Commit f26061fe authored by Sean Christopherson's avatar Sean Christopherson
Browse files

KVM: TDX: Don't copy "cmd" back to userspace for KVM_TDX_CAPABILITIES 



Don't copy the kvm_tdx_cmd structure back to userspace when handling
KVM_TDX_CAPABILITIES, as tdx_get_capabilities() doesn't modify hw_error or
any other fields.

Opportunistically hoist the call to tdx_get_capabilities() outside of the
kvm->lock critical section, as getting the capabilities doesn't touch the
VM in any way, e.g. doesn't even take @kvm.

Suggested-by: default avatarKai Huang <kai.huang@intel.com>
Reviewed-by: default avatarKai Huang <kai.huang@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/20251030200951.3402865-26-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent 0b76e827

arch/x86/kvm/vmx/tdx.c

+3 −3
Original line number Diff line number Diff line
@@ -2816,12 +2816,12 @@ int tdx_vm_ioctl(struct kvm *kvm, void __user *argp) 
	if (r)

		return r;



	if (tdx_cmd.id == KVM_TDX_CAPABILITIES)

		return tdx_get_capabilities(&tdx_cmd);



	guard(mutex)(&kvm->lock);



	switch (tdx_cmd.id) {

	case KVM_TDX_CAPABILITIES:

		r = tdx_get_capabilities(&tdx_cmd);

		break;

	case KVM_TDX_INIT_VM:

		r = tdx_td_init(kvm, &tdx_cmd);

		break;