diff mbox series

[PULL,09/14] physmem: disallow direct access to RAM DEVICE in address_space_write_rom()

Message ID 20250211225059.182533-10-peterx@redhat.com (mailing list archive)
State New
Headers show
Series [PULL,01/14] system/physmem: take into account fd_offset for file fallocate | expand

Commit Message

Peter Xu Feb. 11, 2025, 10:50 p.m. UTC 
From: David Hildenbrand <david@redhat.com>

As documented in commit 4a2e242bbb306 ("memory: Don't use memcpy for
ram_device regions"), we disallow direct access to RAM DEVICE regions.

This change implies that address_space_write_rom() and
cpu_memory_rw_debug() won't be able to write to RAM DEVICE regions. It
will also affect cpu_flush_icache_range(), but it's only used by
hw/core/loader.c after writing to ROM, so it is expected to not apply
here with RAM DEVICE.

This fixes direct access to these regions where we don't want direct
access. We'll extend cpu_memory_rw_debug() next to also be able to write to
these (and IO) regions.

This is a preparation for further changes.

Cc: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20250210084648.33798-5-david@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
---
 system/physmem.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/system/physmem.c b/system/physmem.c
index 235015f3ea..cff15ca1df 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -3137,8 +3137,7 @@  static inline MemTxResult address_space_write_rom_internal(AddressSpace *as,
         l = len;
         mr = address_space_translate(as, addr, &addr1, &l, true, attrs);
 
-        if (!(memory_region_is_ram(mr) ||
-              memory_region_is_romd(mr))) {
+        if (!memory_region_supports_direct_access(mr)) {
             l = memory_access_size(mr, l, addr1);
         } else {
             /* ROM/RAM case */