On Wed, Jul 16, 2014 at 11:02 AM, Bandan Das <bsd@xxxxxxxxxx> wrote: > Andy Lutomirski <luto@xxxxxxxxxxxxxx> writes: > >> 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. > > Whoa! the cover letter seems more like virtio-rng bashing rather than > introduction to the patchset (and/or it's advantages over existing methods) > :) That's ok though I guess, these won't be in the commit log. > Yeah, sorry -- I figured that the biggest objection would be "just use virtio-rng". I'll send a v3 later today -- there's a trivial bisectability bug in this version. --Andy >> I sent the corresponding kvm-unit-tests and qemu changes separately. >> >> There's room for bikeshedding on the same arch_get_slow_rng_u64. I >> considered arch_get_rng_seed_u64, but that could be confused with >> arch_get_random_seed_long, which is not interchangeable. >> >> Changes from v1: >> - Split patches 2 and 3 >> - Log all arch sources in init_std_data >> - Fix the 32-bit kaslr build >> >> Andy Lutomirski (5): >> 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 >> random: Log how many bits we managed to seed with in init_std_data >> 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/asm/processor.h | 21 ++++++++++++++++++--- >> 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 | 20 ++++++++++++++++++-- >> include/linux/random.h | 9 +++++++++ >> 11 files changed, 139 insertions(+), 6 deletions(-) >> create mode 100644 arch/x86/include/asm/archslowrng.h -- Andy Lutomirski AMA Capital Management, LLC -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
