diff options
| author | Marc Zyngier <maz@kernel.org> | 2023-03-30 18:47:47 +0100 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2023-03-30 19:01:10 +0100 |
| commit | 30ec7997d175cd689fc61bfc4059f4d35b11858c (patch) | |
| tree | 6d238cd0e5f3c253161a0333c5d5e8c604a69547 /arch/arm64/include | |
| parent | 96906a9150a86a86b0464939625279b8e19f6e88 (diff) | |
KVM: arm64: timers: Allow userspace to set the global counter offset
And this is the moment you have all been waiting for: setting the
counter offset from userspace.
We expose a brand new capability that reports the ability to set
the offset for both the virtual and physical sides.
In keeping with the architecture, the offset is expressed as
a delta that is substracted from the physical counter value.
Once this new API is used, there is no going back, and the counters
cannot be written to to set the offsets implicitly (the writes
are instead ignored).
Reviewed-by: Colton Lewis <coltonlewis@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230330174800.2677007-8-maz@kernel.org
Diffstat (limited to 'arch/arm64/include')
| -rw-r--r-- | arch/arm64/include/asm/kvm_host.h | 4 | ||||
| -rw-r--r-- | arch/arm64/include/uapi/asm/kvm.h | 9 |
2 files changed, 13 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 002a10cbade2..116233a390e9 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -221,6 +221,8 @@ struct kvm_arch { #define KVM_ARCH_FLAG_EL1_32BIT 4 /* PSCI SYSTEM_SUSPEND enabled for the guest */ #define KVM_ARCH_FLAG_SYSTEM_SUSPEND_ENABLED 5 + /* VM counter offset */ +#define KVM_ARCH_FLAG_VM_COUNTER_OFFSET 6 unsigned long flags; @@ -1010,6 +1012,8 @@ int kvm_arm_vcpu_arch_has_attr(struct kvm_vcpu *vcpu, long kvm_vm_ioctl_mte_copy_tags(struct kvm *kvm, struct kvm_arm_copy_mte_tags *copy_tags); +int kvm_vm_ioctl_set_counter_offset(struct kvm *kvm, + struct kvm_arm_counter_offset *offset); /* Guest/host FPSIMD coordination helpers */ int kvm_arch_vcpu_run_map_fp(struct kvm_vcpu *vcpu); diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h index f8129c624b07..12fb0d8a760a 100644 --- a/arch/arm64/include/uapi/asm/kvm.h +++ b/arch/arm64/include/uapi/asm/kvm.h @@ -198,6 +198,15 @@ struct kvm_arm_copy_mte_tags { __u64 reserved[2]; }; +/* + * Counter/Timer offset structure. Describe the virtual/physical offset. + * To be used with KVM_ARM_SET_COUNTER_OFFSET. + */ +struct kvm_arm_counter_offset { + __u64 counter_offset; + __u64 reserved; +}; + #define KVM_ARM_TAGS_TO_GUEST 0 #define KVM_ARM_TAGS_FROM_GUEST 1 |