Re: [PATCHv2 08/12] KVM: TDX: Handle PAMT allocation in fault path

[Chao Gao]

> 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;
> 
> 	/* TODO: handle large pages. */
> 	if (KVM_BUG_ON(level != PG_LEVEL_4K, kvm))

nit: hoist this before the tdx_pamt_get() above. otherwise, tdx_pamt_put()
should be called in this error path.

>@@ -1562,10 +1577,16 @@ int tdx_sept_set_private_spte(struct kvm *kvm, gfn_t gfn,
> 	 * barrier in tdx_td_finalize().
> 	 */
> 	smp_rmb();
>-	if (likely(kvm_tdx->state == TD_STATE_RUNNABLE))
>-		return tdx_mem_page_aug(kvm, gfn, level, page);
> 
>-	return tdx_mem_page_record_premap_cnt(kvm, gfn, level, pfn);
>+	if (likely(kvm_tdx->state == TD_STATE_RUNNABLE))
>+		ret = tdx_mem_page_aug(kvm, gfn, level, page);
>+	else
>+		ret = tdx_mem_page_record_premap_cnt(kvm, gfn, level, pfn);
>+
>+	if (ret)
>+		tdx_pamt_put(page, level);
>+
>+	return ret;
> }

<snip>