On Wed, 25 Feb 2026 15:19:56 +0000 Daniel P. Berrangé <[email protected]> wrote:
> On Thu, Feb 19, 2026 at 01:17:51PM +0100, Igor Mammedov wrote: > > On Wed, 18 Feb 2026 19:08:36 +0000 > > Peter Maydell <[email protected]> wrote: > > > > > On Fri, 6 Feb 2026 at 13:15, Igor Mammedov <[email protected]> wrote: > > > > > > > > Add SBSA generic watchdog to virt machine type with > > > > all necessary wiring for ACPI watchdog. Which includes > > > > setting its frequency to 1KHz (max that WDAT is able to handle). > > > > > > > > Signed-off-by: Igor Mammedov <[email protected]> > > > > --- > > > > > > > diff --git a/hw/arm/virt.c b/hw/arm/virt.c > > > > index 390845c503..caf5700ed2 100644 > > > > --- a/hw/arm/virt.c > > > > +++ b/hw/arm/virt.c > > > > @@ -93,6 +93,7 @@ > > > > #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[] = { > > > > { TYPE_VIRTIO_IOMMU_PCI, "aw-bits", "48" }, > > > > @@ -194,6 +195,8 @@ static const MemMapEntry base_memmap[] = { > > > > [VIRT_PVTIME] = { 0x090a0000, 0x00010000 }, > > > > [VIRT_SECURE_GPIO] = { 0x090b0000, 0x00001000 }, > > > > [VIRT_ACPI_PCIHP] = { 0x090c0000, ACPI_PCIHP_SIZE }, > > > > + [VIRT_GWDT_REFRESH] = { 0x090d0000, 0x00001000 }, > > > > + [VIRT_GWDT_CONTROL] = { 0x090d1000, 0x00001000 }, > > > > [VIRT_MMIO] = { 0x0a000000, 0x00000200 }, > > > > /* ...repeating for a total of NUM_VIRTIO_TRANSPORTS, each of that > > > > size */ > > > > [VIRT_PLATFORM_BUS] = { 0x0c000000, 0x02000000 }, > > > > @@ -245,12 +248,32 @@ static const int a15irqmap[] = { > > > > [VIRT_GPIO] = 7, > > > > [VIRT_UART1] = 8, > > > > [VIRT_ACPI_GED] = 9, > > > > + [VIRT_GWDT_WS0] = 10, > > > > [VIRT_MMIO] = 16, /* ...to 16 + NUM_VIRTIO_TRANSPORTS - 1 */ > > > > [VIRT_GIC_V2M] = 48, /* ...to 48 + NUM_GICV2M_SPIS - 1 */ > > > > [VIRT_SMMU] = 74, /* ...to 74 + NUM_SMMU_IRQS - 1 */ > > > > [VIRT_PLATFORM_BUS] = 112, /* ...to 112 + PLATFORM_BUS_NUM_IRQS -1 > > > > */ > > > > }; > > > > > > > > +static void create_wdt(const VirtMachineState *vms) > > > > +{ > > > > + hwaddr rbase = vms->memmap[VIRT_GWDT_REFRESH].base; > > > > + hwaddr cbase = vms->memmap[VIRT_GWDT_CONTROL].base; > > > > + int irq = vms->irqmap[VIRT_GWDT_WS0]; > > > > + DeviceState *dev = qdev_new(TYPE_WDT_SBSA); > > > > + SysBusDevice *s = SYS_BUS_DEVICE(dev); > > > > + > > > > + /* > > > > + * Set watchdog tick freq to 1Kz as it's the max WDAT driver > > > > + * is able to handle. > > > > + */ > > > > + qdev_prop_set_uint64(dev, "clock-frequency", 1000 /* 1KHz */); > > > > + sysbus_realize_and_unref(s, &error_fatal); > > > > + sysbus_mmio_map(s, 0, rbase); > > > > + sysbus_mmio_map(s, 1, cbase); > > > > + sysbus_connect_irq(s, 0, qdev_get_gpio_in(vms->gic, irq)); > > > > +} > > > > > > Please can you also add support for exposing this device > > > in the device tree ? > > > > It's possible, > > but we probably should not enable it if acpi variant was requested, > > to avoid confusion on guest side. > > > > For Windows it doesn't really mater, for linux it does. > > on x86 linux guest uses a quirk to disable native iTCO watchdog > > in favor of WDAT one if later is present. > > I assume quirk is not desirable so we should expose only a preferred > > variant. > > > > > > > > > + > > > > static void create_randomness(MachineState *ms, const char *node) > > > > { > > > > struct { > > > > @@ -2515,6 +2538,9 @@ static void machvirt_init(MachineState *machine) > > > > vms->highmem_ecam &= (!firmware_loaded || aarch64); > > > > > > > > create_rtc(vms); > > > > + if (machine->acpi_watchdog) { > > > > + create_wdt(vms); > > > > + } > > > > > > Can we have a command line option name that isn't ACPI > > > specific, please? There's nothing inherent to ACPI about > > > "I would like a watchdog device". > > > > that is specifically asking for ACPI flavor being used/configured. > > acpi specific option conflates 2 things: > > 1. watchdog device creation (of the board choice) with properties tuned > > for WDAT usage > > 2. how to expose it on firmware level (in this case ACPI WDAT table) > > > > other option, I've considered was > > -device some_wd[,fw=dt|acpi|none] > > but then 'fw' is not exactly device property but rather a machine one > > (we can 'abuse' it/use as a proxy of cause). > > However it doesn't work for boards that have builtin watchdog. > > Right, if there was a case where we were already using -device to > create the watchdog, then I would suggest having a simple > 'wadt=on|off' property as standard for any watchdog wanting that > ACPI abstraction wrapper. > > That could (hypothetically) be the case if we had chosen to add > WADT suport backed by i6300esb, eg -device i6300esb,wadt=on|off > > For cases built-in to the machine type, I'd suggest <type>-wadt=on|off > > eg for Q35, "-machine q35,itco-wadt=on|off" > > for virt, '-machine virt,gwdt-wadt=on|off' CCin Markus since it touches QAPI stuff. For respin, I've went ahead with a bit more generic approach (as a user, I wouldn't really care what kind of built-in watchdog board ships, and having 1 property instead total instead of machine specific ones makes it easier for mgmt layer to deal with). here is current idea: diff --git a/hw/core/machine.c b/hw/core/machine.c index 6411e68856..a0c6719b58 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -1257,6 +1271,14 @@ static void machine_class_init(ObjectClass *oc, const void *data) NULL, NULL); object_class_property_set_description(oc, "memory", "Memory size configuration"); + + object_class_property_add_enum(oc, "watchdog", "WatchdogType", + &WatchdogType_lookup, + machine_get_watchdog, machine_set_watchdog); + object_class_property_set_description(oc, "watchdog", + "Use: auto (watchdog is configured according board defaults)," + " off (disabled), native (built-in watchdog), wdat (ACPI based watchdog)]. " + " Default: auto"); } diff --git a/qapi/machine-common.json b/qapi/machine-common.json index 92e84dfb14..7f5e10340f 100644 --- a/qapi/machine-common.json +++ b/qapi/machine-common.json @@ -9,6 +9,23 @@ # Common machine types # ******************** ## +## +# @WatchdogType: +# +# On board watchdog configuration. +# +# @auto: Watchdog is configured according to board defaults. +# +# @off: Watchdog disabled (ARM). +# +# @native: Native watchdog (arm/virt: sbsa-gwdt, x86/q53: TCO) +# +# @wdat: ACPI WDAT watchdog. +# +# Since: 10.2 +## +{ 'enum': 'WatchdogType', + 'data': [ 'auto', 'off', 'native', 'wdat' ] } > Q35 is easier as we rely on the guest quirks to disable direct > access via both paths. > > With GWDT we need to decide if gwdt-wadt=on should imply DTB > disabled, or if we just expose both & rely on a guest quirk > or worst case, need a separate property to toggle DTB too. > > > I've used device property for x86 Q35 TCO watchdog and > > then using -global to enable it as workaround in previous version. > > Ugly but doable workaround. It puts a burden on users to learn how > > to configure it for each support watchdog/board combo. > > It's nightmare to discover/maintain though. > > > > Hence in this version, I've used a generic machine property approach > > that exposes feature in uniform way across boards. > > > > enum might work, but ... > > machine.watchdog = [acpi | what else could we put here???] > > > > I'm not married to a way how we expose/configure it and will rewrite > > it to something that works for majority. > > > > > thanks > > > -- PMM > > > > > > > With regards, > Daniel
