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[QEMU][PATCH v1 3/7] softmmu: let qemu_map_ram_ptr() use qemu_ram_ptr_length()

Vikram Garhwal posted 7 patches 2 years, 4 months ago
Maintainers: Peter Maydell <peter.maydell@linaro.org>, Stefano Stabellini <sstabellini@kernel.org>, Anthony Perard <anthony.perard@citrix.com>, Paul Durrant <paul@xen.org>, "Michael S. Tsirkin" <mst@redhat.com>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, Paolo Bonzini <pbonzini@redhat.com>, Richard Henderson <richard.henderson@linaro.org>, Eduardo Habkost <eduardo@habkost.net>, Peter Xu <peterx@redhat.com>, David Hildenbrand <david@redhat.com>, "Philippe Mathieu-Daudé" <philmd@linaro.org>
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[QEMU][PATCH v1 3/7] softmmu: let qemu_map_ram_ptr() use qemu_ram_ptr_length()
Posted by Vikram Garhwal 2 years, 4 months ago 
From: Juergen Gross <jgross@suse.com>

qemu_map_ram_ptr() and qemu_ram_ptr_length() share quite some code, so
modify qemu_ram_ptr_length() a little bit and use it for
qemu_map_ram_ptr(), too.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Vikram Garhwal <vikram.garhwal@amd.com>
---
 softmmu/physmem.c | 58 +++++++++++++++++++----------------------------
 1 file changed, 23 insertions(+), 35 deletions(-)

diff --git a/softmmu/physmem.c b/softmmu/physmem.c
index e182a2fa07..6e5e379dd0 100644
--- a/softmmu/physmem.c
+++ b/softmmu/physmem.c
@@ -2163,38 +2163,8 @@ void qemu_ram_remap(ram_addr_t addr, ram_addr_t length)
 }
 #endif /* !_WIN32 */
 
-/* Return a host pointer to ram allocated with qemu_ram_alloc.
- * This should not be used for general purpose DMA.  Use address_space_map
- * or address_space_rw instead. For local memory (e.g. video ram) that the
- * device owns, use memory_region_get_ram_ptr.
- *
- * Called within RCU critical section.
- */
-void *qemu_map_ram_ptr(RAMBlock *ram_block, ram_addr_t addr)
-{
-    RAMBlock *block = ram_block;
-
-    if (block == NULL) {
-        block = qemu_get_ram_block(addr);
-        addr -= block->offset;
-    }
-
-    if (xen_enabled() && block->host == NULL) {
-        /* We need to check if the requested address is in the RAM
-         * because we don't want to map the entire memory in QEMU.
-         * In that case just map until the end of the page.
-         */
-        if (block->offset == 0) {
-            return xen_map_cache(addr, 0, 0, false);
-        }
-
-        block->host = xen_map_cache(block->offset, block->max_length, 1, false);
-    }
-    return ramblock_ptr(block, addr);
-}
-
-/* Return a host pointer to guest's ram. Similar to qemu_map_ram_ptr
- * but takes a size argument.
+/*
+ * Return a host pointer to guest's ram.
  *
  * Called within RCU critical section.
  */
@@ -2202,7 +2172,9 @@ static void *qemu_ram_ptr_length(RAMBlock *ram_block, ram_addr_t addr,
                                  hwaddr *size, bool lock)
 {
     RAMBlock *block = ram_block;
-    if (*size == 0) {
+    hwaddr len = 0;
+
+    if (size && *size == 0) {
         return NULL;
     }
 
@@ -2210,7 +2182,10 @@ static void *qemu_ram_ptr_length(RAMBlock *ram_block, ram_addr_t addr,
         block = qemu_get_ram_block(addr);
         addr -= block->offset;
     }
-    *size = MIN(*size, block->max_length - addr);
+    if (size) {
+        *size = MIN(*size, block->max_length - addr);
+        len = *size;
+    }
 
     if (xen_enabled() && block->host == NULL) {
         /* We need to check if the requested address is in the RAM
@@ -2218,7 +2193,7 @@ static void *qemu_ram_ptr_length(RAMBlock *ram_block, ram_addr_t addr,
          * In that case just map the requested area.
          */
         if (block->offset == 0) {
-            return xen_map_cache(addr, *size, lock, lock);
+            return xen_map_cache(addr, len, lock, lock);
         }
 
         block->host = xen_map_cache(block->offset, block->max_length, 1, lock);
@@ -2227,6 +2202,19 @@ static void *qemu_ram_ptr_length(RAMBlock *ram_block, ram_addr_t addr,
     return ramblock_ptr(block, addr);
 }
 
+/*
+ * Return a host pointer to ram allocated with qemu_ram_alloc.
+ * This should not be used for general purpose DMA.  Use address_space_map
+ * or address_space_rw instead. For local memory (e.g. video ram) that the
+ * device owns, use memory_region_get_ram_ptr.
+ *
+ * Called within RCU critical section.
+ */
+void *qemu_map_ram_ptr(RAMBlock *ram_block, ram_addr_t addr)
+{
+    return qemu_ram_ptr_length(ram_block, addr, NULL, false);
+}
+
 /* Return the offset of a hostpointer within a ramblock */
 ram_addr_t qemu_ram_block_host_offset(RAMBlock *rb, void *host)
 {
-- 
2.17.1
Re: [QEMU][PATCH v1 3/7] softmmu: let qemu_map_ram_ptr() use qemu_ram_ptr_length()
Posted by Stefano Stabellini 2 years, 4 months ago 
On Thu, 5 Oct 2023, Vikram Garhwal wrote:
> From: Juergen Gross <jgross@suse.com>
> 
> qemu_map_ram_ptr() and qemu_ram_ptr_length() share quite some code, so
> modify qemu_ram_ptr_length() a little bit and use it for
> qemu_map_ram_ptr(), too.
> 
> Signed-off-by: Juergen Gross <jgross@suse.com>
> Signed-off-by: Vikram Garhwal <vikram.garhwal@amd.com>

This patch also doesn't apply due to code movement.

Other than that, the patch looks good to me


> ---
>  softmmu/physmem.c | 58 +++++++++++++++++++----------------------------
>  1 file changed, 23 insertions(+), 35 deletions(-)
> 
> diff --git a/softmmu/physmem.c b/softmmu/physmem.c
> index e182a2fa07..6e5e379dd0 100644
> --- a/softmmu/physmem.c
> +++ b/softmmu/physmem.c
> @@ -2163,38 +2163,8 @@ void qemu_ram_remap(ram_addr_t addr, ram_addr_t length)
>  }
>  #endif /* !_WIN32 */
>  
> -/* Return a host pointer to ram allocated with qemu_ram_alloc.
> - * This should not be used for general purpose DMA.  Use address_space_map
> - * or address_space_rw instead. For local memory (e.g. video ram) that the
> - * device owns, use memory_region_get_ram_ptr.
> - *
> - * Called within RCU critical section.
> - */
> -void *qemu_map_ram_ptr(RAMBlock *ram_block, ram_addr_t addr)
> -{
> -    RAMBlock *block = ram_block;
> -
> -    if (block == NULL) {
> -        block = qemu_get_ram_block(addr);
> -        addr -= block->offset;
> -    }
> -
> -    if (xen_enabled() && block->host == NULL) {
> -        /* We need to check if the requested address is in the RAM
> -         * because we don't want to map the entire memory in QEMU.
> -         * In that case just map until the end of the page.
> -         */
> -        if (block->offset == 0) {
> -            return xen_map_cache(addr, 0, 0, false);
> -        }
> -
> -        block->host = xen_map_cache(block->offset, block->max_length, 1, false);
> -    }
> -    return ramblock_ptr(block, addr);
> -}
> -
> -/* Return a host pointer to guest's ram. Similar to qemu_map_ram_ptr
> - * but takes a size argument.
> +/*
> + * Return a host pointer to guest's ram.
>   *
>   * Called within RCU critical section.
>   */
> @@ -2202,7 +2172,9 @@ static void *qemu_ram_ptr_length(RAMBlock *ram_block, ram_addr_t addr,
>                                   hwaddr *size, bool lock)
>  {
>      RAMBlock *block = ram_block;
> -    if (*size == 0) {
> +    hwaddr len = 0;
> +
> +    if (size && *size == 0) {
>          return NULL;
>      }
>  
> @@ -2210,7 +2182,10 @@ static void *qemu_ram_ptr_length(RAMBlock *ram_block, ram_addr_t addr,
>          block = qemu_get_ram_block(addr);
>          addr -= block->offset;
>      }
> -    *size = MIN(*size, block->max_length - addr);
> +    if (size) {
> +        *size = MIN(*size, block->max_length - addr);
> +        len = *size;
> +    }
>  
>      if (xen_enabled() && block->host == NULL) {
>          /* We need to check if the requested address is in the RAM
> @@ -2218,7 +2193,7 @@ static void *qemu_ram_ptr_length(RAMBlock *ram_block, ram_addr_t addr,
>           * In that case just map the requested area.
>           */
>          if (block->offset == 0) {
> -            return xen_map_cache(addr, *size, lock, lock);
> +            return xen_map_cache(addr, len, lock, lock);
>          }
>  
>          block->host = xen_map_cache(block->offset, block->max_length, 1, lock);
> @@ -2227,6 +2202,19 @@ static void *qemu_ram_ptr_length(RAMBlock *ram_block, ram_addr_t addr,
>      return ramblock_ptr(block, addr);
>  }
>  
> +/*
> + * Return a host pointer to ram allocated with qemu_ram_alloc.
> + * This should not be used for general purpose DMA.  Use address_space_map
> + * or address_space_rw instead. For local memory (e.g. video ram) that the
> + * device owns, use memory_region_get_ram_ptr.
> + *
> + * Called within RCU critical section.
> + */
> +void *qemu_map_ram_ptr(RAMBlock *ram_block, ram_addr_t addr)
> +{
> +    return qemu_ram_ptr_length(ram_block, addr, NULL, false);
> +}
> +
>  /* Return the offset of a hostpointer within a ramblock */
>  ram_addr_t qemu_ram_block_host_offset(RAMBlock *rb, void *host)
>  {
> -- 
> 2.17.1
>
Re: [QEMU][PATCH v1 3/7] softmmu: let qemu_map_ram_ptr() use qemu_ram_ptr_length()
Posted by Vikram Garhwal 2 years, 4 months ago 
On Mon, Oct 09, 2023 at 05:10:43PM -0700, Stefano Stabellini wrote:
> On Thu, 5 Oct 2023, Vikram Garhwal wrote:
> > From: Juergen Gross <jgross@suse.com>
> > 
> > qemu_map_ram_ptr() and qemu_ram_ptr_length() share quite some code, so
> > modify qemu_ram_ptr_length() a little bit and use it for
> > qemu_map_ram_ptr(), too.
> > 
> > Signed-off-by: Juergen Gross <jgross@suse.com>
> > Signed-off-by: Vikram Garhwal <vikram.garhwal@amd.com>
> 
> This patch also doesn't apply due to code movement.
Will rebase it.
> 
> Other than that, the patch looks good to me
> 
> 
> > ---
> >  softmmu/physmem.c | 58 +++++++++++++++++++----------------------------
> >  1 file changed, 23 insertions(+), 35 deletions(-)
> > 
> > diff --git a/softmmu/physmem.c b/softmmu/physmem.c
> > index e182a2fa07..6e5e379dd0 100644
> > --- a/softmmu/physmem.c
> > +++ b/softmmu/physmem.c
> > @@ -2163,38 +2163,8 @@ void qemu_ram_remap(ram_addr_t addr, ram_addr_t length)
> >  }
> >  #endif /* !_WIN32 */
> >  
> > -/* Return a host pointer to ram allocated with qemu_ram_alloc.
> > - * This should not be used for general purpose DMA.  Use address_space_map
> > - * or address_space_rw instead. For local memory (e.g. video ram) that the
> > - * device owns, use memory_region_get_ram_ptr.
> > - *
> > - * Called within RCU critical section.
> > - */
> > -void *qemu_map_ram_ptr(RAMBlock *ram_block, ram_addr_t addr)
> > -{
> > -    RAMBlock *block = ram_block;
> > -
> > -    if (block == NULL) {
> > -        block = qemu_get_ram_block(addr);
> > -        addr -= block->offset;
> > -    }
> > -
> > -    if (xen_enabled() && block->host == NULL) {
> > -        /* We need to check if the requested address is in the RAM
> > -         * because we don't want to map the entire memory in QEMU.
> > -         * In that case just map until the end of the page.
> > -         */
> > -        if (block->offset == 0) {
> > -            return xen_map_cache(addr, 0, 0, false);
> > -        }
> > -
> > -        block->host = xen_map_cache(block->offset, block->max_length, 1, false);
> > -    }
> > -    return ramblock_ptr(block, addr);
> > -}
> > -
> > -/* Return a host pointer to guest's ram. Similar to qemu_map_ram_ptr
> > - * but takes a size argument.
> > +/*
> > + * Return a host pointer to guest's ram.
> >   *
> >   * Called within RCU critical section.
> >   */
> > @@ -2202,7 +2172,9 @@ static void *qemu_ram_ptr_length(RAMBlock *ram_block, ram_addr_t addr,
> >                                   hwaddr *size, bool lock)
> >  {
> >      RAMBlock *block = ram_block;
> > -    if (*size == 0) {
> > +    hwaddr len = 0;
> > +
> > +    if (size && *size == 0) {
> >          return NULL;
> >      }
> >  
> > @@ -2210,7 +2182,10 @@ static void *qemu_ram_ptr_length(RAMBlock *ram_block, ram_addr_t addr,
> >          block = qemu_get_ram_block(addr);
> >          addr -= block->offset;
> >      }
> > -    *size = MIN(*size, block->max_length - addr);
> > +    if (size) {
> > +        *size = MIN(*size, block->max_length - addr);
> > +        len = *size;
> > +    }
> >  
> >      if (xen_enabled() && block->host == NULL) {
> >          /* We need to check if the requested address is in the RAM
> > @@ -2218,7 +2193,7 @@ static void *qemu_ram_ptr_length(RAMBlock *ram_block, ram_addr_t addr,
> >           * In that case just map the requested area.
> >           */
> >          if (block->offset == 0) {
> > -            return xen_map_cache(addr, *size, lock, lock);
> > +            return xen_map_cache(addr, len, lock, lock);
> >          }
> >  
> >          block->host = xen_map_cache(block->offset, block->max_length, 1, lock);
> > @@ -2227,6 +2202,19 @@ static void *qemu_ram_ptr_length(RAMBlock *ram_block, ram_addr_t addr,
> >      return ramblock_ptr(block, addr);
> >  }
> >  
> > +/*
> > + * Return a host pointer to ram allocated with qemu_ram_alloc.
> > + * This should not be used for general purpose DMA.  Use address_space_map
> > + * or address_space_rw instead. For local memory (e.g. video ram) that the
> > + * device owns, use memory_region_get_ram_ptr.
> > + *
> > + * Called within RCU critical section.
> > + */
> > +void *qemu_map_ram_ptr(RAMBlock *ram_block, ram_addr_t addr)
> > +{
> > +    return qemu_ram_ptr_length(ram_block, addr, NULL, false);
> > +}
> > +
> >  /* Return the offset of a hostpointer within a ramblock */
> >  ram_addr_t qemu_ram_block_host_offset(RAMBlock *rb, void *host)
> >  {
> > -- 
> > 2.17.1
> >

Patchew 2.1-devel-b67e4c2

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