Re: [PATCH v2 6/6] x86/vmware: Add TDX hypercall support

[Alexey Makhalov]

On 12/5/23 3:03 PM, Dave Hansen wrote:
> On 12/5/23 13:41, Alexey Makhalov wrote:
> > > I don't really like it much.  This does a generic thing (make a TDX
> > > hypercall) with a specific name ("vmware_").  If you want to make an
> > > argument that a certain chunk of the __tdx_hypercall() space is just for
> > > VMWare and you also add a VMWare-specific check and then export *that*,
> > > it might be acceptable.
> > >
> > > But I don't want random modules able to make random, unrestricted TDX
> > > hypercalls.  That's asking for trouble.
> >
> > Considering exporting of __tdx_hypercall for random modules is not an
> > option, what VMware specific checks you are suggesting?
>
> Make sure it can only be called running on VMWare guests.  A check for
> X86_HYPER_VMWARE seems simple enough.
>
> Second, unless the space is *HUGE*, you want to be exporting things like
> __vmware_platform() or vmware_legacy_x2apic_available(), *NOT* the
> underlying hypercall functions.
>
> We want to make sure that the interfaces are well defined and bounded.

Thanks Dave and Tim for your suggestions. I followed Dave recommendation 
to have a simple check for X86_HYPER_VMWARE.

Please review patch 6, which I'll send shortly.

Thanks,
--Alexey

--
This electronic communication and the information and any files transmitted 
with it, or attached to it, are confidential and are intended solely for 
the use of the individual or entity to whom it is addressed and may contain 
information that is confidential, legally privileged, protected by privacy 
laws, or otherwise restricted from disclosure to anyone else. If you are 
not the intended recipient or the person responsible for delivering the 
e-mail to the intended recipient, you are hereby notified that any use, 
copying, distributing, dissemination, forwarding, printing, or copying of 
this e-mail is strictly prohibited. If you received this e-mail in error, 
please return the e-mail to the sender, delete it from your computer, and 
destroy any printed copy of it.