Thread (67 messages) 67 messages, 8 authors, 2021-05-11

Re: [PATCH Part2 RFC v2 32/37] KVM: SVM: Add support to handle MSR based Page State Change VMGEXIT

From: Peter Gonda <hidden>
Date: 2021-05-10 17:36:01
Also in: lkml

+static int snp_make_page_shared(struct kvm_vcpu *vcpu, gpa_t gpa, kvm_pfn_t pfn, int level)
+{
+       struct rmpupdate val;
+       int rc, rmp_level;
+       struct rmpentry *e;
+
+       e = snp_lookup_page_in_rmptable(pfn_to_page(pfn), &rmp_level);
+       if (!e)
+               return -EINVAL;
+
+       if (!rmpentry_assigned(e))
+               return 0;
+
+       /* Log if the entry is validated */
+       if (rmpentry_validated(e))
+               pr_debug_ratelimited("Remove RMP entry for a validated gpa 0x%llx\n", gpa);
+
+       /*
+        * Is the page part of an existing 2M RMP entry ? Split the 2MB into multiple
+        * of 4K-page before making the memory shared.
+        */
+       if ((level == PG_LEVEL_4K) && (rmp_level == PG_LEVEL_2M)) {
+               rc = snp_rmptable_psmash(vcpu, pfn);
+               if (rc)
+                       return rc;
+       }
+
+       memset(&val, 0, sizeof(val));
+       val.pagesize = X86_TO_RMP_PG_LEVEL(level);
This is slightly different from Rev 2.00 of the GHCB spec. This
defaults to 2MB page sizes, when the spec says the only valid settings
for level are 0 -> 4k pages or 1 -> 2MB pages. Should this enforce the
same strictness as the spec?
+       return rmpupdate(pfn_to_page(pfn), &val);
+}
+
+static int snp_make_page_private(struct kvm_vcpu *vcpu, gpa_t gpa, kvm_pfn_t pfn, int level)
+{
+       struct kvm_sev_info *sev = &to_kvm_svm(vcpu->kvm)->sev_info;
+       struct rmpupdate val;
+       struct rmpentry *e;
+       int rmp_level;
+
+       e = snp_lookup_page_in_rmptable(pfn_to_page(pfn), &rmp_level);
+       if (!e)
+               return -EINVAL;
+
+       /* Log if the entry is validated */
+       if (rmpentry_validated(e))
+               pr_err_ratelimited("Asked to make a pre-validated gpa %llx private\n", gpa);
+
+       memset(&val, 0, sizeof(val));
+       val.gpa = gpa;
+       val.asid = sev->asid;
+       val.pagesize = X86_TO_RMP_PG_LEVEL(level);
Same comment as above.
+       val.assigned = true;
+
+       return rmpupdate(pfn_to_page(pfn), &val);
+}
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help