[QEMU,v3,1/7] softmmu: physmem: Split ram_block_add()

Commit Message

Vikram Garhwal Feb. 27, 2024, 10:34 p.m. UTC

Extract ram block list update to a new function ram_block_add_list(). This is
done to support grant mappings which adds a memory region for granted memory and
updates the ram_block list.

Signed-off-by: Juergen Gross <[e-mail]>
Signed-off-by: Vikram Garhwal <[e-mail]>
Reviewed-by: Stefano Stabellini <[e-mail]>
---
 include/exec/ram_addr.h |  1 +
 system/physmem.c        | 62 ++++++++++++++++++++++++++---------------
 2 files changed, 40 insertions(+), 23 deletions(-)

Comments

Alex Bennée March 1, 2024, 11:33 a.m. UTC | #1

Vikram Garhwal <[e-mail]> writes:

> Extract ram block list update to a new function ram_block_add_list(). This is
> done to support grant mappings which adds a memory region for granted memory and
> updates the ram_block list.
>
> Signed-off-by: Juergen Gross <[e-mail]>
> Signed-off-by: Vikram Garhwal <[e-mail]>
> Reviewed-by: Stefano Stabellini <[e-mail]>

Reviewed-by: Alex Bennée <[e-mail]>

Edgar E. Iglesias April 10, 2024, 11:10 a.m. UTC | #2

On Fri, Mar 1, 2024 at 12:35 PM Alex Bennée <[e-mail]> wrote:

> Vikram Garhwal <[e-mail]> writes:
>
> > Extract ram block list update to a new function ram_block_add_list().
> This is
> > done to support grant mappings which adds a memory region for granted
> memory and
> > updates the ram_block list.
> >
> > Signed-off-by: Juergen Gross <[e-mail]>
> > Signed-off-by: Vikram Garhwal <[e-mail]>
> > Reviewed-by: Stefano Stabellini <[e-mail]>
>
> Reviewed-by: Alex Bennée <[e-mail]>
>
>

Reviewed-by: Edgar E. Iglesias <[e-mail]>

Patch

diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
index 90676093f5..c0b5f9a7d0 100644
--- a/include/exec/ram_addr.h
+++ b/include/exec/ram_addr.h
@@ -139,6 +139,7 @@  void qemu_ram_free(RAMBlock *block);
 int qemu_ram_resize(RAMBlock *block, ram_addr_t newsize, Error **errp);
 
 void qemu_ram_msync(RAMBlock *block, ram_addr_t start, ram_addr_t length);
+void ram_block_add_list(RAMBlock *new_block);
 
 /* Clear whole block of mem */
 static inline void qemu_ram_block_writeback(RAMBlock *block)
diff --git a/system/physmem.c b/system/physmem.c
index e3ebc19eef..84f3022099 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -1803,12 +1803,47 @@  static void dirty_memory_extend(ram_addr_t old_ram_size,
     }
 }
 
+static void ram_block_add_list_locked(RAMBlock *new_block)
+ {
+     RAMBlock *block;
+     RAMBlock *last_block = NULL;
+
+    /*
+     * Keep the list sorted from biggest to smallest block.  Unlike QTAILQ,
+     * QLIST (which has an RCU-friendly variant) does not have insertion at
+     * tail, so save the last element in last_block.
+     */
+    RAMBLOCK_FOREACH(block) {
+        last_block = block;
+        if (block->max_length < new_block->max_length) {
+            break;
+        }
+    }
+    if (block) {
+        QLIST_INSERT_BEFORE_RCU(block, new_block, next);
+    } else if (last_block) {
+        QLIST_INSERT_AFTER_RCU(last_block, new_block, next);
+    } else { /* list is empty */
+        QLIST_INSERT_HEAD_RCU(&ram_list.blocks, new_block, next);
+    }
+    ram_list.mru_block = NULL;
+
+    /* Write list before version */
+    smp_wmb();
+    ram_list.version++;
+}
+
+void ram_block_add_list(RAMBlock *new_block)
+{
+    qemu_mutex_lock_ramlist();
+    ram_block_add_list_locked(new_block);
+    qemu_mutex_unlock_ramlist();
+}
+
 static void ram_block_add(RAMBlock *new_block, Error **errp)
 {
     const bool noreserve = qemu_ram_is_noreserve(new_block);
     const bool shared = qemu_ram_is_shared(new_block);
-    RAMBlock *block;
-    RAMBlock *last_block = NULL;
     ram_addr_t old_ram_size, new_ram_size;
     Error *err = NULL;
 
@@ -1846,28 +1881,9 @@  static void ram_block_add(RAMBlock *new_block, Error **errp)
     if (new_ram_size > old_ram_size) {
         dirty_memory_extend(old_ram_size, new_ram_size);
     }
-    /* Keep the list sorted from biggest to smallest block.  Unlike QTAILQ,
-     * QLIST (which has an RCU-friendly variant) does not have insertion at
-     * tail, so save the last element in last_block.
-     */
-    RAMBLOCK_FOREACH(block) {
-        last_block = block;
-        if (block->max_length < new_block->max_length) {
-            break;
-        }
-    }
-    if (block) {
-        QLIST_INSERT_BEFORE_RCU(block, new_block, next);
-    } else if (last_block) {
-        QLIST_INSERT_AFTER_RCU(last_block, new_block, next);
-    } else { /* list is empty */
-        QLIST_INSERT_HEAD_RCU(&ram_list.blocks, new_block, next);
-    }
-    ram_list.mru_block = NULL;
 
-    /* Write list before version */
-    smp_wmb();
-    ram_list.version++;
+    ram_block_add_list_locked(new_block);
+
     qemu_mutex_unlock_ramlist();
 
     cpu_physical_memory_set_dirty_range(new_block->offset,