[PATCH V1 3/6] xen/virtio: Add option to restrict memory access under Xen
Juergen Gross
jgross at suse.com
Mon Apr 25 22:16:16 PDT 2022
On 25.04.22 23:25, Borislav Petkov wrote:
> On Mon, Apr 25, 2022 at 11:38:36PM +0300, Oleksandr wrote:
>> diff --git a/include/linux/cc_platform.h b/include/linux/cc_platform.h
>> index efd8205..d06bc7a 100644
>> --- a/include/linux/cc_platform.h
>> +++ b/include/linux/cc_platform.h
>> @@ -72,6 +72,19 @@ enum cc_attr {
>> * Examples include TDX guest & SEV.
>> */
>> CC_ATTR_GUEST_UNROLL_STRING_IO,
>> +
>> + /**
>> + * @CC_ATTR_GUEST_MEM_ACCESS_RESTRICTED: Restricted memory access to
>> + * Guest memory is active
>> + *
>> + * The platform/OS is running as a guest/virtual machine and uses
>> + * the restricted access to its memory. This attribute is set if
>> either
>> + * Guest memory encryption or restricted memory access using Xen
>> grant
>> + * mappings is active.
>> + *
>> + * Examples include Xen guest and SEV.
>
> Wait, whaaat?
>
> The cc_platform* stuff is for *confidential computing* guests to check
> different platform aspects.
>
> From quickly skimming over this, this looks like a misuse to me.
Christoph suggested (rather firmly) this would be the way to go.
>
> Why can't you query this from the hypervisor just like you do your other
> querying about what is supported, etc? Hypercalls, CPUID, whatever...
This is needed on guest side at a rather hypervisor independent place.
So a capability of some sort seems appropriate.
Another suggestion of mine was to have a callback (or flag) in
struct x86_hyper_runtime for that purpose.
Juergen
-------------- next part --------------
A non-text attachment was scrubbed...
Name: OpenPGP_0xB0DE9DD628BF132F.asc
Type: application/pgp-keys
Size: 3098 bytes
Desc: OpenPGP public key
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20220426/25fc982e/attachment-0001.bin>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: OpenPGP_signature
Type: application/pgp-signature
Size: 495 bytes
Desc: OpenPGP digital signature
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20220426/25fc982e/attachment-0001.sig>
More information about the linux-arm-kernel
mailing list