[PATCH 0/4] migration: trivial cleanup and refine

[PATCH 0/4] migration: trivial cleanup and refine

[Wei Yang]

This patch set contains several cleanup and refine for migration.

    simplify some calculation
    reuse the result
    fix typo in comment
    provide error message when failed

Wei Yang (4):
  migration/ram: only possible bit set in invalid_flags is
    RAM_SAVE_FLAG_COMPRESS_PAGE
  migration/postcopy: fix typo in mark_postcopy_blocktime_begin's
    comment
  migration: pass in_postcopy instead of check state again
  migration: report SaveStateEntry id and name on failure

 migration/migration.c    | 3 +--
 migration/postcopy-ram.c | 8 +++++---
 migration/ram.c          | 5 +----
 migration/savevm.c       | 2 ++
 4 files changed, 9 insertions(+), 9 deletions(-)

-- 
2.17.1

[PATCH 1/4] migration/ram: only possible bit set in invalid_flags is RAM_SAVE_FLAG_COMPRESS_PAGE

[Wei Yang]

The only possible bit set in invalid_flags is
RAM_SAVE_FLAG_COMPRESS_PAGE at the beginning of function
ram_load_precopy(), which means it is not necessary to do
another check for RAM_SAVE_FLAG_COMPRESS_PAGE bit.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
---
 migration/ram.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/migration/ram.c b/migration/ram.c
index 31051935c8..769d3f6454 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -4263,10 +4263,7 @@ static int ram_load_precopy(QEMUFile *f)
         addr &= TARGET_PAGE_MASK;
 
         if (flags & invalid_flags) {
-            if (flags & invalid_flags & RAM_SAVE_FLAG_COMPRESS_PAGE) {
-                error_report("Received an unexpected compressed page");
-            }
-
+            error_report("Received an unexpected compressed page");
             ret = -EINVAL;
             break;
         }
-- 
2.17.1

[PATCH 2/4] migration/postcopy: fix typo in mark_postcopy_blocktime_begin's comment

[Wei Yang]

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
---
 migration/postcopy-ram.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index d2bdd21ae3..a394c7c3a6 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -768,9 +768,11 @@ static void mark_postcopy_blocktime_begin(uintptr_t addr, uint32_t ptid,
     atomic_xchg(&dc->page_fault_vcpu_time[cpu], low_time_offset);
     atomic_xchg(&dc->vcpu_addr[cpu], addr);
 
-    /* check it here, not at the begining of the function,
-     * due to, check could accur early than bitmap_set in
-     * qemu_ufd_copy_ioctl */
+    /*
+     * check it here, not at the beginning of the function,
+     * due to, check could occur early than bitmap_set in
+     * qemu_ufd_copy_ioctl
+     */
     already_received = ramblock_recv_bitmap_test(rb, (void *)addr);
     if (already_received) {
         atomic_xchg(&dc->vcpu_addr[cpu], 0);
-- 
2.17.1

[PATCH 3/4] migration: pass in_postcopy instead of check state again

[Wei Yang]

Not necessary to do the check again.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
---
 migration/migration.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/migration/migration.c b/migration/migration.c
index c8eaa85867..56031305e3 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -3148,8 +3148,7 @@ static MigIterateState migration_iteration_run(MigrationState *s)
             return MIG_ITERATE_SKIP;
         }
         /* Just another iteration step */
-        qemu_savevm_state_iterate(s->to_dst_file,
-            s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE);
+        qemu_savevm_state_iterate(s->to_dst_file, in_postcopy);
     } else {
         trace_migration_thread_low_pending(pending_size);
         migration_completion(s);
-- 
2.17.1

[PATCH 4/4] migration: report SaveStateEntry id and name on failure

[Wei Yang]

This provides helpful information on which entry failed.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
---
 migration/savevm.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/migration/savevm.c b/migration/savevm.c
index 9f0122583d..feb757de79 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1215,6 +1215,8 @@ int qemu_savevm_state_iterate(QEMUFile *f, bool postcopy)
         save_section_footer(f, se);
 
         if (ret < 0) {
+            error_report("failed to save SaveStateEntry with id(name): %d(%s)",
+                         se->section_id, se->idstr);
             qemu_file_set_error(f, ret);
         }
         if (ret <= 0) {
-- 
2.17.1

Re: [PATCH 2/4] migration/postcopy: fix typo in mark_postcopy_blocktime_begin's comment

[Philippe Mathieu-Daudé]

On 10/6/19 12:05 AM, Wei Yang wrote:
> Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
> ---
>   migration/postcopy-ram.c | 8 +++++---
>   1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
> index d2bdd21ae3..a394c7c3a6 100644
> --- a/migration/postcopy-ram.c
> +++ b/migration/postcopy-ram.c
> @@ -768,9 +768,11 @@ static void mark_postcopy_blocktime_begin(uintptr_t addr, uint32_t ptid,
>       atomic_xchg(&dc->page_fault_vcpu_time[cpu], low_time_offset);
>       atomic_xchg(&dc->vcpu_addr[cpu], addr);
>   
> -    /* check it here, not at the begining of the function,
> -     * due to, check could accur early than bitmap_set in
> -     * qemu_ufd_copy_ioctl */
> +    /*
> +     * check it here, not at the beginning of the function,
> +     * due to, check could occur early than bitmap_set in
> +     * qemu_ufd_copy_ioctl
> +     */
>       already_received = ramblock_recv_bitmap_test(rb, (void *)addr);
>       if (already_received) {
>           atomic_xchg(&dc->vcpu_addr[cpu], 0);
> 

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Re: [PATCH 4/4] migration: report SaveStateEntry id and name on failure

[Philippe Mathieu-Daudé]

On 10/6/19 12:05 AM, Wei Yang wrote:
> This provides helpful information on which entry failed.
> 
> Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
> ---
>   migration/savevm.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/migration/savevm.c b/migration/savevm.c
> index 9f0122583d..feb757de79 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -1215,6 +1215,8 @@ int qemu_savevm_state_iterate(QEMUFile *f, bool postcopy)
>           save_section_footer(f, se);
>   
>           if (ret < 0) {
> +            error_report("failed to save SaveStateEntry with id(name): %d(%s)",
> +                         se->section_id, se->idstr);
>               qemu_file_set_error(f, ret);
>           }
>           if (ret <= 0) {
> 

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Re: [PATCH 1/4] migration/ram: only possible bit set in invalid_flags is RAM_SAVE_FLAG_COMPRESS_PAGE

[Dr. David Alan Gilbert]

* Wei Yang (richardw.yang@linux.intel.com) wrote:
> The only possible bit set in invalid_flags is
> RAM_SAVE_FLAG_COMPRESS_PAGE at the beginning of function
> ram_load_precopy(), which means it is not necessary to do
> another check for RAM_SAVE_FLAG_COMPRESS_PAGE bit.
> 
> Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
> ---
>  migration/ram.c | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)
> 
> diff --git a/migration/ram.c b/migration/ram.c
> index 31051935c8..769d3f6454 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -4263,10 +4263,7 @@ static int ram_load_precopy(QEMUFile *f)
>          addr &= TARGET_PAGE_MASK;
>  
>          if (flags & invalid_flags) {
> -            if (flags & invalid_flags & RAM_SAVE_FLAG_COMPRESS_PAGE) {
> -                error_report("Received an unexpected compressed page");
> -            }
> -
> +            error_report("Received an unexpected compressed page");
>              ret = -EINVAL;

I'd rather keep this one; I think Juan's idea is that we might make
other flags illegal here and then it's easy to add to invalid_flags at
the top.

Dave
>              break;
>          }
> -- 
> 2.17.1
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK

Re: [PATCH 3/4] migration: pass in_postcopy instead of check state again

[Dr. David Alan Gilbert]

* Wei Yang (richardw.yang@linux.intel.com) wrote:
> Not necessary to do the check again.
> 
> Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

> ---
>  migration/migration.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/migration/migration.c b/migration/migration.c
> index c8eaa85867..56031305e3 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -3148,8 +3148,7 @@ static MigIterateState migration_iteration_run(MigrationState *s)
>              return MIG_ITERATE_SKIP;
>          }
>          /* Just another iteration step */
> -        qemu_savevm_state_iterate(s->to_dst_file,
> -            s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE);
> +        qemu_savevm_state_iterate(s->to_dst_file, in_postcopy);
>      } else {
>          trace_migration_thread_low_pending(pending_size);
>          migration_completion(s);
> -- 
> 2.17.1
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK

Re: [PATCH 1/4] migration/ram: only possible bit set in invalid_flags is RAM_SAVE_FLAG_COMPRESS_PAGE

[Wei Yang]

On Tue, Oct 08, 2019 at 06:38:25PM +0100, Dr. David Alan Gilbert wrote:
>* Wei Yang (richardw.yang@linux.intel.com) wrote:
>> The only possible bit set in invalid_flags is
>> RAM_SAVE_FLAG_COMPRESS_PAGE at the beginning of function
>> ram_load_precopy(), which means it is not necessary to do
>> another check for RAM_SAVE_FLAG_COMPRESS_PAGE bit.
>> 
>> Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
>> ---
>>  migration/ram.c | 5 +----
>>  1 file changed, 1 insertion(+), 4 deletions(-)
>> 
>> diff --git a/migration/ram.c b/migration/ram.c
>> index 31051935c8..769d3f6454 100644
>> --- a/migration/ram.c
>> +++ b/migration/ram.c
>> @@ -4263,10 +4263,7 @@ static int ram_load_precopy(QEMUFile *f)
>>          addr &= TARGET_PAGE_MASK;
>>  
>>          if (flags & invalid_flags) {
>> -            if (flags & invalid_flags & RAM_SAVE_FLAG_COMPRESS_PAGE) {
>> -                error_report("Received an unexpected compressed page");
>> -            }
>> -
>> +            error_report("Received an unexpected compressed page");
>>              ret = -EINVAL;
>
>I'd rather keep this one; I think Juan's idea is that we might make
>other flags illegal here and then it's easy to add to invalid_flags at
>the top.
>

Reasonable.

>Dave
>>              break;
>>          }
>> -- 
>> 2.17.1
>> 
>--
>Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK

-- 
Wei Yang
Help you, Help me

Re: [PATCH 0/4] migration: trivial cleanup and refine

[Dr. David Alan Gilbert]

* Wei Yang (richardw.yang@linux.intel.com) wrote:
> This patch set contains several cleanup and refine for migration.
> 
>     simplify some calculation
>     reuse the result
>     fix typo in comment
>     provide error message when failed

2,3,4 queued

> 
> Wei Yang (4):
>   migration/ram: only possible bit set in invalid_flags is
>     RAM_SAVE_FLAG_COMPRESS_PAGE
>   migration/postcopy: fix typo in mark_postcopy_blocktime_begin's
>     comment
>   migration: pass in_postcopy instead of check state again
>   migration: report SaveStateEntry id and name on failure
> 
>  migration/migration.c    | 3 +--
>  migration/postcopy-ram.c | 8 +++++---
>  migration/ram.c          | 5 +----
>  migration/savevm.c       | 2 ++
>  4 files changed, 9 insertions(+), 9 deletions(-)
> 
> -- 
> 2.17.1
> 
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK