Hi Manos,
On 30/7/25 14:21, Manos Pitsidianakis wrote:
NVDIMM is used for fast rootfs with EROFS, for example by kata
containers. To allow booting with static NVDIMM memory, add them to the
device tree in arm virt machine.
This allows users to boot directly with nvdimm memory devices without
having to rely on ACPI and hotplug.
Verified to work with command invocation:
./qemu-system-aarch64 \
-M virt,nvdimm=on \
-cpu cortex-a57 \
-m 4G,slots=2,maxmem=8G \
-object
memory-backend-file,id=mem1,share=on,mem-path=/tmp/nvdimm,size=4G,readonly=off \
-device nvdimm,id=nvdimm1,memdev=mem1,unarmed=off \
-drive file=./debian-12-nocloud-arm64-commited.qcow2,format=qcow2 \
-kernel ./vmlinuz-6.1.0-13-arm64 \
-append "root=/dev/vda1 console=ttyAMA0,115200 acpi=off"
-initrd ./initrd.img-6.1.0-13-arm64 \
-nographic \
-serial mon:stdio
Should we add a functional test covering this non-ACPI case?
Signed-off-by: Manos Pitsidianakis <manos.pitsidiana...@linaro.org>
---
hw/arm/boot.c | 39 +++++++++++++++++++++++++++++++++++++++
hw/arm/virt.c | 8 +++++---
2 files changed, 44 insertions(+), 3 deletions(-)
diff --git a/hw/arm/boot.c b/hw/arm/boot.c
index
d391cd01bb1b92ff213e69b84e5a69413b36c4f8..a0c1bcdf946ca98bb5da63f1a518018eb578dd81
100644
--- a/hw/arm/boot.c
+++ b/hw/arm/boot.c
@@ -25,6 +25,7 @@
#include "hw/boards.h"
#include "system/reset.h"
#include "hw/loader.h"
+#include "hw/mem/memory-device.h"
#include "elf.h"
#include "system/device_tree.h"
#include "qemu/config-file.h"
@@ -515,6 +516,26 @@ static void fdt_add_psci_node(void *fdt, ARMCPU *armcpu)
qemu_fdt_setprop_cell(fdt, "/psci", "migrate", migrate_fn);
}
+static int fdt_add_pmem_node(void *fdt, uint32_t acells, uint32_t scells,
+ int64_t mem_base, int64_t size, int64_t node)
+{
+ int ret;
+
+ g_autofree char *nodename = g_strdup_printf("/pmem@%" PRIx64, mem_base);
+
+ qemu_fdt_add_subnode(fdt, nodename);
+ qemu_fdt_setprop_string(fdt, nodename, "compatible", "pmem-region");
+ ret = qemu_fdt_setprop_sized_cells(fdt, nodename, "reg", acells,
+ mem_base, scells, size);
+ /* only set the NUMA ID if it is specified */
+ if (!ret && node >= 0) {
+ ret = qemu_fdt_setprop_cell(fdt, nodename, "numa-node-id",
+ node);
+ }
+
+ return ret;
+}
+
int arm_load_dtb(hwaddr addr, const struct arm_boot_info *binfo,
hwaddr addr_limit, AddressSpace *as, MachineState *ms,
ARMCPU *cpu)
@@ -525,6 +546,7 @@ int arm_load_dtb(hwaddr addr, const struct arm_boot_info
*binfo,
unsigned int i;
hwaddr mem_base, mem_len;
char **node_path;
+ g_autofree MemoryDeviceInfoList *md_list = NULL;
Error *err = NULL;
if (binfo->dtb_filename) {
@@ -628,6 +650,23 @@ int arm_load_dtb(hwaddr addr, const struct arm_boot_info
*binfo,
}
}
+ md_list = qmp_memory_device_list();
+ for (MemoryDeviceInfoList *m = md_list; m != NULL; m = m->next) {
+ MemoryDeviceInfo *mi = m->value;
+
+ if (mi->type == MEMORY_DEVICE_INFO_KIND_NVDIMM) {
+ PCDIMMDeviceInfo *di = mi->u.nvdimm.data;
+
+ rc = fdt_add_pmem_node(fdt, acells, scells,
+ di->addr, di->size, di->node);
+ if (rc < 0) {
+ fprintf(stderr, "couldn't add NVDIMM /pmem@%"PRIx64" node\n",
+ di->addr);
+ goto fail;
+ }
+ }
+ }
+
rc = fdt_path_offset(fdt, "/chosen");
if (rc < 0) {
qemu_fdt_add_subnode(fdt, "/chosen");
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index
ef6be3660f5fb38da84235c32dc2d13a5c61889c..910f5bb5f66ee217a9140f9128804a5b9f69b5b6
100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -2917,7 +2917,7 @@ static void virt_memory_pre_plug(HotplugHandler
*hotplug_dev, DeviceState *dev,
const MachineState *ms = MACHINE(hotplug_dev);
const bool is_nvdimm = object_dynamic_cast(OBJECT(dev), TYPE_NVDIMM);
- if (!vms->acpi_dev) {
+ if (!vms->acpi_dev && !(is_nvdimm && !dev->hotplugged)) {
error_setg(errp,
"memory hotplug is not enabled: missing acpi-ged device");
return;
@@ -2949,8 +2949,10 @@ static void virt_memory_plug(HotplugHandler *hotplug_dev,
nvdimm_plug(ms->nvdimms_state);
}
- hotplug_handler_plug(HOTPLUG_HANDLER(vms->acpi_dev),
- dev, &error_abort);
+ if (vms->acpi_dev) {
+ hotplug_handler_plug(HOTPLUG_HANDLER(vms->acpi_dev),
+ dev, &error_abort);
+ }
}
static void virt_machine_device_pre_plug_cb(HotplugHandler *hotplug_dev,
---
base-commit: 9b80226ece693197af8a981b424391b68b5bc38e
change-id: 20250730-nvdimm_arm64_virt-931a764bbe0c
--
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