Hi Greg,
Here is the state of the current v5.4 backport. Now that the 32bit code has been merged, it doesn't conflict when KVM's shared 32bit/64bit code needs to use these constants.
I've fixed the two issues that were reported against the v5.10 backport.
I had a go at bringing all the pre-requisites in to add proton-pack.c to v5.4. Its currently 39 patches: https://git.gitlab.arm.com/linux-arm/linux-jm.git /bhb/alternative_backport/UNTESTED/v5.4.183 (or for web browsers: https://gitlab.arm.com/linux-arm/linux-jm/-/commits/bhb/alternative_backport... )
I've not managed to bring b881cdce77b4 "KVM: arm64: Allocate hyp vectors statically" in, as that depends on the hypervisor's per-cpu support. Its this patch that means those 'smccc_wa' templates are needed. I estimate it would be 60 patches in total if we go this way, I don't think its a good idea: All this still has to work around 541ad0150ca4 ("arm: Remove 32bit KVM host support") and 9ed24f4b712b ("KVM: arm64: Move virt/kvm/arm to arch/arm64") being missing. I think this approach creates more problems than it solves as the files have to be in different places because of 32bit. It also creates a significantly larger testing problem: I'm not looking forward to working out how to test KVM guest migration over the variant-4 KVM ABI changes in 29e8910a566a.
This version of the backport still adds the mitigation management code to cpu_errata.c, because that is where this stuff lived in v5.4.
If you prefer, I can try adding proton-pack.c as a new empty file. I think this would only confuse matters as the line-numbers would never match, and there is an interaction with the spectre-v2 mitigations that live in cpu_errata.c.
There is one patch not present in mainline 'KVM: arm64: Add templtes for BHB mitigation sequences'.
Thanks,
James
Anshuman Khandual (1): arm64: Add Cortex-X2 CPU part definition
James Morse (18): arm64: entry.S: Add ventry overflow sanity checks arm64: entry: Make the trampoline cleanup optional arm64: entry: Free up another register on kpti's tramp_exit path arm64: entry: Move the trampoline data page before the text page arm64: entry: Allow tramp_alias to access symbols after the 4K boundary arm64: entry: Don't assume tramp_vectors is the start of the vectors arm64: entry: Move trampoline macros out of ifdef'd section arm64: entry: Make the kpti trampoline's kpti sequence optional arm64: entry: Allow the trampoline text to occupy multiple pages arm64: entry: Add non-kpti __bp_harden_el1_vectors for mitigations arm64: entry: Add vectors that have the bhb mitigation sequences arm64: entry: Add macro for reading symbol addresses from the trampoline arm64: Add percpu vectors for EL1 arm64: proton-pack: Report Spectre-BHB vulnerabilities as part of Spectre-v2 KVM: arm64: Add templates for BHB mitigation sequences arm64: Mitigate spectre style branch history side channels KVM: arm64: Allow SMCCC_ARCH_WORKAROUND_3 to be discovered and migrated arm64: Use the clearbhb instruction in mitigations
Joey Gouly (1): arm64: add ID_AA64ISAR2_EL1 sys register
Rob Herring (1): arm64: Add part number for Arm Cortex-A77
Suzuki K Poulose (1): arm64: Add Neoverse-N2, Cortex-A710 CPU part definition
arch/arm/include/asm/kvm_host.h | 7 + arch/arm/include/uapi/asm/kvm.h | 6 + arch/arm64/Kconfig | 9 + arch/arm64/include/asm/assembler.h | 33 +++ arch/arm64/include/asm/cpu.h | 1 + arch/arm64/include/asm/cpucaps.h | 3 +- arch/arm64/include/asm/cpufeature.h | 40 +++ arch/arm64/include/asm/cputype.h | 16 ++ arch/arm64/include/asm/fixmap.h | 6 +- arch/arm64/include/asm/kvm_host.h | 5 + arch/arm64/include/asm/kvm_mmu.h | 6 +- arch/arm64/include/asm/mmu.h | 8 +- arch/arm64/include/asm/sections.h | 5 + arch/arm64/include/asm/sysreg.h | 17 ++ arch/arm64/include/asm/vectors.h | 73 ++++++ arch/arm64/include/uapi/asm/kvm.h | 5 + arch/arm64/kernel/cpu_errata.c | 385 +++++++++++++++++++++++++++- arch/arm64/kernel/cpufeature.c | 21 ++ arch/arm64/kernel/cpuinfo.c | 1 + arch/arm64/kernel/entry.S | 213 +++++++++++---- arch/arm64/kernel/vmlinux.lds.S | 2 +- arch/arm64/kvm/hyp/hyp-entry.S | 64 +++++ arch/arm64/kvm/hyp/switch.c | 8 +- arch/arm64/kvm/sys_regs.c | 2 +- arch/arm64/mm/mmu.c | 12 +- include/linux/arm-smccc.h | 5 + virt/kvm/arm/psci.c | 34 ++- 27 files changed, 912 insertions(+), 75 deletions(-) create mode 100644 arch/arm64/include/asm/vectors.h