On Mon, Oct 26, 2020 at 01:49:31PM +0000, Mark Rutland wrote: > We finalize caps before initializing kvm hyp code, and any use of > cpus_have_const_cap() in kvm hyp code generates redundant and > potentially unsound code to read the cpu_hwcaps array. > > A number of helper functions used in both hyp context and regular kernel > context use cpus_have_const_cap(), as some regular kernel code runs > before the capabilities are finalized. It's tedious and error-prone to > write separate copies of these for hyp and non-hyp code. > > So that we can avoid the redundant code, let's automatically upgrade > cpus_have_const_cap() to cpus_have_final_cap() when used in hyp context. > With this change, there's never a reason to access to cpu_hwcaps array > from hyp code, and we don't need to create an NVHE alias for this. > > This should have no effect on non-hyp code. > > Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx> > Cc: David Brazdil <dbrazdil@xxxxxxxxxx> > Cc: Marc Zyngier <maz@xxxxxxxxxx> > Cc: Will Deacon <will@xxxxxxxxxx> > --- > arch/arm64/include/asm/cpufeature.h | 26 ++++++++++++++++++++++++-- > arch/arm64/include/asm/virt.h | 12 ------------ > arch/arm64/kernel/image-vars.h | 1 - > 3 files changed, 24 insertions(+), 15 deletions(-) [...] > diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h > index 61684a5009148..c615b285ff5b3 100644 > --- a/arch/arm64/kernel/image-vars.h > +++ b/arch/arm64/kernel/image-vars.h > @@ -87,7 +87,6 @@ KVM_NVHE_ALIAS(__icache_flags); > /* Kernel symbols needed for cpus_have_final/const_caps checks. */ > KVM_NVHE_ALIAS(arm64_const_caps_ready); > KVM_NVHE_ALIAS(cpu_hwcap_keys); > -KVM_NVHE_ALIAS(cpu_hwcaps); Nice! Acked-by: Will Deacon <will@xxxxxxxxxx> Will _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
