[RFC,09/16] hw/arm/boot: Populate realm memory with boot images

Commit Message

Jean-Philippe Brucker Jan. 27, 2023, 3:07 p.m. UTC

When using the Arm RME, register the images to be loaded into Realm
memory at boot. Two operations are needed for each image:
(1) INIT_IPA_REALM: mark the load addresses (IPA) as RAM with
    RMI_RTT_INIT_RIPAS.
(2) POPULATE_REALM: move the page into the Realm with RMI_DATA_CREATE.
    Its content contributes to the initial measurement.

The reason we separate (1) from (2) is that we may need to declare more
RAM than the image size. In particular booting arm64 Linux requires
reserving additional BSS space after the loaded image.

We could declare the whole guest RAM with INIT_IPA_REALM, though that
might be wasteful in terms of stage-2 mappings if the guest is not going
to use all that RAM.

Signed-off-by: Jean-Philippe Brucker <[e-mail]>
---
 hw/arm/boot.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

Patch

diff --git a/hw/arm/boot.c b/hw/arm/boot.c
index 15c2bf1867..115d3f5dcc 100644
--- a/hw/arm/boot.c
+++ b/hw/arm/boot.c
@@ -25,6 +25,7 @@ 
 #include "qemu/config-file.h"
 #include "qemu/option.h"
 #include "qemu/units.h"
+#include "kvm_arm.h"
 
 /* Kernel boot protocol is specified in the kernel docs
  * Documentation/arm/Booting and Documentation/arm64/booting.txt
@@ -192,9 +193,11 @@  static void write_bootloader(const char *name, hwaddr addr,
         code[i] = tswap32(insn);
     }
 
-    assert((len * sizeof(uint32_t)) < BOOTLOADER_MAX_SIZE);
+    len *= sizeof(uint32_t);
+    assert(len < BOOTLOADER_MAX_SIZE);
 
-    rom_add_blob_fixed_as(name, code, len * sizeof(uint32_t), addr, as);
+    rom_add_blob_fixed_as(name, code, len, addr, as);
+    kvm_arm_rme_add_blob(addr, len, len);
 
     g_free(code);
 }
@@ -683,6 +686,7 @@  int arm_load_dtb(hwaddr addr, const struct arm_boot_info *binfo,
      * the DTB is copied again upon reset, even if addr points into RAM.
      */
     rom_add_blob_fixed_as("dtb", fdt, size, addr, as);
+    kvm_arm_rme_add_blob(addr, size, size);
     qemu_register_reset_nosnapshotload(qemu_fdt_randomize_seeds,
                                        rom_ptr_for_as(as, addr, size));
 
@@ -964,6 +968,7 @@  static uint64_t load_aarch64_image(const char *filename, hwaddr mem_base,
 
     *entry = mem_base + kernel_load_offset;
     rom_add_blob_fixed_as(filename, buffer, size, *entry, as);
+    kvm_arm_rme_add_blob(*entry, size, kernel_size);
 
     g_free(buffer);
 
@@ -1119,6 +1124,7 @@  static void arm_setup_direct_kernel_boot(ARMCPU *cpu,
             initrd_size = 0;
         }
         info->initrd_size = initrd_size;
+        kvm_arm_rme_add_blob(info->initrd_start, initrd_size, initrd_size);
 
         fixupcontext[FIXUP_BOARDID] = info->board_id;
         fixupcontext[FIXUP_BOARD_SETUP] = info->board_setup_addr;