[Qemu-devel] [PATCH 2/2] memory: hide mr->ram_addr from qemu_get_ram_ptr users

[Paolo Bonzini]

Let users of qemu_get_ram_ptr and qemu_ram_ptr_length pass in an
address that is relative to the MemoryRegion.  This basically means
what address_space_translate returns.

invalidate_and_set_dirty has to add back mr->ram_addr, but reads do
not need it at all.

Signed-off-by: Paolo Bonzini <address@hidden>
---
 exec.c                       | 40 +++++++++++++++-------------------------
 include/exec/memory.h        |  1 -
 memory.c                     |  4 ++--
 scripts/dump-guest-memory.py | 19 +++----------------
 4 files changed, 20 insertions(+), 44 deletions(-)

diff --git a/exec.c b/exec.c
index 001b669..ca9e3b6 100644
--- a/exec.c
+++ b/exec.c
@@ -1876,6 +1876,7 @@ void *qemu_get_ram_ptr(RAMBlock *ram_block, ram_addr_t 
addr)
 
     if (block == NULL) {
         block = qemu_get_ram_block(addr);
+        addr -= block->offset;
     }
 
     if (xen_enabled() && block->host == NULL) {
@@ -1889,7 +1890,7 @@ void *qemu_get_ram_ptr(RAMBlock *ram_block, ram_addr_t 
addr)
 
         block->host = xen_map_cache(block->offset, block->max_length, 1);
     }
-    return ramblock_ptr(block, addr - block->offset);
+    return ramblock_ptr(block, addr);
 }
 
 /* Return a host pointer to guest's ram. Similar to qemu_get_ram_ptr
@@ -1901,16 +1902,15 @@ static void *qemu_ram_ptr_length(RAMBlock *ram_block, 
ram_addr_t addr,
                                  hwaddr *size)
 {
     RAMBlock *block = ram_block;
-    ram_addr_t offset_inside_block;
     if (*size == 0) {
         return NULL;
     }
 
     if (block == NULL) {
         block = qemu_get_ram_block(addr);
+        addr -= block->offset;
     }
-    offset_inside_block = addr - block->offset;
-    *size = MIN(*size, block->max_length - offset_inside_block);
+    *size = MIN(*size, block->max_length - addr);
 
     if (xen_enabled() && block->host == NULL) {
         /* We need to check if the requested address is in the RAM
@@ -1924,7 +1924,7 @@ static void *qemu_ram_ptr_length(RAMBlock *ram_block, 
ram_addr_t addr,
         block->host = xen_map_cache(block->offset, block->max_length, 1);
     }
 
-    return ramblock_ptr(block, offset_inside_block);
+    return ramblock_ptr(block, addr);
 }
 
 /*
@@ -2504,6 +2504,8 @@ static void invalidate_and_set_dirty(MemoryRegion *mr, 
hwaddr addr,
                                      hwaddr length)
 {
     uint8_t dirty_log_mask = memory_region_get_dirty_log_mask(mr);
+    addr += memory_region_get_ram_addr(mr);
+
     /* No early return if dirty_log_mask is or becomes 0, because
      * cpu_physical_memory_set_dirty_range will still call
      * xen_modified_memory.
@@ -2616,7 +2618,6 @@ static MemTxResult 
address_space_write_continue(AddressSpace *as, hwaddr addr,
                 abort();
             }
         } else {
-            addr1 += memory_region_get_ram_addr(mr);
             /* RAM case */
             ptr = qemu_get_ram_ptr(mr->ram_block, addr1);
             memcpy(ptr, buf, l);
@@ -2709,8 +2710,7 @@ MemTxResult address_space_read_continue(AddressSpace *as, 
hwaddr addr,
             }
         } else {
             /* RAM case */
-            ptr = qemu_get_ram_ptr(mr->ram_block,
-                                   memory_region_get_ram_addr(mr) + addr1);
+            ptr = qemu_get_ram_ptr(mr->ram_block, addr1);
             memcpy(buf, ptr, l);
         }
 
@@ -2793,7 +2793,6 @@ static inline void 
cpu_physical_memory_write_rom_internal(AddressSpace *as,
               memory_region_is_romd(mr))) {
             l = memory_access_size(mr, l, addr1);
         } else {
-            addr1 += memory_region_get_ram_addr(mr);
             /* ROM/RAM case */
             ptr = qemu_get_ram_ptr(mr->ram_block, addr1);
             switch (type) {
@@ -2953,7 +2952,6 @@ void *address_space_map(AddressSpace *as,
     hwaddr done = 0;
     hwaddr l, xlat, base;
     MemoryRegion *mr, *this_mr;
-    ram_addr_t raddr;
     void *ptr;
 
     if (len == 0) {
@@ -2962,7 +2960,7 @@ void *address_space_map(AddressSpace *as,
 
     l = len;
     rcu_read_lock();
-    mr = address_space_translate(as, addr, &xlat, &l, is_write);
+    mr = address_space_translate(as, addr, &base, &l, is_write);
 
     if (!memory_access_is_direct(mr, is_write)) {
         if (atomic_xchg(&bounce.in_use, true)) {
@@ -2987,9 +2985,6 @@ void *address_space_map(AddressSpace *as,
         return bounce.buffer;
     }
 
-    base = xlat;
-    raddr = memory_region_get_ram_addr(mr);
-
     for (;;) {
         len -= l;
         addr += l;
@@ -3007,7 +3002,7 @@ void *address_space_map(AddressSpace *as,
 
     memory_region_ref(mr);
     *plen = done;
-    ptr = qemu_ram_ptr_length(mr->ram_block, raddr + base, plen);
+    ptr = qemu_ram_ptr_length(mr->ram_block, base, plen);
     rcu_read_unlock();
 
     return ptr;
@@ -3091,8 +3086,7 @@ static inline uint32_t 
address_space_ldl_internal(AddressSpace *as, hwaddr addr,
 #endif
     } else {
         /* RAM case */
-        ptr = qemu_get_ram_ptr(mr->ram_block,
-                               memory_region_get_ram_addr(mr) + addr1);
+        ptr = qemu_get_ram_ptr(mr->ram_block, addr1);
         switch (endian) {
         case DEVICE_LITTLE_ENDIAN:
             val = ldl_le_p(ptr);
@@ -3185,8 +3179,7 @@ static inline uint64_t 
address_space_ldq_internal(AddressSpace *as, hwaddr addr,
 #endif
     } else {
         /* RAM case */
-        ptr = qemu_get_ram_ptr(mr->ram_block,
-                               memory_region_get_ram_addr(mr) + addr1);
+        ptr = qemu_get_ram_ptr(mr->ram_block, addr1);
         switch (endian) {
         case DEVICE_LITTLE_ENDIAN:
             val = ldq_le_p(ptr);
@@ -3299,8 +3292,7 @@ static inline uint32_t 
address_space_lduw_internal(AddressSpace *as,
 #endif
     } else {
         /* RAM case */
-        ptr = qemu_get_ram_ptr(mr->ram_block,
-                               memory_region_get_ram_addr(mr) + addr1);
+        ptr = qemu_get_ram_ptr(mr->ram_block, addr1);
         switch (endian) {
         case DEVICE_LITTLE_ENDIAN:
             val = lduw_le_p(ptr);
@@ -3382,13 +3374,13 @@ void address_space_stl_notdirty(AddressSpace *as, 
hwaddr addr, uint32_t val,
 
         r = memory_region_dispatch_write(mr, addr1, val, 4, attrs);
     } else {
-        addr1 += memory_region_get_ram_addr(mr);
         ptr = qemu_get_ram_ptr(mr->ram_block, addr1);
         stl_p(ptr, val);
 
         dirty_log_mask = memory_region_get_dirty_log_mask(mr);
         dirty_log_mask &= ~(1 << DIRTY_MEMORY_CODE);
-        cpu_physical_memory_set_dirty_range(addr1, 4, dirty_log_mask);
+        cpu_physical_memory_set_dirty_range(memory_region_get_ram_addr(mr) + 
addr,
+                                            4, dirty_log_mask);
         r = MEMTX_OK;
     }
     if (result) {
@@ -3437,7 +3429,6 @@ static inline void 
address_space_stl_internal(AddressSpace *as,
         r = memory_region_dispatch_write(mr, addr1, val, 4, attrs);
     } else {
         /* RAM case */
-        addr1 += memory_region_get_ram_addr(mr);
         ptr = qemu_get_ram_ptr(mr->ram_block, addr1);
         switch (endian) {
         case DEVICE_LITTLE_ENDIAN:
@@ -3547,7 +3538,6 @@ static inline void 
address_space_stw_internal(AddressSpace *as,
         r = memory_region_dispatch_write(mr, addr1, val, 2, attrs);
     } else {
         /* RAM case */
-        addr1 += memory_region_get_ram_addr(mr);
         ptr = qemu_get_ram_ptr(mr->ram_block, addr1);
         switch (endian) {
         case DEVICE_LITTLE_ENDIAN:
diff --git a/include/exec/memory.h b/include/exec/memory.h
index 2de7898..326c2a2 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -1419,7 +1419,6 @@ MemTxResult address_space_read(AddressSpace *as, hwaddr 
addr, MemTxAttrs attrs,
             l = len;
             mr = address_space_translate(as, addr, &addr1, &l, false);
             if (len == l && memory_access_is_direct(mr, false)) {
-                addr1 += memory_region_get_ram_addr(mr);
                 ptr = qemu_get_ram_ptr(mr->ram_block, addr1);
                 memcpy(buf, ptr, len);
             } else {
diff --git a/memory.c b/memory.c
index 49c9b14..bc47d0b 100644
--- a/memory.c
+++ b/memory.c
@@ -1654,10 +1654,10 @@ void *memory_region_get_ram_ptr(MemoryRegion *mr)
         mr = mr->alias;
     }
     assert(mr->ram_block);
-    ptr = qemu_get_ram_ptr(mr->ram_block, memory_region_get_ram_addr(mr));
+    ptr = qemu_get_ram_ptr(mr->ram_block, offset);
     rcu_read_unlock();
 
-    return ptr + offset;
+    return ptr;
 }
 
 ram_addr_t memory_region_get_ram_addr(MemoryRegion *mr)
diff --git a/scripts/dump-guest-memory.py b/scripts/dump-guest-memory.py
index c0a2e99..ae21f97 100644
--- a/scripts/dump-guest-memory.py
+++ b/scripts/dump-guest-memory.py
@@ -328,23 +328,10 @@ def qlist_foreach(head, field_str):
         yield var
 
 
-def qemu_get_ram_block(ram_addr):
-    """Returns the RAMBlock struct to which the given address belongs."""
-
-    ram_blocks = gdb.parse_and_eval("ram_list.blocks")
-
-    for block in qlist_foreach(ram_blocks, "next"):
-        if (ram_addr - block["offset"]) < block["used_length"]:
-            return block
-
-    raise gdb.GdbError("Bad ram offset %x" % ram_addr)
-
-
-def qemu_get_ram_ptr(ram_addr):
+def qemu_get_ram_ptr(block, offset):
     """Returns qemu vaddr for given guest physical address."""
 
-    block = qemu_get_ram_block(ram_addr)
-    return block["host"] + (ram_addr - block["offset"])
+    return block["host"] + offset
 
 
 def memory_region_get_ram_ptr(memory_region):
@@ -352,7 +339,7 @@ def memory_region_get_ram_ptr(memory_region):
         return (memory_region_get_ram_ptr(memory_region["alias"].dereference())
                 + memory_region["alias_offset"])
 
-    return qemu_get_ram_ptr(memory_region["ram_block"]["offset"])
+    return qemu_get_ram_ptr(memory_region["ram_block"], 0)
 
 
 def get_guest_phys_blocks():
-- 
1.8.3.1