Re: [PATCH v7 011/102] KVM: TDX: Initialize TDX module when loading kvm_intel.ko

Isaku Yamahata
2022-07-12T00:46:46Z

On Tue, Jun 28, 2022 at 04:31:35PM +1200,
Kai Huang <kai.huang@intel.com> wrote:

> On Mon, 2022-06-27 at 14:53 -0700, isaku.yamahata@intel.com wrote:
> > From: Isaku Yamahata <isaku.yamahata@intel.com>
> >
> > To use TDX functionality, TDX module needs to be loaded and initialized.
> > A TDX host patch series[1] implements the detection of the TDX module,
> > tdx_detect() and its initialization, tdx_init().
>
> "A TDX host patch series[1]" really isn't a commit message material. You can
> put it to the cover letter, but not here.
>
> Also tdx_detect() is removed in latest code.

How about the followings?

KVM: TDX: Initialize TDX module when loading kvm_intel.ko

To use TDX functionality, TDX module needs to be loaded and initialized.
This patch is to call a function, tdx_init(), when loading kvm_intel.ko.

Add a hook, kvm_arch_post_hardware_enable_setup, to module initialization
while hardware is enabled, i.e. after hardware_enable_all() and before
hardware_disable_all(). Because TDX requires all present CPUs to enable
VMX (VMXON).

> > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> > index 30af2bd0b4d5..fb7a33fbc136 100644
> > --- a/arch/x86/kvm/x86.c
> > +++ b/arch/x86/kvm/x86.c
> > @@ -11792,6 +11792,14 @@ int kvm_arch_hardware_setup(void *opaque)
> > return 0;
> > }
> >
> > +int kvm_arch_post_hardware_enable_setup(void *opaque)
> > +{
> > + struct kvm_x86_init_ops *ops = opaque;
> > + if (ops->post_hardware_enable_setup)
> > + return ops->post_hardware_enable_setup();
> > + return 0;
> > +}
> > +
>
> Where is this kvm_arch_post_hardware_enable_setup() called?
>
> Shouldn't the code change which calls it be part of this patch?

The patch of "4/102 KVM: Refactor CPU compatibility check on module
initialiization" introduces it. Because the patch affects multiple archs
(mips, x86, poerpc, s390, and arm), I deliberately put it in early.
--
Isaku Yamahata <isaku.yamahata@gmail.com>