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From: "Philippe Mathieu-Daudé" <philmd@linaro.org>
To: qemu-devel@nongnu.org
Cc: "Michael S. Tsirkin" <mst@redhat.com>,
	"Nicholas Piggin" <npiggin@gmail.com>,
	"Elena Ufimtseva" <elena.ufimtseva@oracle.com>,
	qemu-arm@nongnu.org, "Jagannathan Raman" <jag.raman@oracle.com>,
	"David Hildenbrand" <david@redhat.com>,
	"Philippe Mathieu-Daudé" <philmd@linaro.org>,
	"Halil Pasic" <pasic@linux.ibm.com>,
	"Eric Farman" <farman@linux.ibm.com>,
	"Thomas Huth" <thuth@redhat.com>,
	"Matthew Rosato" <mjrosato@linux.ibm.com>,
	"Jason Herne" <jjherne@linux.ibm.com>,
	"Cédric Le Goater" <clg@redhat.com>,
	kvm@vger.kernel.org,
	"Christian Borntraeger" <borntraeger@linux.ibm.com>,
	"Ilya Leoshkevich" <iii@linux.ibm.com>,
	"Peter Maydell" <peter.maydell@linaro.org>,
	qemu-ppc@nongnu.org, "Harsh Prateek Bora" <harshpb@linux.ibm.com>,
	"Fabiano Rosas" <farosas@suse.de>,
	"Richard Henderson" <richard.henderson@linaro.org>,
	"Alex Williamson" <alex.williamson@redhat.com>,
	"Paolo Bonzini" <pbonzini@redhat.com>,
	qemu-s390x@nongnu.org, "Peter Xu" <peterx@redhat.com>
Subject: [PATCH 23/25] system/physmem: Reduce cpu_physical_memory_sync_dirty_bitmap() scope
Date: Wed,  1 Oct 2025 10:21:23 +0200	[thread overview]
Message-ID: <20251001082127.65741-24-philmd@linaro.org> (raw)
In-Reply-To: <20251001082127.65741-1-philmd@linaro.org>

cpu_physical_memory_sync_dirty_bitmap() is now only called within
system/physmem.c, by ramblock_sync_dirty_bitmap(). Reduce its scope
by making it internal to this file. Since it doesn't involve any CPU,
remove the 'cpu_' prefix.
Remove the now unneeded "qemu/rcu.h" and "system/memory.h" headers.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 include/system/ram_addr.h | 79 ---------------------------------------
 migration/ram.c           | 78 +++++++++++++++++++++++++++++++++++++-
 2 files changed, 77 insertions(+), 80 deletions(-)

diff --git a/include/system/ram_addr.h b/include/system/ram_addr.h
index c55e3849b0e..24dba1fba1c 100644
--- a/include/system/ram_addr.h
+++ b/include/system/ram_addr.h
@@ -21,10 +21,7 @@
 
 #include "exec/ramlist.h"
 #include "system/ramblock.h"
-#include "system/memory.h"
 #include "exec/target_page.h"
-#include "qemu/rcu.h"
-
 #include "exec/hwaddr.h"
 
 extern uint64_t total_dirty_pages;
@@ -177,80 +174,4 @@ bool cpu_physical_memory_snapshot_get_dirty(DirtyBitmapSnapshot *snap,
                                             ram_addr_t start,
                                             ram_addr_t length);
 
-/* Called with RCU critical section */
-static inline
-uint64_t cpu_physical_memory_sync_dirty_bitmap(RAMBlock *rb,
-                                               ram_addr_t start,
-                                               ram_addr_t length)
-{
-    ram_addr_t addr;
-    unsigned long word = BIT_WORD((start + rb->offset) >> TARGET_PAGE_BITS);
-    uint64_t num_dirty = 0;
-    unsigned long *dest = rb->bmap;
-
-    /* start address and length is aligned at the start of a word? */
-    if (((word * BITS_PER_LONG) << TARGET_PAGE_BITS) ==
-         (start + rb->offset) &&
-        !(length & ((BITS_PER_LONG << TARGET_PAGE_BITS) - 1))) {
-        int k;
-        int nr = BITS_TO_LONGS(length >> TARGET_PAGE_BITS);
-        unsigned long * const *src;
-        unsigned long idx = (word * BITS_PER_LONG) / DIRTY_MEMORY_BLOCK_SIZE;
-        unsigned long offset = BIT_WORD((word * BITS_PER_LONG) %
-                                        DIRTY_MEMORY_BLOCK_SIZE);
-        unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
-
-        src = qatomic_rcu_read(
-                &ram_list.dirty_memory[DIRTY_MEMORY_MIGRATION])->blocks;
-
-        for (k = page; k < page + nr; k++) {
-            if (src[idx][offset]) {
-                unsigned long bits = qatomic_xchg(&src[idx][offset], 0);
-                unsigned long new_dirty;
-                new_dirty = ~dest[k];
-                dest[k] |= bits;
-                new_dirty &= bits;
-                num_dirty += ctpopl(new_dirty);
-            }
-
-            if (++offset >= BITS_TO_LONGS(DIRTY_MEMORY_BLOCK_SIZE)) {
-                offset = 0;
-                idx++;
-            }
-        }
-        if (num_dirty) {
-            cpu_physical_memory_dirty_bits_cleared(start, length);
-        }
-
-        if (rb->clear_bmap) {
-            /*
-             * Postpone the dirty bitmap clear to the point before we
-             * really send the pages, also we will split the clear
-             * dirty procedure into smaller chunks.
-             */
-            clear_bmap_set(rb, start >> TARGET_PAGE_BITS,
-                           length >> TARGET_PAGE_BITS);
-        } else {
-            /* Slow path - still do that in a huge chunk */
-            memory_region_clear_dirty_bitmap(rb->mr, start, length);
-        }
-    } else {
-        ram_addr_t offset = rb->offset;
-
-        for (addr = 0; addr < length; addr += TARGET_PAGE_SIZE) {
-            if (cpu_physical_memory_test_and_clear_dirty(
-                        start + addr + offset,
-                        TARGET_PAGE_SIZE,
-                        DIRTY_MEMORY_MIGRATION)) {
-                long k = (start + addr) >> TARGET_PAGE_BITS;
-                if (!test_and_set_bit(k, dest)) {
-                    num_dirty++;
-                }
-            }
-        }
-    }
-
-    return num_dirty;
-}
-
 #endif
diff --git a/migration/ram.c b/migration/ram.c
index 91e65be83d8..e797c0710d3 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -935,11 +935,87 @@ bool ramblock_page_is_discarded(RAMBlock *rb, ram_addr_t start)
     return false;
 }
 
+/* Called with RCU critical section */
+static inline
+uint64_t physical_memory_sync_dirty_bitmap(RAMBlock *rb,
+                                           ram_addr_t start,
+                                           ram_addr_t length)
+{
+    ram_addr_t addr;
+    unsigned long word = BIT_WORD((start + rb->offset) >> TARGET_PAGE_BITS);
+    uint64_t num_dirty = 0;
+    unsigned long *dest = rb->bmap;
+
+    /* start address and length is aligned at the start of a word? */
+    if (((word * BITS_PER_LONG) << TARGET_PAGE_BITS) ==
+         (start + rb->offset) &&
+        !(length & ((BITS_PER_LONG << TARGET_PAGE_BITS) - 1))) {
+        int k;
+        int nr = BITS_TO_LONGS(length >> TARGET_PAGE_BITS);
+        unsigned long * const *src;
+        unsigned long idx = (word * BITS_PER_LONG) / DIRTY_MEMORY_BLOCK_SIZE;
+        unsigned long offset = BIT_WORD((word * BITS_PER_LONG) %
+                                        DIRTY_MEMORY_BLOCK_SIZE);
+        unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
+
+        src = qatomic_rcu_read(
+                &ram_list.dirty_memory[DIRTY_MEMORY_MIGRATION])->blocks;
+
+        for (k = page; k < page + nr; k++) {
+            if (src[idx][offset]) {
+                unsigned long bits = qatomic_xchg(&src[idx][offset], 0);
+                unsigned long new_dirty;
+                new_dirty = ~dest[k];
+                dest[k] |= bits;
+                new_dirty &= bits;
+                num_dirty += ctpopl(new_dirty);
+            }
+
+            if (++offset >= BITS_TO_LONGS(DIRTY_MEMORY_BLOCK_SIZE)) {
+                offset = 0;
+                idx++;
+            }
+        }
+        if (num_dirty) {
+            cpu_physical_memory_dirty_bits_cleared(start, length);
+        }
+
+        if (rb->clear_bmap) {
+            /*
+             * Postpone the dirty bitmap clear to the point before we
+             * really send the pages, also we will split the clear
+             * dirty procedure into smaller chunks.
+             */
+            clear_bmap_set(rb, start >> TARGET_PAGE_BITS,
+                           length >> TARGET_PAGE_BITS);
+        } else {
+            /* Slow path - still do that in a huge chunk */
+            memory_region_clear_dirty_bitmap(rb->mr, start, length);
+        }
+    } else {
+        ram_addr_t offset = rb->offset;
+
+        for (addr = 0; addr < length; addr += TARGET_PAGE_SIZE) {
+            if (cpu_physical_memory_test_and_clear_dirty(
+                        start + addr + offset,
+                        TARGET_PAGE_SIZE,
+                        DIRTY_MEMORY_MIGRATION)) {
+                long k = (start + addr) >> TARGET_PAGE_BITS;
+                if (!test_and_set_bit(k, dest)) {
+                    num_dirty++;
+                }
+            }
+        }
+    }
+
+    return num_dirty;
+}
+
 /* Called with RCU critical section */
 static void ramblock_sync_dirty_bitmap(RAMState *rs, RAMBlock *rb)
 {
     uint64_t new_dirty_pages =
-        cpu_physical_memory_sync_dirty_bitmap(rb, 0, rb->used_length);
+        physical_memory_sync_dirty_bitmap(rb, 0, rb->used_length);
 
     rs->migration_dirty_pages += new_dirty_pages;
     rs->num_dirty_pages_period += new_dirty_pages;
-- 
2.51.0



  parent reply	other threads:[~2025-10-01  8:26 UTC|newest]

Thread overview: 50+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-10-01  8:21 [PATCH 00/25] system/physmem: Extract API out of 'system/ram_addr.h' header Philippe Mathieu-Daudé
2025-10-01  8:21 ` [PATCH 01/25] system/ram_addr: Remove unnecessary 'exec/cpu-common.h' header Philippe Mathieu-Daudé
2025-10-01  8:41   ` Thomas Huth
2025-10-01 14:30   ` Richard Henderson
2025-10-01  8:21 ` [PATCH 02/25] accel/kvm: Include missing 'exec/target_page.h' header Philippe Mathieu-Daudé
2025-10-01 14:30   ` Richard Henderson
2025-10-01  8:21 ` [PATCH 03/25] hw/s390x/s390-stattrib: " Philippe Mathieu-Daudé
2025-10-01 14:49   ` Richard Henderson
2025-10-06 13:01   ` Thomas Huth
2025-10-01  8:21 ` [PATCH 04/25] hw/vfio/listener: " Philippe Mathieu-Daudé
2025-10-01 14:50   ` Richard Henderson
2025-10-01  8:21 ` [PATCH 05/25] target/arm/tcg/mte: " Philippe Mathieu-Daudé
2025-10-01 14:50   ` Richard Henderson
2025-10-01  8:21 ` [PATCH 06/25] hw: Remove unnecessary 'system/ram_addr.h' header Philippe Mathieu-Daudé
2025-10-01 14:53   ` Richard Henderson
2025-10-06 13:02   ` Thomas Huth
2025-10-06 13:12   ` Michael S. Tsirkin
2025-10-01  8:21 ` [PATCH 07/25] accel/tcg: Document rcu_read_lock is held when calling tlb_reset_dirty() Philippe Mathieu-Daudé
2025-10-01 14:58   ` Richard Henderson
2025-10-01  8:21 ` [PATCH 08/25] accel/tcg: Rename @start argument of tlb_reset_dirty*() Philippe Mathieu-Daudé
2025-10-01 15:06   ` Richard Henderson
2025-10-01  8:21 ` [PATCH 09/25] system/physmem: Rename @start argument of physical_memory_get_dirty() Philippe Mathieu-Daudé
2025-10-01  8:21 ` [PATCH 10/25] system/physmem: Un-inline cpu_physical_memory_get_dirty_flag() Philippe Mathieu-Daudé
2025-10-01 15:07   ` Richard Henderson
2025-10-01  8:21 ` [PATCH 11/25] system/physmem: Un-inline cpu_physical_memory_is_clean() Philippe Mathieu-Daudé
2025-10-01 15:09   ` Richard Henderson
2025-10-01  8:21 ` [PATCH 12/25] system/physmem: Rename @start argument of physical_memory_all_dirty() Philippe Mathieu-Daudé
2025-10-01  8:21 ` [PATCH 13/25] system/physmem: Rename @start argument of physical_memory_range*() Philippe Mathieu-Daudé
2025-10-01  8:21 ` [PATCH 14/25] system/physmem: Un-inline cpu_physical_memory_range_includes_clean() Philippe Mathieu-Daudé
2025-10-01 15:15   ` Richard Henderson
2025-10-01  8:21 ` [PATCH 15/25] system/physmem: Un-inline cpu_physical_memory_set_dirty_flag() Philippe Mathieu-Daudé
2025-10-01 15:16   ` Richard Henderson
2025-10-01  8:21 ` [PATCH 16/25] system/physmem: Rename @start argument of physical_memory_*range() Philippe Mathieu-Daudé
2025-10-01  8:21 ` [PATCH 17/25] system/physmem: Un-inline cpu_physical_memory_set_dirty_range() Philippe Mathieu-Daudé
2025-10-01 15:17   ` Richard Henderson
2025-10-01  8:21 ` [PATCH 18/25] system/physmem: Un-inline cpu_physical_memory_set_dirty_lebitmap() Philippe Mathieu-Daudé
2025-10-01 15:23   ` Richard Henderson
2025-10-01  8:21 ` [PATCH 19/25] system/physmem: Rename @start argument of physmem_dirty_bits_cleared() Philippe Mathieu-Daudé
2025-10-01  8:21 ` [PATCH 20/25] system/physmem: Un-inline cpu_physical_memory_dirty_bits_cleared() Philippe Mathieu-Daudé
2025-10-01 15:50   ` Richard Henderson
2025-10-01  8:21 ` [PATCH 21/25] system/physmem: Rename @start argument of physmem_test_and_clear_dirty() Philippe Mathieu-Daudé
2025-10-01  8:21 ` [PATCH 22/25] system/physmem: Reduce cpu_physical_memory_clear_dirty_range() scope Philippe Mathieu-Daudé
2025-10-01 15:51   ` Richard Henderson
2025-10-01  8:21 ` Philippe Mathieu-Daudé [this message]
2025-10-01 15:53   ` [PATCH 23/25] system/physmem: Reduce cpu_physical_memory_sync_dirty_bitmap() scope Richard Henderson
2025-10-01  8:21 ` [PATCH 24/25] system/physmem: Drop 'cpu_' prefix in Physical Memory API Philippe Mathieu-Daudé
2025-10-01 15:54   ` Richard Henderson
2025-10-01  8:21 ` [PATCH 25/25] system/physmem: Extract API out of 'system/ram_addr.h' header Philippe Mathieu-Daudé
2025-10-01 15:55   ` Richard Henderson
2025-10-01  8:25 ` [PATCH 00/25] " Philippe Mathieu-Daudé

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