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

Elliot Berman
2023-01-20T23:13:00Z

Some VM functions need to acquire Gunyah resources. For instance, Gunyah
vCPUs are exposed to the host as a resource. The Gunyah vCPU function
will register a resource ticket and be able to interact with the
hypervisor once the resource ticket is filled.

Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
---
drivers/virt/gunyah/vm_mgr.c | 105 +++++++++++++++++++++++++++++++++-
drivers/virt/gunyah/vm_mgr.h | 5 ++
include/linux/gunyah.h | 4 ++
include/linux/gunyah_vm_mgr.h | 14 +++++
4 files changed, 127 insertions(+), 1 deletion(-)

diff --git a/drivers/virt/gunyah/vm_mgr.c b/drivers/virt/gunyah/vm_mgr.c
index 1e795f3d19d5..ee593cf1b074 100644
--- a/drivers/virt/gunyah/vm_mgr.c
+++ b/drivers/virt/gunyah/vm_mgr.c
@@ -135,6 +135,56 @@ static long gh_vm_rm_function(struct gunyah_vm *ghvm, struct gh_vm_function *fn)
return 0;
}

+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);
+ }
+ }
+out:
+ mutex_unlock(&ghvm->resources_lock);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(ghvm_add_resource_ticket);
+
+void ghvm_remove_resource_ticket(struct gunyah_vm *ghvm, struct gunyah_vm_resource_ticket *ticket)
+{
+ struct gunyah_resource *ghrsc, *iter;
+
+ mutex_lock(&ghvm->resources_lock);
+ list_for_each_entry_safe(ghrsc, iter, &ticket->resources, list) {
+ ticket->unpopulate(ticket, ghrsc);
+ list_move(&ghrsc->list, &ghvm->resources);
+ }
+
+ module_put(ticket->owner);
+ list_del(&ticket->list);
+ mutex_unlock(&ghvm->resources_lock);
+}
+EXPORT_SYMBOL_GPL(ghvm_remove_resource_ticket);
+
static void ghvm_put(struct kref *kref)
{
struct gunyah_vm *ghvm = container_of(kref, struct gunyah_vm, kref);
@@ -180,17 +230,40 @@ static __must_check struct gunyah_vm *gunyah_vm_alloc(struct gh_rm *rm)
INIT_LIST_HEAD(&ghvm->memory_mappings);
init_rwsem(&ghvm->status_lock);
kref_init(&ghvm->kref);
+ mutex_init(&ghvm->resources_lock);
+ INIT_LIST_HEAD(&ghvm->resources);
+ INIT_LIST_HEAD(&ghvm->resource_tickets);
INIT_LIST_HEAD(&ghvm->functions);

return ghvm;
}

+static void gh_vm_add_resource(struct gunyah_vm *ghvm, struct gunyah_resource *ghrsc)
+{
+ struct gunyah_vm_resource_ticket *ticket;
+
+ mutex_lock(&ghvm->resources_lock);
+ list_for_each_entry(ticket, &ghvm->resource_tickets, list) {
+ if (ghrsc->type == ticket->resource_type && ghrsc->rm_label == ticket->label) {
+ if (!ticket->populate(ticket, ghrsc)) {
+ list_add(&ghrsc->list, &ticket->resources);
+ goto found;
+ }
+ }
+ }
+ list_add(&ghrsc->list, &ghvm->resources);
+found:
+ mutex_unlock(&ghvm->resources_lock);
+}
+
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++) {
+ ghrsc = gh_rm_alloc_resource(ghvm->rm, &resources->entries[i]);
+ if (!ghrsc) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ gh_vm_add_resource(ghvm, ghrsc);
+ }
+
ret = gh_rm_vm_start(ghvm->rm, ghvm->vmid);
if (ret) {
pr_warn("Failed to start VM: %d\n", ret);
@@ -380,6 +469,8 @@ static int gh_vm_release(struct inode *inode, struct file *filp)
struct gunyah_vm *ghvm = filp->private_data;
struct gunyah_vm_memory_mapping *mapping, *tmp;
struct gunyah_vm_function *f, *fiter;
+ struct gunyah_vm_resource_ticket *ticket, *titer;
+ struct gunyah_resource *ghrsc, *riter;

gh_vm_stop(ghvm);

@@ -394,6 +485,18 @@ static int gh_vm_release(struct inode *inode, struct file *filp)
kfree(mapping);
}

+ if (!list_empty(&ghvm->resource_tickets)) {
+ pr_warn("Dangling resource tickets:\n");
+ list_for_each_entry_safe(ticket, titer, &ghvm->resource_tickets, list) {
+ pr_warn(" %pS\n", ticket->populate);
+ ghvm_remove_resource_ticket(ghvm, ticket);
+ }
+ }
+
+ list_for_each_entry_safe(ghrsc, riter, &ghvm->resources, list) {
+ gh_rm_free_resource(ghrsc);
+ }
+
put_gh_rm(ghvm->rm);
put_gunyah_vm(ghvm);
return 0;
diff --git a/drivers/virt/gunyah/vm_mgr.h b/drivers/virt/gunyah/vm_mgr.h
index 8d3b0678fb96..f52350145010 100644
--- a/drivers/virt/gunyah/vm_mgr.h
+++ b/drivers/virt/gunyah/vm_mgr.h
@@ -7,6 +7,7 @@
#define _GH_PRIV_VM_MGR_H

#include <linux/gunyah_rsc_mgr.h>
+#include <linux/gunyah_vm_mgr.h>
#include <linux/list.h>
#include <linux/kref.h>
#include <linux/miscdevice.h>
@@ -47,6 +48,10 @@ struct gunyah_vm {
struct mutex mm_lock;
struct list_head memory_mappings;

+ struct mutex resources_lock;
+ struct list_head resources;
+ struct list_head resource_tickets;
+
struct list_head functions;
};

diff --git a/include/linux/gunyah.h b/include/linux/gunyah.h
index 91d2c9f5b2f0..d745916cabcc 100644
--- a/include/linux/gunyah.h
+++ b/include/linux/gunyah.h
@@ -27,6 +27,10 @@ struct gunyah_resource {
enum gunyah_resource_type type;
u64 capid;
int irq;
+
+ /* To help allocator of resource manager */
+ struct list_head list;
+ u32 rm_label;
};

/**
diff --git a/include/linux/gunyah_vm_mgr.h b/include/linux/gunyah_vm_mgr.h
index 69f98eb503e9..995a9b0eb6b7 100644
--- a/include/linux/gunyah_vm_mgr.h
+++ b/include/linux/gunyah_vm_mgr.h
@@ -65,4 +65,18 @@ void gunyah_vm_function_unregister(struct gunyah_vm_function_driver *f);
} \
module_exit(_name##_mod_exit)

+struct gunyah_vm_resource_ticket {
+ struct list_head list;
+ struct list_head resources;
+ enum gunyah_resource_type resource_type;
+ u32 label;
+
+ struct module *owner;
+ int (*populate)(struct gunyah_vm_resource_ticket *ticket, struct gunyah_resource *ghrsc);
+ void (*unpopulate)(struct gunyah_vm_resource_ticket *ticket, struct gunyah_resource *ghrsc);
+};
+
+int ghvm_add_resource_ticket(struct gunyah_vm *ghvm, struct gunyah_vm_resource_ticket *ticket);
+void ghvm_remove_resource_ticket(struct gunyah_vm *ghvm, struct gunyah_vm_resource_ticket *ticket);
+
#endif
--
2.39.0