Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | Date | Fri, 22 Mar 2024 11:26:17 +1300 | Subject | Re: [PATCH v19 036/130] KVM: TDX: x86: Add ioctl to get TDX systemwide parameters | From | "Huang, Kai" <> |
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On 26/02/2024 9:25 pm, Yamahata, Isaku wrote: > From: Sean Christopherson <sean.j.christopherson@intel.com> > > Implement an ioctl to get system-wide parameters for TDX. Although the > function is systemwide, vm scoped mem_enc ioctl works for userspace VMM > like qemu and device scoped version is not define, re-use vm scoped > mem_enc.
-EPARSE for the part starting from "and device scoped ...".
Grammar check please.
> > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> > Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com> > --- > v18: > - drop the use of tdhsysinfo_struct and TDH.SYS.INFO, use TDH.SYS.RD(). > For that, dynamically allocate/free tdx_info. > - drop the change of tools/arch/x86/include/uapi/asm/kvm.h. > > v14 -> v15: > - ABI change: added supported_gpaw and reserved area. > > Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com> > --- > arch/x86/include/uapi/asm/kvm.h | 17 ++++++++++ > arch/x86/kvm/vmx/tdx.c | 56 +++++++++++++++++++++++++++++++++ > arch/x86/kvm/vmx/tdx.h | 3 ++ > 3 files changed, 76 insertions(+) > > diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h > index 9ea46d143bef..e28189c81691 100644 > --- a/arch/x86/include/uapi/asm/kvm.h > +++ b/arch/x86/include/uapi/asm/kvm.h > @@ -604,4 +604,21 @@ struct kvm_tdx_cpuid_config { > __u32 edx; > }; > > +/* supported_gpaw */ > +#define TDX_CAP_GPAW_48 (1 << 0) > +#define TDX_CAP_GPAW_52 (1 << 1) > + > +struct kvm_tdx_capabilities { > + __u64 attrs_fixed0; > + __u64 attrs_fixed1; > + __u64 xfam_fixed0; > + __u64 xfam_fixed1; > + __u32 supported_gpaw; > + __u32 padding; > + __u64 reserved[251]; > + > + __u32 nr_cpuid_configs; > + struct kvm_tdx_cpuid_config cpuid_configs[]; > +}; > +
I think you should use __DECLARE_FLEX_ARRAY().
It's already used in existing KVM UAPI header:
struct kvm_nested_state { ... union { __DECLARE_FLEX_ARRAY(struct kvm_vmx_nested_state_data, vmx); __DECLARE_FLEX_ARRAY(struct kvm_svm_nested_state_data, svm); } data; }
> #endif /* _ASM_X86_KVM_H */ > diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c > index 07a3f0f75f87..816ccdb4bc41 100644 > --- a/arch/x86/kvm/vmx/tdx.c > +++ b/arch/x86/kvm/vmx/tdx.c > @@ -6,6 +6,7 @@ > #include "capabilities.h" > #include "x86_ops.h" > #include "x86.h" > +#include "mmu.h" > #include "tdx_arch.h" > #include "tdx.h" > > @@ -55,6 +56,58 @@ struct tdx_info { > /* Info about the TDX module. */ > static struct tdx_info *tdx_info; > > +static int tdx_get_capabilities(struct kvm_tdx_cmd *cmd) > +{ > + struct kvm_tdx_capabilities __user *user_caps; > + struct kvm_tdx_capabilities *caps = NULL; > + int ret = 0; > + > + if (cmd->flags) > + return -EINVAL;
Add a comment?
/* flags is reserved for future use */
> + > + caps = kmalloc(sizeof(*caps), GFP_KERNEL); > + if (!caps) > + return -ENOMEM; > + > + user_caps = (void __user *)cmd->data; > + if (copy_from_user(caps, user_caps, sizeof(*caps))) { > + ret = -EFAULT; > + goto out; > + } > + > + if (caps->nr_cpuid_configs < tdx_info->num_cpuid_config) { > + ret = -E2BIG; > + goto out; > + } > + > + *caps = (struct kvm_tdx_capabilities) { > + .attrs_fixed0 = tdx_info->attributes_fixed0, > + .attrs_fixed1 = tdx_info->attributes_fixed1, > + .xfam_fixed0 = tdx_info->xfam_fixed0, > + .xfam_fixed1 = tdx_info->xfam_fixed1, > + .supported_gpaw = TDX_CAP_GPAW_48 | > + ((kvm_get_shadow_phys_bits() >= 52 && > + cpu_has_vmx_ept_5levels()) ? TDX_CAP_GPAW_52 : 0), > + .nr_cpuid_configs = tdx_info->num_cpuid_config, > + .padding = 0, > + }; > + > + if (copy_to_user(user_caps, caps, sizeof(*caps))) { > + ret = -EFAULT; > + goto out; > + }
Add an empty line.
> + if (copy_to_user(user_caps->cpuid_configs, &tdx_info->cpuid_configs, > + tdx_info->num_cpuid_config * > + sizeof(tdx_info->cpuid_configs[0]))) { > + ret = -EFAULT; > + }
I think the '{ }' is needed here. > + > +out: > + /* kfree() accepts NULL. */ > + kfree(caps); > + return ret; > +} > + > int tdx_vm_ioctl(struct kvm *kvm, void __user *argp) > { > struct kvm_tdx_cmd tdx_cmd; > @@ -68,6 +121,9 @@ int tdx_vm_ioctl(struct kvm *kvm, void __user *argp) > mutex_lock(&kvm->lock); > > switch (tdx_cmd.id) { > + case KVM_TDX_CAPABILITIES: > + r = tdx_get_capabilities(&tdx_cmd); > + break; > default: > r = -EINVAL; > goto out; > 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" > +
It appears "tdx_ops.h" is used for making SEAMCALLs.
I don't see this patch uses any SEAMCALL so I am wondering whether this chunk is needed here?
> struct kvm_tdx { > struct kvm kvm; > /* TDX specific members follow. */
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