kernel: add arm experimental patches to support vcpu hotplug and virtio-mem

As the support for vcpu hotplug is on the road, I pick them up here as experimental to let user try cpu hotplug and virtio-mem on arm64. Fixes: #3280 Signed-off-by: Jianyong Wu <jianyong.wu@arm.com>
2025-04-27 11:31:05 +00:00 · 2021-12-16 14:17:28 +08:00 · 2021-12-16 14:17:28 +08:00 · 1b6f7401e0
commit 1b6f7401e0
parent 934788eb53
7 changed files with 690 additions and 0 deletions
--- a/tools/packaging/kernel/patches/5.15.x/arm-experimental/0001-arm64-kernel-Handle-disabled-present-cpus-in-MADT-GI.patch
+++ b/tools/packaging/kernel/patches/5.15.x/arm-experimental/0001-arm64-kernel-Handle-disabled-present-cpus-in-MADT-GI.patch
@ -0,0 +1,145 @@
+From 790af0565140c9df7394c195c22960d92f117c30 Mon Sep 17 00:00:00 2001
+From: Salil Mehta <salil.mehta@huawei.com>
+Date: Wed, 1 Dec 2021 14:58:33 +0800
+Subject: [PATCH 1/7] arm64: kernel: Handle disabled[(+)present] cpus in
+ MADT/GICC during init
+
+With ACPI enabled, cpus get identified by the presence of the GICC
+entry in the MADT Table. Each GICC entry part of MADT presents cpu as
+enabled or disabled. As of now, the disabled cpus are skipped as
+physical cpu hotplug is not supported. These remain disabled even after
+the kernel has booted.
+
+To support virtual cpu hotplug(in which case disabled vcpus could be
+hotplugged even after kernel has booted), QEMU will populate MADT Table
+with appropriate details of GICC entry for each possible(present+disabled)
+vcpu. Now, during the init time vcpus will be identified as present or
+disabled. To achieve this, below changes have been made with respect to
+the present/possible vcpu handling along with the mentioned reasoning:
+
+1. Identify all possible(present+disabled) vcpus at boot/init time
+   and set their present mask and possible mask. In the existing code,
+   cpus are being marked present quite late within smp_prepare_cpus()
+   function, which gets called in context to the kernel thread. Since
+   the cpu hotplug is not supported, present cpus are always equal to
+   the possible cpus. But with cpu hotplug enabled, this assumption is
+   not true. Hence, present cpus should be marked while MADT GICC entries
+   are bring parsed for each vcpu.
+2. Set possible cpus to include disabled. This needs to be done now
+   while parsing MADT GICC entries corresponding to each vcpu as the
+   disabled vcpu info is available only at this point as for hotplug
+   case possible vcpus is not equal to present vcpus.
+3. We will store the parsed madt/gicc entry even for the disabled vcpus
+   during init time. This is needed as some modules like PMU registers
+   IRQs for each possible vcpus during init time. Therefore, a valid
+   entry of the MADT GICC should be present for all possible vcpus.
+4. Refactoring related to DT/OF is also done to align it with the init
+   changes to support vcpu hotplug.
+
+Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
+Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
+---
+ arch/arm64/kernel/smp.c | 28 +++++++++++++++++++++-------
+ 1 file changed, 21 insertions(+), 7 deletions(-)
+
+diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
+index 6f6ff072acbd..4b317e71b1c4 100644
+--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
+@@ -524,13 +524,12 @@ static int __init smp_cpu_setup(int cpu)
+ 	if (ops->cpu_init(cpu))
+ 		return -ENODEV;
+ 
+-	set_cpu_possible(cpu, true);
+-
+ 	return 0;
+ }
+ 
+ static bool bootcpu_valid __initdata;
+ static unsigned int cpu_count = 1;
+static unsigned int disabled_cpu_count;
+ 
+ #ifdef CONFIG_ACPI
+ static struct acpi_madt_generic_interrupt cpu_madt_gicc[NR_CPUS];
+@@ -549,10 +548,17 @@ struct acpi_madt_generic_interrupt *acpi_cpu_get_madt_gicc(int cpu)
+ static void __init
+ acpi_map_gic_cpu_interface(struct acpi_madt_generic_interrupt *processor)
+ {
+	unsigned int total_cpu_count = disabled_cpu_count + cpu_count;
+ 	u64 hwid = processor->arm_mpidr;
+ 
+ 	if (!(processor->flags & ACPI_MADT_ENABLED)) {
+#ifndef CONFIG_ACPI_HOTPLUG_CPU
+ 		pr_debug("skipping disabled CPU entry with 0x%llx MPIDR\n", hwid);
+#else
+		cpu_madt_gicc[total_cpu_count] = *processor;
+		set_cpu_possible(total_cpu_count, true);
+		disabled_cpu_count++;
+#endif
+ 		return;
+ 	}
+ 
+@@ -561,7 +567,7 @@ acpi_map_gic_cpu_interface(struct acpi_madt_generic_interrupt *processor)
+ 		return;
+ 	}
+ 
+-	if (is_mpidr_duplicate(cpu_count, hwid)) {
+	if (is_mpidr_duplicate(total_cpu_count, hwid)) {
+ 		pr_err("duplicate CPU MPIDR 0x%llx in MADT\n", hwid);
+ 		return;
+ 	}
+@@ -582,9 +588,9 @@ acpi_map_gic_cpu_interface(struct acpi_madt_generic_interrupt *processor)
+ 		return;
+ 
+ 	/* map the logical cpu id to cpu MPIDR */
+-	set_cpu_logical_map(cpu_count, hwid);
+	set_cpu_logical_map(total_cpu_count, hwid);
+ 
+-	cpu_madt_gicc[cpu_count] = *processor;
+	cpu_madt_gicc[total_cpu_count] = *processor;
+ 
+ 	/*
+ 	 * Set-up the ACPI parking protocol cpu entries
+@@ -595,7 +601,10 @@ acpi_map_gic_cpu_interface(struct acpi_madt_generic_interrupt *processor)
+ 	 * initialize the cpu if the parking protocol is
+ 	 * the only available enable method).
+ 	 */
+-	acpi_set_mailbox_entry(cpu_count, processor);
+	acpi_set_mailbox_entry(total_cpu_count, processor);
+
+	set_cpu_possible(total_cpu_count, true);
+	set_cpu_present(total_cpu_count, true);
+ 
+ 	cpu_count++;
+ }
+@@ -629,6 +638,9 @@ static void __init acpi_parse_and_init_cpus(void)
+ 	acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_INTERRUPT,
+ 				      acpi_parse_gic_cpu_interface, 0);
+ 
+	pr_debug("possible cpus(%u) present cpus(%u) disabled cpus(%u)\n",
+		 cpu_count+disabled_cpu_count, cpu_count, disabled_cpu_count);
+
+ 	/*
+ 	 * In ACPI, SMP and CPU NUMA information is provided in separate
+ 	 * static tables, namely the MADT and the SRAT.
+@@ -699,6 +711,9 @@ static void __init of_parse_and_init_cpus(void)
+ 		set_cpu_logical_map(cpu_count, hwid);
+ 
+ 		early_map_cpu_to_node(cpu_count, of_node_to_nid(dn));
+
+		set_cpu_possible(cpu_count, true);
+		set_cpu_present(cpu_count, true);
+ next:
+ 		cpu_count++;
+ 	}
+@@ -783,7 +798,6 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
+ 		if (err)
+ 			continue;
+ 
+-		set_cpu_present(cpu, true);
+ 		numa_store_cpu_info(cpu);
+ 	}
+ }
+-- 
+2.17.1
+
--- a/tools/packaging/kernel/patches/5.15.x/arm-experimental/0002-arm64-kernel-Bound-the-total-present-disabled-cpus-w.patch
+++ b/tools/packaging/kernel/patches/5.15.x/arm-experimental/0002-arm64-kernel-Bound-the-total-present-disabled-cpus-w.patch
@ -0,0 +1,86 @@
+From 2bd0439913fde8598113cc3959764a877c0bd1ad Mon Sep 17 00:00:00 2001
+From: Salil Mehta <salil.mehta@huawei.com>
+Date: Wed, 1 Dec 2021 16:01:17 +0800
+Subject: [PATCH 2/7] arm64: kernel: Bound the total(present+disabled) cpus
+ with nr_cpu_ids
+
+Bound the total number of identified cpus(including disabled cpus) by
+maximum allowed limit by the kernel. Max value is either specified as
+part of the kernel parameters 'nr_cpus' or specified during compile
+time using CONFIG_NR_CPUS.
+
+Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
+Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
+---
+ arch/arm64/kernel/smp.c | 18 ++++++++++++------
+ 1 file changed, 12 insertions(+), 6 deletions(-)
+
+diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
+index 4b317e71b1c4..18a0576f2721 100644
+--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
+@@ -528,6 +528,7 @@ static int __init smp_cpu_setup(int cpu)
+ }
+ 
+ static bool bootcpu_valid __initdata;
+static bool cpus_clipped __initdata = false;
+ static unsigned int cpu_count = 1;
+ static unsigned int disabled_cpu_count;
+ 
+@@ -551,6 +552,11 @@ acpi_map_gic_cpu_interface(struct acpi_madt_generic_interrupt *processor)
+ 	unsigned int total_cpu_count = disabled_cpu_count + cpu_count;
+ 	u64 hwid = processor->arm_mpidr;
+ 
+	if (total_cpu_count > nr_cpu_ids) {
+		cpus_clipped = true;
+		return;
+	}
+
+ 	if (!(processor->flags & ACPI_MADT_ENABLED)) {
+ #ifndef CONFIG_ACPI_HOTPLUG_CPU
+ 		pr_debug("skipping disabled CPU entry with 0x%llx MPIDR\n", hwid);
+@@ -584,9 +590,6 @@ acpi_map_gic_cpu_interface(struct acpi_madt_generic_interrupt *processor)
+ 		return;
+ 	}
+ 
+-	if (cpu_count >= NR_CPUS)
+-		return;
+-
+ 	/* map the logical cpu id to cpu MPIDR */
+ 	set_cpu_logical_map(total_cpu_count, hwid);
+ 
+@@ -704,8 +707,10 @@ static void __init of_parse_and_init_cpus(void)
+ 			continue;
+ 		}
+ 
+-		if (cpu_count >= NR_CPUS)
+		if (cpu_count >= NR_CPUS) {
+			cpus_clipped = true;
+ 			goto next;
+		}
+ 
+ 		pr_debug("cpu logical map 0x%llx\n", hwid);
+ 		set_cpu_logical_map(cpu_count, hwid);
+@@ -726,6 +731,7 @@ static void __init of_parse_and_init_cpus(void)
+  */
+ void __init smp_init_cpus(void)
+ {
+	unsigned int total_cpu_count = disabled_cpu_count + cpu_count;
+ 	int i;
+ 
+ 	if (acpi_disabled)
+@@ -733,9 +739,9 @@ void __init smp_init_cpus(void)
+ 	else
+ 		acpi_parse_and_init_cpus();
+ 
+-	if (cpu_count > nr_cpu_ids)
+	if (cpus_clipped)
+ 		pr_warn("Number of cores (%d) exceeds configured maximum of %u - clipping\n",
+-			cpu_count, nr_cpu_ids);
+			total_cpu_count, nr_cpu_ids);
+ 
+ 	if (!bootcpu_valid) {
+ 		pr_err("missing boot CPU MPIDR, not enabling secondaries\n");
+-- 
+2.17.1
+
--- a/tools/packaging/kernel/patches/5.15.x/arm-experimental/0003-arm64-kernel-Init-cpu-operations-for-all-possible-vc.patch
+++ b/tools/packaging/kernel/patches/5.15.x/arm-experimental/0003-arm64-kernel-Init-cpu-operations-for-all-possible-vc.patch
@ -0,0 +1,116 @@
+From 58ceaa003bab7d2613f01ec58925a75e1f731240 Mon Sep 17 00:00:00 2001
+From: Salil Mehta <salil.mehta@huawei.com>
+Date: Thu, 2 Dec 2021 13:57:51 +0800
+Subject: [PATCH 3/7] arm64: kernel: Init cpu operations for all possible vcpus
+
+Currently, cpu-operations are only initialized for the cpus which
+already have logical cpuid to hwid assoication established. And this
+only happens for the cpus which are present during boot time.
+
+To support virtual cpu hotplug, we shall initialze the cpu-operations
+for all possible(present+disabled) vcpus. This means logical cpuid to
+hwid/mpidr association might not exists(i.e. might be INVALID_HWID)
+during init. Later, when the vcpu is actually hotplugged logical cpuid
+is allocated and associated with the hwid/mpidr.
+
+This patch does some refactoring to support above change.
+
+Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
+Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
+---
+ arch/arm64/kernel/smp.c | 39 +++++++++++++++------------------------
+ 1 file changed, 15 insertions(+), 24 deletions(-)
+
+diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
+index 18a0576f2721..fed4415e8cfe 100644
+--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
+@@ -518,13 +518,16 @@ static int __init smp_cpu_setup(int cpu)
+ 	const struct cpu_operations *ops;
+ 
+ 	if (init_cpu_ops(cpu))
+-		return -ENODEV;
+		goto out;
+ 
+ 	ops = get_cpu_ops(cpu);
+ 	if (ops->cpu_init(cpu))
+-		return -ENODEV;
+		goto out;
+ 
+ 	return 0;
+out:
+	__cpu_logical_map[cpu] = INVALID_HWID;
+	return -ENODEV;
+ }
+ 
+ static bool bootcpu_valid __initdata;
+@@ -562,7 +565,8 @@ acpi_map_gic_cpu_interface(struct acpi_madt_generic_interrupt *processor)
+ 		pr_debug("skipping disabled CPU entry with 0x%llx MPIDR\n", hwid);
+ #else
+ 		cpu_madt_gicc[total_cpu_count] = *processor;
+-		set_cpu_possible(total_cpu_count, true);
+		if (!smp_cpu_setup(total_cpu_count))
+			set_cpu_possible(total_cpu_count, true);
+ 		disabled_cpu_count++;
+ #endif
+ 		return;
+@@ -606,9 +610,10 @@ acpi_map_gic_cpu_interface(struct acpi_madt_generic_interrupt *processor)
+ 	 */
+ 	acpi_set_mailbox_entry(total_cpu_count, processor);
+ 
+-	set_cpu_possible(total_cpu_count, true);
+-	set_cpu_present(total_cpu_count, true);
+-
+	if (!smp_cpu_setup(total_cpu_count)) {
+		set_cpu_possible(total_cpu_count, true);
+		set_cpu_present(total_cpu_count, true);
+	}
+ 	cpu_count++;
+ }
+ 
+@@ -716,9 +721,10 @@ static void __init of_parse_and_init_cpus(void)
+ 		set_cpu_logical_map(cpu_count, hwid);
+ 
+ 		early_map_cpu_to_node(cpu_count, of_node_to_nid(dn));
+-
+-		set_cpu_possible(cpu_count, true);
+-		set_cpu_present(cpu_count, true);
+		if (!smp_cpu_setup(cpu_count)) {
+			set_cpu_possible(cpu_count, true);
+			set_cpu_present(cpu_count, true);
+		}
+ next:
+ 		cpu_count++;
+ 	}
+@@ -732,7 +738,6 @@ static void __init of_parse_and_init_cpus(void)
+ void __init smp_init_cpus(void)
+ {
+ 	unsigned int total_cpu_count = disabled_cpu_count + cpu_count;
+-	int i;
+ 
+ 	if (acpi_disabled)
+ 		of_parse_and_init_cpus();
+@@ -747,20 +752,6 @@ void __init smp_init_cpus(void)
+ 		pr_err("missing boot CPU MPIDR, not enabling secondaries\n");
+ 		return;
+ 	}
+-
+-	/*
+-	 * We need to set the cpu_logical_map entries before enabling
+-	 * the cpus so that cpu processor description entries (DT cpu nodes
+-	 * and ACPI MADT entries) can be retrieved by matching the cpu hwid
+-	 * with entries in cpu_logical_map while initializing the cpus.
+-	 * If the cpu set-up fails, invalidate the cpu_logical_map entry.
+-	 */
+-	for (i = 1; i < nr_cpu_ids; i++) {
+-		if (cpu_logical_map(i) != INVALID_HWID) {
+-			if (smp_cpu_setup(i))
+-				set_cpu_logical_map(i, INVALID_HWID);
+-		}
+-	}
+ }
+ 
+ void __init smp_prepare_cpus(unsigned int max_cpus)
+-- 
+2.17.1
+
--- a/tools/packaging/kernel/patches/5.15.x/arm-experimental/0004-arm64-kernel-Arch-specific-ACPI-hooks-like-logical-c.patch
+++ b/tools/packaging/kernel/patches/5.15.x/arm-experimental/0004-arm64-kernel-Arch-specific-ACPI-hooks-like-logical-c.patch
@ -0,0 +1,125 @@
+From 6b7b492fc89e97e5ee51f9d033000fb6483a5298 Mon Sep 17 00:00:00 2001
+From: Salil Mehta <salil.mehta@huawei.com>
+Date: Wed, 1 Dec 2021 16:21:50 +0800
+Subject: [PATCH 4/7] arm64: kernel: Arch specific ACPI hooks(like logical
+ cpuid<->hwid etc.)
+
+To support virtual cpu hotplug, some arch specifc hooks must be
+facilitated. These hooks are called by the generic ACPI cpu hotplug
+framework during a vcpu hot-(un)plug event handling. The changes
+required involve:
+
+1. Allocation of the logical cpuid corresponding to the hwid/mpidr
+2. Mapping of logical cpuid to hwid/mpidr and marking present
+3. Removing vcpu from present mask during hot-unplug
+4. For arm64, all possible cpus are registered within topology_init()
+   Hence, we need to override the weak ACPI call of arch_register_cpu()
+   (which returns -ENODEV) and return success.
+5. NUMA node mapping set for this vcpu using SRAT Table info during init
+   time will be discarded as the logical cpu-ids used at that time
+   might not be correct. This mapping will be set again using the
+   proximity/node info obtained by evaluating _PXM ACPI method.
+
+Note, during hot unplug of vcpu, we do not unmap the association between
+the logical cpuid and hwid/mpidr. This remains persistent.
+
+Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
+Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
+---
+ arch/arm64/kernel/smp.c | 80 +++++++++++++++++++++++++++++++++++++++++
+ 1 file changed, 80 insertions(+)
+
+diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
+index fed4415e8cfe..8ab68ec01090 100644
+--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
+@@ -543,6 +543,86 @@ struct acpi_madt_generic_interrupt *acpi_cpu_get_madt_gicc(int cpu)
+ 	return &cpu_madt_gicc[cpu];
+ }
+ 
+#ifdef CONFIG_ACPI_HOTPLUG_CPU
+int arch_register_cpu(int num)
+{
+	return 0;
+}
+
+static int set_numa_node_for_cpu(acpi_handle handle, int cpu)
+{
+#ifdef CONFIG_ACPI_NUMA
+	int node_id;
+
+	/* will evaluate _PXM */
+	node_id = acpi_get_node(handle);
+	if (node_id != NUMA_NO_NODE)
+		set_cpu_numa_node(cpu, node_id);
+#endif
+	return 0;
+}
+
+static void unset_numa_node_for_cpu(int cpu)
+{
+#ifdef CONFIG_ACPI_NUMA
+	set_cpu_numa_node(cpu, NUMA_NO_NODE);
+#endif
+}
+
+static int allocate_logical_cpuid(u64 physid)
+{
+	int first_invalid_idx = -1;
+	bool first = true;
+	int i;
+
+	for_each_possible_cpu(i) {
+		/*
+		 * logical cpuid<->hwid association remains persistent once
+		 * established
+		 */
+		if (cpu_logical_map(i) == physid)
+			return i;
+
+		if ((cpu_logical_map(i) == INVALID_HWID) && first) {
+			first_invalid_idx = i;
+			first = false;
+		}
+	}
+
+	return first_invalid_idx;
+}
+
+int acpi_unmap_cpu(int cpu)
+{
+	set_cpu_present(cpu, false);
+	unset_numa_node_for_cpu(cpu);
+
+	return 0;
+}
+
+int acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, u32 acpi_id,
+		 int *cpuid)
+{
+	int cpu;
+
+	cpu = allocate_logical_cpuid(physid);
+	if (cpu < 0) {
+		pr_warn("Unable to map logical cpuid to physid 0x%llx\n",
+			physid);
+		return -ENOSPC;
+	}
+
+	/* map the logical cpu id to cpu MPIDR */
+	__cpu_logical_map[cpu] = physid;
+	set_numa_node_for_cpu(handle, cpu);
+
+	set_cpu_present(cpu, true);
+	*cpuid = cpu;
+
+	return 0;
+}
+#endif
+
+ /*
+  * acpi_map_gic_cpu_interface - parse processor MADT entry
+  *
+-- 
+2.17.1
+
--- a/tools/packaging/kernel/patches/5.15.x/arm-experimental/0005-cpu-numa-fix-failure-when-hot-remove-cpu.patch
+++ b/tools/packaging/kernel/patches/5.15.x/arm-experimental/0005-cpu-numa-fix-failure-when-hot-remove-cpu.patch
@ -0,0 +1,82 @@
+From 5c979f026c1319c712e7fa4882ec3a4ef3e2101b Mon Sep 17 00:00:00 2001
+From: Jianyong Wu <jianyong.wu@arm.com>
+Date: Fri, 3 Dec 2021 17:11:39 +0800
+Subject: [PATCH 5/7] cpu/numa: fix failure when hot-remove cpu
+
+when hot-remove cpu, the map from cpu to numa will set to NUMA_NO_NODE
+which will lead to failure as the map is used by others. thus we need a
+specific map to descrip the unpluged cpu.
+Here we introduce a new map to descrip the unpluged cpu map.
+
+Singed-off-by: Jianyong Wu <jianyong.wu@arm.com>
+---
+ arch/arm64/include/asm/smp.h |  2 ++
+ arch/arm64/kernel/setup.c    | 14 ++++++++++++++
+ arch/arm64/kernel/smp.c      |  5 ++++-
+ 3 files changed, 20 insertions(+), 1 deletion(-)
+
+diff --git a/arch/arm64/include/asm/smp.h b/arch/arm64/include/asm/smp.h
+index fc55f5a57a06..7949f6090eed 100644
+--- a/arch/arm64/include/asm/smp.h
+++ b/arch/arm64/include/asm/smp.h
+@@ -47,6 +47,8 @@ DECLARE_PER_CPU_READ_MOSTLY(int, cpu_number);
+  */
+ extern u64 __cpu_logical_map[NR_CPUS];
+ extern u64 cpu_logical_map(unsigned int cpu);
+extern u64 get_acpicpu_numa_node(unsigned int cpu);
+extern int set_acpicpu_numa_node(unsigned int cpu, unsigned int node);
+ 
+ static inline void set_cpu_logical_map(unsigned int cpu, u64 hwid)
+ {
+diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
+index be5f85b0a24d..68d7a7894e10 100644
+--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
+@@ -284,6 +284,20 @@ static int __init reserve_memblock_reserved_regions(void)
+ }
+ arch_initcall(reserve_memblock_reserved_regions);
+ 
+u64 __acpicpu_node_map[NR_CPUS] = { [0 ... NR_CPUS-1] = NUMA_NO_NODE };
+
+u64 get_acpicpu_numa_node(unsigned int cpu)
+{
+	return __acpicpu_node_map[cpu];
+}
+
+int set_acpicpu_numa_node(unsigned int cpu, unsigned int node)
+{
+	__acpicpu_node_map[cpu] = node;
+
+	return 0;
+}
+
+ u64 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = INVALID_HWID };
+ 
+ u64 cpu_logical_map(unsigned int cpu)
+diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
+index 8ab68ec01090..0c07921b0b61 100644
+--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
+@@ -557,7 +557,10 @@ static int set_numa_node_for_cpu(acpi_handle handle, int cpu)
+ 	/* will evaluate _PXM */
+ 	node_id = acpi_get_node(handle);
+ 	if (node_id != NUMA_NO_NODE)
+	{
+		set_acpicpu_numa_node(cpu, node_id);
+ 		set_cpu_numa_node(cpu, node_id);
+	}
+ #endif
+ 	return 0;
+ }
+@@ -565,7 +568,7 @@ static int set_numa_node_for_cpu(acpi_handle handle, int cpu)
+ static void unset_numa_node_for_cpu(int cpu)
+ {
+ #ifdef CONFIG_ACPI_NUMA
+-	set_cpu_numa_node(cpu, NUMA_NO_NODE);
+	set_acpicpu_numa_node(cpu, NUMA_NO_NODE);
+ #endif
+ }
+ 
+-- 
+2.17.1
+
--- a/tools/packaging/kernel/patches/5.15.x/arm-experimental/0006-arm64-mm-avoid-fixmap-race-condition-when-create-pud.patch
+++ b/tools/packaging/kernel/patches/5.15.x/arm-experimental/0006-arm64-mm-avoid-fixmap-race-condition-when-create-pud.patch
@ -0,0 +1,69 @@
+From e3a11f2f7ccb0dbbb8cf95944e89b34fd928107a Mon Sep 17 00:00:00 2001
+From: Jianyong Wu <jianyong.wu@arm.com>
+Date: Mon, 6 Dec 2021 10:52:37 +0800
+Subject: [PATCH 6/7] arm64/mm: avoid fixmap race condition when create pud
+ mapping
+
+The 'fixmap' is a global resource and is used recursively by
+create pud mapping(), leading to a potential race condition in the
+presence of a concurrent call to alloc_init_pud():
+
+kernel_init thread                          virtio-mem workqueue thread
+==================                          ===========================
+
+  alloc_init_pud(...)                       alloc_init_pud(...)
+  pudp = pud_set_fixmap_offset(...)         pudp = pud_set_fixmap_offset(...)
+  READ_ONCE(*pudp)
+  pud_clear_fixmap(...)
+                                            READ_ONCE(*pudp) // CRASH!
+
+As kernel may sleep during creating pud mapping, introduce a mutex lock to
+serialise use of the fixmap entries by alloc_init_pud(). However, there is
+no need for locking in early boot stage and it doesn't work well with
+KASLR enabled when early boot. So, enable lock when system_state doesn't
+equal to "SYSTEM_BOOTING".
+
+Signed-off-by: Jianyong Wu <jianyong.wu@arm.com>
+Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
+Fixes: f4710445458c ("arm64: mm: use fixmap when creating page tables")
+Link: https://lore.kernel.org/r/20220201114400.56885-1-jianyong.wu@arm.com
+Signed-off-by: Will Deacon <will@kernel.org>
+---
+ arch/arm64/mm/mmu.c | 7 +++++++
+ 1 file changed, 7 insertions(+)
+
+diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
+index cfd9deb347c3..432fab4ce2b4 100644
+--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
+@@ -63,6 +63,7 @@ static pmd_t bm_pmd[PTRS_PER_PMD] __page_aligned_bss __maybe_unused;
+ static pud_t bm_pud[PTRS_PER_PUD] __page_aligned_bss __maybe_unused;
+ 
+ static DEFINE_SPINLOCK(swapper_pgdir_lock);
+static DEFINE_SPINLOCK(fixmap_lock);
+ 
+ void set_swapper_pgd(pgd_t *pgdp, pgd_t pgd)
+ {
+@@ -328,6 +329,11 @@ static void alloc_init_pud(pgd_t *pgdp, unsigned long addr, unsigned long end,
+ 	}
+ 	BUG_ON(p4d_bad(p4d));
+ 
+	/*
+	 * We only have one fixmap entry per page-table level, so take
+	 * the fixmap lock until we're done.
+	 */
+	spin_lock(&fixmap_lock);
+ 	pudp = pud_set_fixmap_offset(p4dp, addr);
+ 	do {
+ 		pud_t old_pud = READ_ONCE(*pudp);
+@@ -358,6 +364,7 @@ static void alloc_init_pud(pgd_t *pgdp, unsigned long addr, unsigned long end,
+ 	} while (pudp++, addr = next, addr != end);
+ 
+ 	pud_clear_fixmap();
+	spin_unlock(&fixmap_lock);
+ }
+ 
+ static void __create_pgd_mapping(pgd_t *pgdir, phys_addr_t phys,
+-- 
+2.17.1
+
--- a/tools/packaging/kernel/patches/5.15.x/arm-experimental/0007-virtio-mem-enable-virtio-mem-on-arm64.patch
+++ b/tools/packaging/kernel/patches/5.15.x/arm-experimental/0007-virtio-mem-enable-virtio-mem-on-arm64.patch
@ -0,0 +1,67 @@
+From b1a3d86afbccb5485d2a53cc7e4e097a40f9d443 Mon Sep 17 00:00:00 2001
+From: Jianyong Wu <jianyong.wu@arm.com>
+Date: Tue, 14 Dec 2021 14:18:39 +0800
+Subject: [PATCH 7/7] virtio-mem: enable virtio-mem on arm64
+
+It seems that virtio-mem works on arm64 now and can be enabled.
+
+Signed-off-by: Jianyong Wu <jianyong.wu@arm.com>
+---
+ arch/arm64/mm/mmu.c    | 12 +++++++-----
+ drivers/virtio/Kconfig |  2 +-
+ 2 files changed, 8 insertions(+), 6 deletions(-)
+
+diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
+index 432fab4ce2b4..809fe52d3035 100644
+--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
+@@ -63,7 +63,7 @@ static pmd_t bm_pmd[PTRS_PER_PMD] __page_aligned_bss __maybe_unused;
+ static pud_t bm_pud[PTRS_PER_PUD] __page_aligned_bss __maybe_unused;
+ 
+ static DEFINE_SPINLOCK(swapper_pgdir_lock);
+-static DEFINE_SPINLOCK(fixmap_lock);
+static DEFINE_MUTEX(fixmap_lock);
+ 
+ void set_swapper_pgd(pgd_t *pgdp, pgd_t pgd)
+ {
+@@ -330,10 +330,11 @@ static void alloc_init_pud(pgd_t *pgdp, unsigned long addr, unsigned long end,
+ 	BUG_ON(p4d_bad(p4d));
+ 
+ 	/*
+-	 * We only have one fixmap entry per page-table level, so take
+-	 * the fixmap lock until we're done.
+	 * No need for locking during early boot. And it doesn't work as
+	 * expected with KASLR enabled.
+ 	 */
+-	spin_lock(&fixmap_lock);
+	if (system_state != SYSTEM_BOOTING)
+		mutex_lock(&fixmap_lock);
+ 	pudp = pud_set_fixmap_offset(p4dp, addr);
+ 	do {
+ 		pud_t old_pud = READ_ONCE(*pudp);
+@@ -364,7 +365,8 @@ static void alloc_init_pud(pgd_t *pgdp, unsigned long addr, unsigned long end,
+ 	} while (pudp++, addr = next, addr != end);
+ 
+ 	pud_clear_fixmap();
+-	spin_unlock(&fixmap_lock);
+	if (system_state != SYSTEM_BOOTING)
+		mutex_unlock(&fixmap_lock);
+ }
+ 
+ static void __create_pgd_mapping(pgd_t *pgdir, phys_addr_t phys,
+diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
+index ce1b3f6ec325..ebabff45935c 100644
+--- a/drivers/virtio/Kconfig
+++ b/drivers/virtio/Kconfig
+@@ -96,7 +96,7 @@ config VIRTIO_BALLOON
+ config VIRTIO_MEM
+ 	tristate "Virtio mem driver"
+ 	default m
+-	depends on X86_64
+	depends on X86_64 || ARM64
+ 	depends on VIRTIO
+ 	depends on MEMORY_HOTPLUG_SPARSE
+ 	depends on MEMORY_HOTREMOVE
+-- 
+2.17.1
+