diff mbox series

hw/loongarch: virt: pass random seed to fdt

Message ID 20240905153316.2038769-1-Jason@zx2c4.com (mailing list archive)
State New
Headers show
Series hw/loongarch: virt: pass random seed to fdt | expand

Commit Message

Jason A. Donenfeld Sept. 5, 2024, 3:33 p.m. UTC
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 the same procedure that's done in b91b6b5a2c ("hw/microblaze:
pass random seed to fdt"), e4b4f0b71c ("hw/riscv: virt: pass random seed
to fdt"), c6fe3e6b4c ("hw/openrisc: virt: pass random seed to fdt"),
67f7e426e5 ("hw/i386: pass RNG seed via setup_data entry"), c287941a4d
("hw/rx: pass random seed to fdt"), 5e19cc68fb ("hw/mips: boston: pass
random seed to fdt"), 6b23a67916 ("hw/nios2: virt: pass random seed to fdt")
c4b075318e ("hw/ppc: pass random seed to fdt"), and 5242876f37
("hw/arm/virt: dt: add rng-seed property").

These earlier commits later were amended to rerandomize the RNG seed on
snapshot load, but the LoongArch code somehow already does that, despite
not having this patch here, presumably due to some lucky copy and
pasting.

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

Comments

Song Gao Sept. 9, 2024, 1:38 a.m. UTC | #1
在 2024/9/5 下午11:33, Jason A. Donenfeld 写道:
> 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 the same procedure that's done in b91b6b5a2c ("hw/microblaze:
> pass random seed to fdt"), e4b4f0b71c ("hw/riscv: virt: pass random seed
> to fdt"), c6fe3e6b4c ("hw/openrisc: virt: pass random seed to fdt"),
> 67f7e426e5 ("hw/i386: pass RNG seed via setup_data entry"), c287941a4d
> ("hw/rx: pass random seed to fdt"), 5e19cc68fb ("hw/mips: boston: pass
> random seed to fdt"), 6b23a67916 ("hw/nios2: virt: pass random seed to fdt")
> c4b075318e ("hw/ppc: pass random seed to fdt"), and 5242876f37
> ("hw/arm/virt: dt: add rng-seed property").
> 
> These earlier commits later were amended to rerandomize the RNG seed on
> snapshot load, but the LoongArch code somehow already does that, despite
> not having this patch here, presumably due to some lucky copy and
> pasting.
> 
> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
> ---
>   hw/loongarch/virt.c | 6 ++++++
>   1 file changed, 6 insertions(+)
> 

Reviewed-by: Song Gao <gaosong@loongson.cn>

Thanks
Song Gao
> diff --git a/hw/loongarch/virt.c b/hw/loongarch/virt.c
> index 29040422aa..0f0b7df205 100644
> --- a/hw/loongarch/virt.c
> +++ b/hw/loongarch/virt.c
> @@ -48,6 +48,7 @@
>   #include "hw/block/flash.h"
>   #include "hw/virtio/virtio-iommu.h"
>   #include "qemu/error-report.h"
> +#include "qemu/guest-random.h"
>   
>   static bool virt_is_veiointc_enabled(LoongArchVirtMachineState *lvms)
>   {
> @@ -303,6 +304,7 @@ static void fdt_add_uart_node(LoongArchVirtMachineState *lvms,
>   static void create_fdt(LoongArchVirtMachineState *lvms)
>   {
>       MachineState *ms = MACHINE(lvms);
> +    uint8_t rng_seed[32];
>   
>       ms->fdt = create_device_tree(&lvms->fdt_size);
>       if (!ms->fdt) {
> @@ -316,6 +318,10 @@ static void create_fdt(LoongArchVirtMachineState *lvms)
>       qemu_fdt_setprop_cell(ms->fdt, "/", "#address-cells", 0x2);
>       qemu_fdt_setprop_cell(ms->fdt, "/", "#size-cells", 0x2);
>       qemu_fdt_add_subnode(ms->fdt, "/chosen");
> +
> +    /* Pass seed to RNG */
> +    qemu_guest_getrandom_nofail(rng_seed, sizeof(rng_seed));
> +    qemu_fdt_setprop(ms->fdt, "/chosen", "rng-seed", rng_seed, sizeof(rng_seed));
>   }
>   
>   static void fdt_add_cpu_nodes(const LoongArchVirtMachineState *lvms)
>
Jason A. Donenfeld Sept. 9, 2024, 1:41 a.m. UTC | #2
On Mon, Sep 9, 2024 at 3:38 AM gaosong <gaosong@loongson.cn> wrote:
>
>
>
> 在 2024/9/5 下午11:33, Jason A. Donenfeld 写道:
> > 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 the same procedure that's done in b91b6b5a2c ("hw/microblaze:
> > pass random seed to fdt"), e4b4f0b71c ("hw/riscv: virt: pass random seed
> > to fdt"), c6fe3e6b4c ("hw/openrisc: virt: pass random seed to fdt"),
> > 67f7e426e5 ("hw/i386: pass RNG seed via setup_data entry"), c287941a4d
> > ("hw/rx: pass random seed to fdt"), 5e19cc68fb ("hw/mips: boston: pass
> > random seed to fdt"), 6b23a67916 ("hw/nios2: virt: pass random seed to fdt")
> > c4b075318e ("hw/ppc: pass random seed to fdt"), and 5242876f37
> > ("hw/arm/virt: dt: add rng-seed property").
> >
> > These earlier commits later were amended to rerandomize the RNG seed on
> > snapshot load, but the LoongArch code somehow already does that, despite
> > not having this patch here, presumably due to some lucky copy and
> > pasting.
> >
> > Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
> > ---
> >   hw/loongarch/virt.c | 6 ++++++
> >   1 file changed, 6 insertions(+)
> >
>
> Reviewed-by: Song Gao <gaosong@loongson.cn>

Do you generally queue these up in
https://gitlab.com/gaosong/qemu/-/commits/loongarch-next/?ref_type=heads
? Or is it a different branch?
Song Gao Sept. 9, 2024, 1:52 a.m. UTC | #3
在 2024/9/9 上午9:41, Jason A. Donenfeld 写道:
> On Mon, Sep 9, 2024 at 3:38 AM gaosong <gaosong@loongson.cn> wrote:
>>
>>
>>
>> 在 2024/9/5 下午11:33, Jason A. Donenfeld 写道:
>>> 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 the same procedure that's done in b91b6b5a2c ("hw/microblaze:
>>> pass random seed to fdt"), e4b4f0b71c ("hw/riscv: virt: pass random seed
>>> to fdt"), c6fe3e6b4c ("hw/openrisc: virt: pass random seed to fdt"),
>>> 67f7e426e5 ("hw/i386: pass RNG seed via setup_data entry"), c287941a4d
>>> ("hw/rx: pass random seed to fdt"), 5e19cc68fb ("hw/mips: boston: pass
>>> random seed to fdt"), 6b23a67916 ("hw/nios2: virt: pass random seed to fdt")
>>> c4b075318e ("hw/ppc: pass random seed to fdt"), and 5242876f37
>>> ("hw/arm/virt: dt: add rng-seed property").
>>>
>>> These earlier commits later were amended to rerandomize the RNG seed on
>>> snapshot load, but the LoongArch code somehow already does that, despite
>>> not having this patch here, presumably due to some lucky copy and
>>> pasting.
>>>
>>> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
>>> ---
>>>    hw/loongarch/virt.c | 6 ++++++
>>>    1 file changed, 6 insertions(+)
>>>
>>
>> Reviewed-by: Song Gao <gaosong@loongson.cn>
> 
> Do you generally queue these up in
> https://gitlab.com/gaosong/qemu/-/commits/loongarch-next/?ref_type=heads
> ? 

Yes, PRs are usually submitted on Thursdays.

Thanks
Song Gao
diff mbox series

Patch

diff --git a/hw/loongarch/virt.c b/hw/loongarch/virt.c
index 29040422aa..0f0b7df205 100644
--- a/hw/loongarch/virt.c
+++ b/hw/loongarch/virt.c
@@ -48,6 +48,7 @@ 
 #include "hw/block/flash.h"
 #include "hw/virtio/virtio-iommu.h"
 #include "qemu/error-report.h"
+#include "qemu/guest-random.h"
 
 static bool virt_is_veiointc_enabled(LoongArchVirtMachineState *lvms)
 {
@@ -303,6 +304,7 @@  static void fdt_add_uart_node(LoongArchVirtMachineState *lvms,
 static void create_fdt(LoongArchVirtMachineState *lvms)
 {
     MachineState *ms = MACHINE(lvms);
+    uint8_t rng_seed[32];
 
     ms->fdt = create_device_tree(&lvms->fdt_size);
     if (!ms->fdt) {
@@ -316,6 +318,10 @@  static void create_fdt(LoongArchVirtMachineState *lvms)
     qemu_fdt_setprop_cell(ms->fdt, "/", "#address-cells", 0x2);
     qemu_fdt_setprop_cell(ms->fdt, "/", "#size-cells", 0x2);
     qemu_fdt_add_subnode(ms->fdt, "/chosen");
+
+    /* Pass seed to RNG */
+    qemu_guest_getrandom_nofail(rng_seed, sizeof(rng_seed));
+    qemu_fdt_setprop(ms->fdt, "/chosen", "rng-seed", rng_seed, sizeof(rng_seed));
 }
 
 static void fdt_add_cpu_nodes(const LoongArchVirtMachineState *lvms)