On 6/4/26 6:48 PM, Eric Auger wrote:
> Hi Igor,
>
> On 3/3/26 10:25 AM, Igor Mammedov wrote:
>> Allow to use SBSA generic watchdog with virt machine type.
>> (includes conditional generation of corresponding FDT and
>> ACPI GTDT descriptors)
>>
>> Use '-device sbsa_gwdt' to command line to enable it.
> don't we use '-' instead of '_' in general. At least this is the case
> for dynamically instantiable arm-smmuv3 device. Better to align
>
> also this is the terminology used in the fdt compat string
> $id: http://devicetree.org/schemas/watchdog/arm,sbsa-gwdt.yaml#
> const: arm,sbsa-gwdt
I realize this is not your choice as the device is already named that
way. #define TYPE_WDT_SBSA "sbsa_gwdt"
So I don't think we can anything about that anymore
although in general other devices use "-" I think
#define TYPE_UEFI_VARS_SYSBUS "uefi-vars-sysbus"
Eric
>
>>
>> Tested with Fedora 43:
>> FDT: -M virt,acpi=off -device sbsa_gwdt
>> ACPI: -M virt -device sbsa_gwdt
>>
>> Signed-off-by: Igor Mammedov <[email protected]>
>> ---
>> hw/arm/Kconfig | 1 +
>> hw/arm/virt-acpi-build.c | 33 +++++++++++++++++++++++++++++++--
>> hw/arm/virt.c | 2 ++
>> hw/core/sysbus-fdt.c | 32 ++++++++++++++++++++++++++++++++
>> hw/watchdog/sbsa_gwdt.c | 1 +
>> 5 files changed, 67 insertions(+), 2 deletions(-)
>>
>> diff --git a/hw/arm/Kconfig b/hw/arm/Kconfig
>> index c66c452737..1222efadd1 100644
>> --- a/hw/arm/Kconfig
>> +++ b/hw/arm/Kconfig
>> @@ -36,6 +36,7 @@ config ARM_VIRT
>> select VIRTIO_MEM_SUPPORTED
>> select ACPI_CXL
>> select ACPI_HMAT
>> + select WDT_SBSA
>>
>> config CUBIEBOARD
>> bool
>> diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
>> index 719d2f994e..9c14b1d4d5 100644
>> --- a/hw/arm/virt-acpi-build.c
>> +++ b/hw/arm/virt-acpi-build.c
>> @@ -64,6 +64,7 @@
>> #include "hw/virtio/virtio-acpi.h"
>> #include "target/arm/cpu.h"
>> #include "target/arm/multiprocessing.h"
>> +#include "hw/watchdog/sbsa_gwdt.h"
>>
>> #define ARM_SPI_BASE 32
>>
>> @@ -863,6 +864,8 @@ build_gtdt(GArray *table_data, BIOSLinker *linker,
>> VirtMachineState *vms)
>> const uint32_t irqflags = 0; /* Interrupt is Level triggered */
>> AcpiTable table = { .sig = "GTDT", .rev = 3, .oem_id = vms->oem_id,
>> .oem_table_id = vms->oem_table_id };
>> + uint32_t gtdt_start = table_data->len;
>> + Object *wdt = object_resolve_type_unambiguous(TYPE_WDT_SBSA, NULL);
>>
>> acpi_table_begin(&table, table_data);
>>
>> @@ -893,10 +896,15 @@ build_gtdt(GArray *table_data, BIOSLinker *linker,
>> VirtMachineState *vms)
>> build_append_int_noprefix(table_data, irqflags, 4);
>> /* CntReadBase Physical address */
>> build_append_int_noprefix(table_data, 0xFFFFFFFFFFFFFFFF, 8);
>> +
>> /* Platform Timer Count */
>> - build_append_int_noprefix(table_data, 0, 4);
>> + build_append_int_noprefix(table_data, wdt ? 1 : 0, 4);
>> /* Platform Timer Offset */
>> - build_append_int_noprefix(table_data, 0, 4);
>> + build_append_int_noprefix(table_data,
>> + wdt ? (table_data->len - gtdt_start) +
>> + 4 + 4 + 4 /* len of this & following 2 fields to skip */
>> + : 0, 4);
>> +
>> if (vms->ns_el2_virt_timer_irq) {
>> /* Virtual EL2 Timer GSIV */
>> build_append_int_noprefix(table_data, ARCH_TIMER_NS_EL2_VIRT_IRQ,
>> 4);
>> @@ -906,6 +914,27 @@ build_gtdt(GArray *table_data, BIOSLinker *linker,
>> VirtMachineState *vms)
>> build_append_int_noprefix(table_data, 0, 4);
>> build_append_int_noprefix(table_data, 0, 4);
>> }
>> +
>> + /* ACPI 6.5 spec: 5.2.25.2 ARM Generic Watchdog Structure (Table 5-124)
>> */
> 5.124
>> + if (wdt) {
>> + PlatformBusDevice *pbus =
>> PLATFORM_BUS_DEVICE(vms->platform_bus_dev);
>> + SysBusDevice *sd = SYS_BUS_DEVICE(wdt);
>> + hwaddr mmio_base = vms->memmap[VIRT_PLATFORM_BUS].base;
>> + hwaddr rbase = mmio_base + platform_bus_get_mmio_addr(pbus, sd, 0);
>> + hwaddr cbase = mmio_base + platform_bus_get_mmio_addr(pbus, sd, 1);
>> + int irq = ARM_SPI_BASE + vms->irqmap[VIRT_PLATFORM_BUS] +
>> + platform_bus_get_irqn(pbus, sd, 0);
>> +
>> + build_append_int_noprefix(table_data, 1 /* Type: Watchdog GT */, 1);
>> + build_append_int_noprefix(table_data, 28 /* Length */, 2);
>> + build_append_int_noprefix(table_data, 0, 1); /* Reserved */
>> + /* RefreshFrame Physical Address */
>> + build_append_int_noprefix(table_data, rbase, 8);
>> + /* WatchdogControlFrame Physical Address */
>> + build_append_int_noprefix(table_data, cbase, 8);
>> + build_append_int_noprefix(table_data, irq, 4); /* Watchdog Timer
>> GSIV */
>> + build_append_int_noprefix(table_data, 0, 4); /* Watchdog Timer
>> Flags */
> level, active high, non secure
>> + }
>> acpi_table_end(linker, &table);
>> }
>>
>> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
>> index cab2e21e8a..a87991b591 100644
>> --- a/hw/arm/virt.c
>> +++ b/hw/arm/virt.c
>> @@ -95,6 +95,7 @@
>> #include "hw/cxl/cxl.h"
>> #include "hw/cxl/cxl_host.h"
>> #include "qemu/guest-random.h"
>> +#include "hw/watchdog/sbsa_gwdt.h"
>>
>> static GlobalProperty arm_virt_compat_defaults[] = {
>> { TYPE_VIRTIO_IOMMU_PCI, "aw-bits", "48" },
>> @@ -3474,6 +3475,7 @@ static void virt_machine_class_init(ObjectClass *oc,
>> const void *data)
>> machine_class_allow_dynamic_sysbus_dev(mc, TYPE_RAMFB_DEVICE);
>> machine_class_allow_dynamic_sysbus_dev(mc, TYPE_UEFI_VARS_SYSBUS);
>> machine_class_allow_dynamic_sysbus_dev(mc, TYPE_ARM_SMMUV3);
>> + machine_class_allow_dynamic_sysbus_dev(mc, TYPE_WDT_SBSA);
>> #ifdef CONFIG_TPM
>> machine_class_allow_dynamic_sysbus_dev(mc, TYPE_TPM_TIS_SYSBUS);
>> #endif
>> diff --git a/hw/core/sysbus-fdt.c b/hw/core/sysbus-fdt.c
>> index 89d0c46445..76aa1bc579 100644
>> --- a/hw/core/sysbus-fdt.c
>> +++ b/hw/core/sysbus-fdt.c
>> @@ -36,6 +36,7 @@
>> #include "hw/display/ramfb.h"
>> #include "hw/uefi/var-service-api.h"
>> #include "hw/arm/fdt.h"
>> +#include "hw/watchdog/sbsa_gwdt.h"
>>
>> /*
>> * internal struct that contains the information to create dynamic
>> @@ -118,6 +119,36 @@ static int add_uefi_vars_node(SysBusDevice *sbdev, void
>> *opaque)
>> return 0;
>> }
>>
>> +static int add_sbsa_gwdt_node(SysBusDevice *sbdev, void *opaque)
>> +{
>> + PlatformBusFDTData *data = opaque;
>> + PlatformBusDevice *pbus = data->pbus;
>> + const char *parent_node = data->pbus_node_name;
>> + void *fdt = data->fdt;
>> + uint64_t cbase, rbase;
>> + char *nodename;
>> + int irq;
>> +
>> + cbase = platform_bus_get_mmio_addr(pbus, sbdev, 1); /* control frame */
>> + rbase = platform_bus_get_mmio_addr(pbus, sbdev, 0); /* refresh frame */
>> + irq = platform_bus_get_irqn(pbus, sbdev, 0);
>> +
>> + nodename = g_strdup_printf("%s/watchdog@%" PRIx64, parent_node, cbase);
>> + qemu_fdt_add_subnode(fdt, nodename);
>> +
>> + qemu_fdt_setprop_string(fdt, nodename, "compatible", "arm,sbsa-gwdt");
>> + qemu_fdt_setprop_cells(fdt, nodename, "reg",
>> + cbase, SBSA_GWDT_CMMIO_SIZE,
>> + rbase, SBSA_GWDT_RMMIO_SIZE);
>> + qemu_fdt_setprop_cells(fdt, nodename, "interrupts",
>> + GIC_FDT_IRQ_TYPE_SPI, data->irq_start + irq,
>> + GIC_FDT_IRQ_FLAGS_LEVEL_HI);
>> + qemu_fdt_setprop_cell(fdt, nodename, "timeout-sec", 30);
>> +
>> + g_free(nodename);
>> + return 0;
>> +}
>> +
>> static int no_fdt_node(SysBusDevice *sbdev, void *opaque)
>> {
>> return 0;
>> @@ -140,6 +171,7 @@ static const BindingEntry bindings[] = {
>> TYPE_BINDING(TYPE_ARM_SMMUV3, no_fdt_node),
>> TYPE_BINDING(TYPE_RAMFB_DEVICE, no_fdt_node),
>> TYPE_BINDING(TYPE_UEFI_VARS_SYSBUS, add_uefi_vars_node),
>> + TYPE_BINDING(TYPE_WDT_SBSA, add_sbsa_gwdt_node),
>> TYPE_BINDING("", NULL), /* last element */
>> };
>>
>> diff --git a/hw/watchdog/sbsa_gwdt.c b/hw/watchdog/sbsa_gwdt.c
>> index acb970e8b3..c4dd8005b7 100644
>> --- a/hw/watchdog/sbsa_gwdt.c
>> +++ b/hw/watchdog/sbsa_gwdt.c
>> @@ -285,6 +285,7 @@ static void wdt_sbsa_gwdt_class_init(ObjectClass *klass,
>> const void *data)
>> dc->realize = wdt_sbsa_gwdt_realize;
>> device_class_set_legacy_reset(dc, wdt_sbsa_gwdt_reset);
>> dc->hotpluggable = false;
>> + dc->user_creatable = true;
>> set_bit(DEVICE_CATEGORY_WATCHDOG, dc->categories);
>> dc->vmsd = &vmstate_sbsa_gwdt;
>> dc->desc = "SBSA-compliant generic watchdog device";
> Thanks
>
> Eric
>
>
