[v1] memory_region: Fix name comments

[Qemu-devel] [PATCH] memory_region: Fix name comments

Posted by Dr. David Alan Gilbert (git) 7 years, 1 month ago

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

The 'name' parameter to memory_region_init_* had been marked as debug
only, however vmstate_region_ram uses it as a parameter to
qemu_ram_set_idstr to set RAMBlock names and these form part of the
migration stream.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 include/exec/memory.h | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/include/exec/memory.h b/include/exec/memory.h
index 6911023..de8f69e 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -307,7 +307,7 @@ struct MemoryRegionSection {
  *
  * @mr: the #MemoryRegion to be initialized
  * @owner: the object that tracks the region's reference count
- * @name: used for debugging; not visible to the user or ABI
+ * @name: Region name, becomes part of RAMBlock name used in migration stream
  * @size: size of the region; any subregions beyond this size will be clipped
  */
 void memory_region_init(MemoryRegion *mr,
@@ -355,7 +355,7 @@ void memory_region_unref(MemoryRegion *mr);
  * @ops: a structure containing read and write callbacks to be used when
  *       I/O is performed on the region.
  * @opaque: passed to the read and write callbacks of the @ops structure.
- * @name: used for debugging; not visible to the user or ABI
+ * @name: Region name, becomes part of RAMBlock name used in migration stream
  * @size: size of the region.
  */
 void memory_region_init_io(MemoryRegion *mr,
@@ -474,7 +474,7 @@ void memory_region_init_ram_device_ptr(MemoryRegion *mr,
  *
  * @mr: the #MemoryRegion to be initialized.
  * @owner: the object that tracks the region's reference count
- * @name: used for debugging; not visible to the user or ABI
+ * @name: Region name, becomes part of RAMBlock name used in migration stream
  * @orig: the region to be referenced; @mr will be equivalent to
  *        @orig between @offset and @offset + @size - 1.
  * @offset: start of the section in @orig to be referenced.
@@ -537,7 +537,7 @@ void memory_region_init_rom_device(MemoryRegion *mr,
  *
  * @mr: the #MemoryRegion to be initialized
  * @owner: the object that tracks the region's reference count
- * @name: used for debugging; not visible to the user or ABI
+ * @name: Region name, becomes part of RAMBlock name used in migration stream
  * @size: size of the region.
  */
 static inline void memory_region_init_reservation(MemoryRegion *mr,
@@ -558,7 +558,7 @@ static inline void memory_region_init_reservation(MemoryRegion *mr,
  * @mr: the #MemoryRegion to be initialized
  * @owner: the object that tracks the region's reference count
  * @ops: a function that translates addresses into the @target region
- * @name: used for debugging; not visible to the user or ABI
+ * @name: Region name, becomes part of RAMBlock name used in migration stream
  * @size: size of the region.
  */
 void memory_region_init_iommu(MemoryRegion *mr,
-- 
2.9.3

Re: [Qemu-devel] [PATCH] memory_region: Fix name comments

Posted by Philippe Mathieu-Daudé 7 years, 1 month ago

On 03/08/2017 07:54 AM, Dr. David Alan Gilbert (git) wrote:
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
>
> The 'name' parameter to memory_region_init_* had been marked as debug
> only, however vmstate_region_ram uses it as a parameter to
> qemu_ram_set_idstr to set RAMBlock names and these form part of the
> migration stream.
>
> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

> ---
>  include/exec/memory.h | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/include/exec/memory.h b/include/exec/memory.h
> index 6911023..de8f69e 100644
> --- a/include/exec/memory.h
> +++ b/include/exec/memory.h
> @@ -307,7 +307,7 @@ struct MemoryRegionSection {
>   *
>   * @mr: the #MemoryRegion to be initialized
>   * @owner: the object that tracks the region's reference count
> - * @name: used for debugging; not visible to the user or ABI
> + * @name: Region name, becomes part of RAMBlock name used in migration stream
>   * @size: size of the region; any subregions beyond this size will be clipped
>   */
>  void memory_region_init(MemoryRegion *mr,
> @@ -355,7 +355,7 @@ void memory_region_unref(MemoryRegion *mr);
>   * @ops: a structure containing read and write callbacks to be used when
>   *       I/O is performed on the region.
>   * @opaque: passed to the read and write callbacks of the @ops structure.
> - * @name: used for debugging; not visible to the user or ABI
> + * @name: Region name, becomes part of RAMBlock name used in migration stream
>   * @size: size of the region.
>   */
>  void memory_region_init_io(MemoryRegion *mr,
> @@ -474,7 +474,7 @@ void memory_region_init_ram_device_ptr(MemoryRegion *mr,
>   *
>   * @mr: the #MemoryRegion to be initialized.
>   * @owner: the object that tracks the region's reference count
> - * @name: used for debugging; not visible to the user or ABI
> + * @name: Region name, becomes part of RAMBlock name used in migration stream
>   * @orig: the region to be referenced; @mr will be equivalent to
>   *        @orig between @offset and @offset + @size - 1.
>   * @offset: start of the section in @orig to be referenced.
> @@ -537,7 +537,7 @@ void memory_region_init_rom_device(MemoryRegion *mr,
>   *
>   * @mr: the #MemoryRegion to be initialized
>   * @owner: the object that tracks the region's reference count
> - * @name: used for debugging; not visible to the user or ABI
> + * @name: Region name, becomes part of RAMBlock name used in migration stream
>   * @size: size of the region.
>   */
>  static inline void memory_region_init_reservation(MemoryRegion *mr,
> @@ -558,7 +558,7 @@ static inline void memory_region_init_reservation(MemoryRegion *mr,
>   * @mr: the #MemoryRegion to be initialized
>   * @owner: the object that tracks the region's reference count
>   * @ops: a function that translates addresses into the @target region
> - * @name: used for debugging; not visible to the user or ABI
> + * @name: Region name, becomes part of RAMBlock name used in migration stream
>   * @size: size of the region.
>   */
>  void memory_region_init_iommu(MemoryRegion *mr,
>

Re: [Qemu-devel] [PATCH] memory_region: Fix name comments

Posted by Peter Maydell 7 years, 1 month ago

On 8 March 2017 at 11:54, Dr. David Alan Gilbert (git)
<dgilbert@redhat.com> wrote:
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
>
> The 'name' parameter to memory_region_init_* had been marked as debug
> only, however vmstate_region_ram uses it as a parameter to
> qemu_ram_set_idstr to set RAMBlock names and these form part of the
> migration stream.
>
> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> ---
>  include/exec/memory.h | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/include/exec/memory.h b/include/exec/memory.h
> index 6911023..de8f69e 100644
> --- a/include/exec/memory.h
> +++ b/include/exec/memory.h
> @@ -307,7 +307,7 @@ struct MemoryRegionSection {
>   *
>   * @mr: the #MemoryRegion to be initialized
>   * @owner: the object that tracks the region's reference count
> - * @name: used for debugging; not visible to the user or ABI
> + * @name: Region name, becomes part of RAMBlock name used in migration stream

...for RAM-backend MRs only, presumably? Also, what are the
uniqueness constraints?

>   * @size: size of the region; any subregions beyond this size will be clipped
>   */
>  void memory_region_init(MemoryRegion *mr,
> @@ -355,7 +355,7 @@ void memory_region_unref(MemoryRegion *mr);
>   * @ops: a structure containing read and write callbacks to be used when
>   *       I/O is performed on the region.
>   * @opaque: passed to the read and write callbacks of the @ops structure.
> - * @name: used for debugging; not visible to the user or ABI
> + * @name: Region name, becomes part of RAMBlock name used in migration stream

ditto.

>   * @size: size of the region.
>   */
>  void memory_region_init_io(MemoryRegion *mr,
> @@ -474,7 +474,7 @@ void memory_region_init_ram_device_ptr(MemoryRegion *mr,
>   *
>   * @mr: the #MemoryRegion to be initialized.
>   * @owner: the object that tracks the region's reference count
> - * @name: used for debugging; not visible to the user or ABI
> + * @name: Region name, becomes part of RAMBlock name used in migration stream
>   * @orig: the region to be referenced; @mr will be equivalent to
>   *        @orig between @offset and @offset + @size - 1.
>   * @offset: start of the section in @orig to be referenced.

The diff here is rather lacking in context, but this comment change
is for memory_region_init_alias(). Aliases presumably don't get
migrated (the thing they alias into will be migrated if it's RAM),
so the comment seems out of place here.

> @@ -537,7 +537,7 @@ void memory_region_init_rom_device(MemoryRegion *mr,
>   *
>   * @mr: the #MemoryRegion to be initialized
>   * @owner: the object that tracks the region's reference count
> - * @name: used for debugging; not visible to the user or ABI
> + * @name: Region name, becomes part of RAMBlock name used in migration stream
>   * @size: size of the region.
>   */
>  static inline void memory_region_init_reservation(MemoryRegion *mr,

Similarly, a reservation MR isn't RAM-backed.

> @@ -558,7 +558,7 @@ static inline void memory_region_init_reservation(MemoryRegion *mr,
>   * @mr: the #MemoryRegion to be initialized
>   * @owner: the object that tracks the region's reference count
>   * @ops: a function that translates addresses into the @target region
> - * @name: used for debugging; not visible to the user or ABI
> + * @name: Region name, becomes part of RAMBlock name used in migration stream
>   * @size: size of the region.
>   */
>  void memory_region_init_iommu(MemoryRegion *mr,

...and nor is an IOMMU MR.

> --
> 2.9.3
>


thanks
-- PMM

-- 
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Re: [Qemu-devel] [PATCH] memory_region: Fix name comments

Posted by Dr. David Alan Gilbert 7 years, 1 month ago

* Peter Maydell (peter.maydell@linaro.org) wrote:
> On 8 March 2017 at 11:54, Dr. David Alan Gilbert (git)
> <dgilbert@redhat.com> wrote:
> > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> >
> > The 'name' parameter to memory_region_init_* had been marked as debug
> > only, however vmstate_region_ram uses it as a parameter to
> > qemu_ram_set_idstr to set RAMBlock names and these form part of the
> > migration stream.
> >
> > Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> > ---
> >  include/exec/memory.h | 10 +++++-----
> >  1 file changed, 5 insertions(+), 5 deletions(-)
> >
> > diff --git a/include/exec/memory.h b/include/exec/memory.h
> > index 6911023..de8f69e 100644
> > --- a/include/exec/memory.h
> > +++ b/include/exec/memory.h
> > @@ -307,7 +307,7 @@ struct MemoryRegionSection {
> >   *
> >   * @mr: the #MemoryRegion to be initialized
> >   * @owner: the object that tracks the region's reference count
> > - * @name: used for debugging; not visible to the user or ABI
> > + * @name: Region name, becomes part of RAMBlock name used in migration stream
> 
> ...for RAM-backend MRs only, presumably? Also, what are the
> uniqueness constraints?

Hmm; yes RAM backed or things that behave like RAM backed (e.g. file-backed).
Uniqueness isn't required in all cases; qemu_ram_set_idstr prefixes this name
by a device name if it's given a device - which it isn't normally for stuff
on boards.  However the code will at least fail if there's a clash.
How about:

 * @name: Region name, becomes part of RAMBlock name used in migration stream
 *        must be unique within any device



> >   * @size: size of the region; any subregions beyond this size will be clipped
> >   */
> >  void memory_region_init(MemoryRegion *mr,
> > @@ -355,7 +355,7 @@ void memory_region_unref(MemoryRegion *mr);
> >   * @ops: a structure containing read and write callbacks to be used when
> >   *       I/O is performed on the region.
> >   * @opaque: passed to the read and write callbacks of the @ops structure.
> > - * @name: used for debugging; not visible to the user or ABI
> > + * @name: Region name, becomes part of RAMBlock name used in migration stream
> 
> ditto.
> 
> >   * @size: size of the region.
> >   */
> >  void memory_region_init_io(MemoryRegion *mr,
> > @@ -474,7 +474,7 @@ void memory_region_init_ram_device_ptr(MemoryRegion *mr,
> >   *
> >   * @mr: the #MemoryRegion to be initialized.
> >   * @owner: the object that tracks the region's reference count
> > - * @name: used for debugging; not visible to the user or ABI
> > + * @name: Region name, becomes part of RAMBlock name used in migration stream
> >   * @orig: the region to be referenced; @mr will be equivalent to
> >   *        @orig between @offset and @offset + @size - 1.
> >   * @offset: start of the section in @orig to be referenced.
> 
> The diff here is rather lacking in context, but this comment change
> is for memory_region_init_alias(). Aliases presumably don't get
> migrated (the thing they alias into will be migrated if it's RAM),
> so the comment seems out of place here.
> 
> > @@ -537,7 +537,7 @@ void memory_region_init_rom_device(MemoryRegion *mr,
> >   *
> >   * @mr: the #MemoryRegion to be initialized
> >   * @owner: the object that tracks the region's reference count
> > - * @name: used for debugging; not visible to the user or ABI
> > + * @name: Region name, becomes part of RAMBlock name used in migration stream
> >   * @size: size of the region.
> >   */
> >  static inline void memory_region_init_reservation(MemoryRegion *mr,
> 
> Similarly, a reservation MR isn't RAM-backed.
> 
> > @@ -558,7 +558,7 @@ static inline void memory_region_init_reservation(MemoryRegion *mr,
> >   * @mr: the #MemoryRegion to be initialized
> >   * @owner: the object that tracks the region's reference count
> >   * @ops: a function that translates addresses into the @target region
> > - * @name: used for debugging; not visible to the user or ABI
> > + * @name: Region name, becomes part of RAMBlock name used in migration stream
> >   * @size: size of the region.
> >   */
> >  void memory_region_init_iommu(MemoryRegion *mr,
> 
> ...and nor is an IOMMU MR.

OK, so I think we need it on:
  memory_region_init, memory_region_init_ram, memory_region_init_resizeable_ram,
  memory_region_init_ram_from_file, memory_region_init_ram_ptr, memory_region_init_rom,
  memory_region_init_rom_device (?)

  I don't think it's needed in memory_region_init_ram_device_ptr

Dave

> > --
> > 2.9.3
> >
> 
> 
> thanks
> -- PMM
> 
> -- 
> 12345678901234567890123456789012345678901234567890123456789012345678901234567890
>          1         2         3         4         5         6         7         8
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK

Re: [Qemu-devel] [PATCH] memory_region: Fix name comments

Posted by Paolo Bonzini 7 years, 1 month ago


On 09/03/2017 12:26, Dr. David Alan Gilbert wrote:
>  * @name: Region name, becomes part of RAMBlock name used in migration stream
>  *        must be unique within any device

Just a note, the uniqueness constraint also applies for RAM regions only.

Paolo

Re: [Qemu-devel] [PATCH] memory_region: Fix name comments

Posted by Dr. David Alan Gilbert 7 years, 1 month ago

* Paolo Bonzini (pbonzini@redhat.com) wrote:
> 
> 
> On 09/03/2017 12:26, Dr. David Alan Gilbert wrote:
> >  * @name: Region name, becomes part of RAMBlock name used in migration stream
> >  *        must be unique within any device
> 
> Just a note, the uniqueness constraint also applies for RAM regions only.

Yes, I'm only adding this comment to the ram/ram like functions now.

Dave

> Paolo
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK