diff options
author | Mark Rutland <mark.rutland@arm.com> | 2020-10-26 13:49:31 +0000 |
---|---|---|
committer | Marc Zyngier <maz@kernel.org> | 2020-10-30 08:53:10 +0000 |
commit | d86de40decaa14e6613af1b2783bf4d589d0f38b (patch) | |
tree | b2403210b1625e1a829a5c43249a2a4f61a409ba | |
parent | dfc4e3f08903ed8fe0b66cc25b64524a82654166 (diff) |
arm64: cpufeature: upgrade hyp caps to final
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@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Cc: David Brazdil <dbrazdil@google.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20201026134931.28246-4-mark.rutland@arm.com
-rw-r--r-- | arch/arm64/include/asm/cpufeature.h | 26 | ||||
-rw-r--r-- | arch/arm64/include/asm/virt.h | 12 | ||||
-rw-r--r-- | arch/arm64/kernel/image-vars.h | 1 |
3 files changed, 24 insertions, 15 deletions
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index 9f671aa0419b..79d6a0371c78 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -375,6 +375,23 @@ cpucap_multi_entry_cap_matches(const struct arm64_cpu_capabilities *entry, return false; } +static __always_inline bool is_vhe_hyp_code(void) +{ + /* Only defined for code run in VHE hyp context */ + return __is_defined(__KVM_VHE_HYPERVISOR__); +} + +static __always_inline bool is_nvhe_hyp_code(void) +{ + /* Only defined for code run in NVHE hyp context */ + return __is_defined(__KVM_NVHE_HYPERVISOR__); +} + +static __always_inline bool is_hyp_code(void) +{ + return is_vhe_hyp_code() || is_nvhe_hyp_code(); +} + extern DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS); extern struct static_key_false cpu_hwcap_keys[ARM64_NCAPS]; extern struct static_key_false arm64_const_caps_ready; @@ -444,8 +461,11 @@ static __always_inline bool cpus_have_final_cap(int num) } /* - * Test for a capability, possibly with a runtime check. + * Test for a capability, possibly with a runtime check for non-hyp code. * + * For hyp code, this behaves the same as cpus_have_final_cap(). + * + * For non-hyp code: * Before capabilities are finalized, this behaves as cpus_have_cap(). * After capabilities are finalized, this is patched to avoid a runtime check. * @@ -453,7 +473,9 @@ static __always_inline bool cpus_have_final_cap(int num) */ static __always_inline bool cpus_have_const_cap(int num) { - if (system_capabilities_finalized()) + if (is_hyp_code()) + return cpus_have_final_cap(num); + else if (system_capabilities_finalized()) return __cpus_have_const_cap(num); else return cpus_have_cap(num); diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h index 300be14ba77b..6069be50baf9 100644 --- a/arch/arm64/include/asm/virt.h +++ b/arch/arm64/include/asm/virt.h @@ -83,18 +83,6 @@ static inline bool is_kernel_in_hyp_mode(void) return read_sysreg(CurrentEL) == CurrentEL_EL2; } -static __always_inline bool is_vhe_hyp_code(void) -{ - /* Only defined for code run in VHE hyp context */ - return __is_defined(__KVM_VHE_HYPERVISOR__); -} - -static __always_inline bool is_nvhe_hyp_code(void) -{ - /* Only defined for code run in NVHE hyp context */ - return __is_defined(__KVM_NVHE_HYPERVISOR__); -} - static __always_inline bool has_vhe(void) { /* diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h index fbd4b6b1fde5..ad8432251733 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); /* Static keys which are set if a vGIC trap should be handled in hyp. */ KVM_NVHE_ALIAS(vgic_v2_cpuif_trap); |