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.
Thanks,
Diana
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