile *f)
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 33/57] Add qemu_savevm_state_complete_postcopy
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (31 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 32/57] Avoid sending vmdescription during postcopy Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 34/57] Postcopy: Maintain unsentmap Juan Quintela
` (24 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Add qemu_savevm_state_complete_postcopy to complement
qemu_savevm_state_complete_precopy together with a new
save_live_complete_postcopy method on devices.
The save_live_complete_precopy method is called on
all devices during a precopy migration, and all non-postcopy
devices during a postcopy migration at the transition.
The save_live_complete_postcopy method is called at
the end of postcopy for all postcopiable devices.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/migration/vmstate.h | 1 +
include/sysemu/sysemu.h | 1 +
migration/ram.c | 1 +
migration/savevm.c | 49 +++++++++++++++++++++++++++++++++++++++++++--
4 files changed, 50 insertions(+), 2 deletions(-)
diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h
index 7f16a38..7267e38 100644
--- a/include/migration/vmstate.h
+++ b/include/migration/vmstate.h
@@ -40,6 +40,7 @@ typedef struct SaveVMHandlers {
SaveStateHandler *save_state;
void (*cleanup)(void *opaque);
+ int (*save_live_complete_postcopy)(QEMUFile *f, void *opaque);
int (*save_live_complete_precopy)(QEMUFile *f, void *opaque);
/* This runs both outside and inside the iothread lock. */
diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index 70835d0..76a0b36 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -111,6 +111,7 @@ void qemu_savevm_state_begin(QEMUFile *f,
void qemu_savevm_state_header(QEMUFile *f);
int qemu_savevm_state_iterate(QEMUFile *f);
void qemu_savevm_state_cleanup(void);
+void qemu_savevm_state_complete_postcopy(QEMUFile *f);
void qemu_savevm_state_complete_precopy(QEMUFile *f);
void qemu_savevm_state_pending(QEMUFile *f, uint64_t max_size,
uint64_t *res_non_postcopiable,
diff --git a/migration/ram.c b/migration/ram.c
index 0e53325..4053ca1 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1704,6 +1704,7 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
static SaveVMHandlers savevm_ram_handlers = {
.save_live_setup = ram_save_setup,
.save_live_iterate = ram_save_iterate,
+ .save_live_complete_postcopy = ram_save_complete,
.save_live_complete_precopy = ram_save_complete,
.save_live_pending = ram_save_pending,
.load_state = ram_load,
diff --git a/migration/savevm.c b/migration/savevm.c
index be61eb1..8e11877 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -978,19 +978,61 @@ static bool should_send_vmdesc(void)
return !machine->suppress_vmdesc && !in_postcopy;
}
+/*
+ * Calls the save_live_complete_postcopy methods
+ * causing the last few pages to be sent immediately and doing any associated
+ * cleanup.
+ * Note postcopy also calls qemu_savevm_state_complete_precopy to complete
+ * all the other devices, but that happens at the point we switch to postcopy.
+ */
+void qemu_savevm_state_complete_postcopy(QEMUFile *f)
+{
+ SaveStateEntry *se;
+ int ret;
+
+ QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
+ if (!se->ops || !se->ops->save_live_complete_postcopy) {
+ continue;
+ }
+ if (se->ops && se->ops->is_active) {
+ if (!se->ops->is_active(se->opaque)) {
+ continue;
+ }
+ }
+ trace_savevm_section_start(se->idstr, se->section_id);
+ /* Section type */
+ qemu_put_byte(f, QEMU_VM_SECTION_END);
+ qemu_put_be32(f, se->section_id);
+
+ ret = se->ops->save_live_complete_postcopy(f, se->opaque);
+ trace_savevm_section_end(se->idstr, se->section_id, ret);
+ save_section_footer(f, se);
+ if (ret < 0) {
+ qemu_file_set_error(f, ret);
+ return;
+ }
+ }
+
+ qemu_put_byte(f, QEMU_VM_EOF);
+ qemu_fflush(f);
+}
+
void qemu_savevm_state_complete_precopy(QEMUFile *f)
{
QJSON *vmdesc;
int vmdesc_len;
SaveStateEntry *se;
int ret;
+ bool in_postcopy = migration_in_postcopy(migrate_get_current());
trace_savevm_state_complete_precopy();
cpu_synchronize_all_states();
QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
- if (!se->ops || !se->ops->save_live_complete_precopy) {
+ if (!se->ops ||
+ (in_postcopy && se->ops->save_live_complete_postcopy) ||
+ !se->ops->save_live_complete_precopy) {
continue;
}
if (se->ops && se->ops->is_active) {
@@ -1039,7 +1081,10 @@ void qemu_savevm_state_complete_precopy(QEMUFile *f)
save_section_footer(f, se);
}
- qemu_put_byte(f, QEMU_VM_EOF);
+ if (!in_postcopy) {
+ /* Postcopy stream will still be going */
+ qemu_put_byte(f, QEMU_VM_EOF);
+ }
json_end_array(vmdesc);
qjson_finish(vmdesc);
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 34/57] Postcopy: Maintain unsentmap
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (32 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 33/57] Add qemu_savevm_state_complete_postcopy Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 35/57] migration_completion: Take current state Juan Quintela
` (23 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Maintain an 'unsentmap' of pages that have yet to be sent.
This is used in the following patches to discard some set of
the pages already sent as we enter postcopy mode.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
migration/ram.c | 51 +++++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 45 insertions(+), 6 deletions(-)
diff --git a/migration/ram.c b/migration/ram.c
index 4053ca1..c703176 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -237,7 +237,14 @@ typedef struct PageSearchStatus PageSearchStatus;
static struct BitmapRcu {
struct rcu_head rcu;
+ /* Main migration bitmap */
unsigned long *bmap;
+ /* bitmap of pages that haven't been sent even once
+ * only maintained and used in postcopy at the moment
+ * where it's used to send the dirtymap at the start
+ * of the postcopy phase
+ */
+ unsigned long *unsentmap;
} *migration_bitmap_rcu;
struct CompressParam {
@@ -531,10 +538,18 @@ static int save_xbzrle_page(QEMUFile *f, uint8_t **current_data,
return 1;
}
-/* Called with rcu_read_lock() to protect migration_bitmap */
+/* Called with rcu_read_lock() to protect migration_bitmap
+ * rb: The RAMBlock to search for dirty pages in
+ * start: Start address (typically so we can continue from previous page)
+ * ram_addr_abs: Pointer into which to store the address of the dirty page
+ * within the global ram_addr space
+ *
+ * Returns: byte offset within memory region of the start of a dirty page
+ */
static inline
ram_addr_t migration_bitmap_find_and_reset_dirty(RAMBlock *rb,
- ram_addr_t start)
+ ram_addr_t start,
+ ram_addr_t *ram_addr_abs)
{
unsigned long base = rb->offset >> TARGET_PAGE_BITS;
unsigned long nr = base + (start >> TARGET_PAGE_BITS);
@@ -555,6 +570,7 @@ ram_addr_t migration_bitmap_find_and_reset_dirty(RAMBlock *rb,
clear_bit(next, bitmap);
migration_dirty_pages--;
}
+ *ram_addr_abs = next << TARGET_PAGE_BITS;
return (next - base) << TARGET_PAGE_BITS;
}
@@ -953,10 +969,11 @@ static int ram_save_compressed_page(QEMUFile *f, RAMBlock *block,
* @*again: Set to false if the search has scanned the whole of RAM
*/
static bool find_dirty_block(QEMUFile *f, PageSearchStatus *pss,
- bool *again)
+ bool *again, ram_addr_t *ram_addr_abs)
{
pss->offset = migration_bitmap_find_and_reset_dirty(pss->block,
- pss->offset);
+ pss->offset,
+ ram_addr_abs);
if (pss->complete_round && pss->block == last_seen_block &&
pss->offset >= last_offset) {
/*
@@ -1014,6 +1031,8 @@ static int ram_find_and_save_block(QEMUFile *f, bool last_stage,
PageSearchStatus pss;
int pages = 0;
bool again, found;
+ ram_addr_t dirty_ram_abs; /* Address of the start of the dirty page in
+ ram_addr_t space */
pss.block = last_seen_block;
pss.offset = last_offset;
@@ -1024,7 +1043,7 @@ static int ram_find_and_save_block(QEMUFile *f, bool last_stage,
}
do {
- found = find_dirty_block(f, &pss, &again);
+ found = find_dirty_block(f, &pss, &again, &dirty_ram_abs);
if (found) {
if (compression_switch && migrate_use_compression()) {
@@ -1038,7 +1057,14 @@ static int ram_find_and_save_block(QEMUFile *f, bool last_stage,
/* if page is unmodified, continue to the next */
if (pages > 0) {
+ unsigned long *unsentmap;
+
+ unsentmap = atomic_rcu_read(&migration_bitmap_rcu)->unsentmap;
last_sent_block = pss.block;
+ if (unsentmap) {
+ clear_bit(dirty_ram_abs >> TARGET_PAGE_BITS, unsentmap);
+ }
+
}
}
} while (!pages && again);
@@ -1097,6 +1123,7 @@ void free_xbzrle_decoded_buf(void)
static void migration_bitmap_free(struct BitmapRcu *bmap)
{
g_free(bmap->bmap);
+ g_free(bmap->unsentmap);
g_free(bmap);
}
@@ -1153,6 +1180,13 @@ void migration_bitmap_extend(ram_addr_t old, ram_addr_t new)
qemu_mutex_lock(&migration_bitmap_mutex);
bitmap_copy(bitmap->bmap, old_bitmap->bmap, old);
bitmap_set(bitmap->bmap, old, new - old);
+
+ /* We don't have a way to safely extend the sentmap
+ * with RCU; so mark it as missing, entry to postcopy
+ * will fail.
+ */
+ bitmap->unsentmap = NULL;
+
atomic_rcu_set(&migration_bitmap_rcu, bitmap);
qemu_mutex_unlock(&migration_bitmap_mutex);
migration_dirty_pages += new - old;
@@ -1253,10 +1287,15 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
reset_ram_globals();
ram_bitmap_pages = last_ram_offset() >> TARGET_PAGE_BITS;
- migration_bitmap_rcu = g_new(struct BitmapRcu, 1);
+ migration_bitmap_rcu = g_new0(struct BitmapRcu, 1);
migration_bitmap_rcu->bmap = bitmap_new(ram_bitmap_pages);
bitmap_set(migration_bitmap_rcu->bmap, 0, ram_bitmap_pages);
+ if (migrate_postcopy_ram()) {
+ migration_bitmap_rcu->unsentmap = bitmap_new(ram_bitmap_pages);
+ bitmap_set(migration_bitmap_rcu->unsentmap, 0, ram_bitmap_pages);
+ }
+
/*
* Count the total number of pages used by ram blocks not including any
* gaps due to alignment or unplugs.
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 35/57] migration_completion: Take current state
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (33 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 34/57] Postcopy: Maintain unsentmap Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 36/57] postcopy: Incoming initialisation Juan Quintela
` (22 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Soon we'll be in either ACTIVE or POSTCOPY_ACTIVE when we
complete migration, and we need to know which we expect to be
in to change state safely.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/migration/migration.h | 5 ++
include/migration/postcopy-ram.h | 35 ++++++++
include/qemu/typedefs.h | 1 +
migration/migration.c | 1 +
migration/postcopy-ram.c | 126 +++++++++++++++++++++++++++
migration/ram.c | 181 ++++++++++++++++++++++++++++++++++++++-
migration/savevm.c | 2 -
trace-events | 6 ++
8 files changed, 354 insertions(+), 3 deletions(-)
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 219032d..b382d77 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -199,6 +199,11 @@ double xbzrle_mig_cache_miss_rate(void);
void ram_handle_compressed(void *host, uint8_t ch, uint64_t size);
void ram_debug_dump_bitmap(unsigned long *todump, bool expected);
+/* For outgoing discard bitmap */
+int ram_postcopy_send_discard_bitmap(MigrationState *ms);
+/* For incoming postcopy discard */
+int ram_discard_range(MigrationIncomingState *mis, const char *block_name,
+ uint64_t start, size_t length);
/**
* @migrate_add_blocker - prevent migration from proceeding
diff --git a/include/migration/postcopy-ram.h b/include/migration/postcopy-ram.h
index d81934f..de79fa7 100644
--- a/include/migration/postcopy-ram.h
+++ b/include/migration/postcopy-ram.h
@@ -16,4 +16,39 @@
/* Return true if the host supports everything we need to do postcopy-ram */
bool postcopy_ram_supported_by_host(void);
+/*
+ * Discard the contents of 'length' bytes from 'start'
+ * We can assume that if we've been called postcopy_ram_hosttest returned true
+ */
+int postcopy_ram_discard_range(MigrationIncomingState *mis, uint8_t *start,
+ size_t length);
+
+
+/*
+ * Called at the start of each RAMBlock by the bitmap code.
+ * 'offset' is the bitmap offset of the named RAMBlock in the migration
+ * bitmap.
+ * Returns a new PDS
+ */
+PostcopyDiscardState *postcopy_discard_send_init(MigrationState *ms,
+ unsigned long offset,
+ const char *name);
+
+/*
+ * Called by the bitmap code for each chunk to discard.
+ * May send a discard message, may just leave it queued to
+ * be sent later.
+ * @start,@length: a range of pages in the migration bitmap in the
+ * RAM block passed to postcopy_discard_send_init() (length=1 is one page)
+ */
+void postcopy_discard_send_range(MigrationState *ms, PostcopyDiscardState *pds,
+ unsigned long start, unsigned long length);
+
+/*
+ * Called at the end of each RAMBlock by the bitmap code.
+ * Sends any outstanding discard messages, frees the PDS.
+ */
+void postcopy_discard_send_finish(MigrationState *ms,
+ PostcopyDiscardState *pds);
+
#endif
diff --git a/include/qemu/typedefs.h b/include/qemu/typedefs.h
index f7e0ed0..6b1093d 100644
--- a/include/qemu/typedefs.h
+++ b/include/qemu/typedefs.h
@@ -67,6 +67,7 @@ typedef struct PCMachineState PCMachineState;
typedef struct PCMachineClass PCMachineClass;
typedef struct PCMCIACardState PCMCIACardState;
typedef struct PixelFormat PixelFormat;
+typedef struct PostcopyDiscardState PostcopyDiscardState;
typedef struct PropertyInfo PropertyInfo;
typedef struct Property Property;
typedef struct QEMUBH QEMUBH;
diff --git a/migration/migration.c b/migration/migration.c
index 2acd0e6..afc863a 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -24,6 +24,7 @@
#include "qemu/sockets.h"
#include "qemu/rcu.h"
#include "migration/block.h"
+#include "migration/postcopy-ram.h"
#include "qemu/thread.h"
#include "qmp-commands.h"
#include "trace.h"
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index cdd0168..261feda 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -27,6 +27,24 @@
#include "qemu/error-report.h"
#include "trace.h"
+/* Arbitrary limit on size of each discard command,
+ * keeps them around ~200 bytes
+ */
+#define MAX_DISCARDS_PER_COMMAND 12
+
+struct PostcopyDiscardState {
+ const char *ramblock_name;
+ uint64_t offset; /* Bitmap entry for the 1st bit of this RAMBlock */
+ uint16_t cur_entry;
+ /*
+ * Start and length of a discard range (bytes)
+ */
+ uint64_t start_list[MAX_DISCARDS_PER_COMMAND];
+ uint64_t length_list[MAX_DISCARDS_PER_COMMAND];
+ unsigned int nsentwords;
+ unsigned int nsentcmds;
+};
+
/* Postcopy needs to detect accesses to pages that haven't yet been copied
* across, and efficiently map new pages in, the techniques for doing this
* are target OS specific.
@@ -145,6 +163,27 @@ out:
return ret;
}
+/**
+ * postcopy_ram_discard_range: Discard a range of memory.
+ * We can assume that if we've been called postcopy_ram_hosttest returned true.
+ *
+ * @mis: Current incoming migration state.
+ * @start, @length: range of memory to discard.
+ *
+ * returns: 0 on success.
+ */
+int postcopy_ram_discard_range(MigrationIncomingState *mis, uint8_t *start,
+ size_t length)
+{
+ trace_postcopy_ram_discard_range(start, length);
+ if (madvise(start, length, MADV_DONTNEED)) {
+ error_report("%s MADV_DONTNEED: %s", __func__, strerror(errno));
+ return -1;
+ }
+
+ return 0;
+}
+
#else
/* No target OS support, stubs just fail */
bool postcopy_ram_supported_by_host(void)
@@ -153,5 +192,92 @@ bool postcopy_ram_supported_by_host(void)
return false;
}
+int postcopy_ram_discard_range(MigrationIncomingState *mis, uint8_t *start,
+ size_t length)
+{
+ assert(0);
+}
#endif
+/* ------------------------------------------------------------------------- */
+
+/**
+ * postcopy_discard_send_init: Called at the start of each RAMBlock before
+ * asking to discard individual ranges.
+ *
+ * @ms: The current migration state.
+ * @offset: the bitmap offset of the named RAMBlock in the migration
+ * bitmap.
+ * @name: RAMBlock that discards will operate on.
+ *
+ * returns: a new PDS.
+ */
+PostcopyDiscardState *postcopy_discard_send_init(MigrationState *ms,
+ unsigned long offset,
+ const char *name)
+{
+ PostcopyDiscardState *res = g_malloc0(sizeof(PostcopyDiscardState));
+
+ if (res) {
+ res->ramblock_name = name;
+ res->offset = offset;
+ }
+
+ return res;
+}
+
+/**
+ * postcopy_discard_send_range: Called by the bitmap code for each chunk to
+ * discard. May send a discard message, may just leave it queued to
+ * be sent later.
+ *
+ * @ms: Current migration state.
+ * @pds: Structure initialised by postcopy_discard_send_init().
+ * @start,@length: a range of pages in the migration bitmap in the
+ * RAM block passed to postcopy_discard_send_init() (length=1 is one page)
+ */
+void postcopy_discard_send_range(MigrationState *ms, PostcopyDiscardState *pds,
+ unsigned long start, unsigned long length)
+{
+ size_t tp_bits = qemu_target_page_bits();
+ /* Convert to byte offsets within the RAM block */
+ pds->start_list[pds->cur_entry] = (start - pds->offset) << tp_bits;
+ pds->length_list[pds->cur_entry] = length << tp_bits;
+ trace_postcopy_discard_send_range(pds->ramblock_name, start, length);
+ pds->cur_entry++;
+ pds->nsentwords++;
+
+ if (pds->cur_entry == MAX_DISCARDS_PER_COMMAND) {
+ /* Full set, ship it! */
+ qemu_savevm_send_postcopy_ram_discard(ms->file, pds->ramblock_name,
+ pds->cur_entry,
+ pds->start_list,
+ pds->length_list);
+ pds->nsentcmds++;
+ pds->cur_entry = 0;
+ }
+}
+
+/**
+ * postcopy_discard_send_finish: Called at the end of each RAMBlock by the
+ * bitmap code. Sends any outstanding discard messages, frees the PDS
+ *
+ * @ms: Current migration state.
+ * @pds: Structure initialised by postcopy_discard_send_init().
+ */
+void postcopy_discard_send_finish(MigrationState *ms, PostcopyDiscardState *pds)
+{
+ /* Anything unsent? */
+ if (pds->cur_entry) {
+ qemu_savevm_send_postcopy_ram_discard(ms->file, pds->ramblock_name,
+ pds->cur_entry,
+ pds->start_list,
+ pds->length_list);
+ pds->nsentcmds++;
+ }
+
+ trace_postcopy_discard_send_finish(pds->ramblock_name, pds->nsentwords,
+ pds->nsentcmds);
+
+ g_free(pds);
+}
diff --git a/migration/ram.c b/migration/ram.c
index c703176..b481d55 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -32,6 +32,7 @@
#include "qemu/timer.h"
#include "qemu/main-loop.h"
#include "migration/migration.h"
+#include "migration/postcopy-ram.h"
#include "exec/address-spaces.h"
#include "migration/page_cache.h"
#include "qemu/error-report.h"
@@ -967,6 +968,8 @@ static int ram_save_compressed_page(QEMUFile *f, RAMBlock *block,
* @f: Current migration stream.
* @pss: Data about the state of the current dirty page scan.
* @*again: Set to false if the search has scanned the whole of RAM
+ * *ram_addr_abs: Pointer into which to store the address of the dirty page
+ * within the global ram_addr space
*/
static bool find_dirty_block(QEMUFile *f, PageSearchStatus *pss,
bool *again, ram_addr_t *ram_addr_abs)
@@ -1064,7 +1067,6 @@ static int ram_find_and_save_block(QEMUFile *f, bool last_stage,
if (unsentmap) {
clear_bit(dirty_ram_abs >> TARGET_PAGE_BITS, unsentmap);
}
-
}
}
} while (!pages && again);
@@ -1233,6 +1235,183 @@ void ram_debug_dump_bitmap(unsigned long *todump, bool expected)
}
}
+/* **** functions for postcopy ***** */
+
+/*
+ * Callback from postcopy_each_ram_send_discard for each RAMBlock
+ * Note: At this point the 'unsentmap' is the processed bitmap combined
+ * with the dirtymap; so a '1' means it's either dirty or unsent.
+ * start,length: Indexes into the bitmap for the first bit
+ * representing the named block and length in target-pages
+ */
+static int postcopy_send_discard_bm_ram(MigrationState *ms,
+ PostcopyDiscardState *pds,
+ unsigned long start,
+ unsigned long length)
+{
+ unsigned long end = start + length; /* one after the end */
+ unsigned long current;
+ unsigned long *unsentmap;
+
+ unsentmap = atomic_rcu_read(&migration_bitmap_rcu)->unsentmap;
+ for (current = start; current < end; ) {
+ unsigned long one = find_next_bit(unsentmap, end, current);
+
+ if (one <= end) {
+ unsigned long zero = find_next_zero_bit(unsentmap, end, one + 1);
+ unsigned long discard_length;
+
+ if (zero >= end) {
+ discard_length = end - one;
+ } else {
+ discard_length = zero - one;
+ }
+ postcopy_discard_send_range(ms, pds, one, discard_length);
+ current = one + discard_length;
+ } else {
+ current = one;
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * Utility for the outgoing postcopy code.
+ * Calls postcopy_send_discard_bm_ram for each RAMBlock
+ * passing it bitmap indexes and name.
+ * Returns: 0 on success
+ * (qemu_ram_foreach_block ends up passing unscaled lengths
+ * which would mean postcopy code would have to deal with target page)
+ */
+static int postcopy_each_ram_send_discard(MigrationState *ms)
+{
+ struct RAMBlock *block;
+ int ret;
+
+ QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+ unsigned long first = block->offset >> TARGET_PAGE_BITS;
+ PostcopyDiscardState *pds = postcopy_discard_send_init(ms,
+ first,
+ block->idstr);
+
+ /*
+ * Postcopy sends chunks of bitmap over the wire, but it
+ * just needs indexes at this point, avoids it having
+ * target page specific code.
+ */
+ ret = postcopy_send_discard_bm_ram(ms, pds, first,
+ block->used_length >> TARGET_PAGE_BITS);
+ postcopy_discard_send_finish(ms, pds);
+ if (ret) {
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * Transmit the set of pages to be discarded after precopy to the target
+ * these are pages that:
+ * a) Have been previously transmitted but are now dirty again
+ * b) Pages that have never been transmitted, this ensures that
+ * any pages on the destination that have been mapped by background
+ * tasks get discarded (transparent huge pages is the specific concern)
+ * Hopefully this is pretty sparse
+ */
+int ram_postcopy_send_discard_bitmap(MigrationState *ms)
+{
+ int ret;
+ unsigned long *bitmap, *unsentmap;
+
+ rcu_read_lock();
+
+ /* This should be our last sync, the src is now paused */
+ migration_bitmap_sync();
+
+ unsentmap = atomic_rcu_read(&migration_bitmap_rcu)->unsentmap;
+ if (!unsentmap) {
+ /* We don't have a safe way to resize the sentmap, so
+ * if the bitmap was resized it will be NULL at this
+ * point.
+ */
+ error_report("migration ram resized during precopy phase");
+ rcu_read_unlock();
+ return -EINVAL;
+ }
+
+ /*
+ * Update the unsentmap to be unsentmap = unsentmap | dirty
+ */
+ bitmap = atomic_rcu_read(&migration_bitmap_rcu)->bmap;
+ bitmap_or(unsentmap, unsentmap, bitmap,
+ last_ram_offset() >> TARGET_PAGE_BITS);
+
+
+ trace_ram_postcopy_send_discard_bitmap();
+#ifdef DEBUG_POSTCOPY
+ ram_debug_dump_bitmap(unsentmap, true);
+#endif
+
+ ret = postcopy_each_ram_send_discard(ms);
+ rcu_read_unlock();
+
+ return ret;
+}
+
+/*
+ * At the start of the postcopy phase of migration, any now-dirty
+ * precopied pages are discarded.
+ *
+ * start, length describe a byte address range within the RAMBlock
+ *
+ * Returns 0 on success.
+ */
+int ram_discard_range(MigrationIncomingState *mis,
+ const char *block_name,
+ uint64_t start, size_t length)
+{
+ int ret = -1;
+
+ rcu_read_lock();
+ RAMBlock *rb = qemu_ram_block_by_name(block_name);
+
+ if (!rb) {
+ error_report("ram_discard_range: Failed to find block '%s'",
+ block_name);
+ goto err;
+ }
+
+ uint8_t *host_startaddr = rb->host + start;
+
+ if ((uintptr_t)host_startaddr & (qemu_host_page_size - 1)) {
+ error_report("ram_discard_range: Unaligned start address: %p",
+ host_startaddr);
+ goto err;
+ }
+
+ if ((start + length) <= rb->used_length) {
+ uint8_t *host_endaddr = host_startaddr + length;
+ if ((uintptr_t)host_endaddr & (qemu_host_page_size - 1)) {
+ error_report("ram_discard_range: Unaligned end address: %p",
+ host_endaddr);
+ goto err;
+ }
+ ret = postcopy_ram_discard_range(mis, host_startaddr, length);
+ } else {
+ error_report("ram_discard_range: Overrun block '%s' (%" PRIu64
+ "/%zu/%zu)",
+ block_name, start, length, rb->used_length);
+ }
+
+err:
+ rcu_read_unlock();
+
+ return ret;
+}
+
+
/* Each of ram_save_setup, ram_save_iterate and ram_save_complete has
* long-running RCU critical section. When rcu-reclaims in the code
* start to become numerous it will be necessary to reduce the
diff --git a/migration/savevm.c b/migration/savevm.c
index 8e11877..8f07abd 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1349,7 +1349,6 @@ static int loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis,
}
trace_loadvm_postcopy_ram_handle_discard_header(ramid, len);
while (len) {
- /* TODO - ram_discard_range gets added in a later patch
uint64_t start_addr, block_length;
start_addr = qemu_get_be64(mis->from_src_file);
block_length = qemu_get_be64(mis->from_src_file);
@@ -1360,7 +1359,6 @@ static int loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis,
if (ret) {
return ret;
}
- */
}
trace_loadvm_postcopy_ram_handle_discard_end();
diff --git a/trace-events b/trace-events
index a51ce22..e74675e 100644
--- a/trace-events
+++ b/trace-events
@@ -1255,6 +1255,7 @@ qemu_file_fclose(void) ""
migration_bitmap_sync_start(void) ""
migration_bitmap_sync_end(uint64_t dirty_pages) "dirty_pages %" PRIu64""
migration_throttle(void) ""
+ram_postcopy_send_discard_bitmap(void) ""
# hw/display/qxl.c
disable qxl_interface_set_mm_time(int qid, uint32_t mm_time) "%d %d"
@@ -1532,6 +1533,11 @@ rdma_start_incoming_migration_after_rdma_listen(void) ""
rdma_start_outgoing_migration_after_rdma_connect(void) ""
rdma_start_outgoing_migration_after_rdma_source_init(void) ""
+# migration/postcopy-ram.c
+postcopy_discard_send_finish(const char *ramblock, int nwords, int ncmds) "%s mask words sent=%d in %d commands"
+postcopy_discard_send_range(const char *ramblock, unsigned long start, unsigned long length) "%s:%lx/%lx"
+postcopy_ram_discard_range(void *start, size_t length) "%p,+%zx"
+
# kvm-all.c
kvm_ioctl(int type, void *arg) "type 0x%x, arg %p"
kvm_vm_ioctl(int type, void *arg) "type 0x%x, arg %p"
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 36/57] postcopy: Incoming initialisation
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (34 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 35/57] migration_completion: Take current state Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 37/57] postcopy: ram_enable_notify to switch on userfault Juan Quintela
` (21 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/migration/migration.h | 3 ++
include/migration/postcopy-ram.h | 12 +++++
migration/postcopy-ram.c | 104 +++++++++++++++++++++++++++++++++++++++
migration/ram.c | 11 +++++
migration/savevm.c | 6 +++
trace-events | 2 +
6 files changed, 138 insertions(+)
diff --git a/include/migration/migration.h b/include/migration/migration.h
index b382d77..6e42b58 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -86,6 +86,8 @@ struct MigrationIncomingState {
*/
QemuEvent main_thread_load_event;
+ /* For the kernel to send us notifications */
+ int userfault_fd;
QEMUFile *to_src_file;
QemuMutex rp_mutex; /* We send replies from multiple threads */
@@ -204,6 +206,7 @@ int ram_postcopy_send_discard_bitmap(MigrationState *ms);
/* For incoming postcopy discard */
int ram_discard_range(MigrationIncomingState *mis, const char *block_name,
uint64_t start, size_t length);
+int ram_postcopy_incoming_init(MigrationIncomingState *mis);
/**
* @migrate_add_blocker - prevent migration from proceeding
diff --git a/include/migration/postcopy-ram.h b/include/migration/postcopy-ram.h
index de79fa7..f87020c 100644
--- a/include/migration/postcopy-ram.h
+++ b/include/migration/postcopy-ram.h
@@ -17,6 +17,18 @@
bool postcopy_ram_supported_by_host(void);
/*
+ * Initialise postcopy-ram, setting the RAM to a state where we can go into
+ * postcopy later; must be called prior to any precopy.
+ * called from ram.c's similarly named ram_postcopy_incoming_init
+ */
+int postcopy_ram_incoming_init(MigrationIncomingState *mis, size_t ram_pages);
+
+/*
+ * At the end of a migration where postcopy_ram_incoming_init was called.
+ */
+int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis);
+
+/*
* Discard the contents of 'length' bytes from 'start'
* We can assume that if we've been called postcopy_ram_hosttest returned true
*/
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index 261feda..8478bfd 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -184,6 +184,97 @@ int postcopy_ram_discard_range(MigrationIncomingState *mis, uint8_t *start,
return 0;
}
+/*
+ * Setup an area of RAM so that it *can* be used for postcopy later; this
+ * must be done right at the start prior to pre-copy.
+ * opaque should be the MIS.
+ */
+static int init_range(const char *block_name, void *host_addr,
+ ram_addr_t offset, ram_addr_t length, void *opaque)
+{
+ MigrationIncomingState *mis = opaque;
+
+ trace_postcopy_init_range(block_name, host_addr, offset, length);
+
+ /*
+ * We need the whole of RAM to be truly empty for postcopy, so things
+ * like ROMs and any data tables built during init must be zero'd
+ * - we're going to get the copy from the source anyway.
+ * (Precopy will just overwrite this data, so doesn't need the discard)
+ */
+ if (postcopy_ram_discard_range(mis, host_addr, length)) {
+ return -1;
+ }
+
+ return 0;
+}
+
+/*
+ * At the end of migration, undo the effects of init_range
+ * opaque should be the MIS.
+ */
+static int cleanup_range(const char *block_name, void *host_addr,
+ ram_addr_t offset, ram_addr_t length, void *opaque)
+{
+ MigrationIncomingState *mis = opaque;
+ struct uffdio_range range_struct;
+ trace_postcopy_cleanup_range(block_name, host_addr, offset, length);
+
+ /*
+ * We turned off hugepage for the precopy stage with postcopy enabled
+ * we can turn it back on now.
+ */
+#ifdef MADV_HUGEPAGE
+ if (madvise(host_addr, length, MADV_HUGEPAGE)) {
+ error_report("%s HUGEPAGE: %s", __func__, strerror(errno));
+ return -1;
+ }
+#endif
+
+ /*
+ * We can also turn off userfault now since we should have all the
+ * pages. It can be useful to leave it on to debug postcopy
+ * if you're not sure it's always getting every page.
+ */
+ range_struct.start = (uintptr_t)host_addr;
+ range_struct.len = length;
+
+ if (ioctl(mis->userfault_fd, UFFDIO_UNREGISTER, &range_struct)) {
+ error_report("%s: userfault unregister %s", __func__, strerror(errno));
+
+ return -1;
+ }
+
+ return 0;
+}
+
+/*
+ * Initialise postcopy-ram, setting the RAM to a state where we can go into
+ * postcopy later; must be called prior to any precopy.
+ * called from arch_init's similarly named ram_postcopy_incoming_init
+ */
+int postcopy_ram_incoming_init(MigrationIncomingState *mis, size_t ram_pages)
+{
+ if (qemu_ram_foreach_block(init_range, mis)) {
+ return -1;
+ }
+
+ return 0;
+}
+
+/*
+ * At the end of a migration where postcopy_ram_incoming_init was called.
+ */
+int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis)
+{
+ /* TODO: Join the fault thread once we're sure it will exit */
+ if (qemu_ram_foreach_block(cleanup_range, mis)) {
+ return -1;
+ }
+
+ return 0;
+}
+
#else
/* No target OS support, stubs just fail */
bool postcopy_ram_supported_by_host(void)
@@ -192,10 +283,23 @@ bool postcopy_ram_supported_by_host(void)
return false;
}
+int postcopy_ram_incoming_init(MigrationIncomingState *mis, size_t ram_pages)
+{
+ error_report("postcopy_ram_incoming_init: No OS support");
+ return -1;
+}
+
+int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis)
+{
+ assert(0);
+ return -1;
+}
+
int postcopy_ram_discard_range(MigrationIncomingState *mis, uint8_t *start,
size_t length)
{
assert(0);
+ return -1;
}
#endif
diff --git a/migration/ram.c b/migration/ram.c
index b481d55..2e27b26 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1794,6 +1794,17 @@ static void decompress_data_with_multi_threads(uint8_t *compbuf,
}
}
+/*
+ * Allocate data structures etc needed by incoming migration with postcopy-ram
+ * postcopy-ram's similarly names postcopy_ram_incoming_init does the work
+ */
+int ram_postcopy_incoming_init(MigrationIncomingState *mis)
+{
+ size_t ram_pages = last_ram_offset() >> TARGET_PAGE_BITS;
+
+ return postcopy_ram_incoming_init(mis, ram_pages);
+}
+
static int ram_load(QEMUFile *f, void *opaque, int version_id)
{
int flags = 0, ret = 0;
diff --git a/migration/savevm.c b/migration/savevm.c
index 8f07abd..674f0fb 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1281,6 +1281,12 @@ static int loadvm_postcopy_handle_advise(MigrationIncomingState *mis)
return -1;
}
+ if (ram_postcopy_incoming_init(mis)) {
+ return -1;
+ }
+
+ postcopy_state_set(POSTCOPY_INCOMING_ADVISE);
+
return 0;
}
diff --git a/trace-events b/trace-events
index e74675e..47d3be3 100644
--- a/trace-events
+++ b/trace-events
@@ -1537,6 +1537,8 @@ rdma_start_outgoing_migration_after_rdma_source_init(void) ""
postcopy_discard_send_finish(const char *ramblock, int nwords, int ncmds) "%s mask words sent=%d in %d commands"
postcopy_discard_send_range(const char *ramblock, unsigned long start, unsigned long length) "%s:%lx/%lx"
postcopy_ram_discard_range(void *start, size_t length) "%p,+%zx"
+postcopy_cleanup_range(const char *ramblock, void *host_addr, size_t offset, size_t length) "%s: %p offset=%zx length=%zx"
+postcopy_init_range(const char *ramblock, void *host_addr, size_t offset, size_t length) "%s: %p offset=%zx length=%zx"
# kvm-all.c
kvm_ioctl(int type, void *arg) "type 0x%x, arg %p"
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 37/57] postcopy: ram_enable_notify to switch on userfault
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (35 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 36/57] postcopy: Incoming initialisation Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 38/57] Postcopy: Postcopy startup in migration thread Juan Quintela
` (20 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Mark the area of RAM as 'userfault'
Start up a fault-thread to handle any userfaults we might receive
from it (to be filled in later)
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/migration/migration.h | 3 ++
include/migration/postcopy-ram.h | 6 ++++
migration/postcopy-ram.c | 69 ++++++++++++++++++++++++++++++++++++++++
migration/savevm.c | 9 ++++++
4 files changed, 87 insertions(+)
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 6e42b58..2ad0d2b 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -86,6 +86,9 @@ struct MigrationIncomingState {
*/
QemuEvent main_thread_load_event;
+ QemuThread fault_thread;
+ QemuSemaphore fault_thread_sem;
+
/* For the kernel to send us notifications */
int userfault_fd;
QEMUFile *to_src_file;
diff --git a/include/migration/postcopy-ram.h b/include/migration/postcopy-ram.h
index f87020c..b10c03d 100644
--- a/include/migration/postcopy-ram.h
+++ b/include/migration/postcopy-ram.h
@@ -17,6 +17,12 @@
bool postcopy_ram_supported_by_host(void);
/*
+ * Make all of RAM sensitive to accesses to areas that haven't yet been written
+ * and wire up anything necessary to deal with it.
+ */
+int postcopy_ram_enable_notify(MigrationIncomingState *mis);
+
+/*
* Initialise postcopy-ram, setting the RAM to a state where we can go into
* postcopy later; must be called prior to any precopy.
* called from ram.c's similarly named ram_postcopy_incoming_init
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index 8478bfd..3110b2a 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -275,6 +275,69 @@ int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis)
return 0;
}
+/*
+ * Mark the given area of RAM as requiring notification to unwritten areas
+ * Used as a callback on qemu_ram_foreach_block.
+ * host_addr: Base of area to mark
+ * offset: Offset in the whole ram arena
+ * length: Length of the section
+ * opaque: MigrationIncomingState pointer
+ * Returns 0 on success
+ */
+static int ram_block_enable_notify(const char *block_name, void *host_addr,
+ ram_addr_t offset, ram_addr_t length,
+ void *opaque)
+{
+ MigrationIncomingState *mis = opaque;
+ struct uffdio_register reg_struct;
+
+ reg_struct.range.start = (uintptr_t)host_addr;
+ reg_struct.range.len = length;
+ reg_struct.mode = UFFDIO_REGISTER_MODE_MISSING;
+
+ /* Now tell our userfault_fd that it's responsible for this area */
+ if (ioctl(mis->userfault_fd, UFFDIO_REGISTER, ®_struct)) {
+ error_report("%s userfault register: %s", __func__, strerror(errno));
+ return -1;
+ }
+
+ return 0;
+}
+
+/*
+ * Handle faults detected by the USERFAULT markings
+ */
+static void *postcopy_ram_fault_thread(void *opaque)
+{
+ MigrationIncomingState *mis = opaque;
+
+ fprintf(stderr, "postcopy_ram_fault_thread\n");
+ /* TODO: In later patch */
+ qemu_sem_post(&mis->fault_thread_sem);
+ while (1) {
+ /* TODO: In later patch */
+ }
+
+ return NULL;
+}
+
+int postcopy_ram_enable_notify(MigrationIncomingState *mis)
+{
+ /* Create the fault handler thread and wait for it to be ready */
+ qemu_sem_init(&mis->fault_thread_sem, 0);
+ qemu_thread_create(&mis->fault_thread, "postcopy/fault",
+ postcopy_ram_fault_thread, mis, QEMU_THREAD_JOINABLE);
+ qemu_sem_wait(&mis->fault_thread_sem);
+ qemu_sem_destroy(&mis->fault_thread_sem);
+
+ /* Mark so that we get notified of accesses to unwritten areas */
+ if (qemu_ram_foreach_block(ram_block_enable_notify, mis)) {
+ return -1;
+ }
+
+ return 0;
+}
+
#else
/* No target OS support, stubs just fail */
bool postcopy_ram_supported_by_host(void)
@@ -301,6 +364,12 @@ int postcopy_ram_discard_range(MigrationIncomingState *mis, uint8_t *start,
assert(0);
return -1;
}
+
+int postcopy_ram_enable_notify(MigrationIncomingState *mis)
+{
+ assert(0);
+ return -1;
+}
#endif
/* ------------------------------------------------------------------------- */
diff --git a/migration/savevm.c b/migration/savevm.c
index 674f0fb..a7210a2 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1381,6 +1381,15 @@ static int loadvm_postcopy_handle_listen(MigrationIncomingState *mis)
return -1;
}
+ /*
+ * Sensitise RAM - can now generate requests for blocks that don't exist
+ * However, at this point the CPU shouldn't be running, and the IO
+ * shouldn't be doing anything yet so don't actually expect requests
+ */
+ if (postcopy_ram_enable_notify(mis)) {
+ return -1;
+ }
+
/* TODO start up the postcopy listening thread */
return 0;
}
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 38/57] Postcopy: Postcopy startup in migration thread
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (36 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 37/57] postcopy: ram_enable_notify to switch on userfault Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 39/57] Postcopy: End of iteration Juan Quintela
` (19 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Rework the migration thread to setup and start postcopy.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/migration/migration.h | 3 +
migration/migration.c | 174 ++++++++++++++++++++++++++++++++++++++++--
trace-events | 4 +
3 files changed, 174 insertions(+), 7 deletions(-)
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 2ad0d2b..ff13ff2 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -135,6 +135,9 @@ struct MigrationState
/* Flag set once the migration has been asked to enter postcopy */
bool start_postcopy;
+
+ /* Flag set once the migration thread is running (and needs joining) */
+ bool migration_thread_running;
};
void process_incoming_migration(QEMUFile *f);
diff --git a/migration/migration.c b/migration/migration.c
index afc863a..064986b 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -745,7 +745,10 @@ static void migrate_fd_cleanup(void *opaque)
if (s->file) {
trace_migrate_fd_cleanup();
qemu_mutex_unlock_iothread();
- qemu_thread_join(&s->thread);
+ if (s->migration_thread_running) {
+ qemu_thread_join(&s->thread);
+ s->migration_thread_running = false;
+ }
qemu_mutex_lock_iothread();
migrate_compress_threads_join();
@@ -1238,7 +1241,6 @@ out:
return NULL;
}
-__attribute__ (( unused )) /* Until later in patch series */
static int open_return_path_on_source(MigrationState *ms)
{
@@ -1279,6 +1281,109 @@ static int await_return_path_close_on_source(MigrationState *ms)
return ms->rp_state.error;
}
+/*
+ * Switch from normal iteration to postcopy
+ * Returns non-0 on error
+ */
+static int postcopy_start(MigrationState *ms, bool *old_vm_running)
+{
+ int ret;
+ const QEMUSizedBuffer *qsb;
+ int64_t time_at_stop = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
+ migrate_set_state(ms, MIGRATION_STATUS_ACTIVE,
+ MIGRATION_STATUS_POSTCOPY_ACTIVE);
+
+ trace_postcopy_start();
+ qemu_mutex_lock_iothread();
+ trace_postcopy_start_set_run();
+
+ qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);
+ *old_vm_running = runstate_is_running();
+ global_state_store();
+ ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
+
+ if (ret < 0) {
+ goto fail;
+ }
+
+ /*
+ * in Finish migrate and with the io-lock held everything should
+ * be quiet, but we've potentially still got dirty pages and we
+ * need to tell the destination to throw any pages it's already received
+ * that are dirty
+ */
+ if (ram_postcopy_send_discard_bitmap(ms)) {
+ error_report("postcopy send discard bitmap failed");
+ goto fail;
+ }
+
+ /*
+ * send rest of state - note things that are doing postcopy
+ * will notice we're in POSTCOPY_ACTIVE and not actually
+ * wrap their state up here
+ */
+ qemu_file_set_rate_limit(ms->file, INT64_MAX);
+ /* Ping just for debugging, helps line traces up */
+ qemu_savevm_send_ping(ms->file, 2);
+
+ /*
+ * While loading the device state we may trigger page transfer
+ * requests and the fd must be free to process those, and thus
+ * the destination must read the whole device state off the fd before
+ * it starts processing it. Unfortunately the ad-hoc migration format
+ * doesn't allow the destination to know the size to read without fully
+ * parsing it through each devices load-state code (especially the open
+ * coded devices that use get/put).
+ * So we wrap the device state up in a package with a length at the start;
+ * to do this we use a qemu_buf to hold the whole of the device state.
+ */
+ QEMUFile *fb = qemu_bufopen("w", NULL);
+ if (!fb) {
+ error_report("Failed to create buffered file");
+ goto fail;
+ }
+
+ qemu_savevm_state_complete_precopy(fb);
+ qemu_savevm_send_ping(fb, 3);
+
+ qemu_savevm_send_postcopy_run(fb);
+
+ /* <><> end of stuff going into the package */
+ qsb = qemu_buf_get(fb);
+
+ /* Now send that blob */
+ if (qemu_savevm_send_packaged(ms->file, qsb)) {
+ goto fail_closefb;
+ }
+ qemu_fclose(fb);
+ ms->downtime = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) - time_at_stop;
+
+ qemu_mutex_unlock_iothread();
+
+ /*
+ * Although this ping is just for debug, it could potentially be
+ * used for getting a better measurement of downtime at the source.
+ */
+ qemu_savevm_send_ping(ms->file, 4);
+
+ ret = qemu_file_get_error(ms->file);
+ if (ret) {
+ error_report("postcopy_start: Migration stream errored");
+ migrate_set_state(ms, MIGRATION_STATUS_POSTCOPY_ACTIVE,
+ MIGRATION_STATUS_FAILED);
+ }
+
+ return ret;
+
+fail_closefb:
+ qemu_fclose(fb);
+fail:
+ migrate_set_state(ms, MIGRATION_STATUS_POSTCOPY_ACTIVE,
+ MIGRATION_STATUS_FAILED);
+ qemu_mutex_unlock_iothread();
+ return -1;
+}
+
/**
* migration_completion: Used by migration_thread when there's not much left.
* The caller 'breaks' the loop when this returns.
@@ -1332,6 +1437,7 @@ fail:
static void *migration_thread(void *opaque)
{
MigrationState *s = opaque;
+ /* Used by the bandwidth calcs, updated later */
int64_t initial_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
int64_t setup_start = qemu_clock_get_ms(QEMU_CLOCK_HOST);
int64_t initial_bytes = 0;
@@ -1339,13 +1445,33 @@ static void *migration_thread(void *opaque)
int64_t start_time = initial_time;
int64_t end_time;
bool old_vm_running = false;
+ bool entered_postcopy = false;
+ /* The active state we expect to be in; ACTIVE or POSTCOPY_ACTIVE */
+ enum MigrationStatus current_active_state = MIGRATION_STATUS_ACTIVE;
rcu_register_thread();
qemu_savevm_state_header(s->file);
+
+ if (migrate_postcopy_ram()) {
+ /* Now tell the dest that it should open its end so it can reply */
+ qemu_savevm_send_open_return_path(s->file);
+
+ /* And do a ping that will make stuff easier to debug */
+ qemu_savevm_send_ping(s->file, 1);
+
+ /*
+ * Tell the destination that we *might* want to do postcopy later;
+ * if the other end can't do postcopy it should fail now, nice and
+ * early.
+ */
+ qemu_savevm_send_postcopy_advise(s->file);
+ }
+
qemu_savevm_state_begin(s->file, &s->params);
s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start;
+ current_active_state = MIGRATION_STATUS_ACTIVE;
migrate_set_state(s, MIGRATION_STATUS_SETUP, MIGRATION_STATUS_ACTIVE);
trace_migration_thread_setup_complete();
@@ -1364,18 +1490,34 @@ static void *migration_thread(void *opaque)
trace_migrate_pending(pending_size, max_size,
pend_post, pend_nonpost);
if (pending_size && pending_size >= max_size) {
+ /* Still a significant amount to transfer */
+
+ current_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
+ if (migrate_postcopy_ram() &&
+ s->state != MIGRATION_STATUS_POSTCOPY_ACTIVE &&
+ pend_nonpost <= max_size &&
+ atomic_read(&s->start_postcopy)) {
+
+ if (!postcopy_start(s, &old_vm_running)) {
+ current_active_state = MIGRATION_STATUS_POSTCOPY_ACTIVE;
+ entered_postcopy = true;
+ }
+
+ continue;
+ }
+ /* Just another iteration step */
qemu_savevm_state_iterate(s->file);
} else {
trace_migration_thread_low_pending(pending_size);
- migration_completion(s, MIGRATION_STATUS_ACTIVE,
+ migration_completion(s, current_active_state,
&old_vm_running, &start_time);
break;
}
}
if (qemu_file_get_error(s->file)) {
- migrate_set_state(s, MIGRATION_STATUS_ACTIVE,
- MIGRATION_STATUS_FAILED);
+ migrate_set_state(s, current_active_state, MIGRATION_STATUS_FAILED);
+ trace_migration_thread_file_err();
break;
}
current_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
@@ -1406,6 +1548,7 @@ static void *migration_thread(void *opaque)
}
}
+ trace_migration_thread_after_loop();
/* If we enabled cpu throttling for auto-converge, turn it off. */
cpu_throttle_stop();
end_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
@@ -1415,14 +1558,16 @@ static void *migration_thread(void *opaque)
if (s->state == MIGRATION_STATUS_COMPLETED) {
uint64_t transferred_bytes = qemu_ftell(s->file);
s->total_time = end_time - s->total_time;
- s->downtime = end_time - start_time;
+ if (!entered_postcopy) {
+ s->downtime = end_time - start_time;
+ }
if (s->total_time) {
s->mbps = (((double) transferred_bytes * 8.0) /
((double) s->total_time)) / 1000;
}
runstate_set(RUN_STATE_POSTMIGRATE);
} else {
- if (old_vm_running) {
+ if (old_vm_running && !entered_postcopy) {
vm_start();
}
}
@@ -1445,9 +1590,24 @@ void migrate_fd_connect(MigrationState *s)
/* Notify before starting migration thread */
notifier_list_notify(&migration_state_notifiers, s);
+ /*
+ * Open the return path; currently for postcopy but other things might
+ * also want it.
+ */
+ if (migrate_postcopy_ram()) {
+ if (open_return_path_on_source(s)) {
+ error_report("Unable to open return-path for postcopy");
+ migrate_set_state(s, MIGRATION_STATUS_SETUP,
+ MIGRATION_STATUS_FAILED);
+ migrate_fd_cleanup(s);
+ return;
+ }
+ }
+
migrate_compress_threads_create();
qemu_thread_create(&s->thread, "migration", migration_thread, s,
QEMU_THREAD_JOINABLE);
+ s->migration_thread_running = true;
}
PostcopyState postcopy_state_get(void)
diff --git a/trace-events b/trace-events
index 47d3be3..9b7876e 100644
--- a/trace-events
+++ b/trace-events
@@ -1453,9 +1453,13 @@ migrate_fd_error(void) ""
migrate_fd_cancel(void) ""
migrate_pending(uint64_t size, uint64_t max, uint64_t post, uint64_t nonpost) "pending size %" PRIu64 " max %" PRIu64 " (post=%" PRIu64 " nonpost=%" PRIu64 ")"
migrate_send_rp_message(int msg_type, uint16_t len) "%d: len %d"
+migration_thread_after_loop(void) ""
+migration_thread_file_err(void) ""
migration_thread_setup_complete(void) ""
open_return_path_on_source(void) ""
open_return_path_on_source_continue(void) ""
+postcopy_start(void) ""
+postcopy_start_set_run(void) ""
source_return_path_thread_bad_end(void) ""
source_return_path_thread_end(void) ""
source_return_path_thread_entry(void) ""
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 39/57] Postcopy: End of iteration
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (37 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 38/57] Postcopy: Postcopy startup in migration thread Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 40/57] Page request: Add MIG_RP_MSG_REQ_PAGES reverse command Juan Quintela
` (18 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
The end of migration in postcopy is a bit different since some of
the things normally done at the end of migration have already been
done on the transition to postcopy.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
migration/migration.c | 51 +++++++++++++++++++++++++++++++++++++--------------
trace-events | 6 +++++-
2 files changed, 42 insertions(+), 15 deletions(-)
diff --git a/migration/migration.c b/migration/migration.c
index 064986b..3cdb4f7 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1258,7 +1258,6 @@ static int open_return_path_on_source(MigrationState *ms)
return 0;
}
-__attribute__ (( unused )) /* Until later in patch series */
/* Returns 0 if the RP was ok, otherwise there was an error on the RP */
static int await_return_path_close_on_source(MigrationState *ms)
{
@@ -1399,23 +1398,47 @@ static void migration_completion(MigrationState *s, int current_active_state,
{
int ret;
- qemu_mutex_lock_iothread();
- *start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
- qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);
- *old_vm_running = runstate_is_running();
+ if (s->state == MIGRATION_STATUS_ACTIVE) {
+ qemu_mutex_lock_iothread();
+ *start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
+ qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);
+ *old_vm_running = runstate_is_running();
+ ret = global_state_store();
- ret = global_state_store();
- if (!ret) {
- ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
- if (ret >= 0) {
- qemu_file_set_rate_limit(s->file, INT64_MAX);
- qemu_savevm_state_complete_precopy(s->file);
+ if (!ret) {
+ ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
+ if (ret >= 0) {
+ qemu_file_set_rate_limit(s->file, INT64_MAX);
+ qemu_savevm_state_complete_precopy(s->file);
+ }
}
+ qemu_mutex_unlock_iothread();
+
+ if (ret < 0) {
+ goto fail;
+ }
+ } else if (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) {
+ trace_migration_completion_postcopy_end();
+
+ qemu_savevm_state_complete_postcopy(s->file);
+ trace_migration_completion_postcopy_end_after_complete();
}
- qemu_mutex_unlock_iothread();
- if (ret < 0) {
- goto fail;
+ /*
+ * If rp was opened we must clean up the thread before
+ * cleaning everything else up (since if there are no failures
+ * it will wait for the destination to send it's status in
+ * a SHUT command).
+ * Postcopy opens rp if enabled (even if it's not avtivated)
+ */
+ if (migrate_postcopy_ram()) {
+ int rp_error;
+ trace_migration_completion_postcopy_end_before_rp();
+ rp_error = await_return_path_close_on_source(s);
+ trace_migration_completion_postcopy_end_after_rp(rp_error);
+ if (rp_error) {
+ goto fail;
+ }
}
if (qemu_file_get_error(s->file)) {
diff --git a/trace-events b/trace-events
index 9b7876e..401d4c3 100644
--- a/trace-events
+++ b/trace-events
@@ -1453,6 +1453,11 @@ migrate_fd_error(void) ""
migrate_fd_cancel(void) ""
migrate_pending(uint64_t size, uint64_t max, uint64_t post, uint64_t nonpost) "pending size %" PRIu64 " max %" PRIu64 " (post=%" PRIu64 " nonpost=%" PRIu64 ")"
migrate_send_rp_message(int msg_type, uint16_t len) "%d: len %d"
+migration_completion_file_err(void) ""
+migration_completion_postcopy_end(void) ""
+migration_completion_postcopy_end_after_complete(void) ""
+migration_completion_postcopy_end_before_rp(void) ""
+migration_completion_postcopy_end_after_rp(int rp_error) "%d"
migration_thread_after_loop(void) ""
migration_thread_file_err(void) ""
migration_thread_setup_complete(void) ""
@@ -1470,7 +1475,6 @@ migrate_transferred(uint64_t tranferred, uint64_t time_spent, double bandwidth,
migrate_state_too_big(void) ""
migrate_global_state_post_load(const char *state) "loaded state: %s"
migrate_global_state_pre_save(const char *state) "saved state: %s"
-migration_completion_file_err(void) ""
migration_thread_low_pending(uint64_t pending) "%" PRIu64
# migration/rdma.c
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 40/57] Page request: Add MIG_RP_MSG_REQ_PAGES reverse command
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (38 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 39/57] Postcopy: End of iteration Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 41/57] Page request: Process incoming page request Juan Quintela
` (17 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Add MIG_RP_MSG_REQ_PAGES command on Return path for the postcopy
destination to request a page from the source.
Two versions exist:
MIG_RP_MSG_REQ_PAGES_ID that includes a RAMBlock name and start/len
MIG_RP_MSG_REQ_PAGES that just has start/len for use with the same
RAMBlock as a previous MIG_RP_MSG_REQ_PAGES_ID
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/migration/migration.h | 5 ++++
migration/migration.c | 70 +++++++++++++++++++++++++++++++++++++++++++
trace-events | 1 +
3 files changed, 76 insertions(+)
diff --git a/include/migration/migration.h b/include/migration/migration.h
index ff13ff2..1046d4e 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -49,6 +49,9 @@ enum mig_rp_message_type {
MIG_RP_MSG_SHUT, /* sibling will not send any more RP messages */
MIG_RP_MSG_PONG, /* Response to a PING; data (seq: be32 ) */
+ MIG_RP_MSG_REQ_PAGES_ID, /* data (start: be64, len: be32, id: string) */
+ MIG_RP_MSG_REQ_PAGES, /* data (start: be64, len: be32) */
+
MIG_RP_MSG_MAX
};
@@ -256,6 +259,8 @@ void migrate_send_rp_shut(MigrationIncomingState *mis,
uint32_t value);
void migrate_send_rp_pong(MigrationIncomingState *mis,
uint32_t value);
+void migrate_send_rp_req_pages(MigrationIncomingState *mis, const char* rbname,
+ ram_addr_t start, size_t len);
void ram_control_before_iterate(QEMUFile *f, uint64_t flags);
void ram_control_after_iterate(QEMUFile *f, uint64_t flags);
diff --git a/migration/migration.c b/migration/migration.c
index 3cdb4f7..6ccdeb8 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -259,6 +259,35 @@ static void deferred_incoming_migration(Error **errp)
deferred_incoming = true;
}
+/* Request a range of pages from the source VM at the given
+ * start address.
+ * rbname: Name of the RAMBlock to request the page in, if NULL it's the same
+ * as the last request (a name must have been given previously)
+ * Start: Address offset within the RB
+ * Len: Length in bytes required - must be a multiple of pagesize
+ */
+void migrate_send_rp_req_pages(MigrationIncomingState *mis, const char *rbname,
+ ram_addr_t start, size_t len)
+{
+ uint8_t bufc[12 + 1 + 255]; /* start (8), len (4), rbname upto 256 */
+ size_t msglen = 12; /* start + len */
+
+ *(uint64_t *)bufc = cpu_to_be64((uint64_t)start);
+ *(uint32_t *)(bufc + 8) = cpu_to_be32((uint32_t)len);
+
+ if (rbname) {
+ int rbname_len = strlen(rbname);
+ assert(rbname_len < 256);
+
+ bufc[msglen++] = rbname_len;
+ memcpy(bufc + msglen, rbname, rbname_len);
+ msglen += rbname_len;
+ migrate_send_rp_message(mis, MIG_RP_MSG_REQ_PAGES_ID, msglen, bufc);
+ } else {
+ migrate_send_rp_message(mis, MIG_RP_MSG_REQ_PAGES, msglen, bufc);
+ }
+}
+
void qemu_start_incoming_migration(const char *uri, Error **errp)
{
const char *p;
@@ -1151,10 +1180,23 @@ static struct rp_cmd_args {
[MIG_RP_MSG_INVALID] = { .len = -1, .name = "INVALID" },
[MIG_RP_MSG_SHUT] = { .len = 4, .name = "SHUT" },
[MIG_RP_MSG_PONG] = { .len = 4, .name = "PONG" },
+ [MIG_RP_MSG_REQ_PAGES] = { .len = 12, .name = "REQ_PAGES" },
+ [MIG_RP_MSG_REQ_PAGES_ID] = { .len = -1, .name = "REQ_PAGES_ID" },
[MIG_RP_MSG_MAX] = { .len = -1, .name = "MAX" },
};
/*
+ * Process a request for pages received on the return path,
+ * We're allowed to send more than requested (e.g. to round to our page size)
+ * and we don't need to send pages that have already been sent.
+ */
+static void migrate_handle_rp_req_pages(MigrationState *ms, const char* rbname,
+ ram_addr_t start, size_t len)
+{
+ trace_migrate_handle_rp_req_pages(rbname, start, len);
+}
+
+/*
* Handles messages sent on the return path towards the source VM
*
*/
@@ -1166,6 +1208,8 @@ static void *source_return_path_thread(void *opaque)
const int max_len = 512;
uint8_t buf[max_len];
uint32_t tmp32, sibling_error;
+ ram_addr_t start = 0; /* =0 to silence warning */
+ size_t len = 0, expected_len;
int res;
trace_source_return_path_thread_entry();
@@ -1225,6 +1269,32 @@ static void *source_return_path_thread(void *opaque)
trace_source_return_path_thread_pong(tmp32);
break;
+ case MIG_RP_MSG_REQ_PAGES:
+ start = be64_to_cpup((uint64_t *)buf);
+ len = be32_to_cpup((uint32_t *)(buf + 8));
+ migrate_handle_rp_req_pages(ms, NULL, start, len);
+ break;
+
+ case MIG_RP_MSG_REQ_PAGES_ID:
+ expected_len = 12 + 1; /* header + termination */
+
+ if (header_len >= expected_len) {
+ start = be64_to_cpup((uint64_t *)buf);
+ len = be32_to_cpup((uint32_t *)(buf + 8));
+ /* Now we expect an idstr */
+ tmp32 = buf[12]; /* Length of the following idstr */
+ buf[13 + tmp32] = '\0';
+ expected_len += tmp32;
+ }
+ if (header_len != expected_len) {
+ error_report("RP: Req_Page_id with length %d expecting %zd",
+ header_len, expected_len);
+ mark_source_rp_bad(ms);
+ goto out;
+ }
+ migrate_handle_rp_req_pages(ms, (char *)&buf[13], start, len);
+ break;
+
default:
break;
}
diff --git a/trace-events b/trace-events
index 401d4c3..2bafa12 100644
--- a/trace-events
+++ b/trace-events
@@ -1451,6 +1451,7 @@ migrate_set_state(int new_state) "new state %d"
migrate_fd_cleanup(void) ""
migrate_fd_error(void) ""
migrate_fd_cancel(void) ""
+migrate_handle_rp_req_pages(const char *rbname, size_t start, size_t len) "in %s at %zx len %zx"
migrate_pending(uint64_t size, uint64_t max, uint64_t post, uint64_t nonpost) "pending size %" PRIu64 " max %" PRIu64 " (post=%" PRIu64 " nonpost=%" PRIu64 ")"
migrate_send_rp_message(int msg_type, uint16_t len) "%d: len %d"
migration_completion_file_err(void) ""
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 41/57] Page request: Process incoming page request
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (39 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 40/57] Page request: Add MIG_RP_MSG_REQ_PAGES reverse command Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 42/57] Page request: Consume pages off the post-copy queue Juan Quintela
` (16 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
On receiving MIG_RPCOMM_REQ_PAGES look up the address and
queue the page.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/migration/migration.h | 22 +++++++++++
migration/migration.c | 31 +++++++++++++++-
migration/ram.c | 85 +++++++++++++++++++++++++++++++++++++++++++
trace-events | 1 +
4 files changed, 138 insertions(+), 1 deletion(-)
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 1046d4e..1491bf3 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -105,6 +105,18 @@ MigrationIncomingState *migration_incoming_get_current(void);
MigrationIncomingState *migration_incoming_state_new(QEMUFile *f);
void migration_incoming_state_destroy(void);
+/*
+ * An outstanding page request, on the source, having been received
+ * and queued
+ */
+struct MigrationSrcPageRequest {
+ RAMBlock *rb;
+ hwaddr offset;
+ hwaddr len;
+
+ QSIMPLEQ_ENTRY(MigrationSrcPageRequest) next_req;
+};
+
struct MigrationState
{
int64_t bandwidth_limit;
@@ -141,6 +153,12 @@ struct MigrationState
/* Flag set once the migration thread is running (and needs joining) */
bool migration_thread_running;
+
+ /* Queue of outstanding page requests from the destination */
+ QemuMutex src_page_req_mutex;
+ QSIMPLEQ_HEAD(src_page_requests, MigrationSrcPageRequest) src_page_requests;
+ /* The RAMBlock used in the last src_page_request */
+ RAMBlock *last_req_rb;
};
void process_incoming_migration(QEMUFile *f);
@@ -288,6 +306,10 @@ void savevm_skip_configuration(void);
int global_state_store(void);
void global_state_store_running(void);
+void flush_page_queue(MigrationState *ms);
+int ram_save_queue_pages(MigrationState *ms, const char *rbname,
+ ram_addr_t start, ram_addr_t len);
+
PostcopyState postcopy_state_get(void);
/* Set the state and return the old state */
PostcopyState postcopy_state_set(PostcopyState new_state);
diff --git a/migration/migration.c b/migration/migration.c
index 6ccdeb8..7d64cd3 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -21,6 +21,7 @@
#include "sysemu/sysemu.h"
#include "block/block.h"
#include "qapi/qmp/qerror.h"
+#include "qapi/util.h"
#include "qemu/sockets.h"
#include "qemu/rcu.h"
#include "migration/block.h"
@@ -28,9 +29,10 @@
#include "qemu/thread.h"
#include "qmp-commands.h"
#include "trace.h"
-#include "qapi/util.h"
#include "qapi-event.h"
#include "qom/cpu.h"
+#include "exec/memory.h"
+#include "exec/address-spaces.h"
#define MAX_THROTTLE (32 << 20) /* Migration transfer speed throttling */
@@ -72,6 +74,7 @@ static PostcopyState incoming_postcopy_state;
/* For outgoing */
MigrationState *migrate_get_current(void)
{
+ static bool once;
static MigrationState current_migration = {
.state = MIGRATION_STATUS_NONE,
.bandwidth_limit = MAX_THROTTLE,
@@ -89,6 +92,10 @@ MigrationState *migrate_get_current(void)
DEFAULT_MIGRATE_X_CPU_THROTTLE_INCREMENT,
};
+ if (!once) {
+ qemu_mutex_init(¤t_migration.src_page_req_mutex);
+ once = true;
+ }
return ¤t_migration;
}
@@ -771,6 +778,8 @@ static void migrate_fd_cleanup(void *opaque)
qemu_bh_delete(s->cleanup_bh);
s->cleanup_bh = NULL;
+ flush_page_queue(s);
+
if (s->file) {
trace_migrate_fd_cleanup();
qemu_mutex_unlock_iothread();
@@ -903,6 +912,8 @@ MigrationState *migrate_init(const MigrationParams *params)
s->bandwidth_limit = bandwidth_limit;
migrate_set_state(s, MIGRATION_STATUS_NONE, MIGRATION_STATUS_SETUP);
+ QSIMPLEQ_INIT(&s->src_page_requests);
+
s->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
return s;
}
@@ -1193,7 +1204,25 @@ static struct rp_cmd_args {
static void migrate_handle_rp_req_pages(MigrationState *ms, const char* rbname,
ram_addr_t start, size_t len)
{
+ long our_host_ps = getpagesize();
+
trace_migrate_handle_rp_req_pages(rbname, start, len);
+
+ /*
+ * Since we currently insist on matching page sizes, just sanity check
+ * we're being asked for whole host pages.
+ */
+ if (start & (our_host_ps-1) ||
+ (len & (our_host_ps-1))) {
+ error_report("%s: Misaligned page request, start: " RAM_ADDR_FMT
+ " len: %zd", __func__, start, len);
+ mark_source_rp_bad(ms);
+ return;
+ }
+
+ if (ram_save_queue_pages(ms, rbname, start, len)) {
+ mark_source_rp_bad(ms);
+ }
}
/*
diff --git a/migration/ram.c b/migration/ram.c
index 2e27b26..8302d09 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1016,6 +1016,91 @@ static bool find_dirty_block(QEMUFile *f, PageSearchStatus *pss,
}
/**
+ * flush_page_queue: Flush any remaining pages in the ram request queue
+ * it should be empty at the end anyway, but in error cases there may be
+ * some left.
+ *
+ * ms: MigrationState
+ */
+void flush_page_queue(MigrationState *ms)
+{
+ struct MigrationSrcPageRequest *mspr, *next_mspr;
+ /* This queue generally should be empty - but in the case of a failed
+ * migration might have some droppings in.
+ */
+ rcu_read_lock();
+ QSIMPLEQ_FOREACH_SAFE(mspr, &ms->src_page_requests, next_req, next_mspr) {
+ memory_region_unref(mspr->rb->mr);
+ QSIMPLEQ_REMOVE_HEAD(&ms->src_page_requests, next_req);
+ g_free(mspr);
+ }
+ rcu_read_unlock();
+}
+
+/**
+ * Queue the pages for transmission, e.g. a request from postcopy destination
+ * ms: MigrationStatus in which the queue is held
+ * rbname: The RAMBlock the request is for - may be NULL (to mean reuse last)
+ * start: Offset from the start of the RAMBlock
+ * len: Length (in bytes) to send
+ * Return: 0 on success
+ */
+int ram_save_queue_pages(MigrationState *ms, const char *rbname,
+ ram_addr_t start, ram_addr_t len)
+{
+ RAMBlock *ramblock;
+
+ rcu_read_lock();
+ if (!rbname) {
+ /* Reuse last RAMBlock */
+ ramblock = ms->last_req_rb;
+
+ if (!ramblock) {
+ /*
+ * Shouldn't happen, we can't reuse the last RAMBlock if
+ * it's the 1st request.
+ */
+ error_report("ram_save_queue_pages no previous block");
+ goto err;
+ }
+ } else {
+ ramblock = qemu_ram_block_by_name(rbname);
+
+ if (!ramblock) {
+ /* We shouldn't be asked for a non-existent RAMBlock */
+ error_report("ram_save_queue_pages no block '%s'", rbname);
+ goto err;
+ }
+ ms->last_req_rb = ramblock;
+ }
+ trace_ram_save_queue_pages(ramblock->idstr, start, len);
+ if (start+len > ramblock->used_length) {
+ error_report("%s request overrun start=%zx len=%zx blocklen=%zx",
+ __func__, start, len, ramblock->used_length);
+ goto err;
+ }
+
+ struct MigrationSrcPageRequest *new_entry =
+ g_malloc0(sizeof(struct MigrationSrcPageRequest));
+ new_entry->rb = ramblock;
+ new_entry->offset = start;
+ new_entry->len = len;
+
+ memory_region_ref(ramblock->mr);
+ qemu_mutex_lock(&ms->src_page_req_mutex);
+ QSIMPLEQ_INSERT_TAIL(&ms->src_page_requests, new_entry, next_req);
+ qemu_mutex_unlock(&ms->src_page_req_mutex);
+ rcu_read_unlock();
+
+ return 0;
+
+err:
+ rcu_read_unlock();
+ return -1;
+}
+
+
+/**
* ram_find_and_save_block: Finds a dirty page and sends it to f
*
* Called within an RCU critical section.
diff --git a/trace-events b/trace-events
index 2bafa12..0914e0a 100644
--- a/trace-events
+++ b/trace-events
@@ -1256,6 +1256,7 @@ migration_bitmap_sync_start(void) ""
migration_bitmap_sync_end(uint64_t dirty_pages) "dirty_pages %" PRIu64""
migration_throttle(void) ""
ram_postcopy_send_discard_bitmap(void) ""
+ram_save_queue_pages(const char *rbname, size_t start, size_t len) "%s: start: %zx len: %zx"
# hw/display/qxl.c
disable qxl_interface_set_mm_time(int qid, uint32_t mm_time) "%d %d"
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 42/57] Page request: Consume pages off the post-copy queue
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (40 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 41/57] Page request: Process incoming page request Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-12 11:53 ` Peter Maydell
2015-11-10 14:25 ` [Qemu-devel] [PULL 43/57] postcopy_ram.c: place_page and helpers Juan Quintela
` (15 subsequent siblings)
57 siblings, 1 reply; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
When transmitting RAM pages, consume pages that have been queued by
MIG_RPCOMM_REQPAGE commands and send them ahead of normal page scanning.
Note:
a) After a queued page the linear walk carries on from after the
unqueued page; there is a reasonable chance that the destination
was about to ask for other closeby pages anyway.
b) We have to be careful of any assumptions that the page walking
code makes, in particular it does some short cuts on its first linear
walk that break as soon as we do a queued page.
c) We have to be careful to not break up host-page size chunks, since
this makes it harder to place the pages on the destination.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
migration/ram.c | 249 +++++++++++++++++++++++++++++++++++++++++++++++++-------
trace-events | 2 +
2 files changed, 220 insertions(+), 31 deletions(-)
diff --git a/migration/ram.c b/migration/ram.c
index 8302d09..d09d5ab 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -548,9 +548,9 @@ static int save_xbzrle_page(QEMUFile *f, uint8_t **current_data,
* Returns: byte offset within memory region of the start of a dirty page
*/
static inline
-ram_addr_t migration_bitmap_find_and_reset_dirty(RAMBlock *rb,
- ram_addr_t start,
- ram_addr_t *ram_addr_abs)
+ram_addr_t migration_bitmap_find_dirty(RAMBlock *rb,
+ ram_addr_t start,
+ ram_addr_t *ram_addr_abs)
{
unsigned long base = rb->offset >> TARGET_PAGE_BITS;
unsigned long nr = base + (start >> TARGET_PAGE_BITS);
@@ -567,15 +567,24 @@ ram_addr_t migration_bitmap_find_and_reset_dirty(RAMBlock *rb,
next = find_next_bit(bitmap, size, nr);
}
- if (next < size) {
- clear_bit(next, bitmap);
- migration_dirty_pages--;
- }
*ram_addr_abs = next << TARGET_PAGE_BITS;
return (next - base) << TARGET_PAGE_BITS;
}
-/* Called with rcu_read_lock() to protect migration_bitmap */
+static inline bool migration_bitmap_clear_dirty(ram_addr_t addr)
+{
+ bool ret;
+ int nr = addr >> TARGET_PAGE_BITS;
+ unsigned long *bitmap = atomic_rcu_read(&migration_bitmap_rcu)->bmap;
+
+ ret = test_and_clear_bit(nr, bitmap);
+
+ if (ret) {
+ migration_dirty_pages--;
+ }
+ return ret;
+}
+
static void migration_bitmap_sync_range(ram_addr_t start, ram_addr_t length)
{
unsigned long *bitmap;
@@ -974,9 +983,8 @@ static int ram_save_compressed_page(QEMUFile *f, RAMBlock *block,
static bool find_dirty_block(QEMUFile *f, PageSearchStatus *pss,
bool *again, ram_addr_t *ram_addr_abs)
{
- pss->offset = migration_bitmap_find_and_reset_dirty(pss->block,
- pss->offset,
- ram_addr_abs);
+ pss->offset = migration_bitmap_find_dirty(pss->block, pss->offset,
+ ram_addr_abs);
if (pss->complete_round && pss->block == last_seen_block &&
pss->offset >= last_offset) {
/*
@@ -1015,6 +1023,107 @@ static bool find_dirty_block(QEMUFile *f, PageSearchStatus *pss,
}
}
+/*
+ * Helper for 'get_queued_page' - gets a page off the queue
+ * ms: MigrationState in
+ * *offset: Used to return the offset within the RAMBlock
+ * ram_addr_abs: global offset in the dirty/sent bitmaps
+ *
+ * Returns: block (or NULL if none available)
+ */
+static RAMBlock *unqueue_page(MigrationState *ms, ram_addr_t *offset,
+ ram_addr_t *ram_addr_abs)
+{
+ RAMBlock *block = NULL;
+
+ qemu_mutex_lock(&ms->src_page_req_mutex);
+ if (!QSIMPLEQ_EMPTY(&ms->src_page_requests)) {
+ struct MigrationSrcPageRequest *entry =
+ QSIMPLEQ_FIRST(&ms->src_page_requests);
+ block = entry->rb;
+ *offset = entry->offset;
+ *ram_addr_abs = (entry->offset + entry->rb->offset) &
+ TARGET_PAGE_MASK;
+
+ if (entry->len > TARGET_PAGE_SIZE) {
+ entry->len -= TARGET_PAGE_SIZE;
+ entry->offset += TARGET_PAGE_SIZE;
+ } else {
+ memory_region_unref(block->mr);
+ QSIMPLEQ_REMOVE_HEAD(&ms->src_page_requests, next_req);
+ g_free(entry);
+ }
+ }
+ qemu_mutex_unlock(&ms->src_page_req_mutex);
+
+ return block;
+}
+
+/*
+ * Unqueue a page from the queue fed by postcopy page requests; skips pages
+ * that are already sent (!dirty)
+ *
+ * ms: MigrationState in
+ * pss: PageSearchStatus structure updated with found block/offset
+ * ram_addr_abs: global offset in the dirty/sent bitmaps
+ *
+ * Returns: true if a queued page is found
+ */
+static bool get_queued_page(MigrationState *ms, PageSearchStatus *pss,
+ ram_addr_t *ram_addr_abs)
+{
+ RAMBlock *block;
+ ram_addr_t offset;
+ bool dirty;
+
+ do {
+ block = unqueue_page(ms, &offset, ram_addr_abs);
+ /*
+ * We're sending this page, and since it's postcopy nothing else
+ * will dirty it, and we must make sure it doesn't get sent again
+ * even if this queue request was received after the background
+ * search already sent it.
+ */
+ if (block) {
+ unsigned long *bitmap;
+ bitmap = atomic_rcu_read(&migration_bitmap_rcu)->bmap;
+ dirty = test_bit(*ram_addr_abs >> TARGET_PAGE_BITS, bitmap);
+ if (!dirty) {
+ trace_get_queued_page_not_dirty(
+ block->idstr, (uint64_t)offset,
+ (uint64_t)*ram_addr_abs,
+ test_bit(*ram_addr_abs >> TARGET_PAGE_BITS,
+ atomic_rcu_read(&migration_bitmap_rcu)->unsentmap));
+ } else {
+ trace_get_queued_page(block->idstr,
+ (uint64_t)offset,
+ (uint64_t)*ram_addr_abs);
+ }
+ }
+
+ } while (block && !dirty);
+
+ if (block) {
+ /*
+ * As soon as we start servicing pages out of order, then we have
+ * to kill the bulk stage, since the bulk stage assumes
+ * in (migration_bitmap_find_and_reset_dirty) that every page is
+ * dirty, that's no longer true.
+ */
+ ram_bulk_stage = false;
+
+ /*
+ * We want the background search to continue from the queued page
+ * since the guest is likely to want other pages near to the page
+ * it just requested.
+ */
+ pss->block = block;
+ pss->offset = offset;
+ }
+
+ return !!block;
+}
+
/**
* flush_page_queue: Flush any remaining pages in the ram request queue
* it should be empty at the end anyway, but in error cases there may be
@@ -1099,6 +1208,90 @@ err:
return -1;
}
+/**
+ * ram_save_target_page: Save one target page
+ *
+ *
+ * @f: QEMUFile where to send the data
+ * @block: pointer to block that contains the page we want to send
+ * @offset: offset inside the block for the page;
+ * @last_stage: if we are at the completion stage
+ * @bytes_transferred: increase it with the number of transferred bytes
+ * @dirty_ram_abs: Address of the start of the dirty page in ram_addr_t space
+ *
+ * Returns: Number of pages written.
+ */
+static int ram_save_target_page(MigrationState *ms, QEMUFile *f,
+ RAMBlock *block, ram_addr_t offset,
+ bool last_stage,
+ uint64_t *bytes_transferred,
+ ram_addr_t dirty_ram_abs)
+{
+ int res = 0;
+
+ /* Check the pages is dirty and if it is send it */
+ if (migration_bitmap_clear_dirty(dirty_ram_abs)) {
+ unsigned long *unsentmap;
+ if (compression_switch && migrate_use_compression()) {
+ res = ram_save_compressed_page(f, block, offset,
+ last_stage,
+ bytes_transferred);
+ } else {
+ res = ram_save_page(f, block, offset, last_stage,
+ bytes_transferred);
+ }
+
+ if (res < 0) {
+ return res;
+ }
+ unsentmap = atomic_rcu_read(&migration_bitmap_rcu)->unsentmap;
+ if (unsentmap) {
+ clear_bit(dirty_ram_abs >> TARGET_PAGE_BITS, unsentmap);
+ }
+ }
+
+ return res;
+}
+
+/**
+ * ram_save_host_page: Starting at *offset send pages upto the end
+ * of the current host page. It's valid for the initial
+ * offset to point into the middle of a host page
+ * in which case the remainder of the hostpage is sent.
+ * Only dirty target pages are sent.
+ *
+ * Returns: Number of pages written.
+ *
+ * @f: QEMUFile where to send the data
+ * @block: pointer to block that contains the page we want to send
+ * @offset: offset inside the block for the page; updated to last target page
+ * sent
+ * @last_stage: if we are at the completion stage
+ * @bytes_transferred: increase it with the number of transferred bytes
+ * @dirty_ram_abs: Address of the start of the dirty page in ram_addr_t space
+ */
+static int ram_save_host_page(MigrationState *ms, QEMUFile *f, RAMBlock *block,
+ ram_addr_t *offset, bool last_stage,
+ uint64_t *bytes_transferred,
+ ram_addr_t dirty_ram_abs)
+{
+ int tmppages, pages = 0;
+ do {
+ tmppages = ram_save_target_page(ms, f, block, *offset, last_stage,
+ bytes_transferred, dirty_ram_abs);
+ if (tmppages < 0) {
+ return tmppages;
+ }
+
+ pages += tmppages;
+ *offset += TARGET_PAGE_SIZE;
+ dirty_ram_abs += TARGET_PAGE_SIZE;
+ } while (*offset & (qemu_host_page_size - 1));
+
+ /* The offset we leave with is the last one we looked at */
+ *offset -= TARGET_PAGE_SIZE;
+ return pages;
+}
/**
* ram_find_and_save_block: Finds a dirty page and sends it to f
@@ -1111,12 +1304,16 @@ err:
* @f: QEMUFile where to send the data
* @last_stage: if we are at the completion stage
* @bytes_transferred: increase it with the number of transferred bytes
+ *
+ * On systems where host-page-size > target-page-size it will send all the
+ * pages in a host page that are dirty.
*/
static int ram_find_and_save_block(QEMUFile *f, bool last_stage,
uint64_t *bytes_transferred)
{
PageSearchStatus pss;
+ MigrationState *ms = migrate_get_current();
int pages = 0;
bool again, found;
ram_addr_t dirty_ram_abs; /* Address of the start of the dirty page in
@@ -1131,28 +1328,18 @@ static int ram_find_and_save_block(QEMUFile *f, bool last_stage,
}
do {
- found = find_dirty_block(f, &pss, &again, &dirty_ram_abs);
+ again = true;
+ found = get_queued_page(ms, &pss, &dirty_ram_abs);
+
+ if (!found) {
+ /* priority queue empty, so just search for something dirty */
+ found = find_dirty_block(f, &pss, &again, &dirty_ram_abs);
+ }
if (found) {
- if (compression_switch && migrate_use_compression()) {
- pages = ram_save_compressed_page(f, pss.block, pss.offset,
- last_stage,
- bytes_transferred);
- } else {
- pages = ram_save_page(f, pss.block, pss.offset, last_stage,
- bytes_transferred);
- }
-
- /* if page is unmodified, continue to the next */
- if (pages > 0) {
- unsigned long *unsentmap;
-
- unsentmap = atomic_rcu_read(&migration_bitmap_rcu)->unsentmap;
- last_sent_block = pss.block;
- if (unsentmap) {
- clear_bit(dirty_ram_abs >> TARGET_PAGE_BITS, unsentmap);
- }
- }
+ pages = ram_save_host_page(ms, f, pss.block, &pss.offset,
+ last_stage, bytes_transferred,
+ dirty_ram_abs);
}
} while (!pages && again);
diff --git a/trace-events b/trace-events
index 0914e0a..3df3656 100644
--- a/trace-events
+++ b/trace-events
@@ -1252,6 +1252,8 @@ vmstate_subsection_load_good(const char *parent) "%s"
qemu_file_fclose(void) ""
# migration/ram.c
+get_queued_page(const char *block_name, uint64_t tmp_offset, uint64_t ram_addr) "%s/%" PRIx64 " ram_addr=%" PRIx64
+get_queued_page_not_dirty(const char *block_name, uint64_t tmp_offset, uint64_t ram_addr, int sent) "%s/%" PRIx64 " ram_addr=%" PRIx64 " (sent=%d)"
migration_bitmap_sync_start(void) ""
migration_bitmap_sync_end(uint64_t dirty_pages) "dirty_pages %" PRIu64""
migration_throttle(void) ""
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* Re: [Qemu-devel] [PULL 42/57] Page request: Consume pages off the post-copy queue
2015-11-10 14:25 ` [Qemu-devel] [PULL 42/57] Page request: Consume pages off the post-copy queue Juan Quintela
@ 2015-11-12 11:53 ` Peter Maydell
2015-11-12 12:04 ` Dr. David Alan Gilbert
0 siblings, 1 reply; 81+ messages in thread
From: Peter Maydell @ 2015-11-12 11:53 UTC (permalink / raw)
To: Juan Quintela; +Cc: Amit Shah, QEMU Developers, Dr. David Alan Gilbert
On 10 November 2015 at 14:25, Juan Quintela <quintela@redhat.com> wrote:
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
>
> When transmitting RAM pages, consume pages that have been queued by
> MIG_RPCOMM_REQPAGE commands and send them ahead of normal page scanning.
>
> Note:
> a) After a queued page the linear walk carries on from after the
> unqueued page; there is a reasonable chance that the destination
> was about to ask for other closeby pages anyway.
>
> b) We have to be careful of any assumptions that the page walking
> code makes, in particular it does some short cuts on its first linear
> walk that break as soon as we do a queued page.
>
> c) We have to be careful to not break up host-page size chunks, since
> this makes it harder to place the pages on the destination.
>
> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> Reviewed-by: Juan Quintela <quintela@redhat.com>
> Signed-off-by: Juan Quintela <quintela@redhat.com>
I've just discovered that this is causing 'make check' failures on
my OSX host (unfortunately something in my setup is causing
'make check' failures to not always cause a build failure, so I
didn't notice earlier):
manooth$ (make -C build/x86 -j8 && cd build/x86 &&
QTEST_QEMU_BINARY=x86_64-softmmu/qemu-system-x86_64
QTEST_QEMU_IMG=qemu-img MALLOC_PERTURB_=${MALLOC_PERTURB_:-$((RANDOM %
255 + 1))} tests/ahci-test)
[...]
/x86_64/ahci/flush/simple: OK
/x86_64/ahci/flush/retry: OK
/x86_64/ahci/flush/migrate: qemu: qemu_mutex_lock: Invalid argument
qemu-system-x86_64:Broken pipe
Not a migration stream
qemu-system-x86_64: load of migration failed: Invalid argument
thanks
-- PMM
^ permalink raw reply [flat|nested] 81+ messages in thread* Re: [Qemu-devel] [PULL 42/57] Page request: Consume pages off the post-copy queue
2015-11-12 11:53 ` Peter Maydell
@ 2015-11-12 12:04 ` Dr. David Alan Gilbert
2015-11-12 12:15 ` Peter Maydell
0 siblings, 1 reply; 81+ messages in thread
From: Dr. David Alan Gilbert @ 2015-11-12 12:04 UTC (permalink / raw)
To: Peter Maydell; +Cc: Amit Shah, QEMU Developers, Juan Quintela
* Peter Maydell (peter.maydell@linaro.org) wrote:
> On 10 November 2015 at 14:25, Juan Quintela <quintela@redhat.com> wrote:
> > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> >
> > When transmitting RAM pages, consume pages that have been queued by
> > MIG_RPCOMM_REQPAGE commands and send them ahead of normal page scanning.
> >
> > Note:
> > a) After a queued page the linear walk carries on from after the
> > unqueued page; there is a reasonable chance that the destination
> > was about to ask for other closeby pages anyway.
> >
> > b) We have to be careful of any assumptions that the page walking
> > code makes, in particular it does some short cuts on its first linear
> > walk that break as soon as we do a queued page.
> >
> > c) We have to be careful to not break up host-page size chunks, since
> > this makes it harder to place the pages on the destination.
> >
> > Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> > Reviewed-by: Juan Quintela <quintela@redhat.com>
> > Signed-off-by: Juan Quintela <quintela@redhat.com>
>
> I've just discovered that this is causing 'make check' failures on
> my OSX host (unfortunately something in my setup is causing
> 'make check' failures to not always cause a build failure, so I
> didn't notice earlier):
It's only failing on OSX? Every time or only sometimes?
> manooth$ (make -C build/x86 -j8 && cd build/x86 &&
> QTEST_QEMU_BINARY=x86_64-softmmu/qemu-system-x86_64
> QTEST_QEMU_IMG=qemu-img MALLOC_PERTURB_=${MALLOC_PERTURB_:-$((RANDOM %
> 255 + 1))} tests/ahci-test)
> [...]
>
> /x86_64/ahci/flush/simple: OK
> /x86_64/ahci/flush/retry: OK
> /x86_64/ahci/flush/migrate: qemu: qemu_mutex_lock: Invalid argument
> qemu-system-x86_64:Broken pipe
> Not a migration stream
> qemu-system-x86_64: load of migration failed: Invalid argument
OK, let me see if I can find - I do add a mutex in there (src_page_req_mutex)
that I guess is the most likely culprit; it's initialised by migrate_get_current (once
using a bool) so it should be OK.
If you can find a way to get a backtrace off that qemu_mutex_lock case
that would be great; I'd assume the later errors are the fall out from that.
Dave
>
> thanks
> -- PMM
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
^ permalink raw reply [flat|nested] 81+ messages in thread* Re: [Qemu-devel] [PULL 42/57] Page request: Consume pages off the post-copy queue
2015-11-12 12:04 ` Dr. David Alan Gilbert
@ 2015-11-12 12:15 ` Peter Maydell
2015-11-12 12:23 ` Dr. David Alan Gilbert
2015-11-12 13:36 ` Markus Armbruster
0 siblings, 2 replies; 81+ messages in thread
From: Peter Maydell @ 2015-11-12 12:15 UTC (permalink / raw)
To: Dr. David Alan Gilbert; +Cc: Amit Shah, QEMU Developers, Juan Quintela
On 12 November 2015 at 12:04, Dr. David Alan Gilbert
<dgilbert@redhat.com> wrote:
> * Peter Maydell (peter.maydell@linaro.org) wrote:
>> On 10 November 2015 at 14:25, Juan Quintela <quintela@redhat.com> wrote:
>> > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
>> >
>> > When transmitting RAM pages, consume pages that have been queued by
>> > MIG_RPCOMM_REQPAGE commands and send them ahead of normal page scanning.
>> >
>> > Note:
>> > a) After a queued page the linear walk carries on from after the
>> > unqueued page; there is a reasonable chance that the destination
>> > was about to ask for other closeby pages anyway.
>> >
>> > b) We have to be careful of any assumptions that the page walking
>> > code makes, in particular it does some short cuts on its first linear
>> > walk that break as soon as we do a queued page.
>> >
>> > c) We have to be careful to not break up host-page size chunks, since
>> > this makes it harder to place the pages on the destination.
>> >
>> > Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
>> > Reviewed-by: Juan Quintela <quintela@redhat.com>
>> > Signed-off-by: Juan Quintela <quintela@redhat.com>
>>
>> I've just discovered that this is causing 'make check' failures on
>> my OSX host (unfortunately something in my setup is causing
>> 'make check' failures to not always cause a build failure, so I
>> didn't notice earlier):
>
> It's only failing on OSX? Every time or only sometimes?
Only OSX, and always. I think OSX is pickier about mutexes really
needing to be initialized before use.
> If you can find a way to get a backtrace off that qemu_mutex_lock case
> that would be great; I'd assume the later errors are the fall out from that.
I'll have a look after lunch, but it's usually painful to get a
backtrace out of this kind of qtest, because it's clearly starting
a whole pile of QEMUs and there's no way I know of to say "only
run a few of these tests, not the whole huge pile".
thanks
-- PMM
^ permalink raw reply [flat|nested] 81+ messages in thread
* Re: [Qemu-devel] [PULL 42/57] Page request: Consume pages off the post-copy queue
2015-11-12 12:15 ` Peter Maydell
@ 2015-11-12 12:23 ` Dr. David Alan Gilbert
2015-11-12 12:57 ` Peter Maydell
2015-11-12 13:36 ` Markus Armbruster
1 sibling, 1 reply; 81+ messages in thread
From: Dr. David Alan Gilbert @ 2015-11-12 12:23 UTC (permalink / raw)
To: Peter Maydell; +Cc: Amit Shah, QEMU Developers, Juan Quintela
* Peter Maydell (peter.maydell@linaro.org) wrote:
> On 12 November 2015 at 12:04, Dr. David Alan Gilbert
> <dgilbert@redhat.com> wrote:
> > * Peter Maydell (peter.maydell@linaro.org) wrote:
> >> On 10 November 2015 at 14:25, Juan Quintela <quintela@redhat.com> wrote:
> >> > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> >> >
> >> > When transmitting RAM pages, consume pages that have been queued by
> >> > MIG_RPCOMM_REQPAGE commands and send them ahead of normal page scanning.
> >> >
> >> > Note:
> >> > a) After a queued page the linear walk carries on from after the
> >> > unqueued page; there is a reasonable chance that the destination
> >> > was about to ask for other closeby pages anyway.
> >> >
> >> > b) We have to be careful of any assumptions that the page walking
> >> > code makes, in particular it does some short cuts on its first linear
> >> > walk that break as soon as we do a queued page.
> >> >
> >> > c) We have to be careful to not break up host-page size chunks, since
> >> > this makes it harder to place the pages on the destination.
> >> >
> >> > Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> >> > Reviewed-by: Juan Quintela <quintela@redhat.com>
> >> > Signed-off-by: Juan Quintela <quintela@redhat.com>
> >>
> >> I've just discovered that this is causing 'make check' failures on
> >> my OSX host (unfortunately something in my setup is causing
> >> 'make check' failures to not always cause a build failure, so I
> >> didn't notice earlier):
> >
> > It's only failing on OSX? Every time or only sometimes?
>
> Only OSX, and always. I think OSX is pickier about mutexes really
> needing to be initialized before use.
OK, at least an 'always' should be easier to debug.
> > If you can find a way to get a backtrace off that qemu_mutex_lock case
> > that would be great; I'd assume the later errors are the fall out from that.
>
> I'll have a look after lunch, but it's usually painful to get a
> backtrace out of this kind of qtest, because it's clearly starting
> a whole pile of QEMUs and there's no way I know of to say "only
> run a few of these tests, not the whole huge pile".
You could add an abort/assert into util/qemu-thread-posix.c qemu_mutex_lock
in the error path.
Could you also add:
diff --git a/migration/migration.c b/migration/migration.c
index 9bd2ce7..85e5766 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -93,6 +93,7 @@ MigrationState *migrate_get_current(void)
};
if (!once) {
+ fprintf(stderr,"migrate_get_current do init of current_migration %d\n", getpid());
qemu_mutex_init(¤t_migration.src_page_req_mutex);
once = true;
}
diff --git a/migration/ram.c b/migration/ram.c
index 4266687..72b46f2 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1036,6 +1036,7 @@ static RAMBlock *unqueue_page(MigrationState *ms, ram_addr_t *offset,
{
RAMBlock *block = NULL;
+ fprintf(stderr,"unqueue_page %d\n", getpid());
qemu_mutex_lock(&ms->src_page_req_mutex);
if (!QSIMPLEQ_EMPTY(&ms->src_page_requests)) {
struct MigrationSrcPageRequest *entry =
and make sure that the init happens before the first unqueue (you'll get
loads of calls to unqueue).
Dave
>
> thanks
> -- PMM
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
^ permalink raw reply related [flat|nested] 81+ messages in thread* Re: [Qemu-devel] [PULL 42/57] Page request: Consume pages off the post-copy queue
2015-11-12 12:23 ` Dr. David Alan Gilbert
@ 2015-11-12 12:57 ` Peter Maydell
2015-11-12 13:08 ` Dr. David Alan Gilbert
0 siblings, 1 reply; 81+ messages in thread
From: Peter Maydell @ 2015-11-12 12:57 UTC (permalink / raw)
To: Dr. David Alan Gilbert; +Cc: Amit Shah, QEMU Developers, Juan Quintela
On 12 November 2015 at 12:23, Dr. David Alan Gilbert
<dgilbert@redhat.com> wrote:
> * Peter Maydell (peter.maydell@linaro.org) wrote:
>> On 12 November 2015 at 12:04, Dr. David Alan Gilbert
>> <dgilbert@redhat.com> wrote:
>> > * Peter Maydell (peter.maydell@linaro.org) wrote:
>> >> On 10 November 2015 at 14:25, Juan Quintela <quintela@redhat.com> wrote:
>> >> > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
>> >> >
>> >> > When transmitting RAM pages, consume pages that have been queued by
>> >> > MIG_RPCOMM_REQPAGE commands and send them ahead of normal page scanning.
>> >> >
>> >> > Note:
>> >> > a) After a queued page the linear walk carries on from after the
>> >> > unqueued page; there is a reasonable chance that the destination
>> >> > was about to ask for other closeby pages anyway.
>> >> >
>> >> > b) We have to be careful of any assumptions that the page walking
>> >> > code makes, in particular it does some short cuts on its first linear
>> >> > walk that break as soon as we do a queued page.
>> >> >
>> >> > c) We have to be careful to not break up host-page size chunks, since
>> >> > this makes it harder to place the pages on the destination.
>> >> >
>> >> > Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
>> >> > Reviewed-by: Juan Quintela <quintela@redhat.com>
>> >> > Signed-off-by: Juan Quintela <quintela@redhat.com>
>> >>
>> >> I've just discovered that this is causing 'make check' failures on
>> >> my OSX host (unfortunately something in my setup is causing
>> >> 'make check' failures to not always cause a build failure, so I
>> >> didn't notice earlier):
>> >
>> > It's only failing on OSX? Every time or only sometimes?
>>
>> Only OSX, and always. I think OSX is pickier about mutexes really
>> needing to be initialized before use.
>
> OK, at least an 'always' should be easier to debug.
>
>> > If you can find a way to get a backtrace off that qemu_mutex_lock case
>> > that would be great; I'd assume the later errors are the fall out from that.
>>
>> I'll have a look after lunch, but it's usually painful to get a
>> backtrace out of this kind of qtest, because it's clearly starting
>> a whole pile of QEMUs and there's no way I know of to say "only
>> run a few of these tests, not the whole huge pile".
>
> You could add an abort/assert into util/qemu-thread-posix.c qemu_mutex_lock
> in the error path.
abort/assert doesn't print a backtrace.
I added some OSX backtrace-gathering/printing functions to the errorpath,
and got this:
0 qemu-system-x86_64 0x000000010c66d203 qemu_mutex_lock + 83
1 qemu-system-x86_64 0x000000010c2ac7af unqueue_page + 47
2 qemu-system-x86_64 0x000000010c2ac386 get_queued_page + 54
3 qemu-system-x86_64 0x000000010c2ac135
ram_find_and_save_block + 165
4 qemu-system-x86_64 0x000000010c2ab5a2
ram_save_iterate + 130
5 qemu-system-x86_64 0x000000010c2afa2e
qemu_savevm_state_iterate + 302
6 qemu-system-x86_64 0x000000010c53acbb
migration_thread + 571
7 libsystem_pthread.dylib 0x00007fff9146c05a _pthread_body + 131
8 libsystem_pthread.dylib 0x00007fff9146bfd7 _pthread_body + 0
9 libsystem_pthread.dylib 0x00007fff914693ed thread_start + 13
>
> Could you also add:
>
> diff --git a/migration/migration.c b/migration/migration.c
> index 9bd2ce7..85e5766 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -93,6 +93,7 @@ MigrationState *migrate_get_current(void)
> };
>
> if (!once) {
> + fprintf(stderr,"migrate_get_current do init of current_migration %d\n", getpid());
> qemu_mutex_init(¤t_migration.src_page_req_mutex);
> once = true;
> }
> diff --git a/migration/ram.c b/migration/ram.c
> index 4266687..72b46f2 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -1036,6 +1036,7 @@ static RAMBlock *unqueue_page(MigrationState *ms, ram_addr_t *offset,
> {
> RAMBlock *block = NULL;
>
> + fprintf(stderr,"unqueue_page %d\n", getpid());
> qemu_mutex_lock(&ms->src_page_req_mutex);
> if (!QSIMPLEQ_EMPTY(&ms->src_page_requests)) {
> struct MigrationSrcPageRequest *entry =
>
>
> and make sure that the init happens before the first unqueue (you'll get
> loads of calls to unqueue).
With that change, plus the backtracing:
/x86_64/ahci/flush/retry: OK
/x86_64/ahci/flush/migrate: migrate_get_current do init of
current_migration 60427
migrate_get_current do init of current_migration 60428
unqueue_page 60427
0 qemu-system-x86_64 0x0000000101a751c3 qemu_mutex_lock + 83
1 qemu-system-x86_64 0x00000001016b4749 unqueue_page + 89
2 qemu-system-x86_64 0x00000001016b42f6 get_queued_page + 54
3 qemu-system-x86_64 0x00000001016b40a5
ram_find_and_save_block + 165
4 qemu-system-x86_64 0x00000001016b3512
ram_save_iterate + 130
5 qemu-system-x86_64 0x00000001016b79be
qemu_savevm_state_iterate + 302
6 qemu-system-x86_64 0x0000000101942c7b
migration_thread + 571
7 libsystem_pthread.dylib 0x00007fff9146c05a _pthread_body + 131
8 libsystem_pthread.dylib 0x00007fff9146bfd7 _pthread_body + 0
9 libsystem_pthread.dylib 0x00007fff914693ed thread_start + 13
qemu: qemu_mutex_lock: Invalid argument
qemu-system-x86_64:Broken pipe
Not a migration stream
qemu-system-x86_64: load of migration failed: Invalid argument
thanks
-- PMM
^ permalink raw reply [flat|nested] 81+ messages in thread* Re: [Qemu-devel] [PULL 42/57] Page request: Consume pages off the post-copy queue
2015-11-12 12:57 ` Peter Maydell
@ 2015-11-12 13:08 ` Dr. David Alan Gilbert
2015-11-12 13:18 ` Peter Maydell
0 siblings, 1 reply; 81+ messages in thread
From: Dr. David Alan Gilbert @ 2015-11-12 13:08 UTC (permalink / raw)
To: Peter Maydell; +Cc: Amit Shah, QEMU Developers, Juan Quintela
* Peter Maydell (peter.maydell@linaro.org) wrote:
> abort/assert doesn't print a backtrace.
>
> I added some OSX backtrace-gathering/printing functions to the errorpath,
> and got this:
>
> 0 qemu-system-x86_64 0x000000010c66d203 qemu_mutex_lock + 83
> 1 qemu-system-x86_64 0x000000010c2ac7af unqueue_page + 47
OK, it is the mutex that I added in that patch.
> 2 qemu-system-x86_64 0x000000010c2ac386 get_queued_page + 54
> 3 qemu-system-x86_64 0x000000010c2ac135
> ram_find_and_save_block + 165
> 4 qemu-system-x86_64 0x000000010c2ab5a2
> ram_save_iterate + 130
> 5 qemu-system-x86_64 0x000000010c2afa2e
> qemu_savevm_state_iterate + 302
> 6 qemu-system-x86_64 0x000000010c53acbb
> migration_thread + 571
> 7 libsystem_pthread.dylib 0x00007fff9146c05a _pthread_body + 131
> 8 libsystem_pthread.dylib 0x00007fff9146bfd7 _pthread_body + 0
> 9 libsystem_pthread.dylib 0x00007fff914693ed thread_start + 13
>
>
> >
> > Could you also add:
> >
> > diff --git a/migration/migration.c b/migration/migration.c
> > index 9bd2ce7..85e5766 100644
> > --- a/migration/migration.c
> > +++ b/migration/migration.c
> > @@ -93,6 +93,7 @@ MigrationState *migrate_get_current(void)
> > };
> >
> > if (!once) {
> > + fprintf(stderr,"migrate_get_current do init of current_migration %d\n", getpid());
> > qemu_mutex_init(¤t_migration.src_page_req_mutex);
> > once = true;
> > }
> > diff --git a/migration/ram.c b/migration/ram.c
> > index 4266687..72b46f2 100644
> > --- a/migration/ram.c
> > +++ b/migration/ram.c
> > @@ -1036,6 +1036,7 @@ static RAMBlock *unqueue_page(MigrationState *ms, ram_addr_t *offset,
> > {
> > RAMBlock *block = NULL;
> >
> > + fprintf(stderr,"unqueue_page %d\n", getpid());
> > qemu_mutex_lock(&ms->src_page_req_mutex);
> > if (!QSIMPLEQ_EMPTY(&ms->src_page_requests)) {
> > struct MigrationSrcPageRequest *entry =
> >
> >
> > and make sure that the init happens before the first unqueue (you'll get
> > loads of calls to unqueue).
>
> With that change, plus the backtracing:
>
> /x86_64/ahci/flush/retry: OK
> /x86_64/ahci/flush/migrate: migrate_get_current do init of
> current_migration 60427
> migrate_get_current do init of current_migration 60428
> unqueue_page 60427
> 0 qemu-system-x86_64 0x0000000101a751c3 qemu_mutex_lock + 83
> 1 qemu-system-x86_64 0x00000001016b4749 unqueue_page + 89
OK, so the lock I added is apparently being initialised before it's being locked,
so that's good.
OK, can you try a simple migration by hand outside of the test harness;
just something simple like:
./bin/qemu-system-x86_64 -M pc -nographic
(qemu) migrate "exec: cat > /dev/null"
and the same with q35 ?
Dave
> 2 qemu-system-x86_64 0x00000001016b42f6 get_queued_page + 54
> 3 qemu-system-x86_64 0x00000001016b40a5
> ram_find_and_save_block + 165
> 4 qemu-system-x86_64 0x00000001016b3512
> ram_save_iterate + 130
> 5 qemu-system-x86_64 0x00000001016b79be
> qemu_savevm_state_iterate + 302
> 6 qemu-system-x86_64 0x0000000101942c7b
> migration_thread + 571
> 7 libsystem_pthread.dylib 0x00007fff9146c05a _pthread_body + 131
> 8 libsystem_pthread.dylib 0x00007fff9146bfd7 _pthread_body + 0
> 9 libsystem_pthread.dylib 0x00007fff914693ed thread_start + 13
> qemu: qemu_mutex_lock: Invalid argument
> qemu-system-x86_64:Broken pipe
> Not a migration stream
> qemu-system-x86_64: load of migration failed: Invalid argument
>
> thanks
> -- PMM
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
^ permalink raw reply [flat|nested] 81+ messages in thread* Re: [Qemu-devel] [PULL 42/57] Page request: Consume pages off the post-copy queue
2015-11-12 13:08 ` Dr. David Alan Gilbert
@ 2015-11-12 13:18 ` Peter Maydell
2015-11-12 13:53 ` Peter Maydell
0 siblings, 1 reply; 81+ messages in thread
From: Peter Maydell @ 2015-11-12 13:18 UTC (permalink / raw)
To: Dr. David Alan Gilbert; +Cc: Amit Shah, QEMU Developers, Juan Quintela
On 12 November 2015 at 13:08, Dr. David Alan Gilbert
<dgilbert@redhat.com> wrote:
> OK, can you try a simple migration by hand outside of the test harness;
> just something simple like:
>
> ./bin/qemu-system-x86_64 -M pc -nographic
> (qemu) migrate "exec: cat > /dev/null"
>
> and the same with q35 ?
(qemu) migrate "exec: cat > /dev/null"
migrate_get_current do init of current_migration 65307
unqueue_page 65307
0 qemu-system-x86_64 0x00000001067c01c3 qemu_mutex_lock + 83
1 qemu-system-x86_64 0x00000001063ff749 unqueue_page + 89
2 qemu-system-x86_64 0x00000001063ff2f6 get_queued_page + 54
3 qemu-system-x86_64 0x00000001063ff0a5
ram_find_and_save_block + 165
4 qemu-system-x86_64 0x00000001063fe512
ram_save_iterate + 130
5 qemu-system-x86_64 0x00000001064029be
qemu_savevm_state_iterate + 302
6 qemu-system-x86_64 0x000000010668dc7b
migration_thread + 571
7 libsystem_pthread.dylib 0x00007fff9146c05a _pthread_body + 131
8 libsystem_pthread.dylib 0x00007fff9146bfd7 _pthread_body + 0
9 libsystem_pthread.dylib 0x00007fff914693ed thread_start + 13
(identical behaviour for q35 and pc).
thanks
-- PMM
^ permalink raw reply [flat|nested] 81+ messages in thread
* Re: [Qemu-devel] [PULL 42/57] Page request: Consume pages off the post-copy queue
2015-11-12 13:18 ` Peter Maydell
@ 2015-11-12 13:53 ` Peter Maydell
2015-11-12 14:20 ` Dr. David Alan Gilbert
2015-11-12 14:22 ` Juan Quintela
0 siblings, 2 replies; 81+ messages in thread
From: Peter Maydell @ 2015-11-12 13:53 UTC (permalink / raw)
To: Dr. David Alan Gilbert; +Cc: Amit Shah, QEMU Developers, Juan Quintela
On 12 November 2015 at 13:18, Peter Maydell <peter.maydell@linaro.org> wrote:
> On 12 November 2015 at 13:08, Dr. David Alan Gilbert
> <dgilbert@redhat.com> wrote:
>> OK, can you try a simple migration by hand outside of the test harness;
>> just something simple like:
>>
>> ./bin/qemu-system-x86_64 -M pc -nographic
>> (qemu) migrate "exec: cat > /dev/null"
>>
>> and the same with q35 ?
>
> (qemu) migrate "exec: cat > /dev/null"
> migrate_get_current do init of current_migration 65307
> unqueue_page 65307
> 0 qemu-system-x86_64 0x00000001067c01c3 qemu_mutex_lock + 83
This turns out to be because migrate_init() is corrupting the
mutex memory when it does "memset(s, 0, sizeof(*s))". Presumably
Linux's initialized-mutex is all-zeroes, but OSX's is not.
thanks
-- PMM
^ permalink raw reply [flat|nested] 81+ messages in thread
* Re: [Qemu-devel] [PULL 42/57] Page request: Consume pages off the post-copy queue
2015-11-12 13:53 ` Peter Maydell
@ 2015-11-12 14:20 ` Dr. David Alan Gilbert
2015-11-12 15:25 ` Juan Quintela
2015-11-12 14:22 ` Juan Quintela
1 sibling, 1 reply; 81+ messages in thread
From: Dr. David Alan Gilbert @ 2015-11-12 14:20 UTC (permalink / raw)
To: Peter Maydell; +Cc: Amit Shah, QEMU Developers, Juan Quintela
* Peter Maydell (peter.maydell@linaro.org) wrote:
> On 12 November 2015 at 13:18, Peter Maydell <peter.maydell@linaro.org> wrote:
> > On 12 November 2015 at 13:08, Dr. David Alan Gilbert
> > <dgilbert@redhat.com> wrote:
> >> OK, can you try a simple migration by hand outside of the test harness;
> >> just something simple like:
> >>
> >> ./bin/qemu-system-x86_64 -M pc -nographic
> >> (qemu) migrate "exec: cat > /dev/null"
> >>
> >> and the same with q35 ?
> >
> > (qemu) migrate "exec: cat > /dev/null"
> > migrate_get_current do init of current_migration 65307
> > unqueue_page 65307
> > 0 qemu-system-x86_64 0x00000001067c01c3 qemu_mutex_lock + 83
>
> This turns out to be because migrate_init() is corrupting the
> mutex memory when it does "memset(s, 0, sizeof(*s))". Presumably
> Linux's initialized-mutex is all-zeroes, but OSX's is not.
OK, thanks for finding that; I've just smoke tested the following
patch and will post it properly after I test it more thoroughly in
a couple of hours.
Dave
commit 689d4964442c3ee34a2dac77411a30b96c214288
Author: Dr. David Alan Gilbert <dgilbert@redhat.com>
Date: Thu Nov 12 14:10:33 2015 +0000
migration_init: Fix lock initialisation/make it explicit
Peter reported a lock error on MacOS after my a82d593b
patch.
migrate_get_current does one-time initialisation of
a bunch of variables.
migrate_init does reinitialisation even on a 2nd
migrate after a cancel.
The problem here was that I'd initialised the mutex
in migrate_get_current, and the memset in migrate_init
corrupted it.
Remove the memset and replace it by explicit initialisation
of fields that need initialising; this also turns out to be simpler
than the old code that had to preserve some fields.
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Fixes: a82d593b
diff --git a/migration/migration.c b/migration/migration.c
index 9bd2ce7..7e4e27b 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -902,38 +902,31 @@ bool migration_in_postcopy(MigrationState *s)
MigrationState *migrate_init(const MigrationParams *params)
{
MigrationState *s = migrate_get_current();
- int64_t bandwidth_limit = s->bandwidth_limit;
- bool enabled_capabilities[MIGRATION_CAPABILITY_MAX];
- int64_t xbzrle_cache_size = s->xbzrle_cache_size;
- int compress_level = s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL];
- int compress_thread_count =
- s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS];
- int decompress_thread_count =
- s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS];
- int x_cpu_throttle_initial =
- s->parameters[MIGRATION_PARAMETER_X_CPU_THROTTLE_INITIAL];
- int x_cpu_throttle_increment =
- s->parameters[MIGRATION_PARAMETER_X_CPU_THROTTLE_INCREMENT];
-
- memcpy(enabled_capabilities, s->enabled_capabilities,
- sizeof(enabled_capabilities));
- memset(s, 0, sizeof(*s));
+ /*
+ * Reinitialise all migration state, except
+ * parameters/capabilities that the user set, and
+ * locks.
+ */
+ s->bytes_xfer = 0;
+ s->xfer_limit = 0;
+ s->cleanup_bh = 0;
+ s->file = NULL;
+ s->state = MIGRATION_STATUS_NONE;
s->params = *params;
- memcpy(s->enabled_capabilities, enabled_capabilities,
- sizeof(enabled_capabilities));
- s->xbzrle_cache_size = xbzrle_cache_size;
-
- s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL] = compress_level;
- s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS] =
- compress_thread_count;
- s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS] =
- decompress_thread_count;
- s->parameters[MIGRATION_PARAMETER_X_CPU_THROTTLE_INITIAL] =
- x_cpu_throttle_initial;
- s->parameters[MIGRATION_PARAMETER_X_CPU_THROTTLE_INCREMENT] =
- x_cpu_throttle_increment;
- s->bandwidth_limit = bandwidth_limit;
+ s->rp_state.from_dst_file = NULL;
+ s->rp_state.error = false;
+ s->mbps = 0.0;
+ s->downtime = 0;
+ s->expected_downtime = 0;
+ s->dirty_pages_rate = 0;
+ s->dirty_bytes_rate = 0;
+ s->setup_time = 0;
+ s->dirty_sync_count = 0;
+ s->start_postcopy = false;
+ s->migration_thread_running = false;
+ s->last_req_rb = NULL;
+
migrate_set_state(s, MIGRATION_STATUS_NONE, MIGRATION_STATUS_SETUP);
QSIMPLEQ_INIT(&s->src_page_requests);
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
^ permalink raw reply related [flat|nested] 81+ messages in thread* Re: [Qemu-devel] [PULL 42/57] Page request: Consume pages off the post-copy queue
2015-11-12 14:20 ` Dr. David Alan Gilbert
@ 2015-11-12 15:25 ` Juan Quintela
2015-11-12 15:57 ` Dr. David Alan Gilbert
0 siblings, 1 reply; 81+ messages in thread
From: Juan Quintela @ 2015-11-12 15:25 UTC (permalink / raw)
To: Dr. David Alan Gilbert; +Cc: Amit Shah, Peter Maydell, QEMU Developers
"Dr. David Alan Gilbert" <dgilbert@redhat.com> wrote:
> * Peter Maydell (peter.maydell@linaro.org) wrote:
>> On 12 November 2015 at 13:18, Peter Maydell <peter.maydell@linaro.org> wrote:
>> > On 12 November 2015 at 13:08, Dr. David Alan Gilbert
>> > <dgilbert@redhat.com> wrote:
>> >> OK, can you try a simple migration by hand outside of the test harness;
>> >> just something simple like:
>> >>
>> >> ./bin/qemu-system-x86_64 -M pc -nographic
>> >> (qemu) migrate "exec: cat > /dev/null"
>> >>
>> >> and the same with q35 ?
>> >
>> > (qemu) migrate "exec: cat > /dev/null"
>> > migrate_get_current do init of current_migration 65307
>> > unqueue_page 65307
>> > 0 qemu-system-x86_64 0x00000001067c01c3 qemu_mutex_lock + 83
>>
>> This turns out to be because migrate_init() is corrupting the
>> mutex memory when it does "memset(s, 0, sizeof(*s))". Presumably
>> Linux's initialized-mutex is all-zeroes, but OSX's is not.
>
> OK, thanks for finding that; I've just smoke tested the following
> patch and will post it properly after I test it more thoroughly in
> a couple of hours.
I did a patch that was almost identical. It is passing for me virt-test.
Later, Juan.
^ permalink raw reply [flat|nested] 81+ messages in thread
* Re: [Qemu-devel] [PULL 42/57] Page request: Consume pages off the post-copy queue
2015-11-12 15:25 ` Juan Quintela
@ 2015-11-12 15:57 ` Dr. David Alan Gilbert
0 siblings, 0 replies; 81+ messages in thread
From: Dr. David Alan Gilbert @ 2015-11-12 15:57 UTC (permalink / raw)
To: Juan Quintela; +Cc: Amit Shah, Peter Maydell, QEMU Developers
* Juan Quintela (quintela@redhat.com) wrote:
> "Dr. David Alan Gilbert" <dgilbert@redhat.com> wrote:
> > * Peter Maydell (peter.maydell@linaro.org) wrote:
> >> On 12 November 2015 at 13:18, Peter Maydell <peter.maydell@linaro.org> wrote:
> >> > On 12 November 2015 at 13:08, Dr. David Alan Gilbert
> >> > <dgilbert@redhat.com> wrote:
> >> >> OK, can you try a simple migration by hand outside of the test harness;
> >> >> just something simple like:
> >> >>
> >> >> ./bin/qemu-system-x86_64 -M pc -nographic
> >> >> (qemu) migrate "exec: cat > /dev/null"
> >> >>
> >> >> and the same with q35 ?
> >> >
> >> > (qemu) migrate "exec: cat > /dev/null"
> >> > migrate_get_current do init of current_migration 65307
> >> > unqueue_page 65307
> >> > 0 qemu-system-x86_64 0x00000001067c01c3 qemu_mutex_lock + 83
> >>
> >> This turns out to be because migrate_init() is corrupting the
> >> mutex memory when it does "memset(s, 0, sizeof(*s))". Presumably
> >> Linux's initialized-mutex is all-zeroes, but OSX's is not.
> >
> > OK, thanks for finding that; I've just smoke tested the following
> > patch and will post it properly after I test it more thoroughly in
> > a couple of hours.
>
> I did a patch that was almost identical. It is passing for me virt-test.
and the one I posted seems to survive postcopy as well; so looks good.
Dave
>
> Later, Juan.
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
^ permalink raw reply [flat|nested] 81+ messages in thread
* Re: [Qemu-devel] [PULL 42/57] Page request: Consume pages off the post-copy queue
2015-11-12 13:53 ` Peter Maydell
2015-11-12 14:20 ` Dr. David Alan Gilbert
@ 2015-11-12 14:22 ` Juan Quintela
1 sibling, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-12 14:22 UTC (permalink / raw)
To: Peter Maydell; +Cc: Amit Shah, Dr. David Alan Gilbert, QEMU Developers
Peter Maydell <peter.maydell@linaro.org> wrote:
> On 12 November 2015 at 13:18, Peter Maydell <peter.maydell@linaro.org> wrote:
>> On 12 November 2015 at 13:08, Dr. David Alan Gilbert
>> <dgilbert@redhat.com> wrote:
>>> OK, can you try a simple migration by hand outside of the test harness;
>>> just something simple like:
>>>
>>> ./bin/qemu-system-x86_64 -M pc -nographic
>>> (qemu) migrate "exec: cat > /dev/null"
>>>
>>> and the same with q35 ?
>>
>> (qemu) migrate "exec: cat > /dev/null"
>> migrate_get_current do init of current_migration 65307
>> unqueue_page 65307
>> 0 qemu-system-x86_64 0x00000001067c01c3 qemu_mutex_lock + 83
>
> This turns out to be because migrate_init() is corrupting the
> mutex memory when it does "memset(s, 0, sizeof(*s))". Presumably
> Linux's initialized-mutex is all-zeroes, but OSX's is not.
grrr, that is probably the case. Thanks for pinponting this.
>
> thanks
> -- PMM
^ permalink raw reply [flat|nested] 81+ messages in thread
* Re: [Qemu-devel] [PULL 42/57] Page request: Consume pages off the post-copy queue
2015-11-12 12:15 ` Peter Maydell
2015-11-12 12:23 ` Dr. David Alan Gilbert
@ 2015-11-12 13:36 ` Markus Armbruster
2015-11-16 10:10 ` Andreas Färber
1 sibling, 1 reply; 81+ messages in thread
From: Markus Armbruster @ 2015-11-12 13:36 UTC (permalink / raw)
To: Peter Maydell
Cc: Amit Shah, Juan Quintela, Dr. David Alan Gilbert, QEMU Developers
Peter Maydell <peter.maydell@linaro.org> writes:
> On 12 November 2015 at 12:04, Dr. David Alan Gilbert
> <dgilbert@redhat.com> wrote:
>> * Peter Maydell (peter.maydell@linaro.org) wrote:
>>> On 10 November 2015 at 14:25, Juan Quintela <quintela@redhat.com> wrote:
>>> > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
>>> >
>>> > When transmitting RAM pages, consume pages that have been queued by
>>> > MIG_RPCOMM_REQPAGE commands and send them ahead of normal page scanning.
>>> >
>>> > Note:
>>> > a) After a queued page the linear walk carries on from after the
>>> > unqueued page; there is a reasonable chance that the destination
>>> > was about to ask for other closeby pages anyway.
>>> >
>>> > b) We have to be careful of any assumptions that the page walking
>>> > code makes, in particular it does some short cuts on its first linear
>>> > walk that break as soon as we do a queued page.
>>> >
>>> > c) We have to be careful to not break up host-page size chunks, since
>>> > this makes it harder to place the pages on the destination.
>>> >
>>> > Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
>>> > Reviewed-by: Juan Quintela <quintela@redhat.com>
>>> > Signed-off-by: Juan Quintela <quintela@redhat.com>
>>>
>>> I've just discovered that this is causing 'make check' failures on
>>> my OSX host (unfortunately something in my setup is causing
>>> 'make check' failures to not always cause a build failure, so I
>>> didn't notice earlier):
>>
>> It's only failing on OSX? Every time or only sometimes?
>
> Only OSX, and always. I think OSX is pickier about mutexes really
> needing to be initialized before use.
>
>> If you can find a way to get a backtrace off that qemu_mutex_lock case
>> that would be great; I'd assume the later errors are the fall out from that.
>
> I'll have a look after lunch, but it's usually painful to get a
> backtrace out of this kind of qtest, because it's clearly starting
> a whole pile of QEMUs and there's no way I know of to say "only
> run a few of these tests, not the whole huge pile".
Not sure this helps, but here goes anyway: run the make with V=1, fish
out the gtester line, add -p /name/of/the/test. Here's an example from
my shell history:
$ MALLOC_PERTURB_=${MALLOC_PERTURB_:-$((RANDOM % 255 + 1))} gtester -k --verbose -m=quick -p /dicts/large_dict tests/check-qjson
^ permalink raw reply [flat|nested] 81+ messages in thread* Re: [Qemu-devel] [PULL 42/57] Page request: Consume pages off the post-copy queue
2015-11-12 13:36 ` Markus Armbruster
@ 2015-11-16 10:10 ` Andreas Färber
0 siblings, 0 replies; 81+ messages in thread
From: Andreas Färber @ 2015-11-16 10:10 UTC (permalink / raw)
To: Markus Armbruster, Peter Maydell
Cc: Amit Shah, QEMU Developers, Dr. David Alan Gilbert, Juan Quintela
Am 12.11.2015 um 14:36 schrieb Markus Armbruster:
> Peter Maydell <peter.maydell@linaro.org> writes:
>
>> [...] it's usually painful to get a
>> backtrace out of this kind of qtest, because it's clearly starting
>> a whole pile of QEMUs and there's no way I know of to say "only
>> run a few of these tests, not the whole huge pile".
>
> Not sure this helps, but here goes anyway: run the make with V=1, fish
> out the gtester line, add -p /name/of/the/test. Here's an example from
> my shell history:
>
> $ MALLOC_PERTURB_=${MALLOC_PERTURB_:-$((RANDOM % 255 + 1))} gtester -k --verbose -m=quick -p /dicts/large_dict tests/check-qjson
You can just run the test from the command line. For QTests you also
need to pass a variable telling it which QEMU binary to use and since
recently also which qemu-img or so.
If someone has an idea how we could implement make
check-qtest-<target>-<testname> or check-unit-<testname> that would be
appreciated. check-qtest-<testname> would seem to collide with our
wildcard handling of targets, but might be handy, too.
Regards,
Andreas
--
SUSE Linux GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Felix Imendörffer, Jane Smithard, Graham Norton; HRB 21284 (AG Nürnberg)
^ permalink raw reply [flat|nested] 81+ messages in thread
* [Qemu-devel] [PULL 43/57] postcopy_ram.c: place_page and helpers
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (41 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 42/57] Page request: Consume pages off the post-copy queue Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 44/57] Postcopy: Use helpers to map pages during migration Juan Quintela
` (14 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
postcopy_place_page (etc) provide a way for postcopy to place a page
into guests memory atomically (using the copy ioctl on the ufd).
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/migration/migration.h | 1 +
include/migration/postcopy-ram.h | 21 ++++++++
migration/postcopy-ram.c | 100 +++++++++++++++++++++++++++++++++++++++
trace-events | 2 +
4 files changed, 124 insertions(+)
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 1491bf3..a48471e 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -96,6 +96,7 @@ struct MigrationIncomingState {
int userfault_fd;
QEMUFile *to_src_file;
QemuMutex rp_mutex; /* We send replies from multiple threads */
+ void *postcopy_tmp_page;
/* See savevm.c */
LoadStateEntry_Head loadvm_handlers;
diff --git a/include/migration/postcopy-ram.h b/include/migration/postcopy-ram.h
index b10c03d..d7c292f 100644
--- a/include/migration/postcopy-ram.h
+++ b/include/migration/postcopy-ram.h
@@ -69,4 +69,25 @@ void postcopy_discard_send_range(MigrationState *ms, PostcopyDiscardState *pds,
void postcopy_discard_send_finish(MigrationState *ms,
PostcopyDiscardState *pds);
+/*
+ * Place a page (from) at (host) efficiently
+ * There are restrictions on how 'from' must be mapped, in general best
+ * to use other postcopy_ routines to allocate.
+ * returns 0 on success
+ */
+int postcopy_place_page(MigrationIncomingState *mis, void *host, void *from);
+
+/*
+ * Place a zero page at (host) atomically
+ * returns 0 on success
+ */
+int postcopy_place_page_zero(MigrationIncomingState *mis, void *host);
+
+/*
+ * Allocate a page of memory that can be mapped at a later point in time
+ * using postcopy_place_page
+ * Returns: Pointer to allocated page
+ */
+void *postcopy_get_tmp_page(MigrationIncomingState *mis);
+
#endif
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index 3110b2a..58492c0 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -272,6 +272,10 @@ int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis)
return -1;
}
+ if (mis->postcopy_tmp_page) {
+ munmap(mis->postcopy_tmp_page, getpagesize());
+ mis->postcopy_tmp_page = NULL;
+ }
return 0;
}
@@ -338,6 +342,83 @@ int postcopy_ram_enable_notify(MigrationIncomingState *mis)
return 0;
}
+/*
+ * Place a host page (from) at (host) atomically
+ * returns 0 on success
+ */
+int postcopy_place_page(MigrationIncomingState *mis, void *host, void *from)
+{
+ struct uffdio_copy copy_struct;
+
+ copy_struct.dst = (uint64_t)(uintptr_t)host;
+ copy_struct.src = (uint64_t)(uintptr_t)from;
+ copy_struct.len = getpagesize();
+ copy_struct.mode = 0;
+
+ /* copy also acks to the kernel waking the stalled thread up
+ * TODO: We can inhibit that ack and only do it if it was requested
+ * which would be slightly cheaper, but we'd have to be careful
+ * of the order of updating our page state.
+ */
+ if (ioctl(mis->userfault_fd, UFFDIO_COPY, ©_struct)) {
+ int e = errno;
+ error_report("%s: %s copy host: %p from: %p",
+ __func__, strerror(e), host, from);
+
+ return -e;
+ }
+
+ trace_postcopy_place_page(host);
+ return 0;
+}
+
+/*
+ * Place a zero page at (host) atomically
+ * returns 0 on success
+ */
+int postcopy_place_page_zero(MigrationIncomingState *mis, void *host)
+{
+ struct uffdio_zeropage zero_struct;
+
+ zero_struct.range.start = (uint64_t)(uintptr_t)host;
+ zero_struct.range.len = getpagesize();
+ zero_struct.mode = 0;
+
+ if (ioctl(mis->userfault_fd, UFFDIO_ZEROPAGE, &zero_struct)) {
+ int e = errno;
+ error_report("%s: %s zero host: %p",
+ __func__, strerror(e), host);
+
+ return -e;
+ }
+
+ trace_postcopy_place_page_zero(host);
+ return 0;
+}
+
+/*
+ * Returns a target page of memory that can be mapped at a later point in time
+ * using postcopy_place_page
+ * The same address is used repeatedly, postcopy_place_page just takes the
+ * backing page away.
+ * Returns: Pointer to allocated page
+ *
+ */
+void *postcopy_get_tmp_page(MigrationIncomingState *mis)
+{
+ if (!mis->postcopy_tmp_page) {
+ mis->postcopy_tmp_page = mmap(NULL, getpagesize(),
+ PROT_READ | PROT_WRITE, MAP_PRIVATE |
+ MAP_ANONYMOUS, -1, 0);
+ if (!mis->postcopy_tmp_page) {
+ error_report("%s: %s", __func__, strerror(errno));
+ return NULL;
+ }
+ }
+
+ return mis->postcopy_tmp_page;
+}
+
#else
/* No target OS support, stubs just fail */
bool postcopy_ram_supported_by_host(void)
@@ -370,6 +451,25 @@ int postcopy_ram_enable_notify(MigrationIncomingState *mis)
assert(0);
return -1;
}
+
+int postcopy_place_page(MigrationIncomingState *mis, void *host, void *from)
+{
+ assert(0);
+ return -1;
+}
+
+int postcopy_place_page_zero(MigrationIncomingState *mis, void *host)
+{
+ assert(0);
+ return -1;
+}
+
+void *postcopy_get_tmp_page(MigrationIncomingState *mis)
+{
+ assert(0);
+ return NULL;
+}
+
#endif
/* ------------------------------------------------------------------------- */
diff --git a/trace-events b/trace-events
index 3df3656..c493f5d 100644
--- a/trace-events
+++ b/trace-events
@@ -1551,6 +1551,8 @@ postcopy_discard_send_range(const char *ramblock, unsigned long start, unsigned
postcopy_ram_discard_range(void *start, size_t length) "%p,+%zx"
postcopy_cleanup_range(const char *ramblock, void *host_addr, size_t offset, size_t length) "%s: %p offset=%zx length=%zx"
postcopy_init_range(const char *ramblock, void *host_addr, size_t offset, size_t length) "%s: %p offset=%zx length=%zx"
+postcopy_place_page(void *host_addr) "host=%p"
+postcopy_place_page_zero(void *host_addr) "host=%p"
# kvm-all.c
kvm_ioctl(int type, void *arg) "type 0x%x, arg %p"
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 44/57] Postcopy: Use helpers to map pages during migration
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (42 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 43/57] postcopy_ram.c: place_page and helpers Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 45/57] postcopy: Check order of received target pages Juan Quintela
` (13 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
In postcopy, the destination guest is running at the same time
as it's receiving pages; as we receive new pages we must put
them into the guests address space atomically to avoid a running
CPU accessing a partially written page.
Use the helpers in postcopy-ram.c to map these pages.
qemu_get_buffer_in_place is used to avoid a copy out of qemu_file
in the case that postcopy is going to do a copy anyway.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
migration/ram.c | 130 +++++++++++++++++++++++++++++++++++++++++++++++++++++++-
trace-events | 1 +
2 files changed, 130 insertions(+), 1 deletion(-)
diff --git a/migration/ram.c b/migration/ram.c
index d09d5ab..af5f369 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1932,6 +1932,14 @@ static int load_xbzrle(QEMUFile *f, ram_addr_t addr, void *host)
/* Must be called from within a rcu critical section.
* Returns a pointer from within the RCU-protected ram_list.
*/
+/*
+ * Read a RAMBlock ID from the stream f, find the host address of the
+ * start of that block and add on 'offset'
+ *
+ * f: Stream to read from
+ * offset: Offset within the block
+ * flags: Page flags (mostly to see if it's a continuation of previous block)
+ */
static inline void *host_from_stream_offset(QEMUFile *f,
ram_addr_t offset,
int flags)
@@ -2077,11 +2085,126 @@ int ram_postcopy_incoming_init(MigrationIncomingState *mis)
return postcopy_ram_incoming_init(mis, ram_pages);
}
+/*
+ * Called in postcopy mode by ram_load().
+ * rcu_read_lock is taken prior to this being called.
+ */
+static int ram_load_postcopy(QEMUFile *f)
+{
+ int flags = 0, ret = 0;
+ bool place_needed = false;
+ bool matching_page_sizes = qemu_host_page_size == TARGET_PAGE_SIZE;
+ MigrationIncomingState *mis = migration_incoming_get_current();
+ /* Temporary page that is later 'placed' */
+ void *postcopy_host_page = postcopy_get_tmp_page(mis);
+
+ while (!ret && !(flags & RAM_SAVE_FLAG_EOS)) {
+ ram_addr_t addr;
+ void *host = NULL;
+ void *page_buffer = NULL;
+ void *place_source = NULL;
+ uint8_t ch;
+ bool all_zero = false;
+
+ addr = qemu_get_be64(f);
+ flags = addr & ~TARGET_PAGE_MASK;
+ addr &= TARGET_PAGE_MASK;
+
+ trace_ram_load_postcopy_loop((uint64_t)addr, flags);
+ place_needed = false;
+ if (flags & (RAM_SAVE_FLAG_COMPRESS | RAM_SAVE_FLAG_PAGE)) {
+ host = host_from_stream_offset(f, addr, flags);
+ if (!host) {
+ error_report("Illegal RAM offset " RAM_ADDR_FMT, addr);
+ ret = -EINVAL;
+ break;
+ }
+ page_buffer = host;
+ /*
+ * Postcopy requires that we place whole host pages atomically.
+ * To make it atomic, the data is read into a temporary page
+ * that's moved into place later.
+ * The migration protocol uses, possibly smaller, target-pages
+ * however the source ensures it always sends all the components
+ * of a host page in order.
+ */
+ page_buffer = postcopy_host_page +
+ ((uintptr_t)host & ~qemu_host_page_mask);
+ /* If all TP are zero then we can optimise the place */
+ if (!((uintptr_t)host & ~qemu_host_page_mask)) {
+ all_zero = true;
+ }
+
+ /*
+ * If it's the last part of a host page then we place the host
+ * page
+ */
+ place_needed = (((uintptr_t)host + TARGET_PAGE_SIZE) &
+ ~qemu_host_page_mask) == 0;
+ place_source = postcopy_host_page;
+ }
+
+ switch (flags & ~RAM_SAVE_FLAG_CONTINUE) {
+ case RAM_SAVE_FLAG_COMPRESS:
+ ch = qemu_get_byte(f);
+ memset(page_buffer, ch, TARGET_PAGE_SIZE);
+ if (ch) {
+ all_zero = false;
+ }
+ break;
+
+ case RAM_SAVE_FLAG_PAGE:
+ all_zero = false;
+ if (!place_needed || !matching_page_sizes) {
+ qemu_get_buffer(f, page_buffer, TARGET_PAGE_SIZE);
+ } else {
+ /* Avoids the qemu_file copy during postcopy, which is
+ * going to do a copy later; can only do it when we
+ * do this read in one go (matching page sizes)
+ */
+ qemu_get_buffer_in_place(f, (uint8_t **)&place_source,
+ TARGET_PAGE_SIZE);
+ }
+ break;
+ case RAM_SAVE_FLAG_EOS:
+ /* normal exit */
+ break;
+ default:
+ error_report("Unknown combination of migration flags: %#x"
+ " (postcopy mode)", flags);
+ ret = -EINVAL;
+ }
+
+ if (place_needed) {
+ /* This gets called at the last target page in the host page */
+ if (all_zero) {
+ ret = postcopy_place_page_zero(mis,
+ host + TARGET_PAGE_SIZE -
+ qemu_host_page_size);
+ } else {
+ ret = postcopy_place_page(mis, host + TARGET_PAGE_SIZE -
+ qemu_host_page_size,
+ place_source);
+ }
+ }
+ if (!ret) {
+ ret = qemu_file_get_error(f);
+ }
+ }
+
+ return ret;
+}
+
static int ram_load(QEMUFile *f, void *opaque, int version_id)
{
int flags = 0, ret = 0;
static uint64_t seq_iter;
int len = 0;
+ /*
+ * If system is running in postcopy mode, page inserts to host memory must
+ * be atomic
+ */
+ bool postcopy_running = postcopy_state_get() >= POSTCOPY_INCOMING_LISTENING;
seq_iter++;
@@ -2095,7 +2218,12 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
* critical section.
*/
rcu_read_lock();
- while (!ret && !(flags & RAM_SAVE_FLAG_EOS)) {
+
+ if (postcopy_running) {
+ ret = ram_load_postcopy(f);
+ }
+
+ while (!postcopy_running && !ret && !(flags & RAM_SAVE_FLAG_EOS)) {
ram_addr_t addr, total_ram_bytes;
void *host = NULL;
uint8_t ch;
diff --git a/trace-events b/trace-events
index c493f5d..ad7afcb 100644
--- a/trace-events
+++ b/trace-events
@@ -1257,6 +1257,7 @@ get_queued_page_not_dirty(const char *block_name, uint64_t tmp_offset, uint64_t
migration_bitmap_sync_start(void) ""
migration_bitmap_sync_end(uint64_t dirty_pages) "dirty_pages %" PRIu64""
migration_throttle(void) ""
+ram_load_postcopy_loop(uint64_t addr, int flags) "@%" PRIx64 " %x"
ram_postcopy_send_discard_bitmap(void) ""
ram_save_queue_pages(const char *rbname, size_t start, size_t len) "%s: start: %zx len: %zx"
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 45/57] postcopy: Check order of received target pages
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (43 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 44/57] Postcopy: Use helpers to map pages during migration Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 46/57] Don't sync dirty bitmaps in postcopy Juan Quintela
` (12 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Ensure that target pages received within a host page are in order.
This shouldn't trigger, but in the cases where the sender goes
wrong and sends stuff out of order it produces a corruption that's
really nasty to debug.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
migration/ram.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/migration/ram.c b/migration/ram.c
index af5f369..8bf0841 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -2097,6 +2097,7 @@ static int ram_load_postcopy(QEMUFile *f)
MigrationIncomingState *mis = migration_incoming_get_current();
/* Temporary page that is later 'placed' */
void *postcopy_host_page = postcopy_get_tmp_page(mis);
+ void *last_host = NULL;
while (!ret && !(flags & RAM_SAVE_FLAG_EOS)) {
ram_addr_t addr;
@@ -2133,8 +2134,17 @@ static int ram_load_postcopy(QEMUFile *f)
/* If all TP are zero then we can optimise the place */
if (!((uintptr_t)host & ~qemu_host_page_mask)) {
all_zero = true;
+ } else {
+ /* not the 1st TP within the HP */
+ if (host != (last_host + TARGET_PAGE_SIZE)) {
+ error_report("Non-sequential target page %p/%p\n",
+ host, last_host);
+ ret = -EINVAL;
+ break;
+ }
}
+
/*
* If it's the last part of a host page then we place the host
* page
@@ -2143,6 +2153,7 @@ static int ram_load_postcopy(QEMUFile *f)
~qemu_host_page_mask) == 0;
place_source = postcopy_host_page;
}
+ last_host = host;
switch (flags & ~RAM_SAVE_FLAG_CONTINUE) {
case RAM_SAVE_FLAG_COMPRESS:
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 46/57] Don't sync dirty bitmaps in postcopy
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (44 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 45/57] postcopy: Check order of received target pages Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 47/57] Don't iterate on precopy-only devices during postcopy Juan Quintela
` (11 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Once we're in postcopy the source processors are stopped and memory
shouldn't change any more, so there's no need to look at the dirty
map.
There are two notes to this:
1) If we do resync and a page had changed then the page would get
sent again, which the destination wouldn't allow (since it might
have also modified the page)
2) Before disabling this I'd seen very rare cases where a page had been
marked dirtied although the memory contents are apparently identical
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
migration/ram.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/migration/ram.c b/migration/ram.c
index 8bf0841..339b001 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1846,7 +1846,9 @@ static int ram_save_complete(QEMUFile *f, void *opaque)
{
rcu_read_lock();
- migration_bitmap_sync();
+ if (!migration_in_postcopy(migrate_get_current())) {
+ migration_bitmap_sync();
+ }
ram_control_before_iterate(f, RAM_CONTROL_FINISH);
@@ -1881,7 +1883,8 @@ static void ram_save_pending(QEMUFile *f, void *opaque, uint64_t max_size,
remaining_size = ram_save_remaining() * TARGET_PAGE_SIZE;
- if (remaining_size < max_size) {
+ if (!migration_in_postcopy(migrate_get_current()) &&
+ remaining_size < max_size) {
qemu_mutex_lock_iothread();
rcu_read_lock();
migration_bitmap_sync();
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 47/57] Don't iterate on precopy-only devices during postcopy
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (45 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 46/57] Don't sync dirty bitmaps in postcopy Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 48/57] Host page!=target page: Cleanup bitmaps Juan Quintela
` (10 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
During the postcopy phase we must not call the iterate method on
precopy-only devices, since they may have done some cleanup during
the _complete call at the end of the precopy phase.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/sysemu/sysemu.h | 2 +-
migration/migration.c | 2 +-
migration/savevm.c | 13 +++++++++++--
3 files changed, 13 insertions(+), 4 deletions(-)
diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index 76a0b36..05d1982 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -109,7 +109,7 @@ bool qemu_savevm_state_blocked(Error **errp);
void qemu_savevm_state_begin(QEMUFile *f,
const MigrationParams *params);
void qemu_savevm_state_header(QEMUFile *f);
-int qemu_savevm_state_iterate(QEMUFile *f);
+int qemu_savevm_state_iterate(QEMUFile *f, bool postcopy);
void qemu_savevm_state_cleanup(void);
void qemu_savevm_state_complete_postcopy(QEMUFile *f);
void qemu_savevm_state_complete_precopy(QEMUFile *f);
diff --git a/migration/migration.c b/migration/migration.c
index 7d64cd3..38d64ea 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1628,7 +1628,7 @@ static void *migration_thread(void *opaque)
continue;
}
/* Just another iteration step */
- qemu_savevm_state_iterate(s->file);
+ qemu_savevm_state_iterate(s->file, entered_postcopy);
} else {
trace_migration_thread_low_pending(pending_size);
migration_completion(s, current_active_state,
diff --git a/migration/savevm.c b/migration/savevm.c
index a7210a2..308b7d1 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -931,7 +931,7 @@ void qemu_savevm_state_begin(QEMUFile *f,
* 0 : We haven't finished, caller have to go again
* 1 : We have finished, we can go to complete phase
*/
-int qemu_savevm_state_iterate(QEMUFile *f)
+int qemu_savevm_state_iterate(QEMUFile *f, bool postcopy)
{
SaveStateEntry *se;
int ret = 1;
@@ -946,6 +946,15 @@ int qemu_savevm_state_iterate(QEMUFile *f)
continue;
}
}
+ /*
+ * In the postcopy phase, any device that doesn't know how to
+ * do postcopy should have saved it's state in the _complete
+ * call that's already run, it might get confused if we call
+ * iterate afterwards.
+ */
+ if (postcopy && !se->ops->save_live_complete_postcopy) {
+ continue;
+ }
if (qemu_file_rate_limit(f)) {
return 0;
}
@@ -1160,7 +1169,7 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp)
qemu_mutex_lock_iothread();
while (qemu_file_get_error(f) == 0) {
- if (qemu_savevm_state_iterate(f) > 0) {
+ if (qemu_savevm_state_iterate(f, false) > 0) {
break;
}
}
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 48/57] Host page!=target page: Cleanup bitmaps
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (46 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 47/57] Don't iterate on precopy-only devices during postcopy Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 49/57] Round up RAMBlock sizes to host page sizes Juan Quintela
` (9 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Prior to the start of postcopy, ensure that everything that will
be transferred later is a whole host-page in size.
This is accomplished by discarding partially transferred host pages
and marking any that are partially dirty as fully dirty.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
migration/ram.c | 172 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 172 insertions(+)
diff --git a/migration/ram.c b/migration/ram.c
index 339b001..62cf42b 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1584,6 +1584,171 @@ static int postcopy_each_ram_send_discard(MigrationState *ms)
}
/*
+ * Helper for postcopy_chunk_hostpages; it's called twice to cleanup
+ * the two bitmaps, that are similar, but one is inverted.
+ *
+ * We search for runs of target-pages that don't start or end on a
+ * host page boundary;
+ * unsent_pass=true: Cleans up partially unsent host pages by searching
+ * the unsentmap
+ * unsent_pass=false: Cleans up partially dirty host pages by searching
+ * the main migration bitmap
+ *
+ */
+static void postcopy_chunk_hostpages_pass(MigrationState *ms, bool unsent_pass,
+ RAMBlock *block,
+ PostcopyDiscardState *pds)
+{
+ unsigned long *bitmap;
+ unsigned long *unsentmap;
+ unsigned int host_ratio = qemu_host_page_size / TARGET_PAGE_SIZE;
+ unsigned long first = block->offset >> TARGET_PAGE_BITS;
+ unsigned long len = block->used_length >> TARGET_PAGE_BITS;
+ unsigned long last = first + (len - 1);
+ unsigned long run_start;
+
+ bitmap = atomic_rcu_read(&migration_bitmap_rcu)->bmap;
+ unsentmap = atomic_rcu_read(&migration_bitmap_rcu)->unsentmap;
+
+ if (unsent_pass) {
+ /* Find a sent page */
+ run_start = find_next_zero_bit(unsentmap, last + 1, first);
+ } else {
+ /* Find a dirty page */
+ run_start = find_next_bit(bitmap, last + 1, first);
+ }
+
+ while (run_start <= last) {
+ bool do_fixup = false;
+ unsigned long fixup_start_addr;
+ unsigned long host_offset;
+
+ /*
+ * If the start of this run of pages is in the middle of a host
+ * page, then we need to fixup this host page.
+ */
+ host_offset = run_start % host_ratio;
+ if (host_offset) {
+ do_fixup = true;
+ run_start -= host_offset;
+ fixup_start_addr = run_start;
+ /* For the next pass */
+ run_start = run_start + host_ratio;
+ } else {
+ /* Find the end of this run */
+ unsigned long run_end;
+ if (unsent_pass) {
+ run_end = find_next_bit(unsentmap, last + 1, run_start + 1);
+ } else {
+ run_end = find_next_zero_bit(bitmap, last + 1, run_start + 1);
+ }
+ /*
+ * If the end isn't at the start of a host page, then the
+ * run doesn't finish at the end of a host page
+ * and we need to discard.
+ */
+ host_offset = run_end % host_ratio;
+ if (host_offset) {
+ do_fixup = true;
+ fixup_start_addr = run_end - host_offset;
+ /*
+ * This host page has gone, the next loop iteration starts
+ * from after the fixup
+ */
+ run_start = fixup_start_addr + host_ratio;
+ } else {
+ /*
+ * No discards on this iteration, next loop starts from
+ * next sent/dirty page
+ */
+ run_start = run_end + 1;
+ }
+ }
+
+ if (do_fixup) {
+ unsigned long page;
+
+ /* Tell the destination to discard this page */
+ if (unsent_pass || !test_bit(fixup_start_addr, unsentmap)) {
+ /* For the unsent_pass we:
+ * discard partially sent pages
+ * For the !unsent_pass (dirty) we:
+ * discard partially dirty pages that were sent
+ * (any partially sent pages were already discarded
+ * by the previous unsent_pass)
+ */
+ postcopy_discard_send_range(ms, pds, fixup_start_addr,
+ host_ratio);
+ }
+
+ /* Clean up the bitmap */
+ for (page = fixup_start_addr;
+ page < fixup_start_addr + host_ratio; page++) {
+ /* All pages in this host page are now not sent */
+ set_bit(page, unsentmap);
+
+ /*
+ * Remark them as dirty, updating the count for any pages
+ * that weren't previously dirty.
+ */
+ migration_dirty_pages += !test_and_set_bit(page, bitmap);
+ }
+ }
+
+ if (unsent_pass) {
+ /* Find the next sent page for the next iteration */
+ run_start = find_next_zero_bit(unsentmap, last + 1,
+ run_start);
+ } else {
+ /* Find the next dirty page for the next iteration */
+ run_start = find_next_bit(bitmap, last + 1, run_start);
+ }
+ }
+}
+
+/*
+ * Utility for the outgoing postcopy code.
+ *
+ * Discard any partially sent host-page size chunks, mark any partially
+ * dirty host-page size chunks as all dirty.
+ *
+ * Returns: 0 on success
+ */
+static int postcopy_chunk_hostpages(MigrationState *ms)
+{
+ struct RAMBlock *block;
+
+ if (qemu_host_page_size == TARGET_PAGE_SIZE) {
+ /* Easy case - TPS==HPS - nothing to be done */
+ return 0;
+ }
+
+ /* Easiest way to make sure we don't resume in the middle of a host-page */
+ last_seen_block = NULL;
+ last_sent_block = NULL;
+ last_offset = 0;
+
+ QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+ unsigned long first = block->offset >> TARGET_PAGE_BITS;
+
+ PostcopyDiscardState *pds =
+ postcopy_discard_send_init(ms, first, block->idstr);
+
+ /* First pass: Discard all partially sent host pages */
+ postcopy_chunk_hostpages_pass(ms, true, block, pds);
+ /*
+ * Second pass: Ensure that all partially dirty host pages are made
+ * fully dirty.
+ */
+ postcopy_chunk_hostpages_pass(ms, false, block, pds);
+
+ postcopy_discard_send_finish(ms, pds);
+ } /* ram_list loop */
+
+ return 0;
+}
+
+/*
* Transmit the set of pages to be discarded after precopy to the target
* these are pages that:
* a) Have been previously transmitted but are now dirty again
@@ -1613,6 +1778,13 @@ int ram_postcopy_send_discard_bitmap(MigrationState *ms)
return -EINVAL;
}
+ /* Deal with TPS != HPS */
+ ret = postcopy_chunk_hostpages(ms);
+ if (ret) {
+ rcu_read_unlock();
+ return ret;
+ }
+
/*
* Update the unsentmap to be unsentmap = unsentmap | dirty
*/
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 49/57] Round up RAMBlock sizes to host page sizes
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (47 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 48/57] Host page!=target page: Cleanup bitmaps Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-12-30 0:26 ` Peter Crosthwaite
2015-11-10 14:25 ` [Qemu-devel] [PULL 50/57] Postcopy; Handle userfault requests Juan Quintela
` (8 subsequent siblings)
57 siblings, 1 reply; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
RAMBlocks that are not a multiple of host pages in length
cause problems for postcopy (I've seen an ACPI table on aarch64
be 5k in length - i.e. 5x target-page), so round RAMBlock sizes
up to a host-page.
This potentially breaks migration compatibility due to changes
in RAMBlock sizes; however:
1) x86 and s390 I think always have host=target page size
2) When I've tried on Power the block sizes already seem aligned.
3) I don't think there's anything else that maintains per-version
machine-types for compatibility.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
exec.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/exec.c b/exec.c
index 36886ee..b09f18b 100644
--- a/exec.c
+++ b/exec.c
@@ -1452,7 +1452,7 @@ int qemu_ram_resize(ram_addr_t base, ram_addr_t newsize, Error **errp)
assert(block);
- newsize = TARGET_PAGE_ALIGN(newsize);
+ newsize = HOST_PAGE_ALIGN(newsize);
if (block->used_length == newsize) {
return 0;
@@ -1596,7 +1596,7 @@ ram_addr_t qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr,
return -1;
}
- size = TARGET_PAGE_ALIGN(size);
+ size = HOST_PAGE_ALIGN(size);
new_block = g_malloc0(sizeof(*new_block));
new_block->mr = mr;
new_block->used_length = size;
@@ -1632,8 +1632,8 @@ ram_addr_t qemu_ram_alloc_internal(ram_addr_t size, ram_addr_t max_size,
ram_addr_t addr;
Error *local_err = NULL;
- size = TARGET_PAGE_ALIGN(size);
- max_size = TARGET_PAGE_ALIGN(max_size);
+ size = HOST_PAGE_ALIGN(size);
+ max_size = HOST_PAGE_ALIGN(max_size);
new_block = g_malloc0(sizeof(*new_block));
new_block->mr = mr;
new_block->resized = resized;
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* Re: [Qemu-devel] [PULL 49/57] Round up RAMBlock sizes to host page sizes
2015-11-10 14:25 ` [Qemu-devel] [PULL 49/57] Round up RAMBlock sizes to host page sizes Juan Quintela
@ 2015-12-30 0:26 ` Peter Crosthwaite
2016-01-04 9:48 ` Dr. David Alan Gilbert
2016-01-06 21:27 ` Paolo Bonzini
0 siblings, 2 replies; 81+ messages in thread
From: Peter Crosthwaite @ 2015-12-30 0:26 UTC (permalink / raw)
To: Juan Quintela, Paolo Bonzini
Cc: Amit Shah, qemu-devel@nongnu.org Developers,
Dr. David Alan Gilbert (git)
On Tue, Nov 10, 2015 at 6:25 AM, Juan Quintela <quintela@redhat.com> wrote:
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
>
> RAMBlocks that are not a multiple of host pages in length
> cause problems for postcopy (I've seen an ACPI table on aarch64
> be 5k in length - i.e. 5x target-page), so round RAMBlock sizes
> up to a host-page.
>
> This potentially breaks migration compatibility due to changes
> in RAMBlock sizes; however:
> 1) x86 and s390 I think always have host=target page size
> 2) When I've tried on Power the block sizes already seem aligned.
> 3) I don't think there's anything else that maintains per-version
> machine-types for compatibility.
>
Is there any reason this shouldn't be converted to
REAL_HOST_PAGE_ALIGN given these restrictions?
I'm thinking about multi-arch, where HOST_PAGE_ALIGN is inaccessible
from exec.c as it is target-arch specific. My previous workaround was
to define the target page size for multi-arch so that TARGET_PAGE_SIZE
was usable but not sure that should go viral to these other defs.
The other approach, is to calculate the lowest common denominator for
the page size accross the multi-arch targets (+ the host) for the
implementation of HOST_PAGE_ALIGN and friends.
Regards,
Peter
> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> Reviewed-by: Juan Quintela <quintela@redhat.com>
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> ---
> exec.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/exec.c b/exec.c
> index 36886ee..b09f18b 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -1452,7 +1452,7 @@ int qemu_ram_resize(ram_addr_t base, ram_addr_t newsize, Error **errp)
>
> assert(block);
>
> - newsize = TARGET_PAGE_ALIGN(newsize);
> + newsize = HOST_PAGE_ALIGN(newsize);
>
> if (block->used_length == newsize) {
> return 0;
> @@ -1596,7 +1596,7 @@ ram_addr_t qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr,
> return -1;
> }
>
> - size = TARGET_PAGE_ALIGN(size);
> + size = HOST_PAGE_ALIGN(size);
> new_block = g_malloc0(sizeof(*new_block));
> new_block->mr = mr;
> new_block->used_length = size;
> @@ -1632,8 +1632,8 @@ ram_addr_t qemu_ram_alloc_internal(ram_addr_t size, ram_addr_t max_size,
> ram_addr_t addr;
> Error *local_err = NULL;
>
> - size = TARGET_PAGE_ALIGN(size);
> - max_size = TARGET_PAGE_ALIGN(max_size);
> + size = HOST_PAGE_ALIGN(size);
> + max_size = HOST_PAGE_ALIGN(max_size);
> new_block = g_malloc0(sizeof(*new_block));
> new_block->mr = mr;
> new_block->resized = resized;
> --
> 2.5.0
>
>
^ permalink raw reply [flat|nested] 81+ messages in thread* Re: [Qemu-devel] [PULL 49/57] Round up RAMBlock sizes to host page sizes
2015-12-30 0:26 ` Peter Crosthwaite
@ 2016-01-04 9:48 ` Dr. David Alan Gilbert
2016-01-06 21:27 ` Paolo Bonzini
1 sibling, 0 replies; 81+ messages in thread
From: Dr. David Alan Gilbert @ 2016-01-04 9:48 UTC (permalink / raw)
To: Peter Crosthwaite
Cc: Amit Shah, Paolo Bonzini, qemu-devel@nongnu.org Developers,
Juan Quintela
* Peter Crosthwaite (crosthwaitepeter@gmail.com) wrote:
> On Tue, Nov 10, 2015 at 6:25 AM, Juan Quintela <quintela@redhat.com> wrote:
> > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> >
> > RAMBlocks that are not a multiple of host pages in length
> > cause problems for postcopy (I've seen an ACPI table on aarch64
> > be 5k in length - i.e. 5x target-page), so round RAMBlock sizes
> > up to a host-page.
> >
> > This potentially breaks migration compatibility due to changes
> > in RAMBlock sizes; however:
> > 1) x86 and s390 I think always have host=target page size
> > 2) When I've tried on Power the block sizes already seem aligned.
> > 3) I don't think there's anything else that maintains per-version
> > machine-types for compatibility.
> >
>
> Is there any reason this shouldn't be converted to
> REAL_HOST_PAGE_ALIGN given these restrictions?
If I remember correctly the only time host_page_size and real_host_page_size
are different is the odd case where host_page_size < target_page_size;
since we need to ensure alignment to the larger of the two, I don't
think it's right to use real_host_page_size, since you might be aligning
to something smaller than target_page_size.
(I don't know if migration already works in that case anyway)
> I'm thinking about multi-arch, where HOST_PAGE_ALIGN is inaccessible
> from exec.c as it is target-arch specific. My previous workaround was
> to define the target page size for multi-arch so that TARGET_PAGE_SIZE
> was usable but not sure that should go viral to these other defs.
Would it help to move qemu_ram_resize elsewhere?
> The other approach, is to calculate the lowest common denominator for
> the page size accross the multi-arch targets (+ the host) for the
> implementation of HOST_PAGE_ALIGN and friends.
I'm not sure I understand what happens to the migration bitmaps in multi-arch;
the bitmaps are one bit per target-page.
Dave
>
> Regards,
> Peter
>
> > Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> > Reviewed-by: Juan Quintela <quintela@redhat.com>
> > Signed-off-by: Juan Quintela <quintela@redhat.com>
> > ---
> > exec.c | 8 ++++----
> > 1 file changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/exec.c b/exec.c
> > index 36886ee..b09f18b 100644
> > --- a/exec.c
> > +++ b/exec.c
> > @@ -1452,7 +1452,7 @@ int qemu_ram_resize(ram_addr_t base, ram_addr_t newsize, Error **errp)
> >
> > assert(block);
> >
> > - newsize = TARGET_PAGE_ALIGN(newsize);
> > + newsize = HOST_PAGE_ALIGN(newsize);
> >
> > if (block->used_length == newsize) {
> > return 0;
> > @@ -1596,7 +1596,7 @@ ram_addr_t qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr,
> > return -1;
> > }
> >
> > - size = TARGET_PAGE_ALIGN(size);
> > + size = HOST_PAGE_ALIGN(size);
> > new_block = g_malloc0(sizeof(*new_block));
> > new_block->mr = mr;
> > new_block->used_length = size;
> > @@ -1632,8 +1632,8 @@ ram_addr_t qemu_ram_alloc_internal(ram_addr_t size, ram_addr_t max_size,
> > ram_addr_t addr;
> > Error *local_err = NULL;
> >
> > - size = TARGET_PAGE_ALIGN(size);
> > - max_size = TARGET_PAGE_ALIGN(max_size);
> > + size = HOST_PAGE_ALIGN(size);
> > + max_size = HOST_PAGE_ALIGN(max_size);
> > new_block = g_malloc0(sizeof(*new_block));
> > new_block->mr = mr;
> > new_block->resized = resized;
> > --
> > 2.5.0
> >
> >
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
^ permalink raw reply [flat|nested] 81+ messages in thread* Re: [Qemu-devel] [PULL 49/57] Round up RAMBlock sizes to host page sizes
2015-12-30 0:26 ` Peter Crosthwaite
2016-01-04 9:48 ` Dr. David Alan Gilbert
@ 2016-01-06 21:27 ` Paolo Bonzini
1 sibling, 0 replies; 81+ messages in thread
From: Paolo Bonzini @ 2016-01-06 21:27 UTC (permalink / raw)
To: Peter Crosthwaite, Juan Quintela
Cc: Amit Shah, qemu-devel@nongnu.org Developers,
Dr. David Alan Gilbert (git)
On 30/12/2015 01:26, Peter Crosthwaite wrote:
> On Tue, Nov 10, 2015 at 6:25 AM, Juan Quintela <quintela@redhat.com> wrote:
>> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
>>
>> RAMBlocks that are not a multiple of host pages in length
>> cause problems for postcopy (I've seen an ACPI table on aarch64
>> be 5k in length - i.e. 5x target-page), so round RAMBlock sizes
>> up to a host-page.
>>
>> This potentially breaks migration compatibility due to changes
>> in RAMBlock sizes; however:
>> 1) x86 and s390 I think always have host=target page size
>> 2) When I've tried on Power the block sizes already seem aligned.
>> 3) I don't think there's anything else that maintains per-version
>> machine-types for compatibility.
>>
>
> Is there any reason this shouldn't be converted to
> REAL_HOST_PAGE_ALIGN given these restrictions?
>
> I'm thinking about multi-arch, where HOST_PAGE_ALIGN is inaccessible
> from exec.c as it is target-arch specific. My previous workaround was
> to define the target page size for multi-arch so that TARGET_PAGE_SIZE
> was usable but not sure that should go viral to these other defs.
host_page_size and host_page_mask are really just MAX(host_page_size,
TARGET_PAGE_SIZE) and MIN(qemu_host_page_mask, TARGET_PAGE_MASK). If
you convert them to macros this way, the hack you use for multi-arch
TARGET_PAGE_SIZE will work transparently for HOST_PAGE_{SIZE,MASK}.
Paolo
^ permalink raw reply [flat|nested] 81+ messages in thread
* [Qemu-devel] [PULL 50/57] Postcopy; Handle userfault requests
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (48 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 49/57] Round up RAMBlock sizes to host page sizes Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 51/57] Start up a postcopy/listener thread ready for incoming page data Juan Quintela
` (7 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
userfaultfd is a Linux syscall that gives an fd that receives a stream
of notifications of accesses to pages registered with it and allows
the program to acknowledge those stalls and tell the accessing
thread to carry on.
We convert the requests from the kernel into messages back to the
source asking for the pages.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/migration/migration.h | 3 +
migration/postcopy-ram.c | 155 +++++++++++++++++++++++++++++++++++++++---
trace-events | 9 +++
3 files changed, 158 insertions(+), 9 deletions(-)
diff --git a/include/migration/migration.h b/include/migration/migration.h
index a48471e..329d535 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -89,11 +89,14 @@ struct MigrationIncomingState {
*/
QemuEvent main_thread_load_event;
+ bool have_fault_thread;
QemuThread fault_thread;
QemuSemaphore fault_thread_sem;
/* For the kernel to send us notifications */
int userfault_fd;
+ /* To tell the fault_thread to quit */
+ int userfault_quit_fd;
QEMUFile *to_src_file;
QemuMutex rp_mutex; /* We send replies from multiple threads */
void *postcopy_tmp_page;
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index 58492c0..4f1e329 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -51,6 +51,8 @@ struct PostcopyDiscardState {
*/
#if defined(__linux__)
+#include <poll.h>
+#include <sys/eventfd.h>
#include <sys/mman.h>
#include <sys/ioctl.h>
#include <sys/syscall.h>
@@ -267,15 +269,41 @@ int postcopy_ram_incoming_init(MigrationIncomingState *mis, size_t ram_pages)
*/
int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis)
{
- /* TODO: Join the fault thread once we're sure it will exit */
- if (qemu_ram_foreach_block(cleanup_range, mis)) {
- return -1;
+ trace_postcopy_ram_incoming_cleanup_entry();
+
+ if (mis->have_fault_thread) {
+ uint64_t tmp64;
+
+ if (qemu_ram_foreach_block(cleanup_range, mis)) {
+ return -1;
+ }
+ /*
+ * Tell the fault_thread to exit, it's an eventfd that should
+ * currently be at 0, we're going to increment it to 1
+ */
+ tmp64 = 1;
+ if (write(mis->userfault_quit_fd, &tmp64, 8) == 8) {
+ trace_postcopy_ram_incoming_cleanup_join();
+ qemu_thread_join(&mis->fault_thread);
+ } else {
+ /* Not much we can do here, but may as well report it */
+ error_report("%s: incrementing userfault_quit_fd: %s", __func__,
+ strerror(errno));
+ }
+ trace_postcopy_ram_incoming_cleanup_closeuf();
+ close(mis->userfault_fd);
+ close(mis->userfault_quit_fd);
+ mis->have_fault_thread = false;
}
+ postcopy_state_set(POSTCOPY_INCOMING_END);
+ migrate_send_rp_shut(mis, qemu_file_get_error(mis->from_src_file) != 0);
+
if (mis->postcopy_tmp_page) {
munmap(mis->postcopy_tmp_page, getpagesize());
mis->postcopy_tmp_page = NULL;
}
+ trace_postcopy_ram_incoming_cleanup_exit();
return 0;
}
@@ -314,31 +342,140 @@ static int ram_block_enable_notify(const char *block_name, void *host_addr,
static void *postcopy_ram_fault_thread(void *opaque)
{
MigrationIncomingState *mis = opaque;
+ struct uffd_msg msg;
+ int ret;
+ size_t hostpagesize = getpagesize();
+ RAMBlock *rb = NULL;
+ RAMBlock *last_rb = NULL; /* last RAMBlock we sent part of */
- fprintf(stderr, "postcopy_ram_fault_thread\n");
- /* TODO: In later patch */
+ trace_postcopy_ram_fault_thread_entry();
qemu_sem_post(&mis->fault_thread_sem);
- while (1) {
- /* TODO: In later patch */
+
+ while (true) {
+ ram_addr_t rb_offset;
+ ram_addr_t in_raspace;
+ struct pollfd pfd[2];
+
+ /*
+ * We're mainly waiting for the kernel to give us a faulting HVA,
+ * however we can be told to quit via userfault_quit_fd which is
+ * an eventfd
+ */
+ pfd[0].fd = mis->userfault_fd;
+ pfd[0].events = POLLIN;
+ pfd[0].revents = 0;
+ pfd[1].fd = mis->userfault_quit_fd;
+ pfd[1].events = POLLIN; /* Waiting for eventfd to go positive */
+ pfd[1].revents = 0;
+
+ if (poll(pfd, 2, -1 /* Wait forever */) == -1) {
+ error_report("%s: userfault poll: %s", __func__, strerror(errno));
+ break;
+ }
+
+ if (pfd[1].revents) {
+ trace_postcopy_ram_fault_thread_quit();
+ break;
+ }
+
+ ret = read(mis->userfault_fd, &msg, sizeof(msg));
+ if (ret != sizeof(msg)) {
+ if (errno == EAGAIN) {
+ /*
+ * if a wake up happens on the other thread just after
+ * the poll, there is nothing to read.
+ */
+ continue;
+ }
+ if (ret < 0) {
+ error_report("%s: Failed to read full userfault message: %s",
+ __func__, strerror(errno));
+ break;
+ } else {
+ error_report("%s: Read %d bytes from userfaultfd expected %zd",
+ __func__, ret, sizeof(msg));
+ break; /* Lost alignment, don't know what we'd read next */
+ }
+ }
+ if (msg.event != UFFD_EVENT_PAGEFAULT) {
+ error_report("%s: Read unexpected event %ud from userfaultfd",
+ __func__, msg.event);
+ continue; /* It's not a page fault, shouldn't happen */
+ }
+
+ rb = qemu_ram_block_from_host(
+ (void *)(uintptr_t)msg.arg.pagefault.address,
+ true, &in_raspace, &rb_offset);
+ if (!rb) {
+ error_report("postcopy_ram_fault_thread: Fault outside guest: %"
+ PRIx64, (uint64_t)msg.arg.pagefault.address);
+ break;
+ }
+
+ rb_offset &= ~(hostpagesize - 1);
+ trace_postcopy_ram_fault_thread_request(msg.arg.pagefault.address,
+ qemu_ram_get_idstr(rb),
+ rb_offset);
+
+ /*
+ * Send the request to the source - we want to request one
+ * of our host page sizes (which is >= TPS)
+ */
+ if (rb != last_rb) {
+ last_rb = rb;
+ migrate_send_rp_req_pages(mis, qemu_ram_get_idstr(rb),
+ rb_offset, hostpagesize);
+ } else {
+ /* Save some space */
+ migrate_send_rp_req_pages(mis, NULL,
+ rb_offset, hostpagesize);
+ }
}
-
+ trace_postcopy_ram_fault_thread_exit();
return NULL;
}
int postcopy_ram_enable_notify(MigrationIncomingState *mis)
{
- /* Create the fault handler thread and wait for it to be ready */
+ /* Open the fd for the kernel to give us userfaults */
+ mis->userfault_fd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK);
+ if (mis->userfault_fd == -1) {
+ error_report("%s: Failed to open userfault fd: %s", __func__,
+ strerror(errno));
+ return -1;
+ }
+
+ /*
+ * Although the host check already tested the API, we need to
+ * do the check again as an ABI handshake on the new fd.
+ */
+ if (!ufd_version_check(mis->userfault_fd)) {
+ return -1;
+ }
+
+ /* Now an eventfd we use to tell the fault-thread to quit */
+ mis->userfault_quit_fd = eventfd(0, EFD_CLOEXEC);
+ if (mis->userfault_quit_fd == -1) {
+ error_report("%s: Opening userfault_quit_fd: %s", __func__,
+ strerror(errno));
+ close(mis->userfault_fd);
+ return -1;
+ }
+
qemu_sem_init(&mis->fault_thread_sem, 0);
qemu_thread_create(&mis->fault_thread, "postcopy/fault",
postcopy_ram_fault_thread, mis, QEMU_THREAD_JOINABLE);
qemu_sem_wait(&mis->fault_thread_sem);
qemu_sem_destroy(&mis->fault_thread_sem);
+ mis->have_fault_thread = true;
/* Mark so that we get notified of accesses to unwritten areas */
if (qemu_ram_foreach_block(ram_block_enable_notify, mis)) {
return -1;
}
+ trace_postcopy_ram_enable_notify();
+
return 0;
}
diff --git a/trace-events b/trace-events
index ad7afcb..60be299 100644
--- a/trace-events
+++ b/trace-events
@@ -1554,6 +1554,15 @@ postcopy_cleanup_range(const char *ramblock, void *host_addr, size_t offset, siz
postcopy_init_range(const char *ramblock, void *host_addr, size_t offset, size_t length) "%s: %p offset=%zx length=%zx"
postcopy_place_page(void *host_addr) "host=%p"
postcopy_place_page_zero(void *host_addr) "host=%p"
+postcopy_ram_enable_notify(void) ""
+postcopy_ram_fault_thread_entry(void) ""
+postcopy_ram_fault_thread_exit(void) ""
+postcopy_ram_fault_thread_quit(void) ""
+postcopy_ram_fault_thread_request(uint64_t hostaddr, const char *ramblock, size_t offset) "Request for HVA=%" PRIx64 " rb=%s offset=%zx"
+postcopy_ram_incoming_cleanup_closeuf(void) ""
+postcopy_ram_incoming_cleanup_entry(void) ""
+postcopy_ram_incoming_cleanup_exit(void) ""
+postcopy_ram_incoming_cleanup_join(void) ""
# kvm-all.c
kvm_ioctl(int type, void *arg) "type 0x%x, arg %p"
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 51/57] Start up a postcopy/listener thread ready for incoming page data
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (49 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 50/57] Postcopy; Handle userfault requests Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 52/57] postcopy: Wire up loadvm_postcopy_handle_ commands Juan Quintela
` (6 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
The loading of a device state (during postcopy) may access guest
memory that's still on the source machine and thus might need
a page fill; split off a separate thread that handles the incoming
page data so that the original incoming migration code can finish
off the device data.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/migration/migration.h | 4 +++
migration/migration.c | 6 ++++
migration/savevm.c | 79 ++++++++++++++++++++++++++++++++++++++++++-
trace-events | 2 ++
4 files changed, 90 insertions(+), 1 deletion(-)
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 329d535..fd018b7 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -93,6 +93,10 @@ struct MigrationIncomingState {
QemuThread fault_thread;
QemuSemaphore fault_thread_sem;
+ bool have_listen_thread;
+ QemuThread listen_thread;
+ QemuSemaphore listen_thread_sem;
+
/* For the kernel to send us notifications */
int userfault_fd;
/* To tell the fault_thread to quit */
diff --git a/migration/migration.c b/migration/migration.c
index 38d64ea..db3d2dd 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1441,6 +1441,12 @@ static int postcopy_start(MigrationState *ms, bool *old_vm_running)
goto fail;
}
+ /*
+ * Make sure the receiver can get incoming pages before we send the rest
+ * of the state
+ */
+ qemu_savevm_send_postcopy_listen(fb);
+
qemu_savevm_state_complete_precopy(fb);
qemu_savevm_send_ping(fb, 3);
diff --git a/migration/savevm.c b/migration/savevm.c
index 308b7d1..6ef9e62 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1380,6 +1380,65 @@ static int loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis,
return 0;
}
+/*
+ * Triggered by a postcopy_listen command; this thread takes over reading
+ * the input stream, leaving the main thread free to carry on loading the rest
+ * of the device state (from RAM).
+ * (TODO:This could do with being in a postcopy file - but there again it's
+ * just another input loop, not that postcopy specific)
+ */
+static void *postcopy_ram_listen_thread(void *opaque)
+{
+ QEMUFile *f = opaque;
+ MigrationIncomingState *mis = migration_incoming_get_current();
+ int load_res;
+
+ qemu_sem_post(&mis->listen_thread_sem);
+ trace_postcopy_ram_listen_thread_start();
+
+ /*
+ * Because we're a thread and not a coroutine we can't yield
+ * in qemu_file, and thus we must be blocking now.
+ */
+ qemu_file_set_blocking(f, true);
+ load_res = qemu_loadvm_state_main(f, mis);
+ /* And non-blocking again so we don't block in any cleanup */
+ qemu_file_set_blocking(f, false);
+
+ trace_postcopy_ram_listen_thread_exit();
+ if (load_res < 0) {
+ error_report("%s: loadvm failed: %d", __func__, load_res);
+ qemu_file_set_error(f, load_res);
+ } else {
+ /*
+ * This looks good, but it's possible that the device loading in the
+ * main thread hasn't finished yet, and so we might not be in 'RUN'
+ * state yet; wait for the end of the main thread.
+ */
+ qemu_event_wait(&mis->main_thread_load_event);
+ }
+ postcopy_ram_incoming_cleanup(mis);
+ /*
+ * If everything has worked fine, then the main thread has waited
+ * for us to start, and we're the last use of the mis.
+ * (If something broke then qemu will have to exit anyway since it's
+ * got a bad migration state).
+ */
+ migration_incoming_state_destroy();
+
+ if (load_res < 0) {
+ /*
+ * If something went wrong then we have a bad state so exit;
+ * depending how far we got it might be possible at this point
+ * to leave the guest running and fire MCEs for pages that never
+ * arrived as a desperate recovery step.
+ */
+ exit(EXIT_FAILURE);
+ }
+
+ return NULL;
+}
+
/* After this message we must be able to immediately receive postcopy data */
static int loadvm_postcopy_handle_listen(MigrationIncomingState *mis)
{
@@ -1399,7 +1458,20 @@ static int loadvm_postcopy_handle_listen(MigrationIncomingState *mis)
return -1;
}
- /* TODO start up the postcopy listening thread */
+ if (mis->have_listen_thread) {
+ error_report("CMD_POSTCOPY_RAM_LISTEN already has a listen thread");
+ return -1;
+ }
+
+ mis->have_listen_thread = true;
+ /* Start up the listening thread and wait for it to signal ready */
+ qemu_sem_init(&mis->listen_thread_sem, 0);
+ qemu_thread_create(&mis->listen_thread, "postcopy/listen",
+ postcopy_ram_listen_thread, mis->from_src_file,
+ QEMU_THREAD_JOINABLE);
+ qemu_sem_wait(&mis->listen_thread_sem);
+ qemu_sem_destroy(&mis->listen_thread_sem);
+
return 0;
}
@@ -1745,6 +1817,11 @@ int qemu_loadvm_state(QEMUFile *f)
trace_qemu_loadvm_state_post_main(ret);
+ if (mis->have_listen_thread) {
+ /* Listen thread still going, can't clean up yet */
+ return ret;
+ }
+
if (ret == 0) {
ret = qemu_file_get_error(f);
}
diff --git a/trace-events b/trace-events
index 60be299..1130292 100644
--- a/trace-events
+++ b/trace-events
@@ -1220,6 +1220,8 @@ loadvm_postcopy_ram_handle_discard_end(void) ""
loadvm_postcopy_ram_handle_discard_header(const char *ramid, uint16_t len) "%s: %ud"
loadvm_process_command(uint16_t com, uint16_t len) "com=0x%x len=%d"
loadvm_process_command_ping(uint32_t val) "%x"
+postcopy_ram_listen_thread_exit(void) ""
+postcopy_ram_listen_thread_start(void) ""
qemu_savevm_send_postcopy_advise(void) ""
qemu_savevm_send_postcopy_ram_discard(const char *id, uint16_t len) "%s: %ud"
savevm_command_send(uint16_t command, uint16_t len) "com=0x%x len=%d"
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 52/57] postcopy: Wire up loadvm_postcopy_handle_ commands
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (50 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 51/57] Start up a postcopy/listener thread ready for incoming page data Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 53/57] Postcopy: Mark nohugepage before discard Juan Quintela
` (5 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Wire up more of the handlers for the commands on the destination side,
in particular loadvm_postcopy_handle_run now has enough to start the
guest running.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
migration/savevm.c | 28 +++++++++++++++++++++++++++-
trace-events | 2 ++
2 files changed, 29 insertions(+), 1 deletion(-)
diff --git a/migration/savevm.c b/migration/savevm.c
index 6ef9e62..eb32199 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1479,12 +1479,33 @@ static int loadvm_postcopy_handle_listen(MigrationIncomingState *mis)
static int loadvm_postcopy_handle_run(MigrationIncomingState *mis)
{
PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_RUNNING);
+ Error *local_err = NULL;
+
trace_loadvm_postcopy_handle_run();
if (ps != POSTCOPY_INCOMING_LISTENING) {
error_report("CMD_POSTCOPY_RUN in wrong postcopy state (%d)", ps);
return -1;
}
+ /* TODO we should move all of this lot into postcopy_ram.c or a shared code
+ * in migration.c
+ */
+ cpu_synchronize_all_post_init();
+
+ qemu_announce_self();
+
+ /* Make sure all file formats flush their mutable metadata */
+ bdrv_invalidate_cache_all(&local_err);
+ if (local_err) {
+ error_report_err(local_err);
+ return -1;
+ }
+
+ trace_loadvm_postcopy_handle_run_cpu_sync();
+ cpu_synchronize_all_post_init();
+
+ trace_loadvm_postcopy_handle_run_vmstart();
+
if (autostart) {
/* Hold onto your hats, starting the CPU */
vm_start();
@@ -1493,7 +1514,12 @@ static int loadvm_postcopy_handle_run(MigrationIncomingState *mis)
runstate_set(RUN_STATE_PAUSED);
}
- return 0;
+ /* We need to finish reading the stream from the package
+ * and also stop reading anything more from the stream that loaded the
+ * package (since it's now being read by the listener thread).
+ * LOADVM_QUIT will quit all the layers of nested loadvm loops.
+ */
+ return LOADVM_QUIT;
}
/**
diff --git a/trace-events b/trace-events
index 1130292..a89778f 100644
--- a/trace-events
+++ b/trace-events
@@ -1215,6 +1215,8 @@ loadvm_handle_cmd_packaged_received(int ret) "%d"
loadvm_postcopy_handle_advise(void) ""
loadvm_postcopy_handle_listen(void) ""
loadvm_postcopy_handle_run(void) ""
+loadvm_postcopy_handle_run_cpu_sync(void) ""
+loadvm_postcopy_handle_run_vmstart(void) ""
loadvm_postcopy_ram_handle_discard(void) ""
loadvm_postcopy_ram_handle_discard_end(void) ""
loadvm_postcopy_ram_handle_discard_header(const char *ramid, uint16_t len) "%s: %ud"
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 53/57] Postcopy: Mark nohugepage before discard
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (51 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 52/57] postcopy: Wire up loadvm_postcopy_handle_ commands Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 54/57] End of migration for postcopy Juan Quintela
` (4 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Prior to servicing userfault requests we must ensure we've not got
huge pages in the area that might include non-transferred memory,
since a hugepage could incorrectly mark the whole huge page as present.
We mark the area as non-huge page (nhp) just before we perform
discards; the discard code now tells us to discard any areas
that haven't been sent (as well as any that are redirtied);
any already formed transparent-huge-pages get fragmented
by this discard process if they cotnain any discards.
Transparent huge pages that have been entirely transferred
and don't contain any discards are not broken by this mechanism;
they stay as huge pages.
By starting postcopy after a full precopy pass, many of the pages
then stay as huge pages; this is important for maintaining performance
after the end of the migration.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/migration/postcopy-ram.h | 6 +++++
migration/postcopy-ram.c | 47 +++++++++++++++++++++++++++++++++++++---
migration/savevm.c | 9 +++++++-
trace-events | 1 +
4 files changed, 59 insertions(+), 4 deletions(-)
diff --git a/include/migration/postcopy-ram.h b/include/migration/postcopy-ram.h
index d7c292f..b6a7491 100644
--- a/include/migration/postcopy-ram.h
+++ b/include/migration/postcopy-ram.h
@@ -41,6 +41,12 @@ int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis);
int postcopy_ram_discard_range(MigrationIncomingState *mis, uint8_t *start,
size_t length);
+/*
+ * Userfault requires us to mark RAM as NOHUGEPAGE prior to discard
+ * however leaving it until after precopy means that most of the precopy
+ * data is still THPd
+ */
+int postcopy_ram_prepare_discard(MigrationIncomingState *mis);
/*
* Called at the start of each RAMBlock by the bitmap code.
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index 4f1e329..8e107fe 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -226,12 +226,10 @@ static int cleanup_range(const char *block_name, void *host_addr,
* We turned off hugepage for the precopy stage with postcopy enabled
* we can turn it back on now.
*/
-#ifdef MADV_HUGEPAGE
- if (madvise(host_addr, length, MADV_HUGEPAGE)) {
+ if (qemu_madvise(host_addr, length, QEMU_MADV_HUGEPAGE)) {
error_report("%s HUGEPAGE: %s", __func__, strerror(errno));
return -1;
}
-#endif
/*
* We can also turn off userfault now since we should have all the
@@ -308,6 +306,43 @@ int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis)
}
/*
+ * Disable huge pages on an area
+ */
+static int nhp_range(const char *block_name, void *host_addr,
+ ram_addr_t offset, ram_addr_t length, void *opaque)
+{
+ trace_postcopy_nhp_range(block_name, host_addr, offset, length);
+
+ /*
+ * Before we do discards we need to ensure those discards really
+ * do delete areas of the page, even if THP thinks a hugepage would
+ * be a good idea, so force hugepages off.
+ */
+ if (qemu_madvise(host_addr, length, QEMU_MADV_NOHUGEPAGE)) {
+ error_report("%s: NOHUGEPAGE: %s", __func__, strerror(errno));
+ return -1;
+ }
+
+ return 0;
+}
+
+/*
+ * Userfault requires us to mark RAM as NOHUGEPAGE prior to discard
+ * however leaving it until after precopy means that most of the precopy
+ * data is still THPd
+ */
+int postcopy_ram_prepare_discard(MigrationIncomingState *mis)
+{
+ if (qemu_ram_foreach_block(nhp_range, mis)) {
+ return -1;
+ }
+
+ postcopy_state_set(POSTCOPY_INCOMING_DISCARD);
+
+ return 0;
+}
+
+/*
* Mark the given area of RAM as requiring notification to unwritten areas
* Used as a callback on qemu_ram_foreach_block.
* host_addr: Base of area to mark
@@ -583,6 +618,12 @@ int postcopy_ram_discard_range(MigrationIncomingState *mis, uint8_t *start,
return -1;
}
+int postcopy_ram_prepare_discard(MigrationIncomingState *mis)
+{
+ assert(0);
+ return -1;
+}
+
int postcopy_ram_enable_notify(MigrationIncomingState *mis)
{
assert(0);
diff --git a/migration/savevm.c b/migration/savevm.c
index eb32199..0596f7b 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1316,7 +1316,7 @@ static int loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis,
switch (ps) {
case POSTCOPY_INCOMING_ADVISE:
/* 1st discard */
- tmp = 0; /* TODO: later patch postcopy_ram_prepare_discard(mis); */
+ tmp = postcopy_ram_prepare_discard(mis);
if (tmp) {
return tmp;
}
@@ -1448,6 +1448,13 @@ static int loadvm_postcopy_handle_listen(MigrationIncomingState *mis)
error_report("CMD_POSTCOPY_LISTEN in wrong postcopy state (%d)", ps);
return -1;
}
+ if (ps == POSTCOPY_INCOMING_ADVISE) {
+ /*
+ * A rare case, we entered listen without having to do any discards,
+ * so do the setup that's normally done at the time of the 1st discard.
+ */
+ postcopy_ram_prepare_discard(mis);
+ }
/*
* Sensitise RAM - can now generate requests for blocks that don't exist
diff --git a/trace-events b/trace-events
index a89778f..452435d 100644
--- a/trace-events
+++ b/trace-events
@@ -1556,6 +1556,7 @@ postcopy_discard_send_range(const char *ramblock, unsigned long start, unsigned
postcopy_ram_discard_range(void *start, size_t length) "%p,+%zx"
postcopy_cleanup_range(const char *ramblock, void *host_addr, size_t offset, size_t length) "%s: %p offset=%zx length=%zx"
postcopy_init_range(const char *ramblock, void *host_addr, size_t offset, size_t length) "%s: %p offset=%zx length=%zx"
+postcopy_nhp_range(const char *ramblock, void *host_addr, size_t offset, size_t length) "%s: %p offset=%zx length=%zx"
postcopy_place_page(void *host_addr) "host=%p"
postcopy_place_page_zero(void *host_addr) "host=%p"
postcopy_ram_enable_notify(void) ""
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 54/57] End of migration for postcopy
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (52 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 53/57] Postcopy: Mark nohugepage before discard Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 55/57] Disable mlock around incoming postcopy Juan Quintela
` (3 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Tweak the end of migration cleanup; we don't want to close stuff down
at the end of the main stream, since the postcopy is still sending pages
on the other thread.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
migration/migration.c | 26 +++++++++++++++++++++++++-
trace-events | 6 ++++--
2 files changed, 29 insertions(+), 3 deletions(-)
diff --git a/migration/migration.c b/migration/migration.c
index db3d2dd..c5c977e 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -325,13 +325,37 @@ static void process_incoming_migration_co(void *opaque)
{
QEMUFile *f = opaque;
Error *local_err = NULL;
+ MigrationIncomingState *mis;
+ PostcopyState ps;
int ret;
- migration_incoming_state_new(f);
+ mis = migration_incoming_state_new(f);
postcopy_state_set(POSTCOPY_INCOMING_NONE);
migrate_generate_event(MIGRATION_STATUS_ACTIVE);
+
ret = qemu_loadvm_state(f);
+ ps = postcopy_state_get();
+ trace_process_incoming_migration_co_end(ret, ps);
+ if (ps != POSTCOPY_INCOMING_NONE) {
+ if (ps == POSTCOPY_INCOMING_ADVISE) {
+ /*
+ * Where a migration had postcopy enabled (and thus went to advise)
+ * but managed to complete within the precopy period, we can use
+ * the normal exit.
+ */
+ postcopy_ram_incoming_cleanup(mis);
+ } else if (ret >= 0) {
+ /*
+ * Postcopy was started, cleanup should happen at the end of the
+ * postcopy thread.
+ */
+ trace_process_incoming_migration_co_postcopy_end_main();
+ return;
+ }
+ /* Else if something went wrong then just fall out of the normal exit */
+ }
+
qemu_fclose(f);
free_xbzrle_decoded_buf();
migration_incoming_state_destroy();
diff --git a/trace-events b/trace-events
index 452435d..ef6bc41 100644
--- a/trace-events
+++ b/trace-events
@@ -1480,11 +1480,13 @@ source_return_path_thread_entry(void) ""
source_return_path_thread_loop_top(void) ""
source_return_path_thread_pong(uint32_t val) "%x"
source_return_path_thread_shut(uint32_t val) "%x"
-migrate_transferred(uint64_t tranferred, uint64_t time_spent, double bandwidth, uint64_t size) "transferred %" PRIu64 " time_spent %" PRIu64 " bandwidth %g max_size %" PRId64
-migrate_state_too_big(void) ""
migrate_global_state_post_load(const char *state) "loaded state: %s"
migrate_global_state_pre_save(const char *state) "saved state: %s"
migration_thread_low_pending(uint64_t pending) "%" PRIu64
+migrate_state_too_big(void) ""
+migrate_transferred(uint64_t tranferred, uint64_t time_spent, double bandwidth, uint64_t size) "transferred %" PRIu64 " time_spent %" PRIu64 " bandwidth %g max_size %" PRId64
+process_incoming_migration_co_end(int ret, int ps) "ret=%d postcopy-state=%d"
+process_incoming_migration_co_postcopy_end_main(void) ""
# migration/rdma.c
qemu_rdma_accept_incoming_migration(void) ""
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 55/57] Disable mlock around incoming postcopy
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (53 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 54/57] End of migration for postcopy Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 56/57] Inhibit ballooning during postcopy Juan Quintela
` (2 subsequent siblings)
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Userfault doesn't work with mlock; mlock is designed to nail down pages
so they don't move, userfault is designed to tell you when they're not
there.
munlock the pages we userfault protect before postcopy.
mlock everything again at the end if mlock is enabled.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
include/sysemu/sysemu.h | 1 +
migration/postcopy-ram.c | 24 ++++++++++++++++++++++++
2 files changed, 25 insertions(+)
diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index 05d1982..f992494 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -172,6 +172,7 @@ extern int boot_menu;
extern bool boot_strict;
extern uint8_t *boot_splash_filedata;
extern size_t boot_splash_filedata_size;
+extern bool enable_mlock;
extern uint8_t qemu_extra_params_fw[2];
extern QEMUClockType rtc_clock;
extern const char *mem_path;
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index 8e107fe..1a24b09 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -87,6 +87,11 @@ static bool ufd_version_check(int ufd)
return true;
}
+/*
+ * Note: This has the side effect of munlock'ing all of RAM, that's
+ * normally fine since if the postcopy succeeds it gets turned back on at the
+ * end.
+ */
bool postcopy_ram_supported_by_host(void)
{
long pagesize = getpagesize();
@@ -115,6 +120,15 @@ bool postcopy_ram_supported_by_host(void)
}
/*
+ * userfault and mlock don't go together; we'll put it back later if
+ * it was enabled.
+ */
+ if (munlockall()) {
+ error_report("%s: munlockall: %s", __func__, strerror(errno));
+ return -1;
+ }
+
+ /*
* We need to check that the ops we need are supported on anon memory
* To do that we need to register a chunk and see the flags that
* are returned.
@@ -294,6 +308,16 @@ int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis)
mis->have_fault_thread = false;
}
+ if (enable_mlock) {
+ if (os_mlock() < 0) {
+ error_report("mlock: %s", strerror(errno));
+ /*
+ * It doesn't feel right to fail at this point, we have a valid
+ * VM state.
+ */
+ }
+ }
+
postcopy_state_set(POSTCOPY_INCOMING_END);
migrate_send_rp_shut(mis, qemu_file_get_error(mis->from_src_file) != 0);
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 56/57] Inhibit ballooning during postcopy
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (54 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 55/57] Disable mlock around incoming postcopy Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 14:25 ` [Qemu-devel] [PULL 57/57] migration: qemu_savevm_state_cleanup becomes mandatory operation Juan Quintela
2015-11-10 22:21 ` [Qemu-devel] [PULL 00/57] Migration pull (take 2) Peter Maydell
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, dgilbert
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Postcopy detects accesses to pages that haven't been transferred yet
using userfaultfd, and it causes exceptions on pages that are 'not
present'.
Ballooning also causes pages to be marked as 'not present' when the
guest inflates the balloon.
Potentially a balloon could be inflated to discard pages that are
currently inflight during postcopy and that may be arriving at about
the same time.
To avoid this confusion, disable ballooning during postcopy.
When disabled we drop balloon requests from the guest. Since ballooning
is generally initiated by the host, the management system should avoid
initiating any balloon instructions to the guest during migration,
although it's not possible to know how long it would take a guest to
process a request made prior to the start of migration.
Guest initiated ballooning will not know if it's really freed a page
of host memory or not.
Queueing the requests until after migration would be nice, but is
non-trivial, since the set of inflate/deflate requests have to
be compared with the state of the page to know what the final
outcome is allowed to be.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
balloon.c | 11 +++++++++++
hw/virtio/virtio-balloon.c | 4 +++-
include/sysemu/balloon.h | 2 ++
migration/postcopy-ram.c | 9 +++++++++
4 files changed, 25 insertions(+), 1 deletion(-)
diff --git a/balloon.c b/balloon.c
index 5d69e8a..0f45d1b 100644
--- a/balloon.c
+++ b/balloon.c
@@ -36,6 +36,17 @@
static QEMUBalloonEvent *balloon_event_fn;
static QEMUBalloonStatus *balloon_stat_fn;
static void *balloon_opaque;
+static bool balloon_inhibited;
+
+bool qemu_balloon_is_inhibited(void)
+{
+ return balloon_inhibited;
+}
+
+void qemu_balloon_inhibit(bool state)
+{
+ balloon_inhibited = state;
+}
static bool have_balloon(Error **errp)
{
diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c
index c419b17..9671635 100644
--- a/hw/virtio/virtio-balloon.c
+++ b/hw/virtio/virtio-balloon.c
@@ -37,9 +37,11 @@
static void balloon_page(void *addr, int deflate)
{
#if defined(__linux__)
- if (!kvm_enabled() || kvm_has_sync_mmu())
+ if (!qemu_balloon_is_inhibited() && (!kvm_enabled() ||
+ kvm_has_sync_mmu())) {
qemu_madvise(addr, TARGET_PAGE_SIZE,
deflate ? QEMU_MADV_WILLNEED : QEMU_MADV_DONTNEED);
+ }
#endif
}
diff --git a/include/sysemu/balloon.h b/include/sysemu/balloon.h
index 17fe300..3f976b4 100644
--- a/include/sysemu/balloon.h
+++ b/include/sysemu/balloon.h
@@ -22,5 +22,7 @@ typedef void (QEMUBalloonStatus)(void *opaque, BalloonInfo *info);
int qemu_add_balloon_handler(QEMUBalloonEvent *event_func,
QEMUBalloonStatus *stat_func, void *opaque);
void qemu_remove_balloon_handler(void *opaque);
+bool qemu_balloon_is_inhibited(void);
+void qemu_balloon_inhibit(bool state);
#endif
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index 1a24b09..22d6b18 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -24,6 +24,7 @@
#include "migration/migration.h"
#include "migration/postcopy-ram.h"
#include "sysemu/sysemu.h"
+#include "sysemu/balloon.h"
#include "qemu/error-report.h"
#include "trace.h"
@@ -308,6 +309,8 @@ int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis)
mis->have_fault_thread = false;
}
+ qemu_balloon_inhibit(false);
+
if (enable_mlock) {
if (os_mlock() < 0) {
error_report("mlock: %s", strerror(errno));
@@ -533,6 +536,12 @@ int postcopy_ram_enable_notify(MigrationIncomingState *mis)
return -1;
}
+ /*
+ * Ballooning can mark pages as absent while we're postcopying
+ * that would cause false userfaults.
+ */
+ qemu_balloon_inhibit(true);
+
trace_postcopy_ram_enable_notify();
return 0;
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* [Qemu-devel] [PULL 57/57] migration: qemu_savevm_state_cleanup becomes mandatory operation
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (55 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 56/57] Inhibit ballooning during postcopy Juan Quintela
@ 2015-11-10 14:25 ` Juan Quintela
2015-11-10 22:21 ` [Qemu-devel] [PULL 00/57] Migration pull (take 2) Peter Maydell
57 siblings, 0 replies; 81+ messages in thread
From: Juan Quintela @ 2015-11-10 14:25 UTC (permalink / raw)
To: qemu-devel; +Cc: amit.shah, Denis V. Lunev, dgilbert, Paolo Bonzini
From: "Denis V. Lunev" <den@openvz.org>
since commit
commit 94f5a43704129ca4995aa3385303c5ae225bde42
Author: Liang Li <liang.z.li@intel.com>
Date: Mon Nov 2 15:37:00 2015 +0800
migration: defer migration_end & blk_mig_cleanup
when actual .cleanup callbacks calling was removed from complete operations.
The patch fixes regression introduced by the commit above results in
100% reliable assert for virtio-scsi VM with iothreads enabled during
'virsh create-snapshot' operation:
assert(i != mr->ioeventfd_nb);
memory_region_del_eventfd
virtio_pci_set_host_notifier_internal
virtio_pci_set_host_notifier
virtio_scsi_dataplane_start
virtio_scsi_handle_cmd
virtio_queue_notify_vq
virtio_queue_host_notifier_read
aio_dispatch
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Liang Li <liang.z.li@intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Juan Quintela <quintela@redhat.com>
CC: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
migration/savevm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/migration/savevm.c b/migration/savevm.c
index 0596f7b..be52314 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1179,8 +1179,8 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp)
qemu_savevm_state_complete_precopy(f);
ret = qemu_file_get_error(f);
}
+ qemu_savevm_state_cleanup();
if (ret != 0) {
- qemu_savevm_state_cleanup();
error_setg_errno(errp, -ret, "Error while writing VM state");
}
return ret;
--
2.5.0
^ permalink raw reply related [flat|nested] 81+ messages in thread* Re: [Qemu-devel] [PULL 00/57] Migration pull (take 2)
2015-11-10 14:24 [Qemu-devel] [PULL 00/57] Migration pull (take 2) Juan Quintela
` (56 preceding siblings ...)
2015-11-10 14:25 ` [Qemu-devel] [PULL 57/57] migration: qemu_savevm_state_cleanup becomes mandatory operation Juan Quintela
@ 2015-11-10 22:21 ` Peter Maydell
57 siblings, 0 replies; 81+ messages in thread
From: Peter Maydell @ 2015-11-10 22:21 UTC (permalink / raw)
To: Juan Quintela; +Cc: Amit Shah, QEMU Developers, Dr. David Alan Gilbert
On 10 November 2015 at 14:24, Juan Quintela <quintela@redhat.com> wrote:
>
>
> Hi
>
> Now with peter changes to make it compile on his windows crosscompiler.
>
> thanks, Peter.
>
>
> two items:
>
> - Postcopy pull request (dave)
> - fix for qemu_completion (Denis)
>
> Please apply.
>
> Thanks, Juan.
>
>
> The following changes since commit a8b4f9585a0bf5186fca793ce2c5d754cd8ec49a:
>
> Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2015-11-10' into staging (2015-11-10 09:39:24 +0000)
>
> are available in the git repository at:
>
> git://github.com/juanquintela/qemu.git tags/migration/20151110
>
> for you to fetch changes up to 15b3b8eaae8dbcc903bb164311ea0066c77536a7:
>
> migration: qemu_savevm_state_cleanup becomes mandatory operation (2015-11-10 15:00:28 +0100)
>
> ----------------------------------------------------------------
> migration/next for 20151110
>
> ----------------------------------------------------------------
Applied, thanks.
-- PMM
^ permalink raw reply [flat|nested] 81+ messages in thread