[Qemu-devel] Re: [patch uq/master 5/8] Export qemu_ram_addr_from_host

[Marcelo Tosatti]

On Tue, Oct 05, 2010 at 07:57:14AM -0500, Anthony Liguori wrote:
> On 10/04/2010 01:54 PM, Marcelo Tosatti wrote:
> >To be used by next patches.
> >
> >Signed-off-by: Marcelo Tosatti<address@hidden>
> >
> >Index: qemu/cpu-common.h
> >===================================================================
> >--- qemu.orig/cpu-common.h
> >+++ qemu/cpu-common.h
> >@@ -47,6 +47,7 @@ void qemu_ram_free(ram_addr_t addr);
> >  /* This should only be used for ram local to a device.  */
> >  void *qemu_get_ram_ptr(ram_addr_t addr);
> >  /* This should not be used by devices.  */
> >+int do_qemu_ram_addr_from_host(void *ptr, ram_addr_t *ram_addr);
> 
> This is not a great name for a function.  A better way to do this
> would be to make the existing qemu_ram_addr_from_host() ->
> qemu_ram_addr_from_host_nofail().

It should fail for all callers in tree now, where address from
qemu_get_ram_ptr() is saved somewhere. MCE handler is an exception to
that.

Are you OK with this:


Index: qemu/cpu-common.h
===================================================================
--- qemu.orig/cpu-common.h
+++ qemu/cpu-common.h
@@ -47,6 +47,7 @@ void qemu_ram_free(ram_addr_t addr);
 /* This should only be used for ram local to a device.  */
 void *qemu_get_ram_ptr(ram_addr_t addr);
 /* This should not be used by devices.  */
+int qemu_ram_addr_from_host_nofail(void *ptr, ram_addr_t *ram_addr);
 ram_addr_t qemu_ram_addr_from_host(void *ptr);
 
 int cpu_register_io_memory(CPUReadMemoryFunc * const *mem_read,
Index: qemu/exec.c
===================================================================
--- qemu.orig/exec.c
+++ qemu/exec.c
@@ -2938,23 +2938,31 @@ void *qemu_get_ram_ptr(ram_addr_t addr)
     return NULL;
 }
 
-/* Some of the softmmu routines need to translate from a host pointer
-   (typically a TLB entry) back to a ram offset.  */
-ram_addr_t qemu_ram_addr_from_host(void *ptr)
+int qemu_ram_addr_from_host_nofail(void *ptr, ram_addr_t *ram_addr)
 {
     RAMBlock *block;
     uint8_t *host = ptr;
 
     QLIST_FOREACH(block, &ram_list.blocks, next) {
         if (host - block->host < block->length) {
-            return block->offset + (host - block->host);
+            *ram_addr = block->offset + (host - block->host);
+            return 0;
         }
     }
+    return -1;
+}
 
-    fprintf(stderr, "Bad ram pointer %p\n", ptr);
-    abort();
+/* Some of the softmmu routines need to translate from a host pointer
+   (typically a TLB entry) back to a ram offset.  */
+ram_addr_t qemu_ram_addr_from_host(void *ptr)
+{
+    ram_addr_t ram_addr;
 
-    return 0;
+    if (qemu_ram_addr_from_host_nofail(ptr, &ram_addr)) {
+        fprintf(stderr, "Bad ram pointer %p\n", ptr);
+        abort();
+    }
+    return ram_addr;
 }
 
 static uint32_t unassigned_mem_readb(void *opaque, target_phys_addr_t addr)