Patchwork [15/19] savevm: introduce qemu_savevm_trans_{begin, commit}.

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Submitter Yoshiaki Tamura
Date Jan. 28, 2011, 7:21 a.m.
Message ID <1296199312-26334-16-git-send-email-tamura.yoshiaki@lab.ntt.co.jp>
Download mbox | patch
Permalink /patch/80804/
State New
Headers show

Comments

Yoshiaki Tamura - Jan. 28, 2011, 7:21 a.m.
Introduce qemu_savevm_state_{begin,commit} to send the memory and
device info together, while avoiding cancelling memory state tracking.

Signed-off-by: Yoshiaki Tamura <tamura.yoshiaki@lab.ntt.co.jp>
---
 savevm.c |   93 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 sysemu.h |    2 +
 2 files changed, 95 insertions(+), 0 deletions(-)
Paolo Bonzini - Jan. 28, 2011, 1:26 p.m.
On 01/28/2011 08:21 AM, Yoshiaki Tamura wrote:
> +int qemu_savevm_trans_begin(Monitor *mon, QEMUFile *f, int init)
> +{
> +    SaveStateEntry *se;
> +    int skipped = 0;
> +
> +    QTAILQ_FOREACH(se,&savevm_handlers, entry) {
> +        int len, stage, ret;
> +
> +        if (se->save_live_state == NULL) {
> +            continue;
> +        }
> +
> +        /* Section type */
> +        qemu_put_byte(f, QEMU_VM_SECTION_START);
> +        qemu_put_be32(f, se->section_id);
> +
> +        /* ID string */
> +        len = strlen(se->idstr);
> +        qemu_put_byte(f, len);
> +        qemu_put_buffer(f, (uint8_t *)se->idstr, len);
> +
> +        qemu_put_be32(f, se->instance_id);
> +        qemu_put_be32(f, se->version_id);
> +
> +        stage = init ? QEMU_VM_SECTION_START : QEMU_VM_SECTION_PART;
> +        ret = se->save_live_state(mon, f, stage, se->opaque);
> +        if (!ret) {
> +            skipped++;
> +        }
> +    }
> +
> +    if (qemu_file_has_error(f)) {
> +        return -EIO;
> +    }
> +
> +    return skipped;
> +}
> +

Right now, this is very similar to qemu_savevm_state_begin and _iterate, 
but not quite.  Perhaps you could abstract it to a single function that 
could be used everywhere live handlers are used.  For example,

/* section says which header to write; incremental == true forces to
    pass SECTION_PART instead of SECTION_START. In code:

if (section == QEMU_VM_SECTION_START) {
     stage = incremental ? QEMU_VM_SECTION_PART : QEMU_VM_SECTION_START;
} else {
     assert(incremental);
     stage = section;
}

    */
int qemu_savevm_state_live(Monitor *mon, QEMUFile *f, int section,
			   int incremental)

Likewise,

> +    QTAILQ_FOREACH(se, &savevm_handlers, entry) {
> +        int len;
> +
> +        if (se->save_state == NULL && se->vmsd == NULL) {
> +            continue;
> +        }
> +
> +        /* Section type */
> +        qemu_put_byte(f, QEMU_VM_SECTION_FULL);
> +        qemu_put_be32(f, se->section_id);
> +
> +        /* ID string */
> +        len = strlen(se->idstr);
> +        qemu_put_byte(f, len);
> +        qemu_put_buffer(f, (uint8_t *)se->idstr, len);
> +
> +        qemu_put_be32(f, se->instance_id);
> +        qemu_put_be32(f, se->version_id);
> +
> +        vmstate_save(f, se);
> +    }

this code is straight from qemu_savevm_state_complete and should be 
moved into its own function.

Paolo
Yoshiaki Tamura - Jan. 28, 2011, 2:41 p.m.
2011/1/28 Paolo Bonzini <pbonzini@redhat.com>:
> On 01/28/2011 08:21 AM, Yoshiaki Tamura wrote:
>>
>> +int qemu_savevm_trans_begin(Monitor *mon, QEMUFile *f, int init)
>> +{
>> +    SaveStateEntry *se;
>> +    int skipped = 0;
>> +
>> +    QTAILQ_FOREACH(se,&savevm_handlers, entry) {
>> +        int len, stage, ret;
>> +
>> +        if (se->save_live_state == NULL) {
>> +            continue;
>> +        }
>> +
>> +        /* Section type */
>> +        qemu_put_byte(f, QEMU_VM_SECTION_START);
>> +        qemu_put_be32(f, se->section_id);
>> +
>> +        /* ID string */
>> +        len = strlen(se->idstr);
>> +        qemu_put_byte(f, len);
>> +        qemu_put_buffer(f, (uint8_t *)se->idstr, len);
>> +
>> +        qemu_put_be32(f, se->instance_id);
>> +        qemu_put_be32(f, se->version_id);
>> +
>> +        stage = init ? QEMU_VM_SECTION_START : QEMU_VM_SECTION_PART;
>> +        ret = se->save_live_state(mon, f, stage, se->opaque);
>> +        if (!ret) {
>> +            skipped++;
>> +        }
>> +    }
>> +
>> +    if (qemu_file_has_error(f)) {
>> +        return -EIO;
>> +    }
>> +
>> +    return skipped;
>> +}
>> +
>
> Right now, this is very similar to qemu_savevm_state_begin and _iterate, but
> not quite.  Perhaps you could abstract it to a single function that could be
> used everywhere live handlers are used.  For example,
>
> /* section says which header to write; incremental == true forces to
>   pass SECTION_PART instead of SECTION_START. In code:
>
> if (section == QEMU_VM_SECTION_START) {
>    stage = incremental ? QEMU_VM_SECTION_PART : QEMU_VM_SECTION_START;
> } else {
>    assert(incremental);
>    stage = section;
> }
>
>   */
> int qemu_savevm_state_live(Monitor *mon, QEMUFile *f, int section,
>                           int incremental)
>
> Likewise,
>
>> +    QTAILQ_FOREACH(se, &savevm_handlers, entry) {
>> +        int len;
>> +
>> +        if (se->save_state == NULL && se->vmsd == NULL) {
>> +            continue;
>> +        }
>> +
>> +        /* Section type */
>> +        qemu_put_byte(f, QEMU_VM_SECTION_FULL);
>> +        qemu_put_be32(f, se->section_id);
>> +
>> +        /* ID string */
>> +        len = strlen(se->idstr);
>> +        qemu_put_byte(f, len);
>> +        qemu_put_buffer(f, (uint8_t *)se->idstr, len);
>> +
>> +        qemu_put_be32(f, se->instance_id);
>> +        qemu_put_be32(f, se->version_id);
>> +
>> +        vmstate_save(f, se);
>> +    }
>
> this code is straight from qemu_savevm_state_complete and should be moved
> into its own function.

Looks reasonable to avoid bit rotten.  Let me see what I can do.

Thanks,

Yoshi

>
> Paolo
>
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Patch

diff --git a/savevm.c b/savevm.c
index 5418280..73465ed 100644
--- a/savevm.c
+++ b/savevm.c
@@ -1726,6 +1726,99 @@  int qemu_savevm_state_complete(Monitor *mon, QEMUFile *f)
     return 0;
 }
 
+int qemu_savevm_trans_begin(Monitor *mon, QEMUFile *f, int init)
+{
+    SaveStateEntry *se;
+    int skipped = 0;
+
+    QTAILQ_FOREACH(se, &savevm_handlers, entry) {
+        int len, stage, ret;
+
+        if (se->save_live_state == NULL) {
+            continue;
+        }
+
+        /* Section type */
+        qemu_put_byte(f, QEMU_VM_SECTION_START);
+        qemu_put_be32(f, se->section_id);
+
+        /* ID string */
+        len = strlen(se->idstr);
+        qemu_put_byte(f, len);
+        qemu_put_buffer(f, (uint8_t *)se->idstr, len);
+
+        qemu_put_be32(f, se->instance_id);
+        qemu_put_be32(f, se->version_id);
+
+        stage = init ? QEMU_VM_SECTION_START : QEMU_VM_SECTION_PART;
+        ret = se->save_live_state(mon, f, stage, se->opaque);
+        if (!ret) {
+            skipped++;
+        }
+    }
+
+    if (qemu_file_has_error(f)) {
+        return -EIO;
+    }
+
+    return skipped;
+}
+
+int qemu_savevm_trans_complete(Monitor *mon, QEMUFile *f)
+{
+    SaveStateEntry *se;
+
+    cpu_synchronize_all_states();
+
+    QTAILQ_FOREACH(se, &savevm_handlers, entry) {
+        int ret;
+
+        if (se->save_live_state == NULL) {
+            continue;
+        }
+
+        /* Section type */
+        qemu_put_byte(f, QEMU_VM_SECTION_PART);
+        qemu_put_be32(f, se->section_id);
+
+        ret = se->save_live_state(mon, f, QEMU_VM_SECTION_PART, se->opaque);
+        if (!ret) {
+            /* do not proceed to the next vmstate. */
+            return 1;
+        }
+    }
+
+    QTAILQ_FOREACH(se, &savevm_handlers, entry) {
+        int len;
+
+        if (se->save_state == NULL && se->vmsd == NULL) {
+            continue;
+        }
+
+        /* Section type */
+        qemu_put_byte(f, QEMU_VM_SECTION_FULL);
+        qemu_put_be32(f, se->section_id);
+
+        /* ID string */
+        len = strlen(se->idstr);
+        qemu_put_byte(f, len);
+        qemu_put_buffer(f, (uint8_t *)se->idstr, len);
+
+        qemu_put_be32(f, se->instance_id);
+        qemu_put_be32(f, se->version_id);
+
+        vmstate_save(f, se);
+    }
+
+    qemu_put_byte(f, QEMU_VM_EOF);
+
+    if (qemu_file_has_error(f)) {
+        return -EIO;
+    }
+
+    return 0;
+}
+
 void qemu_savevm_state_cancel(Monitor *mon, QEMUFile *f)
 {
     SaveStateEntry *se;
diff --git a/sysemu.h b/sysemu.h
index 329415f..ee2c382 100644
--- a/sysemu.h
+++ b/sysemu.h
@@ -81,6 +81,8 @@  int qemu_savevm_state_begin(Monitor *mon, QEMUFile *f, int blk_enable,
 int qemu_savevm_state_iterate(Monitor *mon, QEMUFile *f);
 int qemu_savevm_state_complete(Monitor *mon, QEMUFile *f);
 void qemu_savevm_state_cancel(Monitor *mon, QEMUFile *f);
+int qemu_savevm_trans_begin(Monitor *mon, QEMUFile *f, int init);
+int qemu_savevm_trans_complete(Monitor *mon, QEMUFile *f);
 int qemu_loadvm_state(QEMUFile *f, int skip_header);
 
 /* SLIRP */