On Wed, 30 Jul 2025 15:21:41 +0300
Manos Pitsidianakis <manos.pitsidiana...@linaro.org> 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
>
> Signed-off-by: Manos Pitsidianakis <manos.pitsidiana...@linaro.org>
+CC shameer who might be able to remember how the nvdimm stuff works in ACPI
better
than I can. I think this is fine but more eyes would be good.
> ---
> 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);
I'd burn some lines to avoid a comment covering unrelated ret handling
if (ret)
return ret;
if (node >= 0) {
return qem_fdt_setprop_cell()
}
return 0;
> + /* 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
>
> --
> γαῖα πυρί μιχθήτω
>
>
