diff mbox

[03/17] migration: Test for disabled features on reception

Message ID 1485207141-1941-4-git-send-email-quintela@redhat.com
State New
Headers show

Commit Message

Juan Quintela Jan. 23, 2017, 9:32 p.m. UTC
Right now, if we receive a compressed page or a xbzrle page while this
features are disabled, Bad Things (TM) can happen.  Just add a test for
them.

Signed-off-by: Juan Quintela <quintela@redhat.com>
---
 migration/ram.c | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

Comments

Dr. David Alan Gilbert Jan. 24, 2017, 10:33 a.m. UTC | #1
* Juan Quintela (quintela@redhat.com) wrote:
> Right now, if we receive a compressed page or a xbzrle page while this
> features are disabled, Bad Things (TM) can happen.  Just add a test for
> them.
> 
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> ---
>  migration/ram.c | 23 ++++++++++++++++++++++-
>  1 file changed, 22 insertions(+), 1 deletion(-)
> 
> diff --git a/migration/ram.c b/migration/ram.c
> index ef8fadf..4ad814a 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -2455,7 +2455,7 @@ static int ram_load_postcopy(QEMUFile *f)
> 
>  static int ram_load(QEMUFile *f, void *opaque, int version_id)
>  {
> -    int flags = 0, ret = 0;
> +    int flags = 0, ret = 0, invalid_flags;
>      static uint64_t seq_iter;
>      int len = 0;
>      /*
> @@ -2470,6 +2470,15 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
>          ret = -EINVAL;
>      }
> 
> +    invalid_flags = 0;
> +
> +    if (!migrate_use_xbzrle()) {
> +        invalid_flags |= RAM_SAVE_FLAG_XBZRLE;
> +    }

Is that really the case? I thought we used to ignore the flags on the incoming
side and didn't need to enable xbzrle on the destination?

Dave

> +    if (!migrate_use_compression()) {
> +        invalid_flags |= RAM_SAVE_FLAG_COMPRESS_PAGE;
> +    }
>      /* This RCU critical section can be very long running.
>       * When RCU reclaims in the code start to become numerous,
>       * it will be necessary to reduce the granularity of this
> @@ -2490,6 +2499,18 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
>          flags = addr & ~TARGET_PAGE_MASK;
>          addr &= TARGET_PAGE_MASK;
> 
> +        if (flags & invalid_flags) {
> +            if (flags & invalid_flags  & RAM_SAVE_FLAG_XBZRLE) {
> +                error_report("Received an unexpected XBRLE page");
> +            }
> +            if (flags & invalid_flags  & RAM_SAVE_FLAG_COMPRESS_PAGE) {
> +                error_report("Received an unexpected compressed page");
> +            }
> +
> +            ret = -EINVAL;
> +            break;
> +        }
> +
>          if (flags & (RAM_SAVE_FLAG_COMPRESS | RAM_SAVE_FLAG_PAGE |
>                       RAM_SAVE_FLAG_COMPRESS_PAGE | RAM_SAVE_FLAG_XBZRLE)) {
>              RAMBlock *block = ram_block_from_stream(f, flags);
> -- 
> 2.9.3
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
Juan Quintela Feb. 9, 2017, 5:12 p.m. UTC | #2
"Dr. David Alan Gilbert" <dgilbert@redhat.com> wrote:
> * Juan Quintela (quintela@redhat.com) wrote:
>> Right now, if we receive a compressed page or a xbzrle page while this
>> features are disabled, Bad Things (TM) can happen.  Just add a test for
>> them.
>> 
>> Signed-off-by: Juan Quintela <quintela@redhat.com>
>> ---
>>  migration/ram.c | 23 ++++++++++++++++++++++-
>>  1 file changed, 22 insertions(+), 1 deletion(-)
>> 
>> diff --git a/migration/ram.c b/migration/ram.c
>> index ef8fadf..4ad814a 100644
>> --- a/migration/ram.c
>> +++ b/migration/ram.c
>> @@ -2455,7 +2455,7 @@ static int ram_load_postcopy(QEMUFile *f)
>> 
>>  static int ram_load(QEMUFile *f, void *opaque, int version_id)
>>  {
>> -    int flags = 0, ret = 0;
>> +    int flags = 0, ret = 0, invalid_flags;
>>      static uint64_t seq_iter;
>>      int len = 0;
>>      /*
>> @@ -2470,6 +2470,15 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
>>          ret = -EINVAL;
>>      }
>> 
>> +    invalid_flags = 0;
>> +
>> +    if (!migrate_use_xbzrle()) {
>> +        invalid_flags |= RAM_SAVE_FLAG_XBZRLE;
>> +    }
>
> Is that really the case? I thought we used to ignore the flags on the incoming
> side and didn't need to enable xbzrle on the destination?

we don't need infrastructure for xbzrle, but we need it for compression.

Removing xbzrle.
diff mbox

Patch

diff --git a/migration/ram.c b/migration/ram.c
index ef8fadf..4ad814a 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -2455,7 +2455,7 @@  static int ram_load_postcopy(QEMUFile *f)

 static int ram_load(QEMUFile *f, void *opaque, int version_id)
 {
-    int flags = 0, ret = 0;
+    int flags = 0, ret = 0, invalid_flags;
     static uint64_t seq_iter;
     int len = 0;
     /*
@@ -2470,6 +2470,15 @@  static int ram_load(QEMUFile *f, void *opaque, int version_id)
         ret = -EINVAL;
     }

+    invalid_flags = 0;
+
+    if (!migrate_use_xbzrle()) {
+        invalid_flags |= RAM_SAVE_FLAG_XBZRLE;
+    }
+
+    if (!migrate_use_compression()) {
+        invalid_flags |= RAM_SAVE_FLAG_COMPRESS_PAGE;
+    }
     /* This RCU critical section can be very long running.
      * When RCU reclaims in the code start to become numerous,
      * it will be necessary to reduce the granularity of this
@@ -2490,6 +2499,18 @@  static int ram_load(QEMUFile *f, void *opaque, int version_id)
         flags = addr & ~TARGET_PAGE_MASK;
         addr &= TARGET_PAGE_MASK;

+        if (flags & invalid_flags) {
+            if (flags & invalid_flags  & RAM_SAVE_FLAG_XBZRLE) {
+                error_report("Received an unexpected XBRLE page");
+            }
+            if (flags & invalid_flags  & RAM_SAVE_FLAG_COMPRESS_PAGE) {
+                error_report("Received an unexpected compressed page");
+            }
+
+            ret = -EINVAL;
+            break;
+        }
+
         if (flags & (RAM_SAVE_FLAG_COMPRESS | RAM_SAVE_FLAG_PAGE |
                      RAM_SAVE_FLAG_COMPRESS_PAGE | RAM_SAVE_FLAG_XBZRLE)) {
             RAMBlock *block = ram_block_from_stream(f, flags);