diff options
| author | Jason A. Donenfeld <Jason@zx2c4.com> | 2022-07-17 12:35:24 +0200 |
|---|---|---|
| committer | Jason A. Donenfeld <Jason@zx2c4.com> | 2022-07-25 13:26:14 +0200 |
| commit | d349ab99eec7ab0f977fc4aac27aa476907acf90 (patch) | |
| tree | b98736b45c4f0c00ea2e00e5cefe543bd2ce0759 /arch/powerpc/kvm/book3s_hv.c | |
| parent | 0b9ba6135d7f18b82f3d8bebb55ded725ba88e0e (diff) | |
random: handle archrandom with multiple longs
The archrandom interface was originally designed for x86, which supplies
RDRAND/RDSEED for receiving random words into registers, resulting in
one function to generate an int and another to generate a long. However,
other architectures don't follow this.
On arm64, the SMCCC TRNG interface can return between one and three
longs. On s390, the CPACF TRNG interface can return arbitrary amounts,
with four longs having the same cost as one. On UML, the os_getrandom()
interface can return arbitrary amounts.
So change the api signature to take a "max_longs" parameter designating
the maximum number of longs requested, and then return the number of
longs generated.
Since callers need to check this return value and loop anyway, each arch
implementation does not bother implementing its own loop to try again to
fill the maximum number of longs. Additionally, all existing callers
pass in a constant max_longs parameter. Taken together, these two things
mean that the codegen doesn't really change much for one-word-at-a-time
platforms, while performance is greatly improved on platforms such as
s390.
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Diffstat (limited to 'arch/powerpc/kvm/book3s_hv.c')
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index e08fb3124dca..631062cde6b4 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -1207,7 +1207,7 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu) break; #endif case H_RANDOM: - if (!arch_get_random_seed_long(&vcpu->arch.regs.gpr[4])) + if (!arch_get_random_seed_longs(&vcpu->arch.regs.gpr[4], 1)) ret = H_HARDWARE; break; case H_RPT_INVALIDATE: |