| Message ID | 20240404121327.3107131-5-pbonzini@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | KVM: SEV: allow customizing VMSA features | expand |
On Thu, Apr 04, 2024 at 08:13:14AM -0400, Paolo Bonzini <pbonzini@redhat.com> wrote: > Allow vendor modules to provide their own attributes on /dev/kvm. > To avoid proliferation of vendor ops, implement KVM_HAS_DEVICE_ATTR > and KVM_GET_DEVICE_ATTR in terms of the same function. You're not > supposed to use KVM_GET_DEVICE_ATTR to do complicated computations, > especially on /dev/kvm. > > Reviewed-by: Michael Roth <michael.roth@amd.com> > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > --- > arch/x86/include/asm/kvm-x86-ops.h | 1 + > arch/x86/include/asm/kvm_host.h | 1 + > arch/x86/kvm/x86.c | 38 +++++++++++++++++++----------- > 3 files changed, 26 insertions(+), 14 deletions(-) > > diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h > index 110d7f29ca9a..5187fcf4b610 100644 > --- a/arch/x86/include/asm/kvm-x86-ops.h > +++ b/arch/x86/include/asm/kvm-x86-ops.h > @@ -121,6 +121,7 @@ KVM_X86_OP(enter_smm) > KVM_X86_OP(leave_smm) > KVM_X86_OP(enable_smi_window) > #endif > +KVM_X86_OP_OPTIONAL(dev_get_attr) > KVM_X86_OP_OPTIONAL(mem_enc_ioctl) > KVM_X86_OP_OPTIONAL(mem_enc_register_region) > KVM_X86_OP_OPTIONAL(mem_enc_unregister_region) > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index 16e07a2eee19..04c430eb25cf 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -1778,6 +1778,7 @@ struct kvm_x86_ops { > void (*enable_smi_window)(struct kvm_vcpu *vcpu); > #endif > > + int (*dev_get_attr)(u32 group, u64 attr, u64 *val); > int (*mem_enc_ioctl)(struct kvm *kvm, void __user *argp); > int (*mem_enc_register_region)(struct kvm *kvm, struct kvm_enc_region *argp); > int (*mem_enc_unregister_region)(struct kvm *kvm, struct kvm_enc_region *argp); > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 3d2029402513..3934e7682734 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -4842,34 +4842,44 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) > return r; > } > > -static int kvm_x86_dev_get_attr(struct kvm_device_attr *attr) > +static int __kvm_x86_dev_get_attr(struct kvm_device_attr *attr, u64 *val) > { > - u64 __user *uaddr = u64_to_user_ptr(attr->addr); > - > - if (attr->group) > + if (attr->group) { > + if (kvm_x86_ops.dev_get_attr) > + return static_call(kvm_x86_dev_get_attr)(attr->group, attr->attr, val); > return -ENXIO; > + } > > switch (attr->attr) { > case KVM_X86_XCOMP_GUEST_SUPP: > - if (put_user(kvm_caps.supported_xcr0, uaddr)) > - return -EFAULT; > + *val = kvm_caps.supported_xcr0; > return 0; > default: > return -ENXIO; > } > } > > +static int kvm_x86_dev_get_attr(struct kvm_device_attr *attr) > +{ > + u64 __user *uaddr = u64_to_user_ptr(attr->addr); > + int r; > + u64 val; > + > + r = __kvm_x86_dev_get_attr(attr, &val); > + if (r < 0) > + return r; > + > + if (put_user(val, uaddr)) > + return -EFAULT; > + > + return 0; > +} > + > static int kvm_x86_dev_has_attr(struct kvm_device_attr *attr) > { > - if (attr->group) > - return -ENXIO; > + u64 val; > > - switch (attr->attr) { > - case KVM_X86_XCOMP_GUEST_SUPP: > - return 0; > - default: > - return -ENXIO; > - } > + return __kvm_x86_dev_get_attr(attr, &val); > } > > long kvm_arch_dev_ioctl(struct file *filp, > -- > 2.43.0 > > > Reviewed-by: Isaku Yamahata <isaku.yamahata@intel.com>
diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h index 110d7f29ca9a..5187fcf4b610 100644 --- a/arch/x86/include/asm/kvm-x86-ops.h +++ b/arch/x86/include/asm/kvm-x86-ops.h @@ -121,6 +121,7 @@ KVM_X86_OP(enter_smm) KVM_X86_OP(leave_smm) KVM_X86_OP(enable_smi_window) #endif +KVM_X86_OP_OPTIONAL(dev_get_attr) KVM_X86_OP_OPTIONAL(mem_enc_ioctl) KVM_X86_OP_OPTIONAL(mem_enc_register_region) KVM_X86_OP_OPTIONAL(mem_enc_unregister_region) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 16e07a2eee19..04c430eb25cf 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1778,6 +1778,7 @@ struct kvm_x86_ops { void (*enable_smi_window)(struct kvm_vcpu *vcpu); #endif + int (*dev_get_attr)(u32 group, u64 attr, u64 *val); int (*mem_enc_ioctl)(struct kvm *kvm, void __user *argp); int (*mem_enc_register_region)(struct kvm *kvm, struct kvm_enc_region *argp); int (*mem_enc_unregister_region)(struct kvm *kvm, struct kvm_enc_region *argp); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 3d2029402513..3934e7682734 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4842,34 +4842,44 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) return r; } -static int kvm_x86_dev_get_attr(struct kvm_device_attr *attr) +static int __kvm_x86_dev_get_attr(struct kvm_device_attr *attr, u64 *val) { - u64 __user *uaddr = u64_to_user_ptr(attr->addr); - - if (attr->group) + if (attr->group) { + if (kvm_x86_ops.dev_get_attr) + return static_call(kvm_x86_dev_get_attr)(attr->group, attr->attr, val); return -ENXIO; + } switch (attr->attr) { case KVM_X86_XCOMP_GUEST_SUPP: - if (put_user(kvm_caps.supported_xcr0, uaddr)) - return -EFAULT; + *val = kvm_caps.supported_xcr0; return 0; default: return -ENXIO; } } +static int kvm_x86_dev_get_attr(struct kvm_device_attr *attr) +{ + u64 __user *uaddr = u64_to_user_ptr(attr->addr); + int r; + u64 val; + + r = __kvm_x86_dev_get_attr(attr, &val); + if (r < 0) + return r; + + if (put_user(val, uaddr)) + return -EFAULT; + + return 0; +} + static int kvm_x86_dev_has_attr(struct kvm_device_attr *attr) { - if (attr->group) - return -ENXIO; + u64 val; - switch (attr->attr) { - case KVM_X86_XCOMP_GUEST_SUPP: - return 0; - default: - return -ENXIO; - } + return __kvm_x86_dev_get_attr(attr, &val); } long kvm_arch_dev_ioctl(struct file *filp,