* [Qemu-devel] [PATCH] virtio: unbreak virtio-pci with IOMMU after caching ring translations
@ 2017-03-01 4:10 Jason Wang
2017-03-02 5:10 ` Michael S. Tsirkin
0 siblings, 1 reply; 5+ messages in thread
From: Jason Wang @ 2017-03-01 4:10 UTC (permalink / raw)
To: mst, qemu-devel; +Cc: peterx, wexu, Jason Wang, Paolo Bonzini
Commit c611c76417f5 ("virtio: add MemoryListener to cache ring
translations") registers a memory listener to dma_as. This may not
work when IOMMU is enabled: dma_as(bus_master_as) were initialized in
pcibus_machine_done() after virtio_realize(). This will cause a
segfault. Fixing this by using pci_device_iommu_address_space()
instead to make sure address space were initialized at this time.
With this fix, IOMMU device were required to be initialized before any
virtio-pci devices.
Fixes: c611c76417f5 ("virtio: add MemoryListener to cache ring translations")
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
hw/virtio/virtio-pci.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index 5ce42af..b76f3f6 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -1153,7 +1153,7 @@ static AddressSpace *virtio_pci_get_dma_as(DeviceState *d)
VirtIOPCIProxy *proxy = VIRTIO_PCI(d);
PCIDevice *dev = &proxy->pci_dev;
- return pci_get_address_space(dev);
+ return pci_device_iommu_address_space(dev);
}
static int virtio_pci_add_mem_cap(VirtIOPCIProxy *proxy,
--
2.7.4
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [PATCH] virtio: unbreak virtio-pci with IOMMU after caching ring translations
2017-03-01 4:10 [Qemu-devel] [PATCH] virtio: unbreak virtio-pci with IOMMU after caching ring translations Jason Wang
@ 2017-03-02 5:10 ` Michael S. Tsirkin
2017-03-02 7:47 ` Jason Wang
0 siblings, 1 reply; 5+ messages in thread
From: Michael S. Tsirkin @ 2017-03-02 5:10 UTC (permalink / raw)
To: Jason Wang; +Cc: qemu-devel, peterx, wexu, Paolo Bonzini
On Wed, Mar 01, 2017 at 12:10:40PM +0800, Jason Wang wrote:
> Commit c611c76417f5 ("virtio: add MemoryListener to cache ring
> translations") registers a memory listener to dma_as. This may not
> work when IOMMU is enabled: dma_as(bus_master_as) were initialized in
> pcibus_machine_done() after virtio_realize(). This will cause a
> segfault. Fixing this by using pci_device_iommu_address_space()
> instead to make sure address space were initialized at this time.
>
> With this fix, IOMMU device were required to be initialized before any
> virtio-pci devices.
>
> Fixes: c611c76417f5 ("virtio: add MemoryListener to cache ring translations")
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Signed-off-by: Jason Wang <jasowang@redhat.com>
This is very ugly. I guess it's better than broken IOMMU ...
Paolo?
> ---
> hw/virtio/virtio-pci.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> index 5ce42af..b76f3f6 100644
> --- a/hw/virtio/virtio-pci.c
> +++ b/hw/virtio/virtio-pci.c
> @@ -1153,7 +1153,7 @@ static AddressSpace *virtio_pci_get_dma_as(DeviceState *d)
> VirtIOPCIProxy *proxy = VIRTIO_PCI(d);
> PCIDevice *dev = &proxy->pci_dev;
>
> - return pci_get_address_space(dev);
> + return pci_device_iommu_address_space(dev);
> }
>
> static int virtio_pci_add_mem_cap(VirtIOPCIProxy *proxy,
> --
> 2.7.4
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [PATCH] virtio: unbreak virtio-pci with IOMMU after caching ring translations
2017-03-02 5:10 ` Michael S. Tsirkin
@ 2017-03-02 7:47 ` Jason Wang
2017-03-02 10:30 ` Paolo Bonzini
0 siblings, 1 reply; 5+ messages in thread
From: Jason Wang @ 2017-03-02 7:47 UTC (permalink / raw)
To: Michael S. Tsirkin; +Cc: qemu-devel, peterx, wexu, Paolo Bonzini
On 2017年03月02日 13:10, Michael S. Tsirkin wrote:
> On Wed, Mar 01, 2017 at 12:10:40PM +0800, Jason Wang wrote:
>> Commit c611c76417f5 ("virtio: add MemoryListener to cache ring
>> translations") registers a memory listener to dma_as. This may not
>> work when IOMMU is enabled: dma_as(bus_master_as) were initialized in
>> pcibus_machine_done() after virtio_realize(). This will cause a
>> segfault. Fixing this by using pci_device_iommu_address_space()
>> instead to make sure address space were initialized at this time.
>>
>> With this fix, IOMMU device were required to be initialized before any
>> virtio-pci devices.
>>
>> Fixes: c611c76417f5 ("virtio: add MemoryListener to cache ring translations")
>> Cc: Paolo Bonzini <pbonzini@redhat.com>
>> Signed-off-by: Jason Wang <jasowang@redhat.com>
> This is very ugly. I guess it's better than broken IOMMU ...
> Paolo?
Maybe we can delay the registering of memory listener on bus master
enabling or status setting.
Thanks
>
>> ---
>> hw/virtio/virtio-pci.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
>> index 5ce42af..b76f3f6 100644
>> --- a/hw/virtio/virtio-pci.c
>> +++ b/hw/virtio/virtio-pci.c
>> @@ -1153,7 +1153,7 @@ static AddressSpace *virtio_pci_get_dma_as(DeviceState *d)
>> VirtIOPCIProxy *proxy = VIRTIO_PCI(d);
>> PCIDevice *dev = &proxy->pci_dev;
>>
>> - return pci_get_address_space(dev);
>> + return pci_device_iommu_address_space(dev);
>> }
>>
>> static int virtio_pci_add_mem_cap(VirtIOPCIProxy *proxy,
>> --
>> 2.7.4
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [PATCH] virtio: unbreak virtio-pci with IOMMU after caching ring translations
2017-03-02 7:47 ` Jason Wang
@ 2017-03-02 10:30 ` Paolo Bonzini
2017-03-03 9:11 ` Jason Wang
0 siblings, 1 reply; 5+ messages in thread
From: Paolo Bonzini @ 2017-03-02 10:30 UTC (permalink / raw)
To: Jason Wang, Michael S. Tsirkin; +Cc: qemu-devel, peterx, wexu
On 02/03/2017 08:47, Jason Wang wrote:
>>>
>>> Fixes: c611c76417f5 ("virtio: add MemoryListener to cache ring
>>> translations")
>>> Cc: Paolo Bonzini <pbonzini@redhat.com>
>>> Signed-off-by: Jason Wang <jasowang@redhat.com>
>> This is very ugly. I guess it's better than broken IOMMU ...
>> Paolo?
>
> Maybe we can delay the registering of memory listener on bus master
> enabling or status setting.
Can we add a callback to PCIDeviceClass, and invoke it from
pci_init_bus_master?
Paolo
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [PATCH] virtio: unbreak virtio-pci with IOMMU after caching ring translations
2017-03-02 10:30 ` Paolo Bonzini
@ 2017-03-03 9:11 ` Jason Wang
0 siblings, 0 replies; 5+ messages in thread
From: Jason Wang @ 2017-03-03 9:11 UTC (permalink / raw)
To: Paolo Bonzini, Michael S. Tsirkin; +Cc: qemu-devel, peterx, wexu
On 2017年03月02日 18:30, Paolo Bonzini wrote:
>
> On 02/03/2017 08:47, Jason Wang wrote:
>>>> Fixes: c611c76417f5 ("virtio: add MemoryListener to cache ring
>>>> translations")
>>>> Cc: Paolo Bonzini <pbonzini@redhat.com>
>>>> Signed-off-by: Jason Wang <jasowang@redhat.com>
>>> This is very ugly. I guess it's better than broken IOMMU ...
>>> Paolo?
>> Maybe we can delay the registering of memory listener on bus master
>> enabling or status setting.
> Can we add a callback to PCIDeviceClass, and invoke it from
> pci_init_bus_master?
>
> Paolo
>
This looks pci specific, I post a fix that reset the dma_as during
status set which can solve this issue too. Please have a look.
Thanks
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2017-03-03 9:11 UTC | newest]
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2017-03-01 4:10 [Qemu-devel] [PATCH] virtio: unbreak virtio-pci with IOMMU after caching ring translations Jason Wang
2017-03-02 5:10 ` Michael S. Tsirkin
2017-03-02 7:47 ` Jason Wang
2017-03-02 10:30 ` Paolo Bonzini
2017-03-03 9:11 ` Jason Wang
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