Hi Diana,
On 22/12/2016 13:41, Diana Madalina Craciun wrote:
> Hi Eric,
>
> On 12/13/2016 10:32 PM, Eric Auger wrote:
>> In case the IOMMU does not bypass MSI transactions (typical
>> case on ARM), we check all MSI controllers are IRQ remapping
>> capable. If not the IRQ assignment may be unsafe.
>>
>> At this stage the arm-smmu-(v3) still advertise the
>> IOMMU_CAP_INTR_REMAP capability at IOMMU level. This will be
>> removed in subsequent patches.
>>
>> Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>
>> ---
>> drivers/vfio/vfio_iommu_type1.c | 9 ++++++---
>> 1 file changed, 6 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
>> index d07fe73..a05648b 100644
>> --- a/drivers/vfio/vfio_iommu_type1.c
>> +++ b/drivers/vfio/vfio_iommu_type1.c
>> @@ -37,6 +37,7 @@
>> #include <linux/vfio.h>
>> #include <linux/workqueue.h>
>> #include <linux/dma-iommu.h>
>> +#include <linux/irqdomain.h>
>>
>> #define DRIVER_VERSION "0.2"
>> #define DRIVER_AUTHOR "Alex Williamson <alex.williamson@xxxxxxxxxx>"
>> @@ -765,7 +766,7 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
>> struct vfio_domain *domain, *d;
>> struct bus_type *bus = NULL;
>> int ret;
>> - bool resv_msi;
>> + bool resv_msi, msi_remap;
>> phys_addr_t resv_msi_base;
>>
>> mutex_lock(&iommu->lock);
>> @@ -818,8 +819,10 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
>> INIT_LIST_HEAD(&domain->group_list);
>> list_add(&group->next, &domain->group_list);
>>
>> - if (!allow_unsafe_interrupts &&
>> - !iommu_capable(bus, IOMMU_CAP_INTR_REMAP)) {
>> + msi_remap = resv_msi ? irq_domain_check_msi_remap() :
>> + iommu_capable(bus, IOMMU_CAP_INTR_REMAP);
>> +
>> + if (!allow_unsafe_interrupts && !msi_remap) {
>> pr_warn("%s: No interrupt remapping support. Use the module param \"allow_unsafe_interrupts\" to enable VFIO IOMMU support on this platform\n",
>> __func__);
>> ret = -EPERM;
>
> I tested your v4.9-reserved-v4 branch on a ITS capable hardware (NXP
> LS2080), so I did not set allow_unsafe_interrupts. It fails here
> complaining that the there is no interrupt remapping support. The
> irq_domain_check_msi_remap function returns false as none of the checked
> domains has the IRQ_DOMAIN_FLAG_MSI_REMAP flag set. I think the reason
> is that the flags are not propagated through the domain hierarchy when
> the domain is created.
Hum OK. Please apologize for the inconvenience, all the more so this is
the second time you report the same issue for different cause :-( At the
moment I can't test on a GICv3 ITS based system. I will try to fix that
though.
I would like to get the confirmation introducing this flag is the right
direction though.
Thanks
Eric
>
> Thanks,
>
> Diana
>
>
>
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