[PATCH 0/4] random,x86,kvm: Add and use MSR_KVM_GET_RNG_SEED

Andy Lutomirski
2014-07-16T02:48:22Z

virtio-rng is both too complicated and insufficient for initial rng
seeding. It's far too complicated to use for KASLR or any other
early boot random number needs. It also provides /dev/random-style
bits, which means that making guest boot wait for virtio-rng is
unacceptably slow, and doing it asynchronously means that
/dev/urandom might be predictable when userspace starts.

This introduces a very simple synchronous mechanism to get
/dev/urandom-style bits.

This is a KVM change: am I supposed to write a unit test somewhere?

Andy Lutomirski (4):
x86,kvm: Add MSR_KVM_GET_RNG_SEED and a matching feature bit
random,x86: Add arch_get_slow_rng_u64
random: Seed pools from arch_get_slow_rng_u64 at startup
x86,kaslr: Use MSR_KVM_GET_RNG_SEED for KASLR if available

Documentation/virtual/kvm/cpuid.txt | 3 +++
arch/x86/Kconfig | 4 ++++
arch/x86/boot/compressed/aslr.c | 27 +++++++++++++++++++++++++++
arch/x86/include/asm/archslowrng.h | 30 ++++++++++++++++++++++++++++++
arch/x86/include/uapi/asm/kvm_para.h | 2 ++
arch/x86/kernel/kvm.c | 22 ++++++++++++++++++++++
arch/x86/kvm/cpuid.c | 3 ++-
arch/x86/kvm/x86.c | 4 ++++
drivers/char/random.c | 14 +++++++++++++-
include/linux/random.h | 9 +++++++++
10 files changed, 116 insertions(+), 2 deletions(-)
create mode 100644 arch/x86/include/asm/archslowrng.h

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1.9.3