[v2,8/8] reset: do not re-randomize RNG seed on snapshot load

Commit Message

Jason A. Donenfeld Oct. 11, 2022, 8:50 p.m. UTC

Snapshot loading is supposed to be deterministic, so we shouldn't
re-randomize the various seeds used.

Signed-off-by: Jason A. Donenfeld <[e-mail]>
---
 hw/arm/boot.c      | 3 ++-
 hw/i386/x86.c      | 2 +-
 hw/mips/boston.c   | 2 +-
 hw/openrisc/boot.c | 2 +-
 hw/riscv/boot.c    | 2 +-
 hw/rx/rx-gdbsim.c  | 2 +-
 6 files changed, 7 insertions(+), 6 deletions(-)

Patch

diff --git a/hw/arm/boot.c b/hw/arm/boot.c
index 6a6f4c92c2..511f7b22b1 100644
--- a/hw/arm/boot.c
+++ b/hw/arm/boot.c
@@ -683,7 +683,8 @@  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);
-    qemu_register_reset(qemu_fdt_randomize_seeds, rom_ptr_for_as(as, addr, size));
+    qemu_register_reset_nosnapshotload(qemu_fdt_randomize_seeds,
+                                       rom_ptr_for_as(as, addr, size));
 
     g_free(fdt);
 
diff --git a/hw/i386/x86.c b/hw/i386/x86.c
index 1148f70c03..bd50a064a3 100644
--- a/hw/i386/x86.c
+++ b/hw/i386/x86.c
@@ -1111,7 +1111,7 @@  void x86_load_linux(X86MachineState *x86ms,
         setup_data->type = cpu_to_le32(SETUP_RNG_SEED);
         setup_data->len = cpu_to_le32(RNG_SEED_LENGTH);
         qemu_guest_getrandom_nofail(setup_data->data, RNG_SEED_LENGTH);
-        qemu_register_reset(reset_rng_seed, setup_data);
+        qemu_register_reset_nosnapshotload(reset_rng_seed, setup_data);
         fw_cfg_add_bytes_callback(fw_cfg, FW_CFG_KERNEL_DATA, reset_rng_seed, NULL,
                                   setup_data, kernel, kernel_size, true);
     } else {
diff --git a/hw/mips/boston.c b/hw/mips/boston.c
index a560ce0324..cab63f43bf 100644
--- a/hw/mips/boston.c
+++ b/hw/mips/boston.c
@@ -811,7 +811,7 @@  static void boston_mach_init(MachineState *machine)
             /* Calculate real fdt size after filter */
             dt_size = fdt_totalsize(dtb_load_data);
             rom_add_blob_fixed("dtb", dtb_load_data, dt_size, dtb_paddr);
-            qemu_register_reset(qemu_fdt_randomize_seeds,
+            qemu_register_reset_nosnapshotload(qemu_fdt_randomize_seeds,
                                 rom_ptr(dtb_paddr, dt_size));
         } else {
             /* Try to load file as FIT */
diff --git a/hw/openrisc/boot.c b/hw/openrisc/boot.c
index 8b9f11b6d8..007e80cd5a 100644
--- a/hw/openrisc/boot.c
+++ b/hw/openrisc/boot.c
@@ -112,7 +112,7 @@  uint32_t openrisc_load_fdt(void *fdt, hwaddr load_start,
 
     rom_add_blob_fixed_as("fdt", fdt, fdtsize, fdt_addr,
                           &address_space_memory);
-    qemu_register_reset(qemu_fdt_randomize_seeds,
+    qemu_register_reset_nosnapshotload(qemu_fdt_randomize_seeds,
                         rom_ptr_for_as(&address_space_memory, fdt_addr, fdtsize));
 
     return fdt_addr;
diff --git a/hw/riscv/boot.c b/hw/riscv/boot.c
index aaecf21543..c389edb3cd 100644
--- a/hw/riscv/boot.c
+++ b/hw/riscv/boot.c
@@ -242,7 +242,7 @@  uint64_t riscv_load_fdt(hwaddr dram_base, uint64_t mem_size, void *fdt)
 
     rom_add_blob_fixed_as("fdt", fdt, fdtsize, fdt_addr,
                           &address_space_memory);
-    qemu_register_reset(qemu_fdt_randomize_seeds,
+    qemu_register_reset_nosnapshotload(qemu_fdt_randomize_seeds,
                         rom_ptr_for_as(&address_space_memory, fdt_addr, fdtsize));
 
     return fdt_addr;
diff --git a/hw/rx/rx-gdbsim.c b/hw/rx/rx-gdbsim.c
index 198d048964..47c17026c7 100644
--- a/hw/rx/rx-gdbsim.c
+++ b/hw/rx/rx-gdbsim.c
@@ -149,7 +149,7 @@  static void rx_gdbsim_init(MachineState *machine)
             dtb_offset = ROUND_DOWN(machine->ram_size - dtb_size, 16);
             rom_add_blob_fixed("dtb", dtb, dtb_size,
                                SDRAM_BASE + dtb_offset);
-            qemu_register_reset(qemu_fdt_randomize_seeds,
+            qemu_register_reset_nosnapshotload(qemu_fdt_randomize_seeds,
                                 rom_ptr(SDRAM_BASE + dtb_offset, dtb_size));
             /* Set dtb address to R1 */
             RX_CPU(first_cpu)->env.regs[1] = SDRAM_BASE + dtb_offset;