Thread (76 messages) 76 messages, 6 authors, 2023-03-16

Re: [PATCH v9 22/27] virt: gunyah: Add resource tickets

From: Srivatsa Vaddagiri <hidden>
Date: 2023-02-06 09:50:55
Also in: linux-arm-msm, linux-devicetree, linux-doc, lkml

* Elliot Berman [off-list ref] [2023-01-20 14:46:21]:
+int ghvm_add_resource_ticket(struct gunyah_vm *ghvm, struct gunyah_vm_resource_ticket *ticket)
+{
+	struct gunyah_vm_resource_ticket *iter;
+	struct gunyah_resource *ghrsc;
+	int ret = 0;
+
+	mutex_lock(&ghvm->resources_lock);
+	list_for_each_entry(iter, &ghvm->resource_tickets, list) {
+		if (iter->resource_type == ticket->resource_type && iter->label == ticket->label) {
+			ret = -EEXIST;
+			goto out;
+		}
+	}
+
+	if (!try_module_get(ticket->owner)) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	list_add(&ticket->list, &ghvm->resource_tickets);
+	INIT_LIST_HEAD(&ticket->resources);
+
+	list_for_each_entry(ghrsc, &ghvm->resources, list) {
+		if (ghrsc->type == ticket->resource_type && ghrsc->rm_label == ticket->label) {
+			if (!ticket->populate(ticket, ghrsc))
+				list_move(&ghrsc->list, &ticket->resources);
Do we need the search to continue in case of a hit? 'gh_vm_add_resource' seems to
break loop on first occurrence. 

Also do we have examples of more than one 'gunyah_resource' being associated
with same 'gunyah_vm_resource_ticket'?  Both vcpu and irqfd tickets seem to deal
with just one resource?
quoted hunk ↗ jump to hunk
 static int gh_vm_start(struct gunyah_vm *ghvm)
 {
 	struct gunyah_vm_memory_mapping *mapping;
 	u64 dtb_offset;
 	u32 mem_handle;
-	int ret;
+	struct gunyah_resource *ghrsc;
+	struct gh_rm_hyp_resources *resources;
+	int ret, i;
 
 	down_write(&ghvm->status_lock);
 	if (ghvm->vm_status != GH_RM_VM_STATUS_NO_STATE) {
@@ -241,6 +314,22 @@ static int gh_vm_start(struct gunyah_vm *ghvm)
 		goto err;
 	}
 
+	ret = gh_rm_get_hyp_resources(ghvm->rm, ghvm->vmid, &resources);
+	if (ret) {
+		pr_warn("Failed to get hypervisor resources for VM: %d\n", ret);
+		goto err;
+	}
+
+	for (i = 0; i < le32_to_cpu(resources->n_entries); i++) {
minor nit: not sure if we can rely on compiler to optimize this, but it would
be better if we run le32_to_cpu once and use the result in loop. 
+		ghrsc = gh_rm_alloc_resource(ghvm->rm, &resources->entries[i]);
+		if (!ghrsc) {
+			ret = -ENOMEM;
+			goto err;
+		}
+
+		gh_vm_add_resource(ghvm, ghrsc);
Shouldn't we have gh_vm_add_resource()->  ticket->populate() return a result and
in case of failure we should bail out from this loop?
+	}
+
 	ret = gh_rm_vm_start(ghvm->rm, ghvm->vmid);
 	if (ret) {
 		pr_warn("Failed to start VM: %d\n", ret);
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