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[PATCH v2 7/8] pc: Allow instantiating a virtio-iommu device

Jean-Philippe Brucker posted 8 patches 4 years, 5 months ago
There is a newer version of this series
[PATCH v2 7/8] pc: Allow instantiating a virtio-iommu device
Posted by Jean-Philippe Brucker 4 years, 5 months ago 
From: Eric Auger <eric.auger@redhat.com>

Add a hotplug handler for virtio-iommu on x86 and set the necessary
reserved region property. On x86, the [0xfee00000, 0xfeefffff] DMA
region is reserved for MSIs. DMA transactions to this range either
trigger IRQ remapping in the IOMMU or bypasses IOMMU translation.

Although virtio-iommu does not support IRQ remapping it must be informed
of the reserved region so that it can forward DMA transactions targeting
this region.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
---
 hw/i386/pc.c | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 694fc9ce07..c1e1cffe16 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -797,6 +797,11 @@ void pc_machine_done(Notifier *notifier, void *data)
                      "irqchip support.");
         exit(EXIT_FAILURE);
     }
+
+    if (pcms->virtio_iommu && x86_iommu_get_default()) {
+        error_report("QEMU does not support multiple vIOMMUs for x86 yet.");
+        exit(EXIT_FAILURE);
+    }
 }
 
 void pc_guest_info_init(PCMachineState *pcms)
@@ -1376,6 +1381,14 @@ static void pc_machine_device_pre_plug_cb(HotplugHandler *hotplug_dev,
     } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI) ||
                object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI)) {
         pc_virtio_md_pci_pre_plug(hotplug_dev, dev, errp);
+    } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_IOMMU_PCI)) {
+        /* Declare the reserved MSI region */
+        char *resv_prop_str = g_strdup_printf("0xfee00000:0xfeefffff:%d",
+                                              VIRTIO_IOMMU_RESV_MEM_T_MSI);
+
+        qdev_prop_set_uint32(dev, "len-reserved-regions", 1);
+        qdev_prop_set_string(dev, "reserved-regions[0]", resv_prop_str);
+        g_free(resv_prop_str);
     }
 }
 
@@ -1393,6 +1406,11 @@ static void pc_machine_device_plug_cb(HotplugHandler *hotplug_dev,
         PCMachineState *pcms = PC_MACHINE(hotplug_dev);
         PCIDevice *pdev = PCI_DEVICE(dev);
 
+        if (pcms->virtio_iommu) {
+            error_setg(errp,
+                       "QEMU does not support multiple vIOMMUs for x86 yet.");
+            return;
+        }
         pcms->virtio_iommu = true;
         pcms->virtio_iommu_bdf = pci_get_bdf(pdev);
     }
@@ -1436,7 +1454,8 @@ static HotplugHandler *pc_get_hotplug_handler(MachineState *machine,
     if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM) ||
         object_dynamic_cast(OBJECT(dev), TYPE_CPU) ||
         object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI) ||
-        object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI)) {
+        object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI) ||
+        object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_IOMMU_PCI)) {
         return HOTPLUG_HANDLER(machine);
     }
 
-- 
2.33.0
Re: [PATCH v2 7/8] pc: Allow instantiating a virtio-iommu device
Posted by Eric Auger 4 years, 5 months ago 
Hi Jean,

On 9/3/21 4:32 PM, Jean-Philippe Brucker wrote:
> From: Eric Auger <eric.auger@redhat.com>
>
> Add a hotplug handler for virtio-iommu on x86 and set the necessary
> reserved region property. On x86, the [0xfee00000, 0xfeefffff] DMA
> region is reserved for MSIs. DMA transactions to this range either
> trigger IRQ remapping in the IOMMU or bypasses IOMMU translation.
s/bypasses/bypass.
> Although virtio-iommu does not support IRQ remapping it must be informed
> of the reserved region so that it can forward DMA transactions targeting
> this region.

>
> Signed-off-by: Eric Auger <eric.auger@redhat.com>
Feel free to remove my SoB. I have done much here.
> Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
> ---
>  hw/i386/pc.c | 21 ++++++++++++++++++++-
>  1 file changed, 20 insertions(+), 1 deletion(-)
>
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index 694fc9ce07..c1e1cffe16 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -797,6 +797,11 @@ void pc_machine_done(Notifier *notifier, void *data)
>                       "irqchip support.");
>          exit(EXIT_FAILURE);
>      }
> +
> +    if (pcms->virtio_iommu && x86_iommu_get_default()) {
> +        error_report("QEMU does not support multiple vIOMMUs for x86 yet.");
> +        exit(EXIT_FAILURE);
> +    }
>  }

I think you shall detect the case of dual instantiation of intel_iommu
and virtio-iommu. Maybe pc_hotplug_allowed() can be used for that. Note
that both devices can be refered to in either order.
>  
>  void pc_guest_info_init(PCMachineState *pcms)
> @@ -1376,6 +1381,14 @@ static void pc_machine_device_pre_plug_cb(HotplugHandler *hotplug_dev,
>      } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI) ||
>                 object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI)) {
>          pc_virtio_md_pci_pre_plug(hotplug_dev, dev, errp);
> +    } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_IOMMU_PCI)) {
> +        /* Declare the reserved MSI region */
> +        char *resv_prop_str = g_strdup_printf("0xfee00000:0xfeefffff:%d",
> +                                              VIRTIO_IOMMU_RESV_MEM_T_MSI);
> +
> +        qdev_prop_set_uint32(dev, "len-reserved-regions", 1);
> +        qdev_prop_set_string(dev, "reserved-regions[0]", resv_prop_str);
> +        g_free(resv_prop_str);
>      }
>  }
>  
> @@ -1393,6 +1406,11 @@ static void pc_machine_device_plug_cb(HotplugHandler *hotplug_dev,
>          PCMachineState *pcms = PC_MACHINE(hotplug_dev);
>          PCIDevice *pdev = PCI_DEVICE(dev);
>  
> +        if (pcms->virtio_iommu) {
> +            error_setg(errp,
> +                       "QEMU does not support multiple vIOMMUs for x86 yet.");
> +            return;
> +        }
>          pcms->virtio_iommu = true;
>          pcms->virtio_iommu_bdf = pci_get_bdf(pdev);
>      }
> @@ -1436,7 +1454,8 @@ static HotplugHandler *pc_get_hotplug_handler(MachineState *machine,
>      if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM) ||
>          object_dynamic_cast(OBJECT(dev), TYPE_CPU) ||
>          object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI) ||
> -        object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI)) {
> +        object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI) ||
> +        object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_IOMMU_PCI)) {
>          return HOTPLUG_HANDLER(machine);
>      }
>  
Thanks

Eric
Re: [PATCH v2 7/8] pc: Allow instantiating a virtio-iommu device
Posted by Jean-Philippe Brucker 4 years, 5 months ago 
On Mon, Sep 06, 2021 at 04:57:39PM +0200, Eric Auger wrote:
> Hi Jean,
> 
> On 9/3/21 4:32 PM, Jean-Philippe Brucker wrote:
> > From: Eric Auger <eric.auger@redhat.com>
> >
> > Add a hotplug handler for virtio-iommu on x86 and set the necessary
> > reserved region property. On x86, the [0xfee00000, 0xfeefffff] DMA
> > region is reserved for MSIs. DMA transactions to this range either
> > trigger IRQ remapping in the IOMMU or bypasses IOMMU translation.
> s/bypasses/bypass.
> > Although virtio-iommu does not support IRQ remapping it must be informed
> > of the reserved region so that it can forward DMA transactions targeting
> > this region.
> 
> >
> > Signed-off-by: Eric Auger <eric.auger@redhat.com>
> Feel free to remove my SoB. I have done much here.
> > Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
> > ---
> >  hw/i386/pc.c | 21 ++++++++++++++++++++-
> >  1 file changed, 20 insertions(+), 1 deletion(-)
> >
> > diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> > index 694fc9ce07..c1e1cffe16 100644
> > --- a/hw/i386/pc.c
> > +++ b/hw/i386/pc.c
> > @@ -797,6 +797,11 @@ void pc_machine_done(Notifier *notifier, void *data)
> >                       "irqchip support.");
> >          exit(EXIT_FAILURE);
> >      }
> > +
> > +    if (pcms->virtio_iommu && x86_iommu_get_default()) {
> > +        error_report("QEMU does not support multiple vIOMMUs for x86 yet.");
> > +        exit(EXIT_FAILURE);
> > +    }
> >  }
> 
> I think you shall detect the case of dual instantiation of intel_iommu
> and virtio-iommu.

Those are handled by x86_iommu_set_default() and
pc_machine_device_plug_cb() (below) respectively. I considered factoring
it but I think it just adds complexity.

Thanks,
Jean

> Maybe pc_hotplug_allowed() can be used for that. Note
> that both devices can be refered to in either order.
> >  
> >  void pc_guest_info_init(PCMachineState *pcms)
> > @@ -1376,6 +1381,14 @@ static void pc_machine_device_pre_plug_cb(HotplugHandler *hotplug_dev,
> >      } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI) ||
> >                 object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI)) {
> >          pc_virtio_md_pci_pre_plug(hotplug_dev, dev, errp);
> > +    } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_IOMMU_PCI)) {
> > +        /* Declare the reserved MSI region */
> > +        char *resv_prop_str = g_strdup_printf("0xfee00000:0xfeefffff:%d",
> > +                                              VIRTIO_IOMMU_RESV_MEM_T_MSI);
> > +
> > +        qdev_prop_set_uint32(dev, "len-reserved-regions", 1);
> > +        qdev_prop_set_string(dev, "reserved-regions[0]", resv_prop_str);
> > +        g_free(resv_prop_str);
> >      }
> >  }
> >  
> > @@ -1393,6 +1406,11 @@ static void pc_machine_device_plug_cb(HotplugHandler *hotplug_dev,
> >          PCMachineState *pcms = PC_MACHINE(hotplug_dev);
> >          PCIDevice *pdev = PCI_DEVICE(dev);
> >  
> > +        if (pcms->virtio_iommu) {
> > +            error_setg(errp,
> > +                       "QEMU does not support multiple vIOMMUs for x86 yet.");
> > +            return;
> > +        }
> >          pcms->virtio_iommu = true;
> >          pcms->virtio_iommu_bdf = pci_get_bdf(pdev);
> >      }
> > @@ -1436,7 +1454,8 @@ static HotplugHandler *pc_get_hotplug_handler(MachineState *machine,
> >      if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM) ||
> >          object_dynamic_cast(OBJECT(dev), TYPE_CPU) ||
> >          object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI) ||
> > -        object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI)) {
> > +        object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI) ||
> > +        object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_IOMMU_PCI)) {
> >          return HOTPLUG_HANDLER(machine);
> >      }
> >  
> Thanks
> 
> Eric
>
Re: [PATCH v2 7/8] pc: Allow instantiating a virtio-iommu device
Posted by Eric Auger 4 years, 5 months ago 
Hi jean,

On 9/8/21 11:54 AM, Jean-Philippe Brucker wrote:
> On Mon, Sep 06, 2021 at 04:57:39PM +0200, Eric Auger wrote:
>> Hi Jean,
>>
>> On 9/3/21 4:32 PM, Jean-Philippe Brucker wrote:
>>> From: Eric Auger <eric.auger@redhat.com>
>>>
>>> Add a hotplug handler for virtio-iommu on x86 and set the necessary
>>> reserved region property. On x86, the [0xfee00000, 0xfeefffff] DMA
>>> region is reserved for MSIs. DMA transactions to this range either
>>> trigger IRQ remapping in the IOMMU or bypasses IOMMU translation.
>> s/bypasses/bypass.
>>> Although virtio-iommu does not support IRQ remapping it must be informed
>>> of the reserved region so that it can forward DMA transactions targeting
>>> this region.
>>> Signed-off-by: Eric Auger <eric.auger@redhat.com>
>> Feel free to remove my SoB. I have done much here.
>>> Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
>>> ---
>>>  hw/i386/pc.c | 21 ++++++++++++++++++++-
>>>  1 file changed, 20 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
>>> index 694fc9ce07..c1e1cffe16 100644
>>> --- a/hw/i386/pc.c
>>> +++ b/hw/i386/pc.c
>>> @@ -797,6 +797,11 @@ void pc_machine_done(Notifier *notifier, void *data)
>>>                       "irqchip support.");
>>>          exit(EXIT_FAILURE);
>>>      }
>>> +
>>> +    if (pcms->virtio_iommu && x86_iommu_get_default()) {
>>> +        error_report("QEMU does not support multiple vIOMMUs for x86 yet.");
>>> +        exit(EXIT_FAILURE);
>>> +    }
>>>  }
>> I think you shall detect the case of dual instantiation of intel_iommu
>> and virtio-iommu.
> Those are handled by x86_iommu_set_default() and
Oh I did not notice the x86_iommu_get_default() stuff.

sorry for the noise

Eric


> pc_machine_device_plug_cb() (below) respectively. I considered factoring
> it but I think it just adds complexity.
>
> Thanks,
> Jean
>
>> Maybe pc_hotplug_allowed() can be used for that. Note
>> that both devices can be refered to in either order.
>>>  
>>>  void pc_guest_info_init(PCMachineState *pcms)
>>> @@ -1376,6 +1381,14 @@ static void pc_machine_device_pre_plug_cb(HotplugHandler *hotplug_dev,
>>>      } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI) ||
>>>                 object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI)) {
>>>          pc_virtio_md_pci_pre_plug(hotplug_dev, dev, errp);
>>> +    } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_IOMMU_PCI)) {
>>> +        /* Declare the reserved MSI region */
>>> +        char *resv_prop_str = g_strdup_printf("0xfee00000:0xfeefffff:%d",
>>> +                                              VIRTIO_IOMMU_RESV_MEM_T_MSI);
>>> +
>>> +        qdev_prop_set_uint32(dev, "len-reserved-regions", 1);
>>> +        qdev_prop_set_string(dev, "reserved-regions[0]", resv_prop_str);
>>> +        g_free(resv_prop_str);
>>>      }
>>>  }
>>>  
>>> @@ -1393,6 +1406,11 @@ static void pc_machine_device_plug_cb(HotplugHandler *hotplug_dev,
>>>          PCMachineState *pcms = PC_MACHINE(hotplug_dev);
>>>          PCIDevice *pdev = PCI_DEVICE(dev);
>>>  
>>> +        if (pcms->virtio_iommu) {
>>> +            error_setg(errp,
>>> +                       "QEMU does not support multiple vIOMMUs for x86 yet.");
>>> +            return;
>>> +        }
>>>          pcms->virtio_iommu = true;
>>>          pcms->virtio_iommu_bdf = pci_get_bdf(pdev);
>>>      }
>>> @@ -1436,7 +1454,8 @@ static HotplugHandler *pc_get_hotplug_handler(MachineState *machine,
>>>      if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM) ||
>>>          object_dynamic_cast(OBJECT(dev), TYPE_CPU) ||
>>>          object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI) ||
>>> -        object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI)) {
>>> +        object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI) ||
>>> +        object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_IOMMU_PCI)) {
>>>          return HOTPLUG_HANDLER(machine);
>>>      }
>>>  
>> Thanks
>>
>> Eric
>>

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