diff mbox series

[v2,10/11] hw/openrisc: virt: pass random seed to fdt

Message ID 20220703212823.10067-11-shorne@gmail.com
State New
Headers show
Series OpenRISC Virtual Machine | expand

Commit Message

Stafford Horne July 3, 2022, 9:28 p.m. UTC 
From: "Jason A. Donenfeld" <Jason@zx2c4.com>

If the FDT contains /chosen/rng-seed, then the Linux RNG will use it to
initialize early. Set this using the usual guest random number
generation function. This is confirmed to successfully initialize the
RNG on Linux 5.19-rc2.

Cc: Stafford Horne <shorne@gmail.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Stafford Horne <shorne@gmail.com>
---
 hw/openrisc/virt.c | 6 ++++++
 1 file changed, 6 insertions(+)

Comments

Richard Henderson July 4, 2022, 10:22 a.m. UTC | #1 
On 7/4/22 02:58, Stafford Horne wrote:
> From: "Jason A. Donenfeld" <Jason@zx2c4.com>
> 
> If the FDT contains /chosen/rng-seed, then the Linux RNG will use it to
> initialize early. Set this using the usual guest random number
> generation function. This is confirmed to successfully initialize the
> RNG on Linux 5.19-rc2.
> 
> Cc: Stafford Horne <shorne@gmail.com>
> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
> Signed-off-by: Stafford Horne <shorne@gmail.com>

You could remove yourself from cc now that you've signed it.  :-)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~
diff mbox series

Patch

diff --git a/hw/openrisc/virt.c b/hw/openrisc/virt.c
index f1d1293eeb..a301d0d769 100644
--- a/hw/openrisc/virt.c
+++ b/hw/openrisc/virt.c
@@ -8,6 +8,7 @@ 
 
 #include "qemu/osdep.h"
 #include "qemu/error-report.h"
+#include "qemu/guest-random.h"
 #include "qapi/error.h"
 #include "cpu.h"
 #include "exec/address-spaces.h"
@@ -130,6 +131,7 @@  static void openrisc_create_fdt(OR1KVirtState *state,
     void *fdt;
     int cpu;
     char *nodename;
+    uint8_t rng_seed[32];
 
     fdt = state->fdt = create_device_tree(&state->fdt_size);
     if (!fdt) {
@@ -186,6 +188,10 @@  static void openrisc_create_fdt(OR1KVirtState *state,
         qemu_fdt_setprop_string(fdt, "/chosen", "bootargs", cmdline);
     }
 
+    /* Pass seed to RNG. */
+    qemu_guest_getrandom_nofail(rng_seed, sizeof(rng_seed));
+    qemu_fdt_setprop(fdt, "/chosen", "rng-seed", rng_seed, sizeof(rng_seed));
+
     /* Create aliases node for use by devices. */
     qemu_fdt_add_subnode(fdt, "/aliases");
 }