[PATCH v6 16/21] gunyah: vm_mgr: Add ioctls to support basic non-proxy VM boot

[Elliot Berman]

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.

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>
---
 arch/arm64/include/uapi/asm/gunyah.h | 17 ++++++
 drivers/virt/gunyah/vm_mgr.c         | 91 ++++++++++++++++++++++++++++
 drivers/virt/gunyah/vm_mgr.h         |  9 +++
 drivers/virt/gunyah/vm_mgr_mm.c      | 29 +++++++--
 include/uapi/linux/gunyah.h          |  8 +++
 5 files changed, 149 insertions(+), 5 deletions(-)
 create mode 100644 arch/arm64/include/uapi/asm/gunyah.h

diff --git a/arch/arm64/include/uapi/asm/gunyah.h b/arch/arm64/include/uapi/asm/gunyah.h
new file mode 100644
index 000000000000..54986f075ef5
--- /dev/null
+++ b/arch/arm64/include/uapi/asm/gunyah.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */
+/*
+ * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#ifndef _UAPI_ASM_GUNYAH
+#define _UAPI_ASM_GUNYAH
+
+#define GH_REG_GENERAL	0x10000
+#define GH_REG_X_MASK	0x1f
+#define GH_REG_SPECIAL	0x20000
+
+#define GH_REG_X(n)	(GH_REG_GENERAL | (n & GH_REG_X_MASK))
+#define GH_REG_PC	(GH_REG_SPECIAL)
+#define GH_REG_SP_EL1	(GH_REG_SPECIAL + 1)
+
+#endif
diff --git a/drivers/virt/gunyah/vm_mgr.c b/drivers/virt/gunyah/vm_mgr.c
index a993e81a20e2..3dae2fd9e412 100644
--- a/drivers/virt/gunyah/vm_mgr.c
+++ b/drivers/virt/gunyah/vm_mgr.c
@@ -9,6 +9,7 @@
 #include <linux/file.h>
 #include <linux/gunyah_rsc_mgr.h>
 #include <linux/miscdevice.h>
+#include <linux/mm.h>
 #include <linux/module.h>
 
 #include <uapi/linux/gunyah.h>
@@ -32,10 +33,79 @@ static __must_check struct gunyah_vm *gunyah_vm_alloc(void)
 
 	mutex_init(&ghvm->mm_lock);
 	INIT_LIST_HEAD(&ghvm->memory_mappings);
+	init_rwsem(&ghvm->status_lock);
 
 	return ghvm;
 }
 
+static int gh_vm_start(struct gunyah_vm *ghvm)
+{
+	struct gunyah_vm_memory_mapping *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;
+	}
+
+	mapping = gh_vm_mem_mapping_find_mapping(ghvm,
+			ghvm->dtb_config.gpa, ghvm->dtb_config.size);
+	if (!mapping) {
+		pr_warn("Failed to find the memory_handle for DTB\n");
+		ret = -EINVAL;
+		goto err;
+	}
+
+	mem_handle = mapping->parcel.mem_handle;
+	dtb_offset = ghvm->dtb_config.gpa - mapping->guest_phys_addr;
+
+	ret = gh_rm_vm_configure(ghvm->vmid, ghvm->auth, mem_handle,
+				0, 0, dtb_offset, ghvm->dtb_config.size);
+	if (ret) {
+		pr_warn("Failed to configure VM: %d\n", ret);
+		goto err;
+	}
+
+	ret = gh_rm_vm_init(ghvm->vmid);
+	if (ret) {
+		pr_warn("Failed to initialize VM: %d\n", ret);
+		goto err;
+	}
+
+	ret = gh_rm_vm_start(ghvm->vmid);
+	if (ret) {
+		pr_warn("Failed to start VM: %d\n", ret);
+		goto err;
+	}
+
+	ghvm->vm_status = GH_RM_VM_STATUS_READY;
+
+	up_write(&ghvm->status_lock);
+	return ret;
+err:
+	ghvm->vm_status = GH_RM_VM_STATUS_INIT_FAILED;
+	up_write(&ghvm->status_lock);
+	return ret;
+}
+
+static void gh_vm_stop(struct gunyah_vm *ghvm)
+{
+	int ret;
+
+	down_write(&ghvm->status_lock);
+	if (ghvm->vm_status == GH_RM_VM_STATUS_READY) {
+		ret = gh_rm_vm_stop(ghvm->vmid);
+		if (ret)
+			pr_warn("Failed to stop VM: %d\n", ret);
+	}
+
+	ghvm->vm_status = GH_RM_VM_STATUS_EXITED;
+	up_write(&ghvm->status_lock);
+}
+
 static long gh_vm_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
 	struct gunyah_vm *ghvm = filp->private_data;
@@ -79,6 +149,25 @@ static long gh_vm_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		}
 		break;
 	}
+	case GH_VM_SET_DTB_CONFIG: {
+		struct gh_vm_dtb_config dtb_config;
+
+		r = -EFAULT;
+		if (copy_from_user(&dtb_config, argp, sizeof(dtb_config)))
+			break;
+
+		dtb_config.size = PAGE_ALIGN(dtb_config.size);
+		ghvm->dtb_config = dtb_config;
+
+		r = 0;
+		break;
+	}
+	case GH_VM_START: {
+		r = gh_vm_start(ghvm);
+		if (r)
+			r = -EINVAL;
+		break;
+	}
 	default:
 		r = -ENOTTY;
 		break;
@@ -92,6 +181,8 @@ 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;
 
+	gh_vm_stop(ghvm);
+
 	list_for_each_entry_safe(mapping, tmp, &ghvm->memory_mappings, list) {
 		gh_vm_mem_mapping_reclaim(ghvm, mapping);
 	}
diff --git a/drivers/virt/gunyah/vm_mgr.h b/drivers/virt/gunyah/vm_mgr.h
index ab1f0cb0758a..38ce3a2d9329 100644
--- a/drivers/virt/gunyah/vm_mgr.h
+++ b/drivers/virt/gunyah/vm_mgr.h
@@ -9,6 +9,7 @@
 #include <linux/gunyah_rsc_mgr.h>
 #include <linux/list.h>
 #include <linux/mutex.h>
+#include <linux/rwsem.h>
 
 #include <uapi/linux/gunyah.h>
 
@@ -31,6 +32,12 @@ struct gunyah_vm_memory_mapping {
 struct gunyah_vm {
 	u16 vmid;
 
+	enum gh_rm_vm_auth_mechanism auth;
+	struct gh_vm_dtb_config dtb_config;
+
+	enum gh_rm_vm_status vm_status;
+	struct rw_semaphore status_lock;
+
 	struct mutex mm_lock;
 	struct list_head memory_mappings;
 };
@@ -39,5 +46,7 @@ struct gunyah_vm_memory_mapping *gh_vm_mem_mapping_alloc(struct gunyah_vm *ghvm,
 							struct gh_userspace_memory_region *region);
 void gh_vm_mem_mapping_reclaim(struct gunyah_vm *ghvm, struct gunyah_vm_memory_mapping *mapping);
 struct gunyah_vm_memory_mapping *gh_vm_mem_mapping_find(struct gunyah_vm *ghvm, u32 label);
+struct gunyah_vm_memory_mapping *gh_vm_mem_mapping_find_mapping(struct gunyah_vm *ghvm,
+								u64 gpa, u32 size);
 
 #endif
diff --git a/drivers/virt/gunyah/vm_mgr_mm.c b/drivers/virt/gunyah/vm_mgr_mm.c
index a5a57a38ee09..a7ca9a2e1627 100644
--- a/drivers/virt/gunyah/vm_mgr_mm.c
+++ b/drivers/virt/gunyah/vm_mgr_mm.c
@@ -34,11 +34,6 @@ void gh_vm_mem_mapping_reclaim(struct gunyah_vm *ghvm, struct gunyah_vm_memory_m
 	int i, ret = 0;
 
 	if (mapping->parcel.mem_handle != GH_MEM_HANDLE_INVAL) {
-		down_read(&ghvm->status_lock);
-		if (mapping->parcel.mem_handle == ghvm->primary_mem_handle &&
-			ghvm->vm_status == GH_RM_VM_STATUS_NO_STATE)
-			ghvm->primary_mem_handle = 0;
-		up_read(&ghvm->status_lock);
 		ret = gh_rm_mem_reclaim(&mapping->parcel);
 		if (ret)
 			pr_warn("Failed to reclaim memory parcel for label %d: %d\n",
@@ -58,6 +53,30 @@ void gh_vm_mem_mapping_reclaim(struct gunyah_vm *ghvm, struct gunyah_vm_memory_m
 	mutex_unlock(&ghvm->mm_lock);
 }
 
+struct gunyah_vm_memory_mapping *gh_vm_mem_mapping_find_mapping(struct gunyah_vm *ghvm,
+								u64 gpa, u32 size)
+{
+	struct gunyah_vm_memory_mapping *mapping = NULL;
+	int ret;
+
+	ret = mutex_lock_interruptible(&ghvm->mm_lock);
+	if (ret)
+		return ERR_PTR(ret);
+
+	list_for_each_entry(mapping, &ghvm->memory_mappings, list) {
+		if (gpa >= mapping->guest_phys_addr &&
+			(gpa + size <= mapping->guest_phys_addr +
+			(mapping->npages << PAGE_SHIFT))) {
+			goto unlock;
+		}
+	}
+
+	mapping = NULL;
+unlock:
+	mutex_unlock(&ghvm->mm_lock);
+	return mapping;
+}
+
 struct gunyah_vm_memory_mapping *gh_vm_mem_mapping_find(struct gunyah_vm *ghvm, u32 label)
 {
 	struct gunyah_vm_memory_mapping *mapping;
diff --git a/include/uapi/linux/gunyah.h b/include/uapi/linux/gunyah.h
index 93f4b99fcaf6..575cb1cbd215 100644
--- a/include/uapi/linux/gunyah.h
+++ b/include/uapi/linux/gunyah.h
@@ -42,4 +42,12 @@ struct gh_userspace_memory_region {
 #define GH_VM_SET_USER_MEM_REGION	_IOW(GH_IOCTL_TYPE, 0x41, \
 						struct gh_userspace_memory_region)
 
+struct gh_vm_dtb_config {
+	__u64 gpa;
+	__u64 size;
+};
+#define GH_VM_SET_DTB_CONFIG	_IOW(GH_IOCTL_TYPE, 0x42, struct gh_vm_dtb_config)
+
+#define GH_VM_START		_IO(GH_IOCTL_TYPE, 0x45)
+
 #endif
-- 
2.25.1