[PATCH v3 04/23] xen/riscv: Implement construct_domain()

[Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>]

Implement construct_domain() function for RISC-V, which performs initial setup
for the domain's first vCPU, loads the kernel, initrd, and device tree,
and sets up guest CPU registers for boot.

It also creates additional vCPUs up to max_vcpus and assigns the device tree
address and boot cpuid in registers.

Signed-off-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
---
Changes in v3:
 - s/%d/%u for printing vCPU index in the failure message.
 - Drop dprintk() for successful vCPU creation.
---
Changes in v2:
 - Rework construct_domain() to print that vCPU1...n are created using %pv.
 - Use true instead of 1 for initialization of v->is_initialised.
 - Drop unnessary BUG_ON() in construct_domain().
 - Add TODO comment above *_load() functions.
---
---
 xen/arch/riscv/Makefile       |  1 +
 xen/arch/riscv/domain-build.c | 50 +++++++++++++++++++++++++++++++++++
 2 files changed, 51 insertions(+)
 create mode 100644 xen/arch/riscv/domain-build.c

diff --git a/xen/arch/riscv/Makefile b/xen/arch/riscv/Makefile
index 8f7fd625dddd..fd5e499eb4b9 100644
--- a/xen/arch/riscv/Makefile
+++ b/xen/arch/riscv/Makefile
@@ -1,6 +1,7 @@
 obj-y += aplic.o
 obj-y += cpufeature.o
 obj-y += domain.o
+obj-y += domain-build.init.o
 obj-$(CONFIG_DOM0LESS_BOOT) += dom0less-build.init.o
 obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
 obj-y += entry.o
diff --git a/xen/arch/riscv/domain-build.c b/xen/arch/riscv/domain-build.c
new file mode 100644
index 000000000000..72cccb2c5c22
--- /dev/null
+++ b/xen/arch/riscv/domain-build.c
@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include <xen/fdt-domain-build.h>
+#include <xen/fdt-kernel.h>
+#include <xen/init.h>
+#include <xen/sched.h>
+
+#include <asm/current.h>
+#include <asm/guest_access.h>
+
+int __init construct_domain(struct domain *d, struct kernel_info *kinfo)
+{
+    struct vcpu *v = d->vcpu[0];
+    struct cpu_user_regs *regs = vcpu_guest_cpu_user_regs(v);
+
+    BUG_ON(v->is_initialised);
+
+    /*
+     * At the moment *_load() don't return value and will just panic()
+     * inside.
+     * TODO: it will be good to change that.
+     */
+    kernel_load(kinfo);
+    initrd_load(kinfo, copy_to_guest_phys);
+    dtb_load(kinfo, copy_to_guest_phys);
+
+    regs->sepc = kinfo->entry;
+
+    /* Guest boot cpuid = 0 */
+    regs->a0 = 0;
+    regs->a1 = kinfo->dtb_paddr;
+
+    for ( unsigned int i = 1; i < d->max_vcpus; i++ )
+    {
+        const struct vcpu *tmp_v = vcpu_create(d, i);
+
+        if ( !tmp_v )
+        {
+            printk("Failed to allocate %pd v%u\n", d, i);
+            break;
+        }
+    }
+
+    domain_update_node_affinity(d);
+
+    v->is_initialised = true;
+    clear_bit(_VPF_down, &v->pause_flags);
+
+    return 0;
+}
-- 
2.54.0