[RFC/PATCH v0 08/12] gunyah: Specific device-tree location

[Srivatsa Vaddagiri]

Specify the location of device-tree and its size, as Gunyah requires the
device-tree to be parsed before VM can begin its execution.

Signed-off-by: Srivatsa Vaddagiri <quic_svaddagi@quicinc.com>
---
 MAINTAINERS             |  1 +
 hw/arm/virt.c           |  6 ++++++
 include/sysemu/gunyah.h |  7 +++++++
 target/arm/gunyah.c     | 45 +++++++++++++++++++++++++++++++++++++++++
 target/arm/meson.build  |  4 ++++
 5 files changed, 63 insertions(+)
 create mode 100644 target/arm/gunyah.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 368ba02dce..5a51633d11 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -514,6 +514,7 @@ GUNYAH
 M: Srivatsa Vaddagiri <quic_svaddagi@quicinc.com>
 S: Maintained
 F: accel/gunyah
+F: target/arm/gunyah.c
 F: include/sysemu/gunyah.h
 F: target/arm/arm_gicv3_gunyah.c
 F: include/sysemu/gunyah_int.h
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 0d4c5aa819..4293e01383 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -1676,6 +1676,12 @@ void virt_machine_done(Notifier *notifier, void *data)
         exit(1);
     }
 
+    if (gunyah_enabled()) {
+        if (gunyah_arm_set_dtb(info->dtb_start, vms->fdt_size)) {
+            exit(1);
+        }
+    }
+
     fw_cfg_add_extra_pci_roots(vms->bus, vms->fw_cfg);
 
     virt_acpi_setup(vms);
diff --git a/include/sysemu/gunyah.h b/include/sysemu/gunyah.h
index aded49cdf6..101e190619 100644
--- a/include/sysemu/gunyah.h
+++ b/include/sysemu/gunyah.h
@@ -34,10 +34,17 @@ typedef struct GUNYAHState GUNYAHState;
 DECLARE_INSTANCE_CHECKER(GUNYAHState, GUNYAH_STATE,
                          TYPE_GUNYAH_ACCEL)
 
+int gunyah_arm_set_dtb(__u64 dtb_start, __u64 dtb_size);
+
 #else   /* CONFIG_GUNYAH_IS_POSSIBLE */
 
 #define gunyah_enabled()    0
 
+static inline int gunyah_arm_set_dtb(__u64 dtb_start, __u64 dtb_size)
+{
+    return -1;
+}
+
 #endif  /* CONFIG_GUNYAH_IS_POSSIBLE */
 
 #endif  /* QEMU_GUNYAH_H */
diff --git a/target/arm/gunyah.c b/target/arm/gunyah.c
new file mode 100644
index 0000000000..73c1c2a88a
--- /dev/null
+++ b/target/arm/gunyah.c
@@ -0,0 +1,45 @@
+/*
+ * QEMU Gunyah hypervisor support
+ *
+ * Copyright(c) 2023 Qualcomm Innovation Center, Inc. All Rights Reserved.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/error-report.h"
+#include "sysemu/gunyah.h"
+#include "sysemu/gunyah_int.h"
+#include "linux-headers/linux/gunyah.h"
+
+/*
+ * Specify location of device-tree in guest address space.
+ *
+ * @dtb_start - Guest physical address where VM's device-tree is found
+ * @dtb_size - Size of device-tree (and any free space after it).
+ *
+ * RM or Resource Manager VM is a trusted and privileged VM that works in
+ * collaboration with Gunyah hypevisor to setup resources for a VM before it 
can
+ * begin execution. One of its functions includes inspection/modification of a
+ * VM's device-tree before VM begins its execution. Modification can
+ * include specification of runtime resources allocated by hypervisor,
+ * details of which needs to be visible to VM.  VM's device-tree is modified
+ * "inline" making use of "free" space that could exist at the end of device
+ * tree.
+ */
+int gunyah_arm_set_dtb(__u64 dtb_start, __u64 dtb_size)
+{
+    int ret;
+    struct gh_vm_dtb_config dtb;
+
+    dtb.guest_phys_addr = dtb_start;
+    dtb.size = dtb_size;
+
+    ret = gunyah_vm_ioctl(GH_VM_SET_DTB_CONFIG, &dtb);
+    if (ret != 0) {
+        error_report("GH_VM_SET_DTB_CONFIG failed: %s", strerror(errno));
+        exit(1);
+    }
+
+    return 0;
+}
diff --git a/target/arm/meson.build b/target/arm/meson.build
index e645e456da..c7da15ca89 100644
--- a/target/arm/meson.build
+++ b/target/arm/meson.build
@@ -36,3 +36,7 @@ endif
 
 target_arch += {'arm': arm_ss}
 target_softmmu_arch += {'arm': arm_system_ss}
+
+arm_system_ss.add(when: 'CONFIG_GUNYAH', if_true: files(
+  'gunyah.c',
+))
-- 
2.25.1