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SubjectRe: [PATCH Part2 RFC v4 25/40] KVM: SVM: Reclaim the guest pages when SEV-SNP VM terminates
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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.


+ /* Transition the page state to pre-guest */
+ memset(&e, 0, sizeof(e));
+ e.assigned = 1;
+ e.gpa = gpa;
+ e.asid = sev_get_asid(kvm);
+ e.immutable = true;
+ e.pagesize = X86_TO_RMP_PG_LEVEL(level);
+ ret = rmpupdate(inpages[i], &e);

thanks

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