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

[Alexey Makhalov <alexey.makhalov@broadcom.com>]

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

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