| Message ID | 20231108111806.92604-11-nsaenz@amazon.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: x86: hyperv: Introduce VSM support | expand |
On Wed, 2023-11-08 at 11:17 +0000, Nicolas Saenz Julienne wrote: > 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@amazon.com> > --- > 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 */ Looks reasonable but if we do hypercall patching in userspace as I suggested, we might not need this. Best regards, Maxim Levitsky
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 */
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@amazon.com> --- 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(+)