On Mon, Mar 14, 2022 at 12:08:59PM +1300,
Kai Huang <kai.huang@xxxxxxxxx> wrote:
> On Fri, 2022-03-04 at 11:48 -0800, isaku.yamahata@xxxxxxxxx wrote:
> > From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
> >
> > As first step TDX VM support, return that TDX VM type supported to device
> > model, e.g. qemu. The callback to create guest TD is vm_init callback for
> > KVM_CREATE_VM. Add a place holder function and call a function to
> > initialize TDX module on demand because in that callback VMX is enabled by
> > hardware_enable callback (vmx_hardware_enable).
>
> Should we put this patch at the end of series until all changes required to run
> TD are introduced? This patch essentially tells userspace KVM is ready to
> support a TD but actually it's not ready. And this might also cause bisect
> issue I suppose?
The intention is that developers can exercise the new code step-by-step even if
the TDX KVM isn't complete.
How about introducing new config and remove it at the last of the patch series?
diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
index 2b1548da00eb..a3287440aa9e 100644
--- a/arch/x86/kvm/Kconfig
+++ b/arch/x86/kvm/Kconfig
@@ -98,6 +98,20 @@ config X86_SGX_KVM
If unsure, say N.
+config X86_TDX_KVM_EXPERIMENTAL
+ bool "EXPERIMENTAL Trust Domian Extensions (TDX) KVM support"
+ default n
+ depends on INTEL_TDX_HOST
+ depends on KVM_INTEL
+ help
+ Enable experimental TDX KVM support. TDX KVM needs many patches and
+ the patches will be merged step by step, not at once. Even if TDX KVM
+ support is incomplete, enable TDX KVM support so that developper can
+ exercise TDX KVM code. TODO: Remove this configuration once the
+ (first step of) TDX KVM support is complete.
+
+ If unsure, say N.
+
config KVM_AMD
tristate "KVM for AMD processors support"
depends on KVM
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index b16e2ed3b204..e31d6902e49c 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -170,7 +170,11 @@ int tdx_module_setup(void)
bool tdx_is_vm_type_supported(unsigned long type)
{
+#ifdef CONFIG_X86_TDX_KVM_EXPERIMENTAL
return type == KVM_X86_TDX_VM && READ_ONCE(enable_tdx);
+#else
+ return false;
+#endif
}
static int __init __tdx_hardware_setup(struct kvm_x86_ops *x86_ops)
--
Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
