HVCALL_GET_VP_REGISTERS exposes the VTL call hypercall page entry
offsets to the guest. This hypercall is implemented in user-space while
the hypercall page patching happens in-kernel. So expose it as part of
the partition wide VSM state.
NOTE: Alternatively there is the option of sharing this information
through a VTL KVM device attribute (the device is introduced in
subsequent patches).
Signed-off-by: Nicolas Saenz Julienne <nsaenz@xxxxxxxxxx>
---
arch/x86/include/uapi/asm/kvm.h | 5 +++++
arch/x86/kvm/hyperv.c | 8 ++++++++
arch/x86/kvm/hyperv.h | 2 ++
arch/x86/kvm/x86.c | 18 ++++++++++++++++++
include/uapi/linux/kvm.h | 4 ++++
5 files changed, 37 insertions(+)
diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h
index f73d137784d7..370483d5d5fd 100644
--- a/arch/x86/include/uapi/asm/kvm.h
+++ b/arch/x86/include/uapi/asm/kvm.h
@@ -570,4 +570,9 @@ struct kvm_apic_id_groups {
__u8 n_bits; /* nr of bits used to represent group in the APIC ID */
};
+/* for KVM_HV_GET_VSM_STATE */
+struct kvm_hv_vsm_state {
+ __u64 vsm_code_page_offsets;
+};
+
#endif /* _ASM_X86_KVM_H */
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index 2cf430f6ddd8..caaa859932c5 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -2990,3 +2990,11 @@ int kvm_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid,
return 0;
}
+
+int kvm_vm_ioctl_get_hv_vsm_state(struct kvm *kvm, struct kvm_hv_vsm_state *state)
+{
+ struct kvm_hv* hv = &kvm->arch.hyperv;
+
+ state->vsm_code_page_offsets = hv->vsm_code_page_offsets.as_u64;
+ return 0;
+}
diff --git a/arch/x86/kvm/hyperv.h b/arch/x86/kvm/hyperv.h
index 5433107e7cc8..b3d1113efe82 100644
--- a/arch/x86/kvm/hyperv.h
+++ b/arch/x86/kvm/hyperv.h
@@ -261,4 +261,6 @@ static inline bool kvm_hv_vsm_enabled(struct kvm *kvm)
return kvm->arch.hyperv.hv_enable_vsm;
}
+int kvm_vm_ioctl_get_hv_vsm_state(struct kvm *kvm, struct kvm_hv_vsm_state *state);
+
#endif
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index b0512e433032..57f9c58e1e32 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7132,6 +7132,24 @@ int kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
r = kvm_vm_ioctl_set_apic_id_groups(kvm, &groups);
break;
}
+ case KVM_HV_GET_VSM_STATE: {
+ struct kvm_hv_vsm_state vsm_state;
+
+ r = -EINVAL;
+ if (!kvm_hv_vsm_enabled(kvm))
+ goto out;
+
+ r = kvm_vm_ioctl_get_hv_vsm_state(kvm, &vsm_state);
+ if (r)
+ goto out;
+
+ r = -EFAULT;
+ if (copy_to_user(argp, &vsm_state, sizeof(vsm_state)))
+ goto out;
+
+ r = 0;
+ break;
+ }
default:
r = -ENOTTY;
}
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 168b6ac6ebe5..03f5c08fd7aa 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -2316,4 +2316,8 @@ struct kvm_create_guest_memfd {
#define KVM_GUEST_MEMFD_ALLOW_HUGEPAGE (1ULL << 0)
#define KVM_SET_APIC_ID_GROUPS _IOW(KVMIO, 0xd7, struct kvm_apic_id_groups)
+
+/* Get/Set Hyper-V VSM state. Available with KVM_CAP_HYPERV_VSM */
+#define KVM_HV_GET_VSM_STATE _IOR(KVMIO, 0xd5, struct kvm_hv_vsm_state)
+
#endif /* __LINUX_KVM_H */
--
2.40.1
