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. I thank that in general Peter is not a big fan of dynamic instantiation of sysbus devices. Don't you have means to instantiate it statically in arm virt memory map?
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) > */ > + 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 > */ > + } > 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";
