From e4b4f0b71ccbeb0157489c0904ba4957761528ff Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Mon, 13 Jun 2022 13:58:10 +0200 Subject: [PATCH] hw/riscv: virt: pass random seed to fdt 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: Alistair Francis Signed-off-by: Jason A. Donenfeld Reviewed-by: Bin Meng Message-Id: <20220613115810.178210-1-Jason@zx2c4.com> Signed-off-by: Alistair Francis --- hw/riscv/virt.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c index bc424dd2f5..f2ce5663a4 100644 --- a/hw/riscv/virt.c +++ b/hw/riscv/virt.c @@ -21,6 +21,7 @@ #include "qemu/osdep.h" #include "qemu/units.h" #include "qemu/error-report.h" +#include "qemu/guest-random.h" #include "qapi/error.h" #include "hw/boards.h" #include "hw/loader.h" @@ -998,6 +999,7 @@ static void create_fdt(RISCVVirtState *s, const MemMapEntry *memmap, MachineState *mc = MACHINE(s); uint32_t phandle = 1, irq_mmio_phandle = 1, msi_pcie_phandle = 1; uint32_t irq_pcie_phandle = 1, irq_virtio_phandle = 1; + uint8_t rng_seed[32]; if (mc->dtb) { mc->fdt = load_device_tree(mc->dtb, &s->fdt_size); @@ -1046,6 +1048,10 @@ update_bootargs: if (cmdline && *cmdline) { qemu_fdt_setprop_string(mc->fdt, "/chosen", "bootargs", cmdline); } + + /* Pass seed to RNG */ + qemu_guest_getrandom_nofail(rng_seed, sizeof(rng_seed)); + qemu_fdt_setprop(mc->fdt, "/chosen", "rng-seed", rng_seed, sizeof(rng_seed)); } static inline DeviceState *gpex_pcie_init(MemoryRegion *sys_mem,