diff mbox

[v12,4/9] hw/vfio/platform: add capability to start IRQ propagation

Message ID 1426785402-2091-5-git-send-email-eric.auger@linaro.org
State New
Headers show

Commit Message

Auger Eric March 19, 2015, 5:16 p.m. UTC
Add a reset notify function that enables to start the propagation of
interrupts to the guest.

Signed-off-by: Eric Auger <eric.auger@linaro.org>

---
v10 -> v11:
- comment reword

v8 -> v9:
- handle failure in vfio_irq_starter
---
 hw/vfio/platform.c              | 64 +++++++++++++++++++++++++++++++++++++++++
 include/hw/vfio/vfio-platform.h |  8 ++++++
 2 files changed, 72 insertions(+)

Comments

Auger Eric April 17, 2015, 3:31 p.m. UTC | #1
Hi Alex,
On 04/17/2015 12:04 AM, Alex Williamson wrote:
> On Thu, 2015-03-19 at 17:16 +0000, Eric Auger wrote:
>> Add a reset notify function that enables to start the propagation of
>> interrupts to the guest.
>>
>> Signed-off-by: Eric Auger <eric.auger@linaro.org>
>>
>> ---
>> v10 -> v11:
>> - comment reword
>>
>> v8 -> v9:
>> - handle failure in vfio_irq_starter
>> ---
>>  hw/vfio/platform.c              | 64 +++++++++++++++++++++++++++++++++++++++++
>>  include/hw/vfio/vfio-platform.h |  8 ++++++
>>  2 files changed, 72 insertions(+)
>>
>> diff --git a/hw/vfio/platform.c b/hw/vfio/platform.c
>> index 31c2701..361e01b 100644
>> --- a/hw/vfio/platform.c
>> +++ b/hw/vfio/platform.c
>> @@ -572,6 +572,70 @@ static void vfio_platform_realize(DeviceState *dev, Error **errp)
>>      }
>>  }
>>  
>> +/**
>> + * vfio_irq_starter: Start IRQ forwarding for a specific VFIO device
>> + * @sbdev: Sysbus device handle
>> + * @opaque: DeviceState handle of the interrupt controller the device
>> + *          is attached to
>> + *
>> + * The function retrieves the absolute GSI number each VFIO IRQ
>> + * corresponds to and start forwarding.
>> + */
> 
> Using "forwarding" here is really making me look for your platform's EOI
> trick (IRQ Forwarding), which isn't here.
sure
> 
>> +static int vfio_irq_starter(SysBusDevice *sbdev, void *opaque)
>> +{
>> +    DeviceState *intc = (DeviceState *)opaque;
>> +    VFIOPlatformDevice *vdev;
>> +    VFIOINTp *intp;
>> +    qemu_irq irq;
>> +    int gsi, ret;
>> +
>> +    if (object_dynamic_cast(OBJECT(sbdev), TYPE_VFIO_PLATFORM)) {
>> +        vdev = VFIO_PLATFORM_DEVICE(sbdev);
>> +
>> +        QLIST_FOREACH(intp, &vdev->intp_list, next) {
>> +            gsi = 0;
>> +            while (1) {
>> +                irq = qdev_get_gpio_in(intc, gsi);
>> +                if (irq == intp->qemuirq) {
>> +                    break;
>> +                }
>> +                gsi++;
>> +            }
> 
> A for() loop would be more compact here, but is there some other exit
> condition we can add?  gsi < INT_MAX?
Currently I do not see any way to retrieve the number of input GPIOs.
This is static in core/qdev.c. either I leave as is or introduce getters.

> 
>> +            intp->virtualID = gsi;
>> +            ret = vdev->start_irq_fn(intp);
>> +            if (ret) {
>> +                error_report("%s unable to start propagation of IRQ index %d",
>> +                             vdev->vbasedev.name, intp->pin);
>> +                exit(1);
>> +            }
>> +        }
>> +    }
>> +    return 0;
>> +}
>> +
>> +/**
>> + * vfio_kick_irqs: start IRQ forwarding for all the VFIO devices
>> + * attached to the platform bus
>> + * @data: Device state handle of the interrupt controller the VFIO IRQs
>> + *        must be bound to
>> + *
>> + * Binding to the platform bus IRQs happens on a machine init done
>> + * notifier registered by the platform bus. Only at that time the
>> + * absolute virtual IRQ = GSI is known and allows to setup IRQFD.
>> + * This function typically can be called in a reset notifier registered
>> + * by the machine file.
>> + */
> 
> So there's not actually an irqfd setup done here yet and what is
> currently done by the above starter function doesn't depend at all on
> the GSI.  Do you perhaps want to setup the vfio->eventfd signaling
> during your initfn and then only connect the eventfd->irqfd to KVM in
> the reset function?  Sort of how vfio-pci does the routing update.

Not sure I get what you mean here. In above starter I call start_irq_fn.
This latter starts the injection depending on the chosen technique, 1)
user side handling, 2) standalone irqfd, 2) irqfd + ARM forwarding.
For starting 2) and 3) I actually use the GSI set above by
intp->virtualID = gsi;
See vfio_start_irqfd_injection.

Indeed I noticed in VFIO-PCI you first started eventfd and then irqfd
but I thought I did not need to do that. What is the problem starting
VFIO signaling on reset (notifier) only? Besides, moving back to 2-step
settup would not fix my issue of being able to know the gsi to attach to
my irqfd. I need to further investigate this PCI INTx routing notifier...

Best Regards

Eric

> 
>> +void vfio_kick_irqs(void *data)
>> +{
>> +    DeviceState *intc = (DeviceState *)data;
>> +    DeviceState *dev =
>> +        qdev_find_recursive(sysbus_get_default(), TYPE_PLATFORM_BUS_DEVICE);
>> +    PlatformBusDevice *pbus = PLATFORM_BUS_DEVICE(dev);
>> +
>> +    assert(pbus->done_gathering);
>> +    foreach_dynamic_sysbus_device(vfio_irq_starter, intc);
>> +}
>> +
>>  static const VMStateDescription vfio_platform_vmstate = {
>>      .name = TYPE_VFIO_PLATFORM,
>>      .unmigratable = 1,
>> diff --git a/include/hw/vfio/vfio-platform.h b/include/hw/vfio/vfio-platform.h
>> index 31893a3..c9ee898 100644
>> --- a/include/hw/vfio/vfio-platform.h
>> +++ b/include/hw/vfio/vfio-platform.h
>> @@ -77,4 +77,12 @@ typedef struct VFIOPlatformDeviceClass {
>>  #define VFIO_PLATFORM_DEVICE_GET_CLASS(obj) \
>>       OBJECT_GET_CLASS(VFIOPlatformDeviceClass, (obj), TYPE_VFIO_PLATFORM)
>>  
>> +/**
>> + * vfio_kick_irqs - reset notifier that starts IRQ injection
>> + * for all VFIO dynamic sysbus devices attached to the platform bus.
>> + *
>> + * @opaque: handle to the interrupt controller DeviceState
>> + */
>> +void vfio_kick_irqs(void *opaque);
>> +
>>  #endif /*HW_VFIO_VFIO_PLATFORM_H*/
> 
> 
>
Auger Eric April 21, 2015, 8:42 a.m. UTC | #2
Hi,

I am trying to figure out a clean solution to retrieve the gsi
associated to a sysbus device qemu_irq. Among other things this is
needed to start VFIO platform signaling.

With PCI, it seems the PCI host stores the mapping
(*_route_intx_pin_to_irq). Without PCI, if my understanding is correct
the qemu_irq to gsi function should be implemented by the interrupt
controller.

I would be tempted to register a new function in the interrupt
controller, for instance kvm_arm_gic_get_irq_gsi using some new qdev setter:

qdev_set_gpio_in_gsi_getter(dev, kvm_arm_gic_set_irq,
kvm_arm_gic_get_irq_gsi, i);

or even changing proto of qdev_init_gpio_in but this has a large impact.

Do you think any of this is sensible?

Best Regards

Eric



On 04/17/2015 09:41 PM, Alex Williamson wrote:
> On Fri, 2015-04-17 at 17:31 +0200, Eric Auger wrote:
>> Hi Alex,
>> On 04/17/2015 12:04 AM, Alex Williamson wrote:
>>> On Thu, 2015-03-19 at 17:16 +0000, Eric Auger wrote:
>>>> Add a reset notify function that enables to start the propagation of
>>>> interrupts to the guest.
>>>>
>>>> Signed-off-by: Eric Auger <eric.auger@linaro.org>
>>>>
>>>> ---
>>>> v10 -> v11:
>>>> - comment reword
>>>>
>>>> v8 -> v9:
>>>> - handle failure in vfio_irq_starter
>>>> ---
>>>>  hw/vfio/platform.c              | 64 +++++++++++++++++++++++++++++++++++++++++
>>>>  include/hw/vfio/vfio-platform.h |  8 ++++++
>>>>  2 files changed, 72 insertions(+)
>>>>
>>>> diff --git a/hw/vfio/platform.c b/hw/vfio/platform.c
>>>> index 31c2701..361e01b 100644
>>>> --- a/hw/vfio/platform.c
>>>> +++ b/hw/vfio/platform.c
>>>> @@ -572,6 +572,70 @@ static void vfio_platform_realize(DeviceState *dev, Error **errp)
>>>>      }
>>>>  }
>>>>  
>>>> +/**
>>>> + * vfio_irq_starter: Start IRQ forwarding for a specific VFIO device
>>>> + * @sbdev: Sysbus device handle
>>>> + * @opaque: DeviceState handle of the interrupt controller the device
>>>> + *          is attached to
>>>> + *
>>>> + * The function retrieves the absolute GSI number each VFIO IRQ
>>>> + * corresponds to and start forwarding.
>>>> + */
>>>
>>> Using "forwarding" here is really making me look for your platform's EOI
>>> trick (IRQ Forwarding), which isn't here.
>> sure
>>>
>>>> +static int vfio_irq_starter(SysBusDevice *sbdev, void *opaque)
>>>> +{
>>>> +    DeviceState *intc = (DeviceState *)opaque;
>>>> +    VFIOPlatformDevice *vdev;
>>>> +    VFIOINTp *intp;
>>>> +    qemu_irq irq;
>>>> +    int gsi, ret;
>>>> +
>>>> +    if (object_dynamic_cast(OBJECT(sbdev), TYPE_VFIO_PLATFORM)) {
>>>> +        vdev = VFIO_PLATFORM_DEVICE(sbdev);
>>>> +
>>>> +        QLIST_FOREACH(intp, &vdev->intp_list, next) {
>>>> +            gsi = 0;
>>>> +            while (1) {
>>>> +                irq = qdev_get_gpio_in(intc, gsi);
>>>> +                if (irq == intp->qemuirq) {
>>>> +                    break;
>>>> +                }
>>>> +                gsi++;
>>>> +            }
>>>
>>> A for() loop would be more compact here, but is there some other exit
>>> condition we can add?  gsi < INT_MAX?
>> Currently I do not see any way to retrieve the number of input GPIOs.
>> This is static in core/qdev.c. either I leave as is or introduce getters.
> 
> Well, INT_MAX is always an option, right?  I prefer the way vfio-pci is
> structured where we can ask for the gsi routing via
> pci_device_route_intx_to_irq() rather than searching the entire address
> space.  Can we do something similar on platform to pass in a qemuirq and
> get back a gsi?
>  
>>>> +            intp->virtualID = gsi;
>>>> +            ret = vdev->start_irq_fn(intp);
>>>> +            if (ret) {
>>>> +                error_report("%s unable to start propagation of IRQ index %d",
>>>> +                             vdev->vbasedev.name, intp->pin);
>>>> +                exit(1);
>>>> +            }
>>>> +        }
>>>> +    }
>>>> +    return 0;
>>>> +}
>>>> +
>>>> +/**
>>>> + * vfio_kick_irqs: start IRQ forwarding for all the VFIO devices
>>>> + * attached to the platform bus
>>>> + * @data: Device state handle of the interrupt controller the VFIO IRQs
>>>> + *        must be bound to
>>>> + *
>>>> + * Binding to the platform bus IRQs happens on a machine init done
>>>> + * notifier registered by the platform bus. Only at that time the
>>>> + * absolute virtual IRQ = GSI is known and allows to setup IRQFD.
>>>> + * This function typically can be called in a reset notifier registered
>>>> + * by the machine file.
>>>> + */
>>>
>>> So there's not actually an irqfd setup done here yet and what is
>>> currently done by the above starter function doesn't depend at all on
>>> the GSI.  Do you perhaps want to setup the vfio->eventfd signaling
>>> during your initfn and then only connect the eventfd->irqfd to KVM in
>>> the reset function?  Sort of how vfio-pci does the routing update.
>>
>> Not sure I get what you mean here. In above starter I call start_irq_fn.
>> This latter starts the injection depending on the chosen technique, 1)
>> user side handling, 2) standalone irqfd, 2) irqfd + ARM forwarding.
>> For starting 2) and 3) I actually use the GSI set above by
>> intp->virtualID = gsi;
>> See vfio_start_irqfd_injection.
>>
>> Indeed I noticed in VFIO-PCI you first started eventfd and then irqfd
>> but I thought I did not need to do that. What is the problem starting
>> VFIO signaling on reset (notifier) only? Besides, moving back to 2-step
>> settup would not fix my issue of being able to know the gsi to attach to
>> my irqfd. I need to further investigate this PCI INTx routing notifier...
> 
> vfio-pci effectively has the same issue.  PCI supports supports four
> legacy interrupt lines and we know which of those interrupt lines the
> device uses during the initfn, but we don't know the GSI that the PCI
> line maps to until later.  In our case it's not just system reset, but
> the guest can manipulate the mapping runtime via emulated platform
> chipset registers.  vfio-pci also attempts to handle KVM acceleration as
> optional, enabling userspace signaling first, then augmenting it with an
> irqfd fast path.  We should be able to handle a failure on the
> acceleration path without calling exit() to kill the VM and it would be
> cleaner for the initfn to fail if we can't setup basic signaling via
> eventfd.
> 
> Expecting to be able to configure both basic signaling and acceleration
> at the same time seems to be contributing to this reset notifier hack
> that I'm not a fan of.  vfio-platform could register it's own reset
> notifier, or perhaps a machine_init_done notifier if a path was setup
> where vfio-platform could query the gsi, as I suggest above.  Thanks,
> 
> Alex
> 
>>>> +void vfio_kick_irqs(void *data)
>>>> +{
>>>> +    DeviceState *intc = (DeviceState *)data;
>>>> +    DeviceState *dev =
>>>> +        qdev_find_recursive(sysbus_get_default(), TYPE_PLATFORM_BUS_DEVICE);
>>>> +    PlatformBusDevice *pbus = PLATFORM_BUS_DEVICE(dev);
>>>> +
>>>> +    assert(pbus->done_gathering);
>>>> +    foreach_dynamic_sysbus_device(vfio_irq_starter, intc);
>>>> +}
>>>> +
>>>>  static const VMStateDescription vfio_platform_vmstate = {
>>>>      .name = TYPE_VFIO_PLATFORM,
>>>>      .unmigratable = 1,
>>>> diff --git a/include/hw/vfio/vfio-platform.h b/include/hw/vfio/vfio-platform.h
>>>> index 31893a3..c9ee898 100644
>>>> --- a/include/hw/vfio/vfio-platform.h
>>>> +++ b/include/hw/vfio/vfio-platform.h
>>>> @@ -77,4 +77,12 @@ typedef struct VFIOPlatformDeviceClass {
>>>>  #define VFIO_PLATFORM_DEVICE_GET_CLASS(obj) \
>>>>       OBJECT_GET_CLASS(VFIOPlatformDeviceClass, (obj), TYPE_VFIO_PLATFORM)
>>>>  
>>>> +/**
>>>> + * vfio_kick_irqs - reset notifier that starts IRQ injection
>>>> + * for all VFIO dynamic sysbus devices attached to the platform bus.
>>>> + *
>>>> + * @opaque: handle to the interrupt controller DeviceState
>>>> + */
>>>> +void vfio_kick_irqs(void *opaque);
>>>> +
>>>>  #endif /*HW_VFIO_VFIO_PLATFORM_H*/
>>>
>>>
>>>
>>
> 
> 
>
Auger Eric April 21, 2015, 11:54 a.m. UTC | #3
Hi Alex,
On 04/17/2015 09:41 PM, Alex Williamson wrote:
> On Fri, 2015-04-17 at 17:31 +0200, Eric Auger wrote:
>> Hi Alex,
>> On 04/17/2015 12:04 AM, Alex Williamson wrote:
>>> On Thu, 2015-03-19 at 17:16 +0000, Eric Auger wrote:
>>>> Add a reset notify function that enables to start the propagation of
>>>> interrupts to the guest.
>>>>
>>>> Signed-off-by: Eric Auger <eric.auger@linaro.org>
>>>>
>>>> ---
>>>> v10 -> v11:
>>>> - comment reword
>>>>
>>>> v8 -> v9:
>>>> - handle failure in vfio_irq_starter
>>>> ---
>>>>  hw/vfio/platform.c              | 64 +++++++++++++++++++++++++++++++++++++++++
>>>>  include/hw/vfio/vfio-platform.h |  8 ++++++
>>>>  2 files changed, 72 insertions(+)
>>>>
>>>> diff --git a/hw/vfio/platform.c b/hw/vfio/platform.c
>>>> index 31c2701..361e01b 100644
>>>> --- a/hw/vfio/platform.c
>>>> +++ b/hw/vfio/platform.c
>>>> @@ -572,6 +572,70 @@ static void vfio_platform_realize(DeviceState *dev, Error **errp)
>>>>      }
>>>>  }
>>>>  
>>>> +/**
>>>> + * vfio_irq_starter: Start IRQ forwarding for a specific VFIO device
>>>> + * @sbdev: Sysbus device handle
>>>> + * @opaque: DeviceState handle of the interrupt controller the device
>>>> + *          is attached to
>>>> + *
>>>> + * The function retrieves the absolute GSI number each VFIO IRQ
>>>> + * corresponds to and start forwarding.
>>>> + */
>>>
>>> Using "forwarding" here is really making me look for your platform's EOI
>>> trick (IRQ Forwarding), which isn't here.
>> sure
>>>
>>>> +static int vfio_irq_starter(SysBusDevice *sbdev, void *opaque)
>>>> +{
>>>> +    DeviceState *intc = (DeviceState *)opaque;
>>>> +    VFIOPlatformDevice *vdev;
>>>> +    VFIOINTp *intp;
>>>> +    qemu_irq irq;
>>>> +    int gsi, ret;
>>>> +
>>>> +    if (object_dynamic_cast(OBJECT(sbdev), TYPE_VFIO_PLATFORM)) {
>>>> +        vdev = VFIO_PLATFORM_DEVICE(sbdev);
>>>> +
>>>> +        QLIST_FOREACH(intp, &vdev->intp_list, next) {
>>>> +            gsi = 0;
>>>> +            while (1) {
>>>> +                irq = qdev_get_gpio_in(intc, gsi);
>>>> +                if (irq == intp->qemuirq) {
>>>> +                    break;
>>>> +                }
>>>> +                gsi++;
>>>> +            }
>>>
>>> A for() loop would be more compact here, but is there some other exit
>>> condition we can add?  gsi < INT_MAX?
>> Currently I do not see any way to retrieve the number of input GPIOs.
>> This is static in core/qdev.c. either I leave as is or introduce getters.
> 
> Well, INT_MAX is always an option, right? 
yes it is.
 I prefer the way vfio-pci is
> structured where we can ask for the gsi routing via
> pci_device_route_intx_to_irq() rather than searching the entire address
> space.  Can we do something similar on platform to pass in a qemuirq and
> get back a gsi?
I launched a separate thread to find out a solution for qemu_irq to gsi
conversion.

As for the notification mechanism the intx_routing_notifier is part of
the PCIDevice. By analogy this would mean a similar notifier in the
SysBusDevice. I would add a notifier setter in SysbusDevice and call it
on sysbus_connect_irq. This is what I currently think about. I will send
a separate patch and see what happens ... if anyone already is opposed
to that, please let me know ...

>  
>>>> +            intp->virtualID = gsi;
>>>> +            ret = vdev->start_irq_fn(intp);
>>>> +            if (ret) {
>>>> +                error_report("%s unable to start propagation of IRQ index %d",
>>>> +                             vdev->vbasedev.name, intp->pin);
>>>> +                exit(1);
>>>> +            }
>>>> +        }
>>>> +    }
>>>> +    return 0;
>>>> +}
>>>> +
>>>> +/**
>>>> + * vfio_kick_irqs: start IRQ forwarding for all the VFIO devices
>>>> + * attached to the platform bus
>>>> + * @data: Device state handle of the interrupt controller the VFIO IRQs
>>>> + *        must be bound to
>>>> + *
>>>> + * Binding to the platform bus IRQs happens on a machine init done
>>>> + * notifier registered by the platform bus. Only at that time the
>>>> + * absolute virtual IRQ = GSI is known and allows to setup IRQFD.
>>>> + * This function typically can be called in a reset notifier registered
>>>> + * by the machine file.
>>>> + */
>>>
>>> So there's not actually an irqfd setup done here yet and what is
>>> currently done by the above starter function doesn't depend at all on
>>> the GSI.  Do you perhaps want to setup the vfio->eventfd signaling
>>> during your initfn and then only connect the eventfd->irqfd to KVM in
>>> the reset function?  Sort of how vfio-pci does the routing update.
>>
>> Not sure I get what you mean here. In above starter I call start_irq_fn.
>> This latter starts the injection depending on the chosen technique, 1)
>> user side handling, 2) standalone irqfd, 2) irqfd + ARM forwarding.
>> For starting 2) and 3) I actually use the GSI set above by
>> intp->virtualID = gsi;
>> See vfio_start_irqfd_injection.
>>
>> Indeed I noticed in VFIO-PCI you first started eventfd and then irqfd
>> but I thought I did not need to do that. What is the problem starting
>> VFIO signaling on reset (notifier) only? Besides, moving back to 2-step
>> settup would not fix my issue of being able to know the gsi to attach to
>> my irqfd. I need to further investigate this PCI INTx routing notifier...
> 
> vfio-pci effectively has the same issue.  PCI supports supports four
> legacy interrupt lines and we know which of those interrupt lines the
> device uses during the initfn, but we don't know the GSI that the PCI
> line maps to until later.  In our case it's not just system reset, but
> the guest can manipulate the mapping runtime via emulated platform
> chipset registers.  vfio-pci also attempts to handle KVM acceleration as
> optional, enabling userspace signaling first, then augmenting it with an
> irqfd fast path.  We should be able to handle a failure on the
> acceleration path without calling exit() to kill the VM and it would be
> cleaner for the initfn to fail if we can't setup basic signaling via
> eventfd.
> 
> Expecting to be able to configure both basic signaling and acceleration
> at the same time seems to be contributing to this reset notifier hack
> that I'm not a fan of.  vfio-platform could register it's own reset
> notifier, or perhaps a machine_init_done notifier if a path was setup
> where vfio-platform could query the gsi, as I suggest above.  Thanks,

Thanks for those explanation. I do not have any issue with reverting to
the 2 stage setup.

Best Regards

Eric


> 
> Alex
> 
>>>> +void vfio_kick_irqs(void *data)
>>>> +{
>>>> +    DeviceState *intc = (DeviceState *)data;
>>>> +    DeviceState *dev =
>>>> +        qdev_find_recursive(sysbus_get_default(), TYPE_PLATFORM_BUS_DEVICE);
>>>> +    PlatformBusDevice *pbus = PLATFORM_BUS_DEVICE(dev);
>>>> +
>>>> +    assert(pbus->done_gathering);
>>>> +    foreach_dynamic_sysbus_device(vfio_irq_starter, intc);
>>>> +}
>>>> +
>>>>  static const VMStateDescription vfio_platform_vmstate = {
>>>>      .name = TYPE_VFIO_PLATFORM,
>>>>      .unmigratable = 1,
>>>> diff --git a/include/hw/vfio/vfio-platform.h b/include/hw/vfio/vfio-platform.h
>>>> index 31893a3..c9ee898 100644
>>>> --- a/include/hw/vfio/vfio-platform.h
>>>> +++ b/include/hw/vfio/vfio-platform.h
>>>> @@ -77,4 +77,12 @@ typedef struct VFIOPlatformDeviceClass {
>>>>  #define VFIO_PLATFORM_DEVICE_GET_CLASS(obj) \
>>>>       OBJECT_GET_CLASS(VFIOPlatformDeviceClass, (obj), TYPE_VFIO_PLATFORM)
>>>>  
>>>> +/**
>>>> + * vfio_kick_irqs - reset notifier that starts IRQ injection
>>>> + * for all VFIO dynamic sysbus devices attached to the platform bus.
>>>> + *
>>>> + * @opaque: handle to the interrupt controller DeviceState
>>>> + */
>>>> +void vfio_kick_irqs(void *opaque);
>>>> +
>>>>  #endif /*HW_VFIO_VFIO_PLATFORM_H*/
>>>
>>>
>>>
>>
> 
> 
>
diff mbox

Patch

diff --git a/hw/vfio/platform.c b/hw/vfio/platform.c
index 31c2701..361e01b 100644
--- a/hw/vfio/platform.c
+++ b/hw/vfio/platform.c
@@ -572,6 +572,70 @@  static void vfio_platform_realize(DeviceState *dev, Error **errp)
     }
 }
 
+/**
+ * vfio_irq_starter: Start IRQ forwarding for a specific VFIO device
+ * @sbdev: Sysbus device handle
+ * @opaque: DeviceState handle of the interrupt controller the device
+ *          is attached to
+ *
+ * The function retrieves the absolute GSI number each VFIO IRQ
+ * corresponds to and start forwarding.
+ */
+static int vfio_irq_starter(SysBusDevice *sbdev, void *opaque)
+{
+    DeviceState *intc = (DeviceState *)opaque;
+    VFIOPlatformDevice *vdev;
+    VFIOINTp *intp;
+    qemu_irq irq;
+    int gsi, ret;
+
+    if (object_dynamic_cast(OBJECT(sbdev), TYPE_VFIO_PLATFORM)) {
+        vdev = VFIO_PLATFORM_DEVICE(sbdev);
+
+        QLIST_FOREACH(intp, &vdev->intp_list, next) {
+            gsi = 0;
+            while (1) {
+                irq = qdev_get_gpio_in(intc, gsi);
+                if (irq == intp->qemuirq) {
+                    break;
+                }
+                gsi++;
+            }
+            intp->virtualID = gsi;
+            ret = vdev->start_irq_fn(intp);
+            if (ret) {
+                error_report("%s unable to start propagation of IRQ index %d",
+                             vdev->vbasedev.name, intp->pin);
+                exit(1);
+            }
+        }
+    }
+    return 0;
+}
+
+/**
+ * vfio_kick_irqs: start IRQ forwarding for all the VFIO devices
+ * attached to the platform bus
+ * @data: Device state handle of the interrupt controller the VFIO IRQs
+ *        must be bound to
+ *
+ * Binding to the platform bus IRQs happens on a machine init done
+ * notifier registered by the platform bus. Only at that time the
+ * absolute virtual IRQ = GSI is known and allows to setup IRQFD.
+ * This function typically can be called in a reset notifier registered
+ * by the machine file.
+ */
+void vfio_kick_irqs(void *data)
+{
+    DeviceState *intc = (DeviceState *)data;
+    DeviceState *dev =
+        qdev_find_recursive(sysbus_get_default(), TYPE_PLATFORM_BUS_DEVICE);
+    PlatformBusDevice *pbus = PLATFORM_BUS_DEVICE(dev);
+
+    assert(pbus->done_gathering);
+    foreach_dynamic_sysbus_device(vfio_irq_starter, intc);
+}
+
 static const VMStateDescription vfio_platform_vmstate = {
     .name = TYPE_VFIO_PLATFORM,
     .unmigratable = 1,
diff --git a/include/hw/vfio/vfio-platform.h b/include/hw/vfio/vfio-platform.h
index 31893a3..c9ee898 100644
--- a/include/hw/vfio/vfio-platform.h
+++ b/include/hw/vfio/vfio-platform.h
@@ -77,4 +77,12 @@  typedef struct VFIOPlatformDeviceClass {
 #define VFIO_PLATFORM_DEVICE_GET_CLASS(obj) \
      OBJECT_GET_CLASS(VFIOPlatformDeviceClass, (obj), TYPE_VFIO_PLATFORM)
 
+/**
+ * vfio_kick_irqs - reset notifier that starts IRQ injection
+ * for all VFIO dynamic sysbus devices attached to the platform bus.
+ *
+ * @opaque: handle to the interrupt controller DeviceState
+ */
+void vfio_kick_irqs(void *opaque);
+
 #endif /*HW_VFIO_VFIO_PLATFORM_H*/