Hi Igor,
> -----Original Message-----
> From: Igor Mammedov [mailto:imamm...@redhat.com]
> Sent: 02 May 2019 17:13
> To: Shameerali Kolothum Thodi <shameerali.kolothum.th...@huawei.com>
> Cc: qemu-devel@nongnu.org; qemu-...@nongnu.org;
> eric.au...@redhat.com; peter.mayd...@linaro.org;
> shannon.zha...@gmail.com; sa...@linux.intel.com;
> sebastien.bo...@intel.com; xuwei (O) <xuw...@huawei.com>;
> ler...@redhat.com; ard.biesheu...@linaro.org; Linuxarm
> <linux...@huawei.com>
> Subject: Re: [PATCH v4 3/8] hw/acpi: Add ACPI Generic Event Device Support
>
> On Tue, 9 Apr 2019 11:29:30 +0100
> Shameer Kolothum <shameerali.kolothum.th...@huawei.com> wrote:
>
> > From: Samuel Ortiz <sa...@linux.intel.com>
> >
> > The ACPI Generic Event Device (GED) is a hardware-reduced specific
> > device[ACPI v6.1 Section 5.6.9] that handles all platform events,
> > including the hotplug ones.This patch generates the AML code that
> > defines GEDs.
> >
> > Platforms need to specify their own GedEvent array to describe what
> > kind of events they want to support through GED. Also this uses a
> > a single interrupt for the GED device, relying on IO memory region
> > to communicate the type of device affected by the interrupt. This
> > way, we can support up to 32 events with a unique interrupt.
> >
> > This supports only memory hotplug for now.
> >
> > Signed-off-by: Samuel Ortiz <sa...@linux.intel.com>
> > Signed-off-by: Sebastien Boeuf <sebastien.bo...@intel.com>
> > Signed-off-by: Shameer Kolothum <shameerali.kolothum.th...@huawei.com>
> > ---
> > hw/acpi/Kconfig | 4 +
> > hw/acpi/Makefile.objs | 1 +
> > hw/acpi/generic_event_device.c | 311
> +++++++++++++++++++++++++++++++++
> > include/hw/acpi/generic_event_device.h | 121 +++++++++++++
> > 4 files changed, 437 insertions(+)
> > create mode 100644 hw/acpi/generic_event_device.c
> > create mode 100644 include/hw/acpi/generic_event_device.h
> >
> > diff --git a/hw/acpi/Kconfig b/hw/acpi/Kconfig
> > index eca3bee..01a8b41 100644
> > --- a/hw/acpi/Kconfig
> > +++ b/hw/acpi/Kconfig
> > @@ -27,3 +27,7 @@ config ACPI_VMGENID
> > bool
> > default y
> > depends on PC
> > +
> > +config ACPI_HW_REDUCED
> > + bool
> > + depends on ACPI
> > diff --git a/hw/acpi/Makefile.objs b/hw/acpi/Makefile.objs
> > index 2d46e37..b753232 100644
> > --- a/hw/acpi/Makefile.objs
> > +++ b/hw/acpi/Makefile.objs
> > @@ -6,6 +6,7 @@ common-obj-$(CONFIG_ACPI_MEMORY_HOTPLUG) +=
> memory_hotplug.o
> > common-obj-$(CONFIG_ACPI_CPU_HOTPLUG) += cpu.o
> > common-obj-$(CONFIG_ACPI_NVDIMM) += nvdimm.o
> > common-obj-$(CONFIG_ACPI_VMGENID) += vmgenid.o
> > +common-obj-$(CONFIG_ACPI_HW_REDUCED) += generic_event_device.o
> > common-obj-$(call lnot,$(CONFIG_ACPI_X86)) += acpi-stub.o
> >
> > common-obj-y += acpi_interface.o
> > diff --git a/hw/acpi/generic_event_device.c
> b/hw/acpi/generic_event_device.c
> > new file mode 100644
> > index 0000000..856ca04
> > --- /dev/null
> > +++ b/hw/acpi/generic_event_device.c
> > @@ -0,0 +1,311 @@
> > +/*
> > + *
> > + * Copyright (c) 2018 Intel Corporation
> > + *
> > + * This program is free software; you can redistribute it and/or modify it
> > + * under the terms and conditions of the GNU General Public License,
> > + * version 2 or later, as published by the Free Software Foundation.
> > + *
> > + * This program is distributed in the hope it will be useful, but WITHOUT
> > + * ANY WARRANTY; without even the implied warranty of
> MERCHANTABILITY or
> > + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
> License for
> > + * more details.
> > + *
> > + * You should have received a copy of the GNU General Public License along
> with
> > + * this program. If not, see <http://www.gnu.org/licenses/>.
> > + */
> > +
> > +#include "qemu/osdep.h"
> > +#include "qapi/error.h"
> > +#include "exec/address-spaces.h"
> > +#include "hw/sysbus.h"
> > +#include "hw/acpi/acpi.h"
> > +#include "hw/acpi/generic_event_device.h"
> > +#include "hw/mem/pc-dimm.h"
> > +
> > +static Aml *ged_event_aml(const GedEvent *event)
> > +{
> > +
> > + if (!event) {
> In general, I prefer to check condition for calling something before doing
> call.
> This way one can see in caller why and what is called, which is more clear.
Ok. I will move it then.
>
> > + return NULL;
> > + }
> > +
> > + switch (event->event) {
> > + case GED_MEMORY_HOTPLUG:
> > + /* We run a complete memory SCAN when getting a memory
> hotplug event */
> > + return aml_call0(MEMORY_DEVICES_CONTAINER "."
> MEMORY_SLOT_SCAN_METHOD);
> > + default:
> > + break;
> > + }
> > +
> > + return NULL;
> > +}
> > +
> > +/*
> > + * The ACPI Generic Event Device (GED) is a hardware-reduced specific
> > + * device[ACPI v6.1 Section 5.6.9] that handles all platform events,
> > + * including the hotplug ones. Platforms need to specify their own
> > + * GedEvent array to describe what kind of events they want to support
> > + * through GED. This routine uses a single interrupt for the GED device,
> > + * relying on IO memory region to communicate the type of device
> > + * affected by the interrupt. This way, we can support up to 32 events
> > + * with a unique interrupt.
> > + */
> > +void build_ged_aml(Aml *table, const char *name, HotplugHandler
> *hotplug_dev,
> > + uint32_t ged_irq, AmlRegionSpace rs)
> > +{
> > + AcpiGedState *s = ACPI_GED(hotplug_dev);
> > + GedEvent *ged_events = s->ged_events;
> > + Aml *crs = aml_resource_template();
> > + Aml *evt, *field;
> > + Aml *dev = aml_device("%s", name);
> > + Aml *irq_sel = aml_local(0);
> > + Aml *isel = aml_name(AML_GED_IRQ_SEL);
> > + uint32_t i;
> > +
> > + if (!s->ged_base || !ged_events || !s->ged_events_size) {
> I'd move it up to the caller, it would be obvious right there when
> function should be called.
Ok.
> > + return;
> > + }
> > +
> > + /* _CRS interrupt */
> > + aml_append(crs, aml_interrupt(AML_CONSUMER, AML_EDGE,
> AML_ACTIVE_HIGH,
> > + AML_EXCLUSIVE, &ged_irq, 1));
> > + /*
> > + * For each GED event we:
> > + * - Add an interrupt to the CRS section.
> > + * - Add a conditional block for each event, inside a while loop.
> > + * This is semantically equivalent to a switch/case implementation.
> > + */
> > + evt = aml_method("_EVT", 1, AML_SERIALIZED);
> > + {
> > + Aml *ged_aml;
> > + Aml *if_ctx;
> > +
> > + /* Local0 = ISEL */
> > + aml_append(evt, aml_store(isel, irq_sel));
> > +
> > + /*
> > + * Here we want to call a method for each supported GED event
> type.
> > + * The resulting ASL code looks like:
> > + *
> > + * Local0 = ISEL
> > + * If ((Local0 & irq0) == irq0)
> > + * {
> > + * MethodEvent0()
> > + * }
> > + *
> > + * If ((Local0 & irq1) == irq1)
> > + * {
> > + * MethodEvent1()
> > + * }
> > + * ...
> > + */
> Well, I'm confused.
> do we actually use multiple IRQs or we use only one + MMIO for event type?
It is one irq + MMIO. I will change the comment block something like this,
Local0 = ISEL
If ((Local0 & One) == One)
{
MethodEvent1()
}
If ((Local0 & 0x02) == 0x02)
{
MethodEvent2()
}
...
>
> > + for (i = 0; i < s->ged_events_size; i++) {
>
> > + ged_aml = ged_event_aml(&ged_events[i]);
> > + if (!ged_aml) {
> > + continue;
> > + }
> I'd get rid of ged_event_aml replace it with more 'switch':
> for (i,...)
> if_ctx = aml_if(...)
> switch (event)
> case GED_MEMORY_HOTPLUG:
> aml_append(if_ctx,
> aml_call0(MEMORY_DEVICES_CONTAINER "."
> MEMORY_SLOT_SCAN_METHOD))
> break
> default:
> about(); // make sure that a newly added events have a
> handler
Ok. I will change this.
>
> > +
> > + /* If ((Local1 == irq))*/
> > + if_ctx = aml_if(aml_equal(aml_and(irq_sel,
> > +
> aml_int(ged_events[i].selector), NULL),
> > +
> aml_int(ged_events[i].selector)));
> > + {
> > + /* AML for this specific type of event */
> > + aml_append(if_ctx), ged_aml);
> > + }
> > +
> > + /*
> > + * We append the first "if" to the "while" context.
> > + * Other "if"s will be "elseif"s.
> > + */
> > + aml_append(evt, if_ctx);
> > + }
> > + }
> > +
>
> > + aml_append(dev, aml_name_decl("_HID", aml_string("ACPI0013")));
> > + aml_append(dev, aml_name_decl("_UID", aml_string(GED_DEVICE)));
> > + aml_append(dev, aml_name_decl("_CRS", crs));
> > +
> > + /* Append IO region */
> > + aml_append(dev, aml_operation_region(AML_GED_IRQ_REG, rs,
> > + aml_int(s->ged_base + ACPI_GED_IRQ_SEL_OFFSET),
> > + ACPI_GED_IRQ_SEL_LEN));
> > + field = aml_field(AML_GED_IRQ_REG, AML_DWORD_ACC,
> AML_NOLOCK,
> > + AML_WRITE_AS_ZEROS);
> > + aml_append(field, aml_named_field(AML_GED_IRQ_SEL,
> > + ACPI_GED_IRQ_SEL_LEN *
> 8));
> > + aml_append(dev, field);
>
> I'd move it up above EVT() method, so it would be clear from the begging
> for what device we are building AML
Ok.
>
> > + /* Append _EVT method */
> > + aml_append(dev, evt);
> > +
> > + aml_append(table, dev);
> > +}
> > +
> > +/* Memory read by the GED _EVT AML dynamic method */
> > +static uint64_t ged_read(void *opaque, hwaddr addr, unsigned size)
> > +{
> > + uint64_t val = 0;
> > + GEDState *ged_st = opaque;
> > +
> > + switch (addr) {
> > + case ACPI_GED_IRQ_SEL_OFFSET:
> > + /* Read the selector value and reset it */
> > + qemu_mutex_lock(&ged_st->lock);
> > + val = ged_st->sel;
> > + ged_st->sel = 0;
> > + qemu_mutex_unlock(&ged_st->lock);
> > + break;
> > + default:
> > + break;
> > + }
> > +
> > + return val;
> > +}
> > +
> > +/* Nothing is expected to be written to the GED memory region */
> > +static void ged_write(void *opaque, hwaddr addr, uint64_t data,
> > + unsigned int size)
> > +{
> > +}
> > +
> > +static const MemoryRegionOps ged_ops = {
> > + .read = ged_read,
> > + .write = ged_write,
> > + .endianness = DEVICE_LITTLE_ENDIAN,
> > + .valid = {
> > + .min_access_size = 4,
> > + .max_access_size = 4,
> > + },
> > +};
> > +
> > +static void acpi_ged_event(GEDState *ged_st, uint32_t ged_irq_sel)
> > +{
> > + /*
> > + * Set the GED IRQ selector to the expected device type value. This
> > + * way, the ACPI method will be able to trigger the right code based
> > + * on a unique IRQ.
> > + */
> > + qemu_mutex_lock(&ged_st->lock);
> > + ged_st->sel = ged_irq_sel;
> what if there are 2 events with different sel value and 2nd event happens
> before guesr read the first one?
This was previously,
ged_st->sel |= ged_irq_sel;
and was changed based on the assumption that there won't be any multiple
events. But I think the scenario above is right. I will change it back so that
we won't overwrite.
>
> > + qemu_mutex_unlock(&ged_st->lock);
> > +
> > + /* Trigger the event by sending an interrupt to the guest. */
> > + qemu_irq_pulse(ged_st->gsi[ged_st->irq]);
> > +}
> > +
> > +static void acpi_ged_init(MemoryRegion *as, DeviceState *dev, GEDState
> *ged_st)
> > +{
> > + AcpiGedState *s = ACPI_GED(dev);
> > +
> > + assert(s->ged_base);
> > +
> > + ged_st->irq = s->ged_irq;
> > + ged_st->gsi = s->gsi;
> > + qemu_mutex_init(&ged_st->lock);
> > + memory_region_init_io(&ged_st->io, OBJECT(dev), &ged_ops, ged_st,
> > + "acpi-ged-event", ACPI_GED_REG_LEN);
> > + memory_region_add_subregion(as, s->ged_base, &ged_st->io);
> > +}
> > +
> > +static void acpi_ged_device_plug_cb(HotplugHandler *hotplug_dev,
> > + DeviceState *dev, Error **errp)
> > +{
> > + AcpiGedState *s = ACPI_GED(hotplug_dev);
> > +
> > + if (s->memhp_state.is_enabled &&
> > + object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
> > + acpi_memory_plug_cb(hotplug_dev, &s->memhp_state,
> > + dev, errp);
> > + } else {
> > + error_setg(errp, "virt: device plug request for unsupported
> device"
> > + " type: %s", object_get_typename(OBJECT(dev)));
> > + }
> > +}
> > +
> > +static void acpi_ged_send_event(AcpiDeviceIf *adev, AcpiEventStatusBits
> ev)
> > +{
> > + AcpiGedState *s = ACPI_GED(adev);
> > + uint32_t sel;
> > +
> > + if (ev & ACPI_MEMORY_HOTPLUG_STATUS) {
> > + sel = ACPI_GED_IRQ_SEL_MEM;
> > + } else {
> > + /* Unknown event. Return without generating interrupt. */
> > + return;
> > + }
> > +
> > + /*
> > + * We inject the hotplug interrupt. The IRQ selector will make
> > + * the difference from the ACPI table.
> > + */
> > + acpi_ged_event(&s->ged_state, sel);
> > +}
> > +
> > +static void acpi_ged_device_realize(DeviceState *dev, Error **errp)
> > +{
> > + AcpiGedState *s = ACPI_GED(dev);
> > +
> > + if (s->memhp_state.is_enabled) {
> > + acpi_memory_hotplug_init(get_system_memory(), OBJECT(dev),
> > + &s->memhp_state,
> > + s->memhp_base);
> > + acpi_ged_init(get_system_memory(), dev, &s->ged_state);
> > + }
> > +}
> > +
> > +static Property acpi_ged_properties[] = {
> > + /*
> > + * Memory hotplug base address is a property of GED here,
> > + * because GED handles memory hotplug event and
> MEMORY_HOTPLUG_DEVICE
> > + * gets initialized when GED device is realized.
> > + */
> > + DEFINE_PROP_UINT64("memhp-base", AcpiGedState, memhp_base,
> 0),
> > + DEFINE_PROP_BOOL("memory-hotplug-support", AcpiGedState,
> > + memhp_state.is_enabled, true),
> > + DEFINE_PROP_PTR("gsi", AcpiGedState, gsi),
>
> PTR shouldn't be used in new code, look at object_property_add_link() & co
Ok. I will take a look at that.
>
> > + DEFINE_PROP_UINT64("ged-base", AcpiGedState, ged_base, 0),
> > + DEFINE_PROP_UINT32("ged-irq", AcpiGedState, ged_irq, 0),
> > + DEFINE_PROP_PTR("ged-events", AcpiGedState, ged_events),
> > + DEFINE_PROP_UINT32("ged-events-size", AcpiGedState,
> ged_events_size, 0),
> > + DEFINE_PROP_END_OF_LIST(),
> > +};
> > +
> > +static void acpi_ged_class_init(ObjectClass *class, void *data)
> > +{
> > + DeviceClass *dc = DEVICE_CLASS(class);
> > + HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(class);
> > + AcpiDeviceIfClass *adevc = ACPI_DEVICE_IF_CLASS(class);
> > +
> > + dc->desc = "ACPI";
> > + dc->props = acpi_ged_properties;
> > + dc->realize = acpi_ged_device_realize;
> > +
> > + /* Reason: pointer properties "gsi" and "ged_events" */
> > + dc->user_creatable = false;
> > +
> > + hc->plug = acpi_ged_device_plug_cb;
> > +
> > + adevc->send_event = acpi_ged_send_event;
> > +}
> > +
> > +static const TypeInfo acpi_ged_info = {
> > + .name = TYPE_ACPI_GED,
> > + .parent = TYPE_DEVICE,
> > + .instance_size = sizeof(AcpiGedState),
> > + .class_init = acpi_ged_class_init,
> > + .interfaces = (InterfaceInfo[]) {
> > + { TYPE_HOTPLUG_HANDLER },
> > + { TYPE_ACPI_DEVICE_IF },
> > + { }
> > + }
> > +};
> > +
> > +static void acpi_ged_register_types(void)
> > +{
> > + type_register_static(&acpi_ged_info);
> > +}
> > +
> > +type_init(acpi_ged_register_types)
> > diff --git a/include/hw/acpi/generic_event_device.h
> b/include/hw/acpi/generic_event_device.h
> > new file mode 100644
> > index 0000000..9c840d8
> > --- /dev/null
> > +++ b/include/hw/acpi/generic_event_device.h
> > @@ -0,0 +1,121 @@
> > +/*
> > + *
> > + * Copyright (c) 2018 Intel Corporation
> > + *
> > + * This program is free software; you can redistribute it and/or modify it
> > + * under the terms and conditions of the GNU General Public License,
> > + * version 2 or later, as published by the Free Software Foundation.
> > + *
> > + * This program is distributed in the hope it will be useful, but WITHOUT
> > + * ANY WARRANTY; without even the implied warranty of
> MERCHANTABILITY or
> > + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
> License for
> > + * more details.
> > + *
> > + * You should have received a copy of the GNU General Public License along
> with
> > + * this program. If not, see <http://www.gnu.org/licenses/>.
> > + *
> > + * The ACPI Generic Event Device (GED) is a hardware-reduced specific
> > + * device[ACPI v6.1 Section 5.6.9] that handles all platform events,
> > + * including the hotplug ones. Generic Event Device allows platforms
> > + * to handle interrupts in ACPI ASL statements. It follows a very
> > + * similar approach like the _EVT method from GPIO events. All
> > + * interrupts are listed in _CRS and the handler is written in _EVT
> > + * method. Here, we use a single interrupt for the GED device, relying
> > + * on IO memory region to communicate the type of device affected by
> > + * the interrupt. This way, we can support up to 32 events with a
> > + * unique interrupt.
> > + *
> > + * Here is an example.
> > + *
> > + * Device (\_SB.GED)
> > + * {
> > + * Name (_HID, "ACPI0013")
> > + * Name (_UID, Zero)
> > + * Name (_CRS, ResourceTemplate ()
> > + * {
> > + * Interrupt (ResourceConsumer, Edge, ActiveHigh, Exclusive, ,, )
> > + * {
> > + * 0x00000029,
> > + * }
> > + * })
> > + * OperationRegion (IREG, SystemMemory, 0x09080000, 0x04)
> > + * Field (IREG, DWordAcc, NoLock, WriteAsZeros)
> > + * {
> > + * ISEL, 32
> > + * }
> > + *
> > + * Method (_EVT, 1, Serialized) // _EVT: Event
> > + * {
> > + * Local0 = ISEL // ISEL = IO memory region which specifies the
> > + * // device type.
> > + * If (((Local0 & irq0) == irq0))
> > + * {
> > + * MethodEvent0()
> > + * }
> > + * ElseIf ((Local0 & irq1) == irq1)
> > + * {
> > + * MethodEvent1()
> > + * }
> > + * ...
> > + * }
> > + * }
> > + *
> > + */
> > +
> > +#ifndef HW_ACPI_GED_H
> > +#define HW_ACPI_GED_H
> > +
> > +#include "hw/acpi/memory_hotplug.h"
> > +
> > +#define TYPE_ACPI_GED "acpi-ged"
> > +#define ACPI_GED(obj) \
> > + OBJECT_CHECK(AcpiGedState, (obj), TYPE_ACPI_GED)
> > +
> > +#define ACPI_GED_IRQ_SEL_OFFSET 0x0
> > +#define ACPI_GED_IRQ_SEL_LEN 0x4
> > +#define ACPI_GED_IRQ_SEL_MEM 0x1
> > +#define ACPI_GED_REG_LEN 0x4
> > +
> > +#define GED_DEVICE "GED"
> > +#define AML_GED_IRQ_REG "IREG"
> > +#define AML_GED_IRQ_SEL "ISEL"
> > +
> > +typedef enum {
> > + GED_MEMORY_HOTPLUG = 1,
> > +} GedEventType;
> > +
> > +/*
> > + * Platforms need to specify their own GedEvent array
> > + * to describe what kind of events they want to support
> > + * through GED.
> > + */
> > +typedef struct GedEvent {
> > + uint32_t selector;
> > + GedEventType event;
> > +} GedEvent;
> > +
> > +typedef struct GEDState {
> > + MemoryRegion io;
> > + uint32_t sel;
>
> do we need to migrate this during migration?
TBH, I don't know and currently this series doesn't address migration
as we don't have any VMStateDescription and friends. Is this something
we can sort later?
Thanks,
Shameer
> > + uint32_t irq;
> > + qemu_irq *gsi;
> > + QemuMutex lock;
> > +} GEDState;
> > +
> > +
> > +typedef struct AcpiGedState {
> > + DeviceClass parent_obj;
> > + MemHotplugState memhp_state;
> > + hwaddr memhp_base;
> > + void *gsi;
> > + hwaddr ged_base;
> > + GEDState ged_state;
> > + uint32_t ged_irq;
> > + void *ged_events;
> > + uint32_t ged_events_size;
> > +} AcpiGedState;
> > +
> > +void build_ged_aml(Aml *table, const char* name, HotplugHandler
> *hotplug_dev,
> > + uint32_t ged_irq, AmlRegionSpace rs);
> > +
> > +#endif
