diff mbox series

[v4,14/17] xen: Add xen_mr_is_memory()

Message ID 20240430164939.925307-15-edgar.iglesias@gmail.com (mailing list archive)
State New, archived
Headers show
Series xen: Support grant mappings | expand

Commit Message

Edgar E. Iglesias April 30, 2024, 4:49 p.m. UTC 
From: "Edgar E. Iglesias" <edgar.iglesias@amd.com>

Add xen_mr_is_memory() to abstract away tests for the
xen_memory MR.

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@amd.com>
---
 hw/xen/xen-hvm-common.c | 8 +++++++-
 include/sysemu/xen.h    | 8 ++++++++
 system/physmem.c        | 2 +-
 3 files changed, 16 insertions(+), 2 deletions(-)

Comments

Stefano Stabellini May 1, 2024, 9:06 p.m. UTC | #1 
On Tue, 30 Apr 2024, Edgar E. Iglesias wrote:
> From: "Edgar E. Iglesias" <edgar.iglesias@amd.com>
> 
> Add xen_mr_is_memory() to abstract away tests for the
> xen_memory MR.
> 
> Signed-off-by: Edgar E. Iglesias <edgar.iglesias@amd.com>

There is an important change in this patch below


> ---
>  hw/xen/xen-hvm-common.c | 8 +++++++-
>  include/sysemu/xen.h    | 8 ++++++++
>  system/physmem.c        | 2 +-
>  3 files changed, 16 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/xen/xen-hvm-common.c b/hw/xen/xen-hvm-common.c
> index 1627da7398..0267b88d26 100644
> --- a/hw/xen/xen-hvm-common.c
> +++ b/hw/xen/xen-hvm-common.c
> @@ -12,6 +12,12 @@
>  
>  MemoryRegion xen_memory;
>  
> +/* Check for xen memory.  */
> +bool xen_mr_is_memory(MemoryRegion *mr)
> +{
> +    return mr == &xen_memory;
> +}
> +
>  void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size, MemoryRegion *mr,
>                     Error **errp)
>  {
> @@ -28,7 +34,7 @@ void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size, MemoryRegion *mr,
>          return;
>      }
>  
> -    if (mr == &xen_memory) {
> +    if (xen_mr_is_memory(mr)) {
>          return;
>      }
>  
> diff --git a/include/sysemu/xen.h b/include/sysemu/xen.h
> index 754ec2e6cb..dc72f83bcb 100644
> --- a/include/sysemu/xen.h
> +++ b/include/sysemu/xen.h
> @@ -34,6 +34,8 @@ void xen_hvm_modified_memory(ram_addr_t start, ram_addr_t length);
>  void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size,
>                     struct MemoryRegion *mr, Error **errp);
>  
> +bool xen_mr_is_memory(MemoryRegion *mr);
> +
>  #else /* !CONFIG_XEN_IS_POSSIBLE */
>  
>  #define xen_enabled() 0
> @@ -47,6 +49,12 @@ static inline void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size,
>      g_assert_not_reached();
>  }
>  
> +static inline bool xen_mr_is_memory(MemoryRegion *mr)
> +{
> +    g_assert_not_reached();
> +    return false;
> +}
> +
>  #endif /* CONFIG_XEN_IS_POSSIBLE */
>  
>  #endif
> diff --git a/system/physmem.c b/system/physmem.c
> index ad7a8c7d95..1a5ffcba2a 100644
> --- a/system/physmem.c
> +++ b/system/physmem.c
> @@ -2227,7 +2227,7 @@ static void *qemu_ram_ptr_length(RAMBlock *block, ram_addr_t addr,
>           * because we don't want to map the entire memory in QEMU.
>           * In that case just map the requested area.
>           */
> -        if (block->offset == 0) {
> +        if (xen_mr_is_memory(block->mr)) {

This changes this check from block->offset == 0 to block->mr ==
&xen_memory. I think that's correct in all cases (x86 machines, ARM
machines) but I wanted to highlight it.

Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>





>              return xen_map_cache(block->mr, addr, len, lock, lock,
>                                   is_write);
>          }
> -- 
> 2.40.1
>
David Hildenbrand May 2, 2024, 7:26 a.m. UTC | #2 
On 30.04.24 18:49, Edgar E. Iglesias wrote:
> From: "Edgar E. Iglesias" <edgar.iglesias@amd.com>
> 
> Add xen_mr_is_memory() to abstract away tests for the
> xen_memory MR.
> 
> Signed-off-by: Edgar E. Iglesias <edgar.iglesias@amd.com>
> ---

[...]

>   #endif
> diff --git a/system/physmem.c b/system/physmem.c
> index ad7a8c7d95..1a5ffcba2a 100644
> --- a/system/physmem.c
> +++ b/system/physmem.c
> @@ -2227,7 +2227,7 @@ static void *qemu_ram_ptr_length(RAMBlock *block, ram_addr_t addr,
>            * because we don't want to map the entire memory in QEMU.
>            * In that case just map the requested area.
>            */
> -        if (block->offset == 0) {
> +        if (xen_mr_is_memory(block->mr)) {
>               return xen_map_cache(block->mr, addr, len, lock, lock,
>                                    is_write);
>           }

I'd have moved that into a separate patch, because this is not a simple 
abstraction here.

Acked-by: David Hildenbrand <david@redhat.com>
Philippe Mathieu-Daudé May 6, 2024, 9:59 a.m. UTC | #3 
On 2/5/24 09:26, David Hildenbrand wrote:
> On 30.04.24 18:49, Edgar E. Iglesias wrote:
>> From: "Edgar E. Iglesias" <edgar.iglesias@amd.com>
>>
>> Add xen_mr_is_memory() to abstract away tests for the
>> xen_memory MR.
>>
>> Signed-off-by: Edgar E. Iglesias <edgar.iglesias@amd.com>
>> ---
> 
> [...]
> 
>>   #endif
>> diff --git a/system/physmem.c b/system/physmem.c
>> index ad7a8c7d95..1a5ffcba2a 100644
>> --- a/system/physmem.c
>> +++ b/system/physmem.c
>> @@ -2227,7 +2227,7 @@ static void *qemu_ram_ptr_length(RAMBlock 
>> *block, ram_addr_t addr,
>>            * because we don't want to map the entire memory in QEMU.
>>            * In that case just map the requested area.
>>            */
>> -        if (block->offset == 0) {
>> +        if (xen_mr_is_memory(block->mr)) {
>>               return xen_map_cache(block->mr, addr, len, lock, lock,
>>                                    is_write);
>>           }
> 
> I'd have moved that into a separate patch, because this is not a simple 
> abstraction here.

Yes please, maybe using Stefano review comment in the description.

> 
> Acked-by: David Hildenbrand <david@redhat.com>
>
Edgar E. Iglesias May 6, 2024, 1:26 p.m. UTC | #4 
On Mon, May 6, 2024 at 11:59 AM Philippe Mathieu-Daudé
<philmd@linaro.org> wrote:
>
> On 2/5/24 09:26, David Hildenbrand wrote:
> > On 30.04.24 18:49, Edgar E. Iglesias wrote:
> >> From: "Edgar E. Iglesias" <edgar.iglesias@amd.com>
> >>
> >> Add xen_mr_is_memory() to abstract away tests for the
> >> xen_memory MR.
> >>
> >> Signed-off-by: Edgar E. Iglesias <edgar.iglesias@amd.com>
> >> ---
> >
> > [...]
> >
> >>   #endif
> >> diff --git a/system/physmem.c b/system/physmem.c
> >> index ad7a8c7d95..1a5ffcba2a 100644
> >> --- a/system/physmem.c
> >> +++ b/system/physmem.c
> >> @@ -2227,7 +2227,7 @@ static void *qemu_ram_ptr_length(RAMBlock
> >> *block, ram_addr_t addr,
> >>            * because we don't want to map the entire memory in QEMU.
> >>            * In that case just map the requested area.
> >>            */
> >> -        if (block->offset == 0) {
> >> +        if (xen_mr_is_memory(block->mr)) {
> >>               return xen_map_cache(block->mr, addr, len, lock, lock,
> >>                                    is_write);
> >>           }
> >
> > I'd have moved that into a separate patch, because this is not a simple
> > abstraction here.
>
> Yes please, maybe using Stefano review comment in the description.
>

Thanks, for v5 I've split out this particular change into a separate patch:

    softmmu: Replace check for RAMBlock offset 0 with xen_mr_is_memory

    For xen, when checking for the first RAM (xen_memory), use
    xen_mr_is_memory() rather than checking for a RAMBlock with
    offset 0.

    All Xen machines create xen_memory first so this has no
    functional change for existing machines.

    Signed-off-by: Edgar E. Iglesias <edgar.iglesias@amd.com>

diff --git a/system/physmem.c b/system/physmem.c
index ad7a8c7d95..1a5ffcba2a 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -2227,7 +2227,7 @@ static void *qemu_ram_ptr_length(RAMBlock
*block, ram_addr_t addr,
          * because we don't want to map the entire memory in QEMU.
          * In that case just map the requested area.
          */
-        if (block->offset == 0) {
+        if (xen_mr_is_memory(block->mr)) {
             return xen_map_cache(block->mr, addr, len, lock, lock,
                                  is_write);
         }



> >
> > Acked-by: David Hildenbrand <david@redhat.com>
> >
>
diff mbox series

Patch

diff --git a/hw/xen/xen-hvm-common.c b/hw/xen/xen-hvm-common.c
index 1627da7398..0267b88d26 100644
--- a/hw/xen/xen-hvm-common.c
+++ b/hw/xen/xen-hvm-common.c
@@ -12,6 +12,12 @@ 
 
 MemoryRegion xen_memory;
 
+/* Check for xen memory.  */
+bool xen_mr_is_memory(MemoryRegion *mr)
+{
+    return mr == &xen_memory;
+}
+
 void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size, MemoryRegion *mr,
                    Error **errp)
 {
@@ -28,7 +34,7 @@  void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size, MemoryRegion *mr,
         return;
     }
 
-    if (mr == &xen_memory) {
+    if (xen_mr_is_memory(mr)) {
         return;
     }
 
diff --git a/include/sysemu/xen.h b/include/sysemu/xen.h
index 754ec2e6cb..dc72f83bcb 100644
--- a/include/sysemu/xen.h
+++ b/include/sysemu/xen.h
@@ -34,6 +34,8 @@  void xen_hvm_modified_memory(ram_addr_t start, ram_addr_t length);
 void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size,
                    struct MemoryRegion *mr, Error **errp);
 
+bool xen_mr_is_memory(MemoryRegion *mr);
+
 #else /* !CONFIG_XEN_IS_POSSIBLE */
 
 #define xen_enabled() 0
@@ -47,6 +49,12 @@  static inline void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size,
     g_assert_not_reached();
 }
 
+static inline bool xen_mr_is_memory(MemoryRegion *mr)
+{
+    g_assert_not_reached();
+    return false;
+}
+
 #endif /* CONFIG_XEN_IS_POSSIBLE */
 
 #endif
diff --git a/system/physmem.c b/system/physmem.c
index ad7a8c7d95..1a5ffcba2a 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -2227,7 +2227,7 @@  static void *qemu_ram_ptr_length(RAMBlock *block, ram_addr_t addr,
          * because we don't want to map the entire memory in QEMU.
          * In that case just map the requested area.
          */
-        if (block->offset == 0) {
+        if (xen_mr_is_memory(block->mr)) {
             return xen_map_cache(block->mr, addr, len, lock, lock,
                                  is_write);
         }