diff options
| author | Christoffer Dall <christoffer.dall@arm.com> | 2023-02-09 17:58:05 +0000 |
|---|---|---|
| committer | Oliver Upton <oliver.upton@linux.dev> | 2023-02-11 09:16:11 +0000 |
| commit | 89b0e7de3451a17f23bc1c39bc40eee1811f1669 (patch) | |
| tree | 3e8653407c25c04c0b441919cf2d7703d63c9473 /arch | |
| parent | 8531bd63a8dc6c83fef2e1b7cbfd6f1a50bf87db (diff) | |
KVM: arm64: nv: Introduce nested virtualization VCPU feature
Introduce the feature bit and a primitive that checks if the feature is
set behind a static key check based on the cpus_have_const_cap check.
Checking vcpu_has_nv() on systems without nested virt enabled
should have negligible overhead.
We don't yet allow userspace to actually set this feature.
Reviewed-by: Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230209175820.1939006-4-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/include/asm/kvm_nested.h | 14 | ||||
| -rw-r--r-- | arch/arm64/include/uapi/asm/kvm.h | 1 |
2 files changed, 15 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/kvm_nested.h b/arch/arm64/include/asm/kvm_nested.h new file mode 100644 index 000000000000..fd601ea68d13 --- /dev/null +++ b/arch/arm64/include/asm/kvm_nested.h @@ -0,0 +1,14 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ARM64_KVM_NESTED_H +#define __ARM64_KVM_NESTED_H + +#include <linux/kvm_host.h> + +static inline bool vcpu_has_nv(const struct kvm_vcpu *vcpu) +{ + return (!__is_defined(__KVM_NVHE_HYPERVISOR__) && + cpus_have_final_cap(ARM64_HAS_NESTED_VIRT) && + test_bit(KVM_ARM_VCPU_HAS_EL2, vcpu->arch.features)); +} + +#endif /* __ARM64_KVM_NESTED_H */ diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h index a7a857f1784d..f8129c624b07 100644 --- a/arch/arm64/include/uapi/asm/kvm.h +++ b/arch/arm64/include/uapi/asm/kvm.h @@ -109,6 +109,7 @@ struct kvm_regs { #define KVM_ARM_VCPU_SVE 4 /* enable SVE for this CPU */ #define KVM_ARM_VCPU_PTRAUTH_ADDRESS 5 /* VCPU uses address authentication */ #define KVM_ARM_VCPU_PTRAUTH_GENERIC 6 /* VCPU uses generic authentication */ +#define KVM_ARM_VCPU_HAS_EL2 7 /* Support nested virtualization */ struct kvm_vcpu_init { __u32 target; |