Re: [PATCH v2 2/2] powerpc/kvm: don't crash on missing rng, and use darn

"Jason A. Donenfeld" Jason@zx2c4.com writes:

On POWER8 systems that don't have ibm,power-rng available, a guest that ignores the KVM_CAP_PPC_HWRNG flag and calls H_RANDOM anyway will dereference a NULL pointer. And on machines with darn instead of ibm,power-rng, H_RANDOM won't work at all.

This patch kills two birds with one stone, by routing H_RANDOM calls to ppc_md.get_random_seed, and doing the real mode check inside of it.

Cc: stable@vger.kernel.org # v4.1+ Cc: Michael Ellerman mpe@ellerman.id.au Fixes: e928e9cb3601 ("KVM: PPC: Book3S HV: Add fast real-mode H_RANDOM implementation.") Signed-off-by: Jason A. Donenfeld Jason@zx2c4.com

Reviewed-by: Fabiano Rosas farosas@linux.ibm.com