On 13/11/2020 23:05, Ard Biesheuvel wrote: > On Fri, 13 Nov 2020 at 19:24, Andre Przywara <andre.przywara@xxxxxxx> wrote: >> >> Hi, >> >> an update to v2 with some fixes and a few tweaks. Ard's patch [1] should >> significantly reduce the frequency of arch_get_random_seed_long() calls, >> not sure if that is enough the appease the concerns about the >> potentially long latency of SMC calls. I also dropped the direct >> arch_get_random() call in KVM for the same reason. An alternative could >> be to just use the SMC in the _early() versions, but then we would lose >> the SMCCC entropy source for the periodic reseeds. This could be mitigated >> by using a hwrng driver [2] and rngd. >> The only other non-minor change to v2 is the addition of using the SMCCC >> call in the _early() variant. For a changelog see below. >> >> Sudeep: patch 1/5 is a prerequisite for all other patches, which >> themselves could be considered separate and need to go via different trees. >> If we could agree on that one now and get that merged, it would help the >> handling of the other patches going forward. >> >> Cheers, >> Andre >> ============================== >> >> The ARM architected TRNG firmware interface, described in ARM spec >> DEN0098[3], defines an ARM SMCCC based interface to a true random number >> generator, provided by firmware. >> >> This series collects all the patches implementing this in various >> places: as a user feeding into the ARCH_RANDOM pool, both for ARM and >> arm64, and as a service provider for KVM guests. >> >> Patch 1 introduces the interface definition used by all three entities. >> Patch 2 prepares the Arm SMCCC firmware driver to probe for the >> interface. This patch is needed to avoid a later dependency on *two* >> patches (there might be a better solution to this problem). >> >> Patch 3 implements the ARM part, patch 4 is the arm64 version. >> The final patch 5 adds support to provide random numbers to KVM guests. >> >> This was tested on: >> - QEMU -kernel (no SMCCC, regression test) >> - Juno w/ prototype of the h/w Trusted RNG support >> - mainline KVM (SMCCC, but no TRNG: regression test) >> - ARM and arm64 KVM guests, using the KVM service in patch 5/5 >> >> Based on v5.10-rc3, please let me know if I should rebased on something >> else. A git repo is accessible at: >> https://gitlab.arm.com/linux-arm/linux-ap/-/commits/smccc-trng/v3/ >> >> Cheers, >> Andre >> >> [1] http://lists.infradead.org/pipermail/linux-arm-kernel/2020-November/615446.html >> [2] https://gitlab.arm.com/linux-arm/linux-ap/-/commit/87e3722f437 >> [3] https://developer.arm.com/documentation/den0098/latest/ >> >> Changelog v2 ... v3: >> - ARM: fix compilation with randconfig >> - arm64: use SMCCC call also in arch_get_random_seed_long_early() >> - KVM: comment on return value usage >> - KVM: use more interesting UUID (enjoy, Marc!) > > UUIDs are constructed using certain rules, so probably better to > refrain from playing games with them here. Hey, it's a valid variant 1 version 1 UUID (otherwise this would be no real easter egg). uuidgen -t should be able to generate this one. I found it too easy to use the random variant, but we can revert to that. > If Marc wants an easter egg, he will have to wait until Easter. Don't mess with your maintainer ;-) Cheers, Andre > >> - KVM: use bitmaps instead of open coded long arrays >> - KVM: drop direct usage of arch_get_random() interface >> >> Changelog "v1" ... v2: >> - trigger ARCH_RANDOM initialisation from the SMCCC firmware driver >> - use a single bool in smccc.c to hold the initialisation state for arm64 >> - handle endianess correctly in the KVM provider >> >> Andre Przywara (2): >> firmware: smccc: Introduce SMCCC TRNG framework >> arm64: Add support for SMCCC TRNG entropy source >> >> Ard Biesheuvel (3): >> firmware: smccc: Add SMCCC TRNG function call IDs >> ARM: implement support for SMCCC TRNG entropy source >> KVM: arm64: implement the TRNG hypervisor call >> >> arch/arm/Kconfig | 4 ++ >> arch/arm/include/asm/archrandom.h | 74 +++++++++++++++++++++++++ >> arch/arm64/include/asm/archrandom.h | 79 +++++++++++++++++++++++---- >> arch/arm64/include/asm/kvm_host.h | 2 + >> arch/arm64/kvm/Makefile | 2 +- >> arch/arm64/kvm/hypercalls.c | 6 ++ >> arch/arm64/kvm/trng.c | 85 +++++++++++++++++++++++++++++ >> drivers/firmware/smccc/smccc.c | 5 ++ >> include/linux/arm-smccc.h | 31 +++++++++++ >> 9 files changed, 277 insertions(+), 11 deletions(-) >> create mode 100644 arch/arm/include/asm/archrandom.h >> create mode 100644 arch/arm64/kvm/trng.c >> >> -- >> 2.17.1 >> _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
