Commit 59d5c1ed authored by Sean Christopherson's avatar Sean Christopherson
Browse files

KVM: TDX: Add tdx_get_cmd() helper to get and validate sub-ioctl command 



Add a helper to copy a kvm_tdx_cmd structure from userspace and verify
that must-be-zero fields are indeed zero.

No functional change intended.

Reviewed-by: default avatarRick Edgecombe <rick.p.edgecombe@intel.com>
Reviewed-by: default avatarKai Huang <kai.huang@intel.com>
Reviewed-by: default avatarBinbin Wu <binbin.wu@linux.intel.com>
Reviewed-by: default avatarYan Zhao <yan.y.zhao@intel.com>
Tested-by: default avatarYan Zhao <yan.y.zhao@intel.com>
Tested-by: default avatarKai Huang <kai.huang@intel.com>
Link: https://patch.msgid.link/20251030200951.3402865-23-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent 3d626ce5

arch/x86/kvm/vmx/tdx.c

+20 −13
Original line number Diff line number Diff line
@@ -2792,21 +2792,30 @@ static int tdx_td_finalize(struct kvm *kvm, struct kvm_tdx_cmd *cmd) 
	return 0;

}



int tdx_vm_ioctl(struct kvm *kvm, void __user *argp)

static int tdx_get_cmd(void __user *argp, struct kvm_tdx_cmd *cmd)

{

	struct kvm_tdx_cmd tdx_cmd;

	int r;



	if (copy_from_user(&tdx_cmd, argp, sizeof(struct kvm_tdx_cmd)))

	if (copy_from_user(cmd, argp, sizeof(*cmd)))

		return -EFAULT;



	/*

	 * Userspace should never set hw_error. It is used to fill

	 * hardware-defined error by the kernel.

	 * Userspace should never set hw_error.  KVM writes hw_error to report

	 * hardware-defined error back to userspace.

	 */

	if (tdx_cmd.hw_error)

	if (cmd->hw_error)

		return -EINVAL;



	return 0;

}



int tdx_vm_ioctl(struct kvm *kvm, void __user *argp)

{

	struct kvm_tdx_cmd tdx_cmd;

	int r;



	r = tdx_get_cmd(argp, &tdx_cmd);

	if (r)

		return r;



	mutex_lock(&kvm->lock);



	switch (tdx_cmd.id) {
@@ -3181,11 +3190,9 @@ int tdx_vcpu_ioctl(struct kvm_vcpu *vcpu, void __user *argp) 
	if (!is_hkid_assigned(kvm_tdx) || kvm_tdx->state == TD_STATE_RUNNABLE)

		return -EINVAL;



	if (copy_from_user(&cmd, argp, sizeof(cmd)))

		return -EFAULT;



	if (cmd.hw_error)

		return -EINVAL;

	ret = tdx_get_cmd(argp, &cmd);

	if (ret)

		return ret;



	switch (cmd.id) {

	case KVM_TDX_INIT_VCPU: