[PATCH v14 12/25] gunyah: vm_mgr: Add ioctls to support basic non-proxy VM boot

From: Elliot Berman
Date: Tue Jun 13 2023 - 13:23:12 EST


Add remaining ioctls to support non-proxy VM boot:

- Gunyah Resource Manager uses the VM's devicetree to configure the
virtual machine. The location of the devicetree in the guest's
virtual memory can be declared via the SET_DTB_CONFIG ioctl.
- Trigger start of the virtual machine with VM_START ioctl.

Reviewed-by: Alex Elder <elder@xxxxxxxxxx>
Co-developed-by: Prakruthi Deepak Heragu <quic_pheragu@xxxxxxxxxxx>
Signed-off-by: Prakruthi Deepak Heragu <quic_pheragu@xxxxxxxxxxx>
Signed-off-by: Elliot Berman <quic_eberman@xxxxxxxxxxx>
---
drivers/virt/gunyah/vm_mgr.c | 215 ++++++++++++++++++++++++++++++++
drivers/virt/gunyah/vm_mgr.h | 11 ++
drivers/virt/gunyah/vm_mgr_mm.c | 20 +++
include/uapi/linux/gunyah.h | 15 +++
4 files changed, 261 insertions(+)

diff --git a/drivers/virt/gunyah/vm_mgr.c b/drivers/virt/gunyah/vm_mgr.c
index 297427952b8c7..562ae6ed4a5f1 100644
--- a/drivers/virt/gunyah/vm_mgr.c
+++ b/drivers/virt/gunyah/vm_mgr.c
@@ -17,6 +17,68 @@

static void gh_vm_free(struct work_struct *work);

+static int gh_vm_rm_notification_status(struct gh_vm *ghvm, void *data)
+{
+ struct gh_rm_vm_status_payload *payload = data;
+
+ if (le16_to_cpu(payload->vmid) != ghvm->vmid)
+ return NOTIFY_OK;
+
+ /* All other state transitions are synchronous to a corresponding RM call */
+ if (payload->vm_status == GH_RM_VM_STATUS_RESET) {
+ down_write(&ghvm->status_lock);
+ ghvm->vm_status = payload->vm_status;
+ up_write(&ghvm->status_lock);
+ wake_up(&ghvm->vm_status_wait);
+ }
+
+ return NOTIFY_DONE;
+}
+
+static int gh_vm_rm_notification_exited(struct gh_vm *ghvm, void *data)
+{
+ struct gh_rm_vm_exited_payload *payload = data;
+
+ if (le16_to_cpu(payload->vmid) != ghvm->vmid)
+ return NOTIFY_OK;
+
+ down_write(&ghvm->status_lock);
+ ghvm->vm_status = GH_RM_VM_STATUS_EXITED;
+ up_write(&ghvm->status_lock);
+ wake_up(&ghvm->vm_status_wait);
+
+ return NOTIFY_DONE;
+}
+
+static int gh_vm_rm_notification(struct notifier_block *nb, unsigned long action, void *data)
+{
+ struct gh_vm *ghvm = container_of(nb, struct gh_vm, nb);
+
+ switch (action) {
+ case GH_RM_NOTIFICATION_VM_STATUS:
+ return gh_vm_rm_notification_status(ghvm, data);
+ case GH_RM_NOTIFICATION_VM_EXITED:
+ return gh_vm_rm_notification_exited(ghvm, data);
+ default:
+ return NOTIFY_OK;
+ }
+}
+
+static void gh_vm_stop(struct gh_vm *ghvm)
+{
+ int ret;
+
+ down_write(&ghvm->status_lock);
+ if (ghvm->vm_status == GH_RM_VM_STATUS_RUNNING) {
+ ret = gh_rm_vm_stop(ghvm->rm, ghvm->vmid);
+ if (ret)
+ dev_warn(ghvm->parent, "Failed to stop VM: %d\n", ret);
+ }
+ up_write(&ghvm->status_lock);
+
+ wait_event(ghvm->vm_status_wait, ghvm->vm_status == GH_RM_VM_STATUS_EXITED);
+}
+
static __must_check struct gh_vm *gh_vm_alloc(struct gh_rm *rm)
{
struct gh_vm *ghvm;
@@ -26,17 +88,130 @@ static __must_check struct gh_vm *gh_vm_alloc(struct gh_rm *rm)
return ERR_PTR(-ENOMEM);

ghvm->parent = gh_rm_get(rm);
+ ghvm->vmid = GH_VMID_INVAL;
ghvm->rm = rm;

mmgrab(current->mm);
ghvm->mm = current->mm;
mutex_init(&ghvm->mm_lock);
INIT_LIST_HEAD(&ghvm->memory_mappings);
+ init_rwsem(&ghvm->status_lock);
+ init_waitqueue_head(&ghvm->vm_status_wait);
INIT_WORK(&ghvm->free_work, gh_vm_free);
+ ghvm->vm_status = GH_RM_VM_STATUS_NO_STATE;

return ghvm;
}

+static int gh_vm_start(struct gh_vm *ghvm)
+{
+ struct gh_vm_mem *mapping;
+ u64 dtb_offset;
+ u32 mem_handle;
+ int ret;
+
+ down_write(&ghvm->status_lock);
+ if (ghvm->vm_status != GH_RM_VM_STATUS_NO_STATE) {
+ up_write(&ghvm->status_lock);
+ return 0;
+ }
+
+ ghvm->nb.notifier_call = gh_vm_rm_notification;
+ ret = gh_rm_notifier_register(ghvm->rm, &ghvm->nb);
+ if (ret)
+ goto err;
+
+ ret = gh_rm_alloc_vmid(ghvm->rm, 0);
+ if (ret < 0) {
+ gh_rm_notifier_unregister(ghvm->rm, &ghvm->nb);
+ goto err;
+ }
+ ghvm->vmid = ret;
+ ghvm->vm_status = GH_RM_VM_STATUS_LOAD;
+
+ mutex_lock(&ghvm->mm_lock);
+ list_for_each_entry(mapping, &ghvm->memory_mappings, list) {
+ mapping->parcel.acl_entries[0].vmid = cpu_to_le16(ghvm->vmid);
+ ret = gh_rm_mem_share(ghvm->rm, &mapping->parcel);
+ if (ret) {
+ dev_warn(ghvm->parent, "Failed to share parcel %d: %d\n",
+ mapping->parcel.label, ret);
+ mutex_unlock(&ghvm->mm_lock);
+ goto err;
+ }
+ }
+ mutex_unlock(&ghvm->mm_lock);
+
+ mapping = gh_vm_mem_find_by_addr(ghvm, ghvm->dtb_config.guest_phys_addr,
+ ghvm->dtb_config.size);
+ if (!mapping) {
+ dev_warn(ghvm->parent, "Failed to find the memory_handle for DTB\n");
+ ret = -EINVAL;
+ goto err;
+ }
+
+ mem_handle = mapping->parcel.mem_handle;
+ dtb_offset = ghvm->dtb_config.guest_phys_addr - mapping->guest_phys_addr;
+
+ ret = gh_rm_vm_configure(ghvm->rm, ghvm->vmid, ghvm->auth, mem_handle,
+ 0, 0, dtb_offset, ghvm->dtb_config.size);
+ if (ret) {
+ dev_warn(ghvm->parent, "Failed to configure VM: %d\n", ret);
+ goto err;
+ }
+
+ ret = gh_rm_vm_init(ghvm->rm, ghvm->vmid);
+ if (ret) {
+ ghvm->vm_status = GH_RM_VM_STATUS_INIT_FAILED;
+ dev_warn(ghvm->parent, "Failed to initialize VM: %d\n", ret);
+ goto err;
+ }
+ ghvm->vm_status = GH_RM_VM_STATUS_READY;
+
+ ret = gh_rm_vm_start(ghvm->rm, ghvm->vmid);
+ if (ret) {
+ dev_warn(ghvm->parent, "Failed to start VM: %d\n", ret);
+ goto err;
+ }
+
+ ghvm->vm_status = GH_RM_VM_STATUS_RUNNING;
+ up_write(&ghvm->status_lock);
+ return ret;
+err:
+ /* gh_vm_free will handle releasing resources and reclaiming memory */
+ up_write(&ghvm->status_lock);
+ return ret;
+}
+
+static int gh_vm_ensure_started(struct gh_vm *ghvm)
+{
+ int ret;
+
+ ret = down_read_interruptible(&ghvm->status_lock);
+ if (ret)
+ return ret;
+
+ /* Unlikely because VM is typically started */
+ if (unlikely(ghvm->vm_status == GH_RM_VM_STATUS_NO_STATE)) {
+ up_read(&ghvm->status_lock);
+ ret = gh_vm_start(ghvm);
+ if (ret)
+ return ret;
+ /** gh_vm_start() is guaranteed to bring status out of
+ * GH_RM_VM_STATUS_LOAD, thus infinitely recursive call is not
+ * possible
+ */
+ return gh_vm_ensure_started(ghvm);
+ }
+
+ /* Unlikely because VM is typically running */
+ if (unlikely(ghvm->vm_status != GH_RM_VM_STATUS_RUNNING))
+ ret = -ENODEV;
+
+ up_read(&ghvm->status_lock);
+ return ret;
+}
+
static long gh_vm_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct gh_vm *ghvm = filp->private_data;
@@ -61,6 +236,24 @@ static long gh_vm_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
r = gh_vm_mem_alloc(ghvm, &region);
break;
}
+ case GH_VM_SET_DTB_CONFIG: {
+ struct gh_vm_dtb_config dtb_config;
+
+ if (copy_from_user(&dtb_config, argp, sizeof(dtb_config)))
+ return -EFAULT;
+
+ if (overflows_type(dtb_config.guest_phys_addr + dtb_config.size, u64))
+ return -EOVERFLOW;
+
+ ghvm->dtb_config = dtb_config;
+
+ r = 0;
+ break;
+ }
+ case GH_VM_START: {
+ r = gh_vm_ensure_started(ghvm);
+ break;
+ }
default:
r = -ENOTTY;
break;
@@ -72,8 +265,30 @@ static long gh_vm_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
static void gh_vm_free(struct work_struct *work)
{
struct gh_vm *ghvm = container_of(work, struct gh_vm, free_work);
+ int ret;
+
+ if (ghvm->vm_status == GH_RM_VM_STATUS_RUNNING)
+ gh_vm_stop(ghvm);
+
+ if (ghvm->vm_status != GH_RM_VM_STATUS_NO_STATE &&
+ ghvm->vm_status != GH_RM_VM_STATUS_LOAD &&
+ ghvm->vm_status != GH_RM_VM_STATUS_RESET) {
+ ret = gh_rm_vm_reset(ghvm->rm, ghvm->vmid);
+ if (ret)
+ dev_err(ghvm->parent, "Failed to reset the vm: %d\n", ret);
+ wait_event(ghvm->vm_status_wait, ghvm->vm_status == GH_RM_VM_STATUS_RESET);
+ }

gh_vm_mem_reclaim(ghvm);
+
+ if (ghvm->vm_status > GH_RM_VM_STATUS_NO_STATE) {
+ gh_rm_notifier_unregister(ghvm->rm, &ghvm->nb);
+
+ ret = gh_rm_dealloc_vmid(ghvm->rm, ghvm->vmid);
+ if (ret)
+ dev_warn(ghvm->parent, "Failed to deallocate vmid: %d\n", ret);
+ }
+
gh_rm_put(ghvm->rm);
mmdrop(ghvm->mm);
kfree(ghvm);
diff --git a/drivers/virt/gunyah/vm_mgr.h b/drivers/virt/gunyah/vm_mgr.h
index 434ef9f662a7a..4173bd51f83fe 100644
--- a/drivers/virt/gunyah/vm_mgr.h
+++ b/drivers/virt/gunyah/vm_mgr.h
@@ -10,6 +10,8 @@
#include <linux/list.h>
#include <linux/miscdevice.h>
#include <linux/mutex.h>
+#include <linux/rwsem.h>
+#include <linux/wait.h>

#include <uapi/linux/gunyah.h>

@@ -31,8 +33,16 @@ struct gh_vm_mem {
};

struct gh_vm {
+ u16 vmid;
struct gh_rm *rm;
struct device *parent;
+ enum gh_rm_vm_auth_mechanism auth;
+ struct gh_vm_dtb_config dtb_config;
+
+ struct notifier_block nb;
+ enum gh_rm_vm_status vm_status;
+ wait_queue_head_t vm_status_wait;
+ struct rw_semaphore status_lock;

struct work_struct free_work;
struct mm_struct *mm; /* userspace tied to this vm */
@@ -42,5 +52,6 @@ struct gh_vm {

int gh_vm_mem_alloc(struct gh_vm *ghvm, struct gh_userspace_memory_region *region);
void gh_vm_mem_reclaim(struct gh_vm *ghvm);
+struct gh_vm_mem *gh_vm_mem_find_by_addr(struct gh_vm *ghvm, u64 guest_phys_addr, u32 size);

#endif
diff --git a/drivers/virt/gunyah/vm_mgr_mm.c b/drivers/virt/gunyah/vm_mgr_mm.c
index 6974607f02edd..f8a09e86d6bc1 100644
--- a/drivers/virt/gunyah/vm_mgr_mm.c
+++ b/drivers/virt/gunyah/vm_mgr_mm.c
@@ -75,6 +75,26 @@ void gh_vm_mem_reclaim(struct gh_vm *ghvm)
mutex_unlock(&ghvm->mm_lock);
}

+struct gh_vm_mem *gh_vm_mem_find_by_addr(struct gh_vm *ghvm, u64 guest_phys_addr, u32 size)
+{
+ struct gh_vm_mem *mapping;
+
+ if (overflows_type(guest_phys_addr + size, u64))
+ return NULL;
+
+ mutex_lock(&ghvm->mm_lock);
+
+ list_for_each_entry(mapping, &ghvm->memory_mappings, list) {
+ if (gh_vm_mem_overlap(mapping, guest_phys_addr, size))
+ goto unlock;
+ }
+
+ mapping = NULL;
+unlock:
+ mutex_unlock(&ghvm->mm_lock);
+ return mapping;
+}
+
int gh_vm_mem_alloc(struct gh_vm *ghvm, struct gh_userspace_memory_region *region)
{
struct gh_vm_mem *mapping, *tmp_mapping;
diff --git a/include/uapi/linux/gunyah.h b/include/uapi/linux/gunyah.h
index 91d6dd26fcc89..4b63d0b9b8ba7 100644
--- a/include/uapi/linux/gunyah.h
+++ b/include/uapi/linux/gunyah.h
@@ -57,4 +57,19 @@ struct gh_userspace_memory_region {
#define GH_VM_SET_USER_MEM_REGION _IOW(GH_IOCTL_TYPE, 0x1, \
struct gh_userspace_memory_region)

+/**
+ * struct gh_vm_dtb_config - Set the location of the VM's devicetree blob
+ * @guest_phys_addr: Address of the VM's devicetree in guest memory.
+ * @size: Maximum size of the devicetree including space for overlays.
+ * Resource manager applies an overlay to the DTB and dtb_size should
+ * include room for the overlay. A page of memory is typicaly plenty.
+ */
+struct gh_vm_dtb_config {
+ __u64 guest_phys_addr;
+ __u64 size;
+};
+#define GH_VM_SET_DTB_CONFIG _IOW(GH_IOCTL_TYPE, 0x2, struct gh_vm_dtb_config)
+
+#define GH_VM_START _IO(GH_IOCTL_TYPE, 0x3)
+
#endif
--
2.40.0