[RFC PATCH 27/34] gunyah: Share guest VM dtb configuration to Gunyah

[Karim Manaouil]

From: Elliot Berman <quic_eberman at quicinc.com>

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 at quicinc.com>
Signed-off-by: Karim Manaouil <karim.manaouil at linaro.org>
---
 arch/arm64/kvm/gunyah.c | 27 ++++++++++++++++++++++++---
 include/linux/gunyah.h  | 10 ++++++++++
 2 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kvm/gunyah.c b/arch/arm64/kvm/gunyah.c
index ef0971146b56..687f2beea4e7 100644
--- a/arch/arm64/kvm/gunyah.c
+++ b/arch/arm64/kvm/gunyah.c
@@ -699,8 +699,7 @@ static int gunyah_reclaim_memory_parcel(struct gunyah_vm *ghvm,
 	if (parcel->mem_handle != GUNYAH_MEM_HANDLE_INVAL) {
 		ret = gunyah_rm_mem_reclaim(ghvm->rm, parcel);
 		if (ret) {
-			dev_err(ghvm->parent, "Failed to reclaim parcel: %d\n",
-				ret);
+			pr_err("Failed to reclaim parcel: %d\n", ret);
 			/* We can't reclaim the pages -- hold onto the pages
 			 * forever because we don't know what state the memory
 			 * is in
@@ -1574,6 +1573,7 @@ static void gunyah_vm_stop(struct gunyah_vm *ghvm)
 
 static int gunyah_vm_start(struct gunyah_vm *ghvm)
 {
+	struct kvm *kvm = &ghvm->kvm;
 	struct gunyah_rm_hyp_resources *resources;
 	struct gunyah_resource *ghrsc;
 	int i, n, ret;
@@ -1597,7 +1597,18 @@ 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 = gpa_to_gfn(kvm->dtb.guest_phys_addr);
+	ghvm->dtb.parcel_pages = gpa_to_gfn(kvm->dtb.size);
+	ret = gunyah_share_memory_parcel(ghvm, &ghvm->dtb.parcel,
+					 ghvm->dtb.parcel_start,
+					 ghvm->dtb.parcel_pages);
+	if (ret) {
+		pr_warn("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, 0, kvm->dtb.size);
 	if (ret) {
 		pr_warn("Failed to configure VM: %d\n", ret);
 		goto err;
@@ -1698,6 +1709,16 @@ static void gunyah_destroy_vm(struct gunyah_vm *ghvm)
 	if (ghvm->vm_status == GUNYAH_RM_VM_STATUS_RUNNING)
 		gunyah_vm_stop(ghvm);
 
+	if (ghvm->vm_status == GUNYAH_RM_VM_STATUS_LOAD ||
+	    ghvm->vm_status == GUNYAH_RM_VM_STATUS_READY ||
+	    ghvm->vm_status == GUNYAH_RM_VM_STATUS_INIT_FAILED) {
+		ret = gunyah_reclaim_memory_parcel(ghvm, &ghvm->dtb.parcel,
+						 ghvm->dtb.parcel_start,
+						 ghvm->dtb.parcel_pages);
+		if (ret)
+			pr_err("Failed to reclaim DTB parcel: %d\n", ret);
+	}
+
 	gunyah_vm_remove_resource_ticket(ghvm, &ghvm->addrspace_ticket);
 	gunyah_vm_remove_resource_ticket(ghvm, &ghvm->host_shared_extent_ticket);
 	gunyah_vm_remove_resource_ticket(ghvm, &ghvm->host_private_extent_ticket);
diff --git a/include/linux/gunyah.h b/include/linux/gunyah.h
index 1d363ab8967a..72aafc813664 100644
--- a/include/linux/gunyah.h
+++ b/include/linux/gunyah.h
@@ -94,6 +94,12 @@ struct gunyah_vm_resource_ticket {
  * @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.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
  */
 struct gunyah_vm {
 	u16 vmid;
@@ -113,6 +119,10 @@ struct gunyah_vm {
 	struct gunyah_vm_resource_ticket host_shared_extent_ticket;
 	struct gunyah_vm_resource_ticket guest_private_extent_ticket;
 	struct gunyah_vm_resource_ticket guest_shared_extent_ticket;
+	struct {
+		gfn_t parcel_start, parcel_pages;
+		struct gunyah_rm_mem_parcel parcel;
+	} dtb;
 };
 
 /**
-- 
2.39.5