| Message ID | 20240209183743.22030-3-pbonzini@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: SEV: allow customizing VMSA features | expand |
On Fri, Feb 09, 2024 at 01:37:34PM -0500, Paolo Bonzini 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. > > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Michael Roth <michael.roth@amd.com> > --- > arch/x86/include/asm/kvm-x86-ops.h | 1 + > arch/x86/include/asm/kvm_host.h | 1 + > arch/x86/kvm/x86.c | 52 +++++++++++++++++++----------- > 3 files changed, 36 insertions(+), 18 deletions(-) > > diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h > index 378ed944b849..ac8b7614e79d 100644 > --- a/arch/x86/include/asm/kvm-x86-ops.h > +++ b/arch/x86/include/asm/kvm-x86-ops.h > @@ -122,6 +122,7 @@ 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 d271ba20a0b2..0bcd9ae16097 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -1769,6 +1769,7 @@ struct kvm_x86_ops { > void (*enable_smi_window)(struct kvm_vcpu *vcpu); > #endif > > + int (*dev_get_attr)(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 bf10a9073a09..8746530930d5 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -4804,37 +4804,53 @@ static inline void __user *kvm_get_attr_addr(struct kvm_device_attr *attr) > return uaddr; > } > > -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 = kvm_get_attr_addr(attr); > + int r; > > if (attr->group) > return -ENXIO; > > + switch (attr->attr) { > + case KVM_X86_XCOMP_GUEST_SUPP: > + r = 0; > + *val = kvm_caps.supported_xcr0; > + break; > + default: > + r = -ENXIO; > + if (kvm_x86_ops.dev_get_attr) > + r = kvm_x86_ops.dev_get_attr(attr->attr, val); > + break; > + } > + > + return r; > +} > + > +static int kvm_x86_dev_get_attr(struct kvm_device_attr *attr) > +{ > + u64 __user *uaddr; > + int r; > + u64 val; > + > + r = __kvm_x86_dev_get_attr(attr, &val); > + if (r < 0) > + return r; > + > + uaddr = kvm_get_attr_addr(attr); > if (IS_ERR(uaddr)) > return PTR_ERR(uaddr); > > - switch (attr->attr) { > - case KVM_X86_XCOMP_GUEST_SUPP: > - if (put_user(kvm_caps.supported_xcr0, uaddr)) > - return -EFAULT; > - return 0; > - default: > - return -ENXIO; > - } > + 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, > -- > 2.39.0 > >
diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h index 378ed944b849..ac8b7614e79d 100644 --- a/arch/x86/include/asm/kvm-x86-ops.h +++ b/arch/x86/include/asm/kvm-x86-ops.h @@ -122,6 +122,7 @@ 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 d271ba20a0b2..0bcd9ae16097 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1769,6 +1769,7 @@ struct kvm_x86_ops { void (*enable_smi_window)(struct kvm_vcpu *vcpu); #endif + int (*dev_get_attr)(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 bf10a9073a09..8746530930d5 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4804,37 +4804,53 @@ static inline void __user *kvm_get_attr_addr(struct kvm_device_attr *attr) return uaddr; } -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 = kvm_get_attr_addr(attr); + int r; if (attr->group) return -ENXIO; + switch (attr->attr) { + case KVM_X86_XCOMP_GUEST_SUPP: + r = 0; + *val = kvm_caps.supported_xcr0; + break; + default: + r = -ENXIO; + if (kvm_x86_ops.dev_get_attr) + r = kvm_x86_ops.dev_get_attr(attr->attr, val); + break; + } + + return r; +} + +static int kvm_x86_dev_get_attr(struct kvm_device_attr *attr) +{ + u64 __user *uaddr; + int r; + u64 val; + + r = __kvm_x86_dev_get_attr(attr, &val); + if (r < 0) + return r; + + uaddr = kvm_get_attr_addr(attr); if (IS_ERR(uaddr)) return PTR_ERR(uaddr); - switch (attr->attr) { - case KVM_X86_XCOMP_GUEST_SUPP: - if (put_user(kvm_caps.supported_xcr0, uaddr)) - return -EFAULT; - return 0; - default: - return -ENXIO; - } + 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,
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. 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 | 52 +++++++++++++++++++----------- 3 files changed, 36 insertions(+), 18 deletions(-)