Gunyah Resource Manager sets up a virtual machine based on a device tree
which lives in guest memory. Resource manager requires this memory to be
provided as a memory parcel for it to read and manipulate. Construct a
memory parcel, lend it to the virtual machine, and inform resource
manager about the device tree location (the memory parcel ID and offset
into the memory parcel).
Signed-off-by: Elliot Berman <quic_eberman@xxxxxxxxxxx>
---
drivers/virt/gunyah/vm_mgr.c | 49 ++++++++++++++++++++++++++++++++++++++++++--
drivers/virt/gunyah/vm_mgr.h | 13 +++++++++++-
include/uapi/linux/gunyah.h | 14 +++++++++++++
3 files changed, 73 insertions(+), 3 deletions(-)
diff --git a/drivers/virt/gunyah/vm_mgr.c b/drivers/virt/gunyah/vm_mgr.c
index be2061aa0a06..4379b5ba151e 100644
--- a/drivers/virt/gunyah/vm_mgr.c
+++ b/drivers/virt/gunyah/vm_mgr.c
@@ -445,8 +445,27 @@ static int gunyah_vm_start(struct gunyah_vm *ghvm)
ghvm->vmid = ret;
ghvm->vm_status = GUNYAH_RM_VM_STATUS_LOAD;
- ret = gunyah_rm_vm_configure(ghvm->rm, ghvm->vmid, ghvm->auth, 0, 0, 0,
- 0, 0);
+ ghvm->dtb.parcel_start = ghvm->dtb.config.guest_phys_addr >> PAGE_SHIFT;
+ ghvm->dtb.parcel_pages = ghvm->dtb.config.size >> PAGE_SHIFT;
+ /* RM requires the DTB parcel to be lent to guard against malicious
+ * modifications while starting VM. Force it so.
+ */
+ ghvm->dtb.parcel.n_acl_entries = 1;
+ ret = gunyah_gmem_share_parcel(ghvm, &ghvm->dtb.parcel,
+ &ghvm->dtb.parcel_start,
+ &ghvm->dtb.parcel_pages);
+ if (ret) {
+ dev_warn(ghvm->parent,
+ "Failed to allocate parcel for DTB: %d\n", ret);
+ goto err;
+ }
+
+ ret = gunyah_rm_vm_configure(ghvm->rm, ghvm->vmid, ghvm->auth,
+ ghvm->dtb.parcel.mem_handle, 0, 0,
+ ghvm->dtb.config.guest_phys_addr -
+ (ghvm->dtb.parcel_start
+ << PAGE_SHIFT),
+ ghvm->dtb.config.size);
if (ret) {
dev_warn(ghvm->parent, "Failed to configure VM: %d\n", ret);
goto err;
@@ -485,6 +504,8 @@ static int gunyah_vm_start(struct gunyah_vm *ghvm)
goto err;
}
+ WARN_ON(gunyah_vm_parcel_to_paged(ghvm, &ghvm->dtb.parcel, ghvm->dtb.parcel_start, ghvm->dtb.parcel_pages));
+
ghvm->vm_status = GUNYAH_RM_VM_STATUS_RUNNING;
up_write(&ghvm->status_lock);
return ret;
@@ -531,6 +552,21 @@ static long gunyah_vm_ioctl(struct file *filp, unsigned int cmd,
long r;
switch (cmd) {
+ case GUNYAH_VM_SET_DTB_CONFIG: {
+ struct gunyah_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 GUNYAH_VM_START: {
r = gunyah_vm_ensure_started(ghvm);
break;
@@ -589,6 +625,15 @@ static void _gunyah_vm_put(struct kref *kref)
if (ghvm->vm_status == GUNYAH_RM_VM_STATUS_RUNNING)
gunyah_vm_stop(ghvm);
+ if (ghvm->vm_status == GUNYAH_RM_VM_STATUS_LOAD) {
+ ret = gunyah_gmem_reclaim_parcel(ghvm, &ghvm->dtb.parcel,
+ ghvm->dtb.parcel_start,
+ ghvm->dtb.parcel_pages);
+ if (ret)
+ dev_err(ghvm->parent,
+ "Failed to reclaim DTB parcel: %d\n", ret);
+ }
+
gunyah_vm_remove_functions(ghvm);
down_write(&ghvm->bindings_lock);
diff --git a/drivers/virt/gunyah/vm_mgr.h b/drivers/virt/gunyah/vm_mgr.h
index a79c11f1c3a5..b2ab2f1bda3a 100644
--- a/drivers/virt/gunyah/vm_mgr.h
+++ b/drivers/virt/gunyah/vm_mgr.h
@@ -72,6 +72,13 @@ long gunyah_dev_vm_mgr_ioctl(struct gunyah_rm *rm, unsigned int cmd,
* @resource_tickets: List of &struct gunyah_vm_resource_ticket
* @auth: Authentication mechanism to be used by resource manager when
* launching the VM
+ * @dtb: For tracking dtb configuration when launching the VM
+ * @dtb.config: Location of the DTB in the guest memory
+ * @dtb.parcel_start: Guest frame number where the memory parcel that we lent to
+ * VM (DTB could start in middle of folio; we lend entire
+ * folio; parcel_start is start of the folio)
+ * @dtb.parcel_pages: Number of pages lent for the memory parcel
+ * @dtb.parcel: Data for resource manager to lend the parcel
*
* Members are grouped by hot path.
*/
@@ -101,7 +108,11 @@ struct gunyah_vm {
struct device *parent;
enum gunyah_rm_vm_auth_mechanism auth;
-
+ struct {
+ struct gunyah_vm_dtb_config config;
+ u64 parcel_start, parcel_pages;
+ struct gunyah_rm_mem_parcel parcel;
+ } dtb;
};
int gunyah_vm_parcel_to_paged(struct gunyah_vm *ghvm,
diff --git a/include/uapi/linux/gunyah.h b/include/uapi/linux/gunyah.h
index 1af4c5ae6bc3..a89d9bedf3e5 100644
--- a/include/uapi/linux/gunyah.h
+++ b/include/uapi/linux/gunyah.h
@@ -42,6 +42,20 @@ struct gunyah_create_mem_args {
/*
* ioctls for gunyah-vm fds (returned by GUNYAH_CREATE_VM)
*/
+
+/**
+ * struct gunyah_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 gunyah_vm_dtb_config {
+ __u64 guest_phys_addr;
+ __u64 size;
+};
+#define GUNYAH_VM_SET_DTB_CONFIG _IOW(GUNYAH_IOCTL_TYPE, 0x2, struct gunyah_vm_dtb_config)
+
#define GUNYAH_VM_START _IO(GUNYAH_IOCTL_TYPE, 0x3)
/**
--
2.34.1
