0005-upcall-dragonball-devmgr-suppots-cpu-hotplug-on-arm6.patch

From 16e3b3da9fb8b79b006d8c9d1f68b2dec9980d72 Mon Sep 17 00:00:00 2001
Message-Id: <16e3b3da9fb8b79b006d8c9d1f68b2dec9980d72.1685428663.git.jiyunxue@linux.alibaba.com>
From: xuejun-xj <jiyunxue@linux.alibaba.com>
Date: Wed, 10 May 2023 13:55:43 +0800
Subject: [PATCH 1/3] upcall: dragonball-devmgr suppots cpu hotplug on arm64

Enable vcpuhotplug feature on aarch64 in guest kernel. It communicates
with dragonball by using upcall. This commit does these changes:

1. Wraps x86 related fields with CONFIG_X86_64.
2. Add "cpu_event_notification" for arm64.
3. Add "add_cpu_dev" and "del_cpu_dev" for arm64.

Signed-off-by: xuejun-xj <jiyunxue@linux.alibaba.com>
Reviewed-by : Chao Wu <chaowu@linux.alibaba.com>
Reviewed-by: Zizheng Bian <zizheng.bian@linux.alibaba.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
---
 .../upcall_srv/dragonball_device_manager.c    | 84 ++++++++++++++++++-
 1 file changed, 81 insertions(+), 3 deletions(-)

diff --git a/drivers/misc/dragonball/upcall_srv/dragonball_device_manager.c b/drivers/misc/dragonball/upcall_srv/dragonball_device_manager.c
index 5a95b2ba63e8..088d38623b8d 100644
--- a/drivers/misc/dragonball/upcall_srv/dragonball_device_manager.c
+++ b/drivers/misc/dragonball/upcall_srv/dragonball_device_manager.c
@@ -85,15 +85,21 @@ struct devmgr_req {
 #if defined(CONFIG_DRAGONBALL_HOTPLUG_CPU)
 		struct {
 			uint8_t count;
+#ifdef CONFIG_X86_64
 			uint8_t apic_ver;
 			uint8_t apic_ids[256];
+#endif
 		} cpu_dev_info;
 #endif
 	} msg_load;
 };
 
 struct cpu_dev_reply_info {
+#if defined(CONFIG_X86_64)
 	uint32_t apic_index;
+#elif defined(CONFIG_ARM64)
+	uint32_t cpu_id;
+#endif
 };
 
 struct devmgr_reply {
@@ -190,7 +196,8 @@ static void _fill_msg_header(struct devmgr_msg_header *msg, uint32_t msg_size,
 	msg->msg_flags     = msg_flags;
 }
 
-#if defined(CONFIG_DRAGONBALL_HOTPLUG_CPU) && defined(CONFIG_X86_64)
+#if defined(CONFIG_DRAGONBALL_HOTPLUG_CPU)
+#if defined(CONFIG_X86_64)
 static int get_cpu_id(int apic_id)
 {
 	int i;
@@ -219,6 +226,24 @@ static void cpu_event_notification(
 	_fill_msg_header(&rep->msg_header,
 	sizeof(struct cpu_dev_reply_info), action_type, 0);
 }
+#elif defined(CONFIG_ARM64)
+/**
+ * Return the first failed hotplug index of the cpu_id to dragonball.
+ * If hotplug/hotunplug succeeds, it will equals to the expected cpu count.
+ */
+static void cpu_event_notification(
+	uint8_t cpu_id,
+	int ret,
+	uint32_t action_type,
+	struct devmgr_reply *rep)
+{
+	pr_info("cpu event notification: cpu_id %d\n", cpu_id);
+	rep->msg_load.cpu_dev_info.cpu_id = cpu_id;
+	rep->ret = ret;
+	_fill_msg_header(&rep->msg_header,
+	sizeof(struct cpu_dev_reply_info), action_type, 0);
+}
+#endif
 #endif
 
 #if defined(CONFIG_DRAGONBALL_HOTPLUG_VIRTIO_MMIO)
@@ -262,7 +287,8 @@ static int del_mmio_dev(struct devmgr_req *req,
 #endif
 
 
-#if defined(CONFIG_DRAGONBALL_HOTPLUG_CPU) && defined(CONFIG_X86_64)
+#if defined(CONFIG_DRAGONBALL_HOTPLUG_CPU)
+#if defined(CONFIG_X86_64)
 static int add_cpu_upcall(int apic_id, uint8_t apic_ver)
 {
 	int cpu_id, node_id;
@@ -430,6 +456,58 @@ static int del_cpu_dev(struct devmgr_req *req,
 		cpu_event_notification(i, ret, DEL_CPU, rep);
 	return ret;
 }
+#elif defined(CONFIG_ARM64)
+static int add_cpu_dev(struct devmgr_req *req, struct devmgr_reply *rep)
+{
+	int i, ret = 0;
+	unsigned int cpu_id, nr_online_cpus;
+	uint8_t count = req->msg_load.cpu_dev_info.count;
+
+	nr_online_cpus = num_online_cpus();
+
+	pr_info("Current vcpu number: %d, Add vcpu number: %d\n",
+		nr_online_cpus, count);
+
+	for (i = 0; i < count; ++i) {
+		cpu_id = nr_online_cpus + i;
+		ret = add_cpu(cpu_id);
+		if (ret != 0)
+			break;
+	}
+
+	cpu_event_notification(nr_online_cpus + i, ret, ADD_CPU, rep);
+	return ret;
+}
+
+static int del_cpu_dev(struct devmgr_req *req, struct devmgr_reply *rep)
+{
+	int i, ret = 0;
+	unsigned int cpu_id, nr_online_cpus;
+	uint8_t count = req->msg_load.cpu_dev_info.count;
+
+	nr_online_cpus = num_online_cpus();
+
+	pr_info("Current vcpu number: %d, Delete vcpu number: %d\n",
+		nr_online_cpus, count);
+
+	if (count >= nr_online_cpus) {
+		pr_err("cpu del parameter check error: cannot remove all vcpus\n");
+		ret = -EINVAL;
+		cpu_event_notification(0, ret, DEL_CPU, rep);
+		return ret;
+	}
+
+	for (i = 0; i < count; ++i) {
+		cpu_id = nr_online_cpus - i - 1;
+		ret = remove_cpu(cpu_id);
+		if (ret != 0)
+			break;
+	}
+
+	cpu_event_notification(nr_online_cpus - i, ret, DEL_CPU, rep);
+	return ret;
+}
+#endif
 #endif
 
 static struct {
@@ -440,7 +518,7 @@ static struct {
 	{ADD_MMIO, add_mmio_dev},
 	{DEL_MMIO, del_mmio_dev},
 #endif
-#if defined(CONFIG_DRAGONBALL_HOTPLUG_CPU) && defined(CONFIG_X86_64)
+#if defined(CONFIG_DRAGONBALL_HOTPLUG_CPU)
 	{ADD_CPU, add_cpu_dev},
 	{DEL_CPU, del_cpu_dev},
 #endif
-- 
2.28.0