Re: [RFC v1 10/25] hw/core/loader: Add a ROM loader notifier

[Gavin Shan]

On 7/8/26 8:42 AM, Mathieu Poirier wrote:

From: Jean-Philippe Brucker <jean-phili...@linaro.org>

Add a function to register a notifier that is invoked when ROMs get
loaded into guest memory.

It will be used by Arm confidential guest support, in order to register
all blobs loaded into memory with KVM, so that their content is moved
into Realm state and measured into the initial VM state.

Signed-off-by: Jean-Philippe Brucker <jean-phili...@linaro.org>
Signed-off-by: Mathieu Poirier <mathieu.poir...@linaro.org>
---
  hw/core/loader.c         | 15 +++++++++++++++
  include/hw/core/loader.h | 17 +++++++++++++++++
  2 files changed, 32 insertions(+)

diff --git a/hw/core/loader.c b/hw/core/loader.c
index 5cbfba0a86d2..b3d769bec5cb 100644
--- a/hw/core/loader.c
+++ b/hw/core/loader.c
@@ -74,6 +74,8 @@
  #endif

The (edk2) firmware for the realm guest can be specified by the legacy
'-drive if=pflash' or '-bios'. The memory region corresponding to the
firmware image specified by '-bios' is recorded by the newly added notifier
and populated to TF-RMM properly.

I don't see how the memory region corresponding to (edk2) firmware image
specified by '-drive if=pflash' is recorded and populated to TF-RMM
accordingly in this series. So I guess '-drive if=pflash' isn't supported
yet?

Note that I didn't give '-drive if=pflash' a try yet.

  static int roms_loaded;
+static NotifierList rom_loader_notifier =
+    NOTIFIER_LIST_INITIALIZER(rom_loader_notifier);

/* return the size or -1 if error */

  int64_t get_image_size(const char *filename, Error **errp)
@@ -1201,6 +1203,11 @@ MemoryRegion *rom_add_blob(const char *name, const void 
*blob, size_t len,
      return mr;
  }

+void rom_add_load_notifier(Notifier *notifier)

+{
+    notifier_list_add(&rom_loader_notifier, notifier);
+}
+
  /* This function is specific for elf program because we don't need to allocate
   * all the rom. We just allocate the first part and the rest is just zeros. 
This
   * is why romsize and datasize are different. Also, this function takes its 
own
@@ -1242,6 +1249,7 @@ ssize_t rom_add_option(const char *file, int32_t 
bootindex)
  static void rom_reset(void *unused)
  {
      Rom *rom;
+    RomLoaderNotifyData notify;

QTAILQ_FOREACH(rom, &roms, next) {

          if (rom->fw_file) {
@@ -1290,6 +1298,13 @@ static void rom_reset(void *unused)
          address_space_flush_icache_range(rom->as, rom->addr, rom->datasize);

trace_loader_write_rom(rom->name, rom->addr, rom->datasize, rom->isrom);

+
+        notify = (RomLoaderNotifyData) {
+            .addr = rom->addr,
+            .len = rom->datasize,
+            .as = rom->as,
+        };
+        notifier_list_notify(&rom_loader_notifier, &notify);
      }
  }

diff --git a/include/hw/core/loader.h b/include/hw/core/loader.h

index d9431e8a8d12..94cf6ad2e26b 100644
--- a/include/hw/core/loader.h
+++ b/include/hw/core/loader.h
@@ -342,6 +342,23 @@ void *rom_ptr_for_as(AddressSpace *as, hwaddr addr, size_t 
size);
  ssize_t rom_add_vga(const char *file);
  ssize_t rom_add_option(const char *file, int32_t bootindex);

+typedef struct RomLoaderNotifyData {

+    /* Address of the blob in guest memory */
+    hwaddr addr;
+    /* Length of the blob */
+    size_t len;
+    /* Address space of the blob */
+    AddressSpace *as;
+} RomLoaderNotifyData;
+
+/**
+ * rom_add_load_notifier - Add a notifier for loaded images
+ *
+ * Add a notifier that will be invoked with a RomLoaderNotifyData structure for
+ * each blob loaded into guest memory, after the blob is loaded.
+ */
+void rom_add_load_notifier(Notifier *notifier);
+
  /* This is the usual maximum in uboot, so if a uImage overflows this, it would
   * overflow on real hardware too. */
  #define UBOOT_MAX_DECOMPRESSED_BYTES (64 << 20)

Thanks,
Gavin