| Message ID | 376bdde3fac2fb13579b33b9db3d3d2bc2774ffa.1699368322.git.isaku.yamahata@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM TDX basic feature support | expand |
On 11/7/2023 10:55 PM, isaku.yamahata@intel.com wrote: > From: Isaku Yamahata<isaku.yamahata@intel.com> > > TDX has its own limitation on the maximum number of vcpus that the guest > can accommodate. Allow x86 kvm backend to implement its own KVM_ENABLE_CAP > handler and implement TDX backend for KVM_CAP_MAX_VCPUS. user space VMM, > e.g. qemu, can specify its value instead of KVM_MAX_VCPUS. Should use "TDX" instread of "x86, tdx" in shortlog? > Signed-off-by: Isaku Yamahata<isaku.yamahata@intel.com> > --- > arch/x86/include/asm/kvm-x86-ops.h | 2 ++ > arch/x86/include/asm/kvm_host.h | 2 ++ > arch/x86/kvm/vmx/main.c | 22 ++++++++++++++++++++++ > arch/x86/kvm/vmx/tdx.c | 30 ++++++++++++++++++++++++++++++ > arch/x86/kvm/vmx/tdx.h | 3 +++ > arch/x86/kvm/vmx/x86_ops.h | 5 +++++ > arch/x86/kvm/x86.c | 4 ++++ > 7 files changed, 68 insertions(+) > > diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h > index 09abb53d92ea..b7b591f1ff72 100644 > --- a/arch/x86/include/asm/kvm-x86-ops.h > +++ b/arch/x86/include/asm/kvm-x86-ops.h > @@ -21,6 +21,8 @@ KVM_X86_OP(hardware_unsetup) > KVM_X86_OP(has_emulated_msr) > KVM_X86_OP(vcpu_after_set_cpuid) > KVM_X86_OP(is_vm_type_supported) > +KVM_X86_OP_OPTIONAL(max_vcpus); > +KVM_X86_OP_OPTIONAL(vm_enable_cap) > KVM_X86_OP(vm_init) > KVM_X86_OP_OPTIONAL(vm_destroy) > KVM_X86_OP_OPTIONAL_RET0(vcpu_precreate) > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index 6509e967454a..f240c3d025b1 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -1574,7 +1574,9 @@ struct kvm_x86_ops { > void (*vcpu_after_set_cpuid)(struct kvm_vcpu *vcpu); > > bool (*is_vm_type_supported)(unsigned long vm_type); > + int (*max_vcpus)(struct kvm *kvm); > unsigned int vm_size; > + int (*vm_enable_cap)(struct kvm *kvm, struct kvm_enable_cap *cap); > int (*vm_init)(struct kvm *kvm); > void (*vm_destroy)(struct kvm *kvm); > > diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c > index a95bbd10c3d8..5a857c8defd9 100644 > --- a/arch/x86/kvm/vmx/main.c > +++ b/arch/x86/kvm/vmx/main.c > @@ -6,6 +6,7 @@ > #include "nested.h" > #include "pmu.h" > #include "tdx.h" > +#include "tdx_arch.h" > > static bool enable_tdx __ro_after_init; > module_param_named(tdx, enable_tdx, bool, 0444); > @@ -16,6 +17,17 @@ static bool vt_is_vm_type_supported(unsigned long type) > (enable_tdx && tdx_is_vm_type_supported(type)); > } > > +static int vt_max_vcpus(struct kvm *kvm) > +{ > + if (!kvm) > + return KVM_MAX_VCPUS; > + > + if (is_td(kvm)) > + return min3(kvm->max_vcpus, KVM_MAX_VCPUS, TDX_MAX_VCPUS); kvm->max_vcpus is initialized to KVM_MAX_VCPUS when kvm_create_vm(). Also, when userspace tries to set the value, it's also limited by KVM_MAX_VCPUS. So, for x86, the value is <= KVM_MAX_VCPUS for sure. It could be simpler: + if (is_td(kvm)) + return min(kvm->max_vcpus, TDX_MAX_VCPUS); > + > + return kvm->max_vcpus; > +} > + > static int vt_hardware_enable(void) > { > int ret; > @@ -43,6 +55,14 @@ static __init int vt_hardware_setup(void) > return 0; > } > > +static int vt_vm_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap) > +{ > + if (is_td(kvm)) > + return tdx_vm_enable_cap(kvm, cap); > + > + return -EINVAL; > +} > + > static int vt_vm_init(struct kvm *kvm) > { > if (is_td(kvm)) > @@ -80,7 +100,9 @@ struct kvm_x86_ops vt_x86_ops __initdata = { > .has_emulated_msr = vmx_has_emulated_msr, > > .is_vm_type_supported = vt_is_vm_type_supported, > + .max_vcpus = vt_max_vcpus, > .vm_size = sizeof(struct kvm_vmx), > + .vm_enable_cap = vt_vm_enable_cap, > .vm_init = vt_vm_init, > .vm_destroy = vmx_vm_destroy, > > diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c > index f9e80582865d..331fbaa10d46 100644 > --- a/arch/x86/kvm/vmx/tdx.c > +++ b/arch/x86/kvm/vmx/tdx.c > @@ -17,6 +17,36 @@ > offsetof(struct tdsysinfo_struct, cpuid_configs)) \ > / sizeof(struct tdx_cpuid_config)) > > +int tdx_vm_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap) > +{ > + int r; > + > + switch (cap->cap) { > + case KVM_CAP_MAX_VCPUS: { > + if (cap->flags || cap->args[0] == 0) > + return -EINVAL; > + if (cap->args[0] > KVM_MAX_VCPUS) > + return -E2BIG; > + if (cap->args[0] > TDX_MAX_VCPUS) > + return -E2BIG; Can merge the two if statements into one. + if (cap->args[0] > KVM_MAX_VCPUS || cap->args[0] > TDX_MAX_VCPUS) + return -E2BIG; > + > + mutex_lock(&kvm->lock); > + if (kvm->created_vcpus) > + r = -EBUSY; > + else { > + kvm->max_vcpus = cap->args[0]; > + r = 0; > + } > + mutex_unlock(&kvm->lock); > + break; > + } > + default: > + r = -EINVAL; > + break; > + } > + return r; > +} > + > static int tdx_get_capabilities(struct kvm_tdx_cmd *cmd) > { > struct kvm_tdx_capabilities __user *user_caps; > diff --git a/arch/x86/kvm/vmx/tdx.h b/arch/x86/kvm/vmx/tdx.h > index 473013265bd8..22c0b57f69ca 100644 > --- a/arch/x86/kvm/vmx/tdx.h > +++ b/arch/x86/kvm/vmx/tdx.h > @@ -3,6 +3,9 @@ > #define __KVM_X86_TDX_H > > #ifdef CONFIG_INTEL_TDX_HOST > + > +#include "tdx_ops.h" > + > struct kvm_tdx { > struct kvm kvm; > /* TDX specific members follow. */ > diff --git a/arch/x86/kvm/vmx/x86_ops.h b/arch/x86/kvm/vmx/x86_ops.h > index 6487884a8d8e..ee5d8a38e7f8 100644 > --- a/arch/x86/kvm/vmx/x86_ops.h > +++ b/arch/x86/kvm/vmx/x86_ops.h > @@ -138,11 +138,16 @@ void vmx_setup_mce(struct kvm_vcpu *vcpu); > int __init tdx_hardware_setup(struct kvm_x86_ops *x86_ops); > bool tdx_is_vm_type_supported(unsigned long type); > > +int tdx_vm_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap); > int tdx_vm_ioctl(struct kvm *kvm, void __user *argp); > #else > static inline int tdx_hardware_setup(struct kvm_x86_ops *x86_ops) { return -EOPNOTSUPP; } > static inline bool tdx_is_vm_type_supported(unsigned long type) { return false; } > > +static inline int tdx_vm_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap) > +{ > + return -EINVAL; > +}; > static inline int tdx_vm_ioctl(struct kvm *kvm, void __user *argp) { return -EOPNOTSUPP; } > #endif > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index ced75e9204b9..de6e6462e7f3 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -4694,6 +4694,8 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) > break; > case KVM_CAP_MAX_VCPUS: > r = KVM_MAX_VCPUS; > + if (kvm_x86_ops.max_vcpus) > + r = static_call(kvm_x86_max_vcpus)(kvm); > break; > case KVM_CAP_MAX_VCPU_ID: > r = KVM_MAX_VCPU_IDS; > @@ -6641,6 +6643,8 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm, > break; > default: > r = -EINVAL; > + if (kvm_x86_ops.vm_enable_cap) > + r = static_call(kvm_x86_vm_enable_cap)(kvm, cap); > break; > } > return r;
diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h index 09abb53d92ea..b7b591f1ff72 100644 --- a/arch/x86/include/asm/kvm-x86-ops.h +++ b/arch/x86/include/asm/kvm-x86-ops.h @@ -21,6 +21,8 @@ KVM_X86_OP(hardware_unsetup) KVM_X86_OP(has_emulated_msr) KVM_X86_OP(vcpu_after_set_cpuid) KVM_X86_OP(is_vm_type_supported) +KVM_X86_OP_OPTIONAL(max_vcpus); +KVM_X86_OP_OPTIONAL(vm_enable_cap) KVM_X86_OP(vm_init) KVM_X86_OP_OPTIONAL(vm_destroy) KVM_X86_OP_OPTIONAL_RET0(vcpu_precreate) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 6509e967454a..f240c3d025b1 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1574,7 +1574,9 @@ struct kvm_x86_ops { void (*vcpu_after_set_cpuid)(struct kvm_vcpu *vcpu); bool (*is_vm_type_supported)(unsigned long vm_type); + int (*max_vcpus)(struct kvm *kvm); unsigned int vm_size; + int (*vm_enable_cap)(struct kvm *kvm, struct kvm_enable_cap *cap); int (*vm_init)(struct kvm *kvm); void (*vm_destroy)(struct kvm *kvm); diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c index a95bbd10c3d8..5a857c8defd9 100644 --- a/arch/x86/kvm/vmx/main.c +++ b/arch/x86/kvm/vmx/main.c @@ -6,6 +6,7 @@ #include "nested.h" #include "pmu.h" #include "tdx.h" +#include "tdx_arch.h" static bool enable_tdx __ro_after_init; module_param_named(tdx, enable_tdx, bool, 0444); @@ -16,6 +17,17 @@ static bool vt_is_vm_type_supported(unsigned long type) (enable_tdx && tdx_is_vm_type_supported(type)); } +static int vt_max_vcpus(struct kvm *kvm) +{ + if (!kvm) + return KVM_MAX_VCPUS; + + if (is_td(kvm)) + return min3(kvm->max_vcpus, KVM_MAX_VCPUS, TDX_MAX_VCPUS); + + return kvm->max_vcpus; +} + static int vt_hardware_enable(void) { int ret; @@ -43,6 +55,14 @@ static __init int vt_hardware_setup(void) return 0; } +static int vt_vm_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap) +{ + if (is_td(kvm)) + return tdx_vm_enable_cap(kvm, cap); + + return -EINVAL; +} + static int vt_vm_init(struct kvm *kvm) { if (is_td(kvm)) @@ -80,7 +100,9 @@ struct kvm_x86_ops vt_x86_ops __initdata = { .has_emulated_msr = vmx_has_emulated_msr, .is_vm_type_supported = vt_is_vm_type_supported, + .max_vcpus = vt_max_vcpus, .vm_size = sizeof(struct kvm_vmx), + .vm_enable_cap = vt_vm_enable_cap, .vm_init = vt_vm_init, .vm_destroy = vmx_vm_destroy, diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c index f9e80582865d..331fbaa10d46 100644 --- a/arch/x86/kvm/vmx/tdx.c +++ b/arch/x86/kvm/vmx/tdx.c @@ -17,6 +17,36 @@ offsetof(struct tdsysinfo_struct, cpuid_configs)) \ / sizeof(struct tdx_cpuid_config)) +int tdx_vm_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap) +{ + int r; + + switch (cap->cap) { + case KVM_CAP_MAX_VCPUS: { + if (cap->flags || cap->args[0] == 0) + return -EINVAL; + if (cap->args[0] > KVM_MAX_VCPUS) + return -E2BIG; + if (cap->args[0] > TDX_MAX_VCPUS) + return -E2BIG; + + mutex_lock(&kvm->lock); + if (kvm->created_vcpus) + r = -EBUSY; + else { + kvm->max_vcpus = cap->args[0]; + r = 0; + } + mutex_unlock(&kvm->lock); + break; + } + default: + r = -EINVAL; + break; + } + return r; +} + static int tdx_get_capabilities(struct kvm_tdx_cmd *cmd) { struct kvm_tdx_capabilities __user *user_caps; diff --git a/arch/x86/kvm/vmx/tdx.h b/arch/x86/kvm/vmx/tdx.h index 473013265bd8..22c0b57f69ca 100644 --- a/arch/x86/kvm/vmx/tdx.h +++ b/arch/x86/kvm/vmx/tdx.h @@ -3,6 +3,9 @@ #define __KVM_X86_TDX_H #ifdef CONFIG_INTEL_TDX_HOST + +#include "tdx_ops.h" + struct kvm_tdx { struct kvm kvm; /* TDX specific members follow. */ diff --git a/arch/x86/kvm/vmx/x86_ops.h b/arch/x86/kvm/vmx/x86_ops.h index 6487884a8d8e..ee5d8a38e7f8 100644 --- a/arch/x86/kvm/vmx/x86_ops.h +++ b/arch/x86/kvm/vmx/x86_ops.h @@ -138,11 +138,16 @@ void vmx_setup_mce(struct kvm_vcpu *vcpu); int __init tdx_hardware_setup(struct kvm_x86_ops *x86_ops); bool tdx_is_vm_type_supported(unsigned long type); +int tdx_vm_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap); int tdx_vm_ioctl(struct kvm *kvm, void __user *argp); #else static inline int tdx_hardware_setup(struct kvm_x86_ops *x86_ops) { return -EOPNOTSUPP; } static inline bool tdx_is_vm_type_supported(unsigned long type) { return false; } +static inline int tdx_vm_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap) +{ + return -EINVAL; +}; static inline int tdx_vm_ioctl(struct kvm *kvm, void __user *argp) { return -EOPNOTSUPP; } #endif diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index ced75e9204b9..de6e6462e7f3 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4694,6 +4694,8 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) break; case KVM_CAP_MAX_VCPUS: r = KVM_MAX_VCPUS; + if (kvm_x86_ops.max_vcpus) + r = static_call(kvm_x86_max_vcpus)(kvm); break; case KVM_CAP_MAX_VCPU_ID: r = KVM_MAX_VCPU_IDS; @@ -6641,6 +6643,8 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm, break; default: r = -EINVAL; + if (kvm_x86_ops.vm_enable_cap) + r = static_call(kvm_x86_vm_enable_cap)(kvm, cap); break; } return r;