On Thu, 2025-08-21 at 14:21 -0500, Sagi Shahar wrote:
> > int tdx_sept_set_private_spte(struct kvm *kvm, gfn_t gfn,
> > enum pg_level level, kvm_pfn_t pfn)
> > {
> > + struct kvm_vcpu *vcpu = kvm_get_running_vcpu();
> > struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
> > struct page *page = pfn_to_page(pfn);
> > + int ret;
> > +
> > + ret = tdx_pamt_get(page, level, tdx_alloc_pamt_page_atomic, vcpu);
> > + if (ret)
> > + return ret;
>
> tdx_pamt_get() can return non-zero value in case of success e.g.
> returning 1 in case tdx_pamt_add() lost the race.
No?
+static int tdx_pamt_get(struct page *page, enum pg_level level)
+{
+ unsigned long hpa = page_to_phys(page);
+ atomic_t *pamt_refcount;
+ LIST_HEAD(pamt_pages);
+ int ret;
+
+ if (!tdx_supports_dynamic_pamt(&tdx_sysinfo))
+ return 0;
+
+ if (level != PG_LEVEL_4K)
+ return 0;
+
+ pamt_refcount = tdx_get_pamt_refcount(hpa);
+ WARN_ON_ONCE(atomic_read(pamt_refcount) < 0);
+
+ if (atomic_inc_not_zero(pamt_refcount))
+ return 0;
+
+ if (tdx_alloc_pamt_pages(&pamt_pages))
+ return -ENOMEM;
+
+ ret = tdx_pamt_add(pamt_refcount, hpa, &pamt_pages);
+ if (ret)
+ tdx_free_pamt_pages(&pamt_pages);
+
+ return ret >= 0 ? 0 : ret;
+}
> Shouldn't we check
> for (ret < 0) here and below cases?
I think you are thinking of tdx_pamt_add().
