diff options
author | David Brazdil <dbrazdil@google.com> | 2020-12-02 18:40:58 +0000 |
---|---|---|
committer | Marc Zyngier <maz@kernel.org> | 2020-12-04 08:44:19 +0000 |
commit | 3eb681fba2bf8b67b65ce92d0ebfd7cbfc263da9 (patch) | |
tree | 80f606f3844112537952138f600bcc926a5b1b35 /arch | |
parent | d8b369c4e31430a4746571bcae45a98933827232 (diff) | |
download | linux-3eb681fba2bf8b67b65ce92d0ebfd7cbfc263da9.tar.gz linux-3eb681fba2bf8b67b65ce92d0ebfd7cbfc263da9.tar.bz2 linux-3eb681fba2bf8b67b65ce92d0ebfd7cbfc263da9.zip |
KVM: arm64: Add ARM64_KVM_PROTECTED_MODE CPU capability
Expose the boolean value whether the system is running with KVM in
protected mode (nVHE + kernel param). CPU capability was selected over
a global variable to allow use in alternatives.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201202184122.26046-3-dbrazdil@google.com
Diffstat (limited to 'arch')
-rw-r--r-- | arch/arm64/include/asm/cpucaps.h | 3 | ||||
-rw-r--r-- | arch/arm64/include/asm/kvm_host.h | 1 | ||||
-rw-r--r-- | arch/arm64/include/asm/virt.h | 8 | ||||
-rw-r--r-- | arch/arm64/kernel/cpufeature.c | 22 | ||||
-rw-r--r-- | arch/arm64/kvm/arm.c | 9 |
5 files changed, 41 insertions, 2 deletions
diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h index a7242ef2a2cd..350c98103d45 100644 --- a/arch/arm64/include/asm/cpucaps.h +++ b/arch/arm64/include/asm/cpucaps.h @@ -65,7 +65,8 @@ #define ARM64_MTE 57 #define ARM64_WORKAROUND_1508412 58 #define ARM64_HAS_LDAPR 59 +#define ARM64_KVM_PROTECTED_MODE 60 -#define ARM64_NCAPS 60 +#define ARM64_NCAPS 61 #endif /* __ASM_CPUCAPS_H */ diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 820954ad2477..7119d38e3c56 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -58,6 +58,7 @@ enum kvm_mode { KVM_MODE_DEFAULT, KVM_MODE_PROTECTED, }; +enum kvm_mode kvm_get_mode(void); DECLARE_STATIC_KEY_FALSE(userspace_irqchip_in_use); diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h index 6069be50baf9..eb81dcc220b6 100644 --- a/arch/arm64/include/asm/virt.h +++ b/arch/arm64/include/asm/virt.h @@ -97,6 +97,14 @@ static __always_inline bool has_vhe(void) return cpus_have_final_cap(ARM64_HAS_VIRT_HOST_EXTN); } +static __always_inline bool is_protected_kvm_enabled(void) +{ + if (is_vhe_hyp_code()) + return false; + else + return cpus_have_final_cap(ARM64_KVM_PROTECTED_MODE); +} + #endif /* __ASSEMBLY__ */ #endif /* ! __ASM__VIRT_H */ diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index cffcb0198bae..0c029adf72d3 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -74,6 +74,7 @@ #include <asm/cpufeature.h> #include <asm/cpu_ops.h> #include <asm/fpsimd.h> +#include <asm/kvm_host.h> #include <asm/mmu_context.h> #include <asm/mte.h> #include <asm/processor.h> @@ -1703,6 +1704,21 @@ static void cpu_enable_mte(struct arm64_cpu_capabilities const *cap) } #endif /* CONFIG_ARM64_MTE */ +#ifdef CONFIG_KVM +static bool is_kvm_protected_mode(const struct arm64_cpu_capabilities *entry, int __unused) +{ + if (kvm_get_mode() != KVM_MODE_PROTECTED) + return false; + + if (is_kernel_in_hyp_mode()) { + pr_warn("Protected KVM not available with VHE\n"); + return false; + } + + return true; +} +#endif /* CONFIG_KVM */ + /* Internal helper functions to match cpu capability type */ static bool cpucap_late_cpu_optional(const struct arm64_cpu_capabilities *cap) @@ -1794,6 +1810,12 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .field_pos = ID_AA64PFR0_EL1_SHIFT, .min_field_value = ID_AA64PFR0_EL1_32BIT_64BIT, }, + { + .desc = "Protected KVM", + .capability = ARM64_KVM_PROTECTED_MODE, + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .matches = is_kvm_protected_mode, + }, #endif { .desc = "Kernel page table isolation (KPTI)", diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 5db90680742c..745e1b4bcbe0 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1771,7 +1771,9 @@ int kvm_arch_init(void *opaque) if (err) goto out_hyp; - if (in_hyp_mode) + if (is_protected_kvm_enabled()) + kvm_info("Protected nVHE mode initialized successfully\n"); + else if (in_hyp_mode) kvm_info("VHE mode initialized successfully\n"); else kvm_info("Hyp mode initialized successfully\n"); @@ -1806,6 +1808,11 @@ static int __init early_kvm_mode_cfg(char *arg) } early_param("kvm-arm.mode", early_kvm_mode_cfg); +enum kvm_mode kvm_get_mode(void) +{ + return kvm_mode; +} + static int arm_init(void) { int rc = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE); |