Messages in this thread | | | Subject | Re: [PATCH Part2 RFC v4 25/40] KVM: SVM: Reclaim the guest pages when SEV-SNP VM terminates | From | Brijesh Singh <> | Date | Mon, 19 Jul 2021 14:37:06 -0500 |
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On 7/19/21 2:03 PM, Sean Christopherson wrote: > On Mon, Jul 19, 2021, Brijesh Singh wrote: >> >> On 7/19/21 12:18 PM, Sean Christopherson wrote: >>>> >>>> Okay, I will add helper to make things easier. One case where we will >>>> need to directly call the rmpupdate() is during the LAUNCH_UPDATE >>>> command. In that case the page is private and its immutable bit is also >>>> set. This is because the firmware makes change to the page, and we are >>>> required to set the immutable bit before the call. >>> >>> Or do "int rmp_make_firmware(u64 pfn, bool immutable)"? >> >> That's not what we need. >> >> We need 'rmp_make_private() + immutable' all in one RMPUPDATE. Here is the >> snippet from SNP_LAUNCH_UPDATE. > > Ah, not firmwrare, gotcha. But we can still use a helper, e.g. an inner > double-underscore helper, __rmp_make_private(). >
In that case we are basically passing the all the fields defined in the 'struct rmpupdate' as individual arguments. How about something like this:
* core kernel exports the rmpupdate() * the include/linux/sev.h header file defines the helper functions
int rmp_make_private(u64 pfn, u64 gpa, int psize, int asid) int rmp_make_firmware(u64 pfn, int psize); int rmp_make_shared(u64 pfn, int psize);
In most of the case above 3 helpers are good. If driver finds that the above helper does not fit its need (such as SNP_LAUNCH_UPDATE) then call the rmpupdate() without going through the helper.
-Brijesh
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