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| author | Jintack Lim <jintack.lim@linaro.org> | 2023-02-09 18:58:03 +0100 |
|---|---|---|
| committer | Oliver Upton <oliver.upton@linux.dev> | 2023-02-11 10:16:11 +0100 |
| commit | 675cabc89900732a8a90f19a3c6ed314327a96e0 (patch) | |
| tree | af0c74c5ab86ada3c06b033718a13e653e35a16d /arch | |
| parent | Linux 6.2-rc4 (diff) | |
| download | linux-675cabc89900732a8a90f19a3c6ed314327a96e0.tar.xz linux-675cabc89900732a8a90f19a3c6ed314327a96e0.zip | |
arm64: Add ARM64_HAS_NESTED_VIRT cpufeature
Add a new ARM64_HAS_NESTED_VIRT feature to indicate that the
CPU has the ARMv8.3 nested virtualization capability, together
with the 'kvm-arm.mode=nested' command line option.
This will be used to support nested virtualization in KVM.
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Jintack Lim <jintack.lim@linaro.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
[maz: moved the command-line option to kvm-arm.mode]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230209175820.1939006-2-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/include/asm/kvm_host.h | 5 | ||||
| -rw-r--r-- | arch/arm64/kernel/cpufeature.c | 25 | ||||
| -rw-r--r-- | arch/arm64/kvm/arm.c | 5 | ||||
| -rw-r--r-- | arch/arm64/tools/cpucaps | 1 |
4 files changed, 36 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 35a159d131b5..8919e971abdf 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -60,9 +60,14 @@ enum kvm_mode { KVM_MODE_DEFAULT, KVM_MODE_PROTECTED, + KVM_MODE_NV, KVM_MODE_NONE, }; +#ifdef CONFIG_KVM enum kvm_mode kvm_get_mode(void); +#else +static inline enum kvm_mode kvm_get_mode(void) { return KVM_MODE_NONE; }; +#endif DECLARE_STATIC_KEY_FALSE(userspace_irqchip_in_use); diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index a77315b338e6..3fc14ee86239 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -1956,6 +1956,20 @@ static void cpu_copy_el2regs(const struct arm64_cpu_capabilities *__unused) write_sysreg(read_sysreg(tpidr_el1), tpidr_el2); } +static bool has_nested_virt_support(const struct arm64_cpu_capabilities *cap, + int scope) +{ + if (kvm_get_mode() != KVM_MODE_NV) + return false; + + if (!has_cpuid_feature(cap, scope)) { + pr_warn("unavailable: %s\n", cap->desc); + return false; + } + + return true; +} + #ifdef CONFIG_ARM64_PAN static void cpu_enable_pan(const struct arm64_cpu_capabilities *__unused) { @@ -2216,6 +2230,17 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .cpu_enable = cpu_copy_el2regs, }, { + .desc = "Nested Virtualization Support", + .capability = ARM64_HAS_NESTED_VIRT, + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .matches = has_nested_virt_support, + .sys_reg = SYS_ID_AA64MMFR2_EL1, + .sign = FTR_UNSIGNED, + .field_pos = ID_AA64MMFR2_EL1_NV_SHIFT, + .field_width = 4, + .min_field_value = ID_AA64MMFR2_EL1_NV_IMP, + }, + { .capability = ARM64_HAS_32BIT_EL0_DO_NOT_USE, .type = ARM64_CPUCAP_SYSTEM_FEATURE, .matches = has_32bit_el0, diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 9c5573bc4614..3fd8f37830f2 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -2310,6 +2310,11 @@ static int __init early_kvm_mode_cfg(char *arg) return 0; } + if (strcmp(arg, "nested") == 0 && !WARN_ON(!is_kernel_in_hyp_mode())) { + kvm_mode = KVM_MODE_NV; + return 0; + } + return -EINVAL; } early_param("kvm-arm.mode", early_kvm_mode_cfg); diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps index dfeb2c51e257..1af77a3657f7 100644 --- a/arch/arm64/tools/cpucaps +++ b/arch/arm64/tools/cpucaps @@ -31,6 +31,7 @@ HAS_GENERIC_AUTH_IMP_DEF HAS_IRQ_PRIO_MASKING HAS_LDAPR HAS_LSE_ATOMICS +HAS_NESTED_VIRT HAS_NO_FPSIMD HAS_NO_HW_PREFETCH HAS_PAN |