| Message ID | 20231108111806.92604-27-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: > Introduce KVM_SET_MEMORY_ATTRIBUTES ioctl support for VTL KVM devices. > The attributes are stored in an xarray private to the VTL device. > > The following memory attributes are supported: > - KVM_MEMORY_ATTRIBUTE_READ > - KVM_MEMORY_ATTRIBUTE_WRITE > - KVM_MEMORY_ATTRIBUTE_EXECUTE > - KVM_MEMORY_ATTRIBUTE_NO_ACCESS > Although only some combinations are valid, see code comment below. > > Signed-off-by: Nicolas Saenz Julienne <nsaenz@amazon.com> > --- > arch/x86/kvm/hyperv.c | 61 +++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 61 insertions(+) > > diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c > index 0d8402dba596..bcace0258af1 100644 > --- a/arch/x86/kvm/hyperv.c > +++ b/arch/x86/kvm/hyperv.c > @@ -62,6 +62,10 @@ > */ > #define HV_EXT_CALL_MAX (HV_EXT_CALL_QUERY_CAPABILITIES + 64) > > +#define KVM_HV_VTL_ATTRS \ > + (KVM_MEMORY_ATTRIBUTE_READ | KVM_MEMORY_ATTRIBUTE_WRITE | \ > + KVM_MEMORY_ATTRIBUTE_EXECUTE | KVM_MEMORY_ATTRIBUTE_NO_ACCESS) > + > static void stimer_mark_pending(struct kvm_vcpu_hv_stimer *stimer, > bool vcpu_kick); > > @@ -3025,6 +3029,7 @@ int kvm_vm_ioctl_get_hv_vsm_state(struct kvm *kvm, struct kvm_hv_vsm_state *stat > > struct kvm_hv_vtl_dev { > int vtl; > + struct xarray mem_attrs; > }; > > static int kvm_hv_vtl_get_attr(struct kvm_device *dev, > @@ -3047,16 +3052,71 @@ static void kvm_hv_vtl_release(struct kvm_device *dev) > { > struct kvm_hv_vtl_dev *vtl_dev = dev->private; > > + xa_destroy(&vtl_dev->mem_attrs); > kfree(vtl_dev); > kfree(dev); /* alloc by kvm_ioctl_create_device, free by .release */ > } > > +/* > + * The TLFS lists the valid memory protection combinations (15.9.3): > + * - No access > + * - Read-only, no execute > + * - Read-only, execute > + * - Read/write, no execute > + * - Read/write, execute > + */ > +static bool kvm_hv_validate_vtl_mem_attributes(struct kvm_memory_attributes *attrs) > +{ > + u64 attr = attrs->attributes; > + > + if (attr & ~KVM_HV_VTL_ATTRS) > + return false; > + > + if (attr == KVM_MEMORY_ATTRIBUTE_NO_ACCESS) > + return true; > + > + if (!(attr & KVM_MEMORY_ATTRIBUTE_READ)) > + return false; > + > + return true; > +} > + > +static long kvm_hv_vtl_ioctl(struct kvm_device *dev, unsigned int ioctl, > + unsigned long arg) > +{ > + switch (ioctl) { > + case KVM_SET_MEMORY_ATTRIBUTES: { > + struct kvm_hv_vtl_dev *vtl_dev = dev->private; > + struct kvm_memory_attributes attrs; > + int r; > + > + if (copy_from_user(&attrs, (void __user *)arg, sizeof(attrs))) > + return -EFAULT; > + > + r = -EINVAL; > + if (!kvm_hv_validate_vtl_mem_attributes(&attrs)) > + return r; > + > + r = kvm_ioctl_set_mem_attributes(dev->kvm, &vtl_dev->mem_attrs, > + KVM_HV_VTL_ATTRS, &attrs); > + if (r) > + return r; > + break; > + } > + default: > + return -ENOTTY; > + } > + > + return 0; > +} > + > static int kvm_hv_vtl_create(struct kvm_device *dev, u32 type); > > static struct kvm_device_ops kvm_hv_vtl_ops = { > .name = "kvm-hv-vtl", > .create = kvm_hv_vtl_create, > .release = kvm_hv_vtl_release, > + .ioctl = kvm_hv_vtl_ioctl, > .get_attr = kvm_hv_vtl_get_attr, > }; > > @@ -3076,6 +3136,7 @@ static int kvm_hv_vtl_create(struct kvm_device *dev, u32 type) > vtl++; > > vtl_dev->vtl = vtl; > + xa_init(&vtl_dev->mem_attrs); > dev->private = vtl_dev; > > return 0; It makes sense, but hopefully we won't need it if we adopt the VM per VTL approach. Best regards, Maxim Levitsky
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index 0d8402dba596..bcace0258af1 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -62,6 +62,10 @@ */ #define HV_EXT_CALL_MAX (HV_EXT_CALL_QUERY_CAPABILITIES + 64) +#define KVM_HV_VTL_ATTRS \ + (KVM_MEMORY_ATTRIBUTE_READ | KVM_MEMORY_ATTRIBUTE_WRITE | \ + KVM_MEMORY_ATTRIBUTE_EXECUTE | KVM_MEMORY_ATTRIBUTE_NO_ACCESS) + static void stimer_mark_pending(struct kvm_vcpu_hv_stimer *stimer, bool vcpu_kick); @@ -3025,6 +3029,7 @@ int kvm_vm_ioctl_get_hv_vsm_state(struct kvm *kvm, struct kvm_hv_vsm_state *stat struct kvm_hv_vtl_dev { int vtl; + struct xarray mem_attrs; }; static int kvm_hv_vtl_get_attr(struct kvm_device *dev, @@ -3047,16 +3052,71 @@ static void kvm_hv_vtl_release(struct kvm_device *dev) { struct kvm_hv_vtl_dev *vtl_dev = dev->private; + xa_destroy(&vtl_dev->mem_attrs); kfree(vtl_dev); kfree(dev); /* alloc by kvm_ioctl_create_device, free by .release */ } +/* + * The TLFS lists the valid memory protection combinations (15.9.3): + * - No access + * - Read-only, no execute + * - Read-only, execute + * - Read/write, no execute + * - Read/write, execute + */ +static bool kvm_hv_validate_vtl_mem_attributes(struct kvm_memory_attributes *attrs) +{ + u64 attr = attrs->attributes; + + if (attr & ~KVM_HV_VTL_ATTRS) + return false; + + if (attr == KVM_MEMORY_ATTRIBUTE_NO_ACCESS) + return true; + + if (!(attr & KVM_MEMORY_ATTRIBUTE_READ)) + return false; + + return true; +} + +static long kvm_hv_vtl_ioctl(struct kvm_device *dev, unsigned int ioctl, + unsigned long arg) +{ + switch (ioctl) { + case KVM_SET_MEMORY_ATTRIBUTES: { + struct kvm_hv_vtl_dev *vtl_dev = dev->private; + struct kvm_memory_attributes attrs; + int r; + + if (copy_from_user(&attrs, (void __user *)arg, sizeof(attrs))) + return -EFAULT; + + r = -EINVAL; + if (!kvm_hv_validate_vtl_mem_attributes(&attrs)) + return r; + + r = kvm_ioctl_set_mem_attributes(dev->kvm, &vtl_dev->mem_attrs, + KVM_HV_VTL_ATTRS, &attrs); + if (r) + return r; + break; + } + default: + return -ENOTTY; + } + + return 0; +} + static int kvm_hv_vtl_create(struct kvm_device *dev, u32 type); static struct kvm_device_ops kvm_hv_vtl_ops = { .name = "kvm-hv-vtl", .create = kvm_hv_vtl_create, .release = kvm_hv_vtl_release, + .ioctl = kvm_hv_vtl_ioctl, .get_attr = kvm_hv_vtl_get_attr, }; @@ -3076,6 +3136,7 @@ static int kvm_hv_vtl_create(struct kvm_device *dev, u32 type) vtl++; vtl_dev->vtl = vtl; + xa_init(&vtl_dev->mem_attrs); dev->private = vtl_dev; return 0;
Introduce KVM_SET_MEMORY_ATTRIBUTES ioctl support for VTL KVM devices. The attributes are stored in an xarray private to the VTL device. The following memory attributes are supported: - KVM_MEMORY_ATTRIBUTE_READ - KVM_MEMORY_ATTRIBUTE_WRITE - KVM_MEMORY_ATTRIBUTE_EXECUTE - KVM_MEMORY_ATTRIBUTE_NO_ACCESS Although only some combinations are valid, see code comment below. Signed-off-by: Nicolas Saenz Julienne <nsaenz@amazon.com> --- arch/x86/kvm/hyperv.c | 61 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+)