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spapr/iommu: Enable in-kernel TCE acceleration via VFIO KVM device

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In order to enable TCE operations support in KVM, we have to inform
the KVM about VFIO groups being attached to specific LIOBNs;
the necessary bits are implemented already by IOMMU MR and VFIO.

This defines get_attr() for the SPAPR TCE IOMMU MR which makes VFIO
call the KVM_DEV_VFIO_GROUP_SET_SPAPR_TCE ioctl and establish
LIOBN-to-IOMMU link.

This changes spapr_tce_set_need_vfio() to avoid TCE table reallocation
if the kernel supports the TCE acceleration.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
[aw - remove unnecessary sys/ioctl.h include]
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This commit is contained in:
Alexey Kardashevskiy 2018-02-06 11:08:24 -07:00 • committed by Alex Williamson
parent 07bc681a33
commit 9ded780c4c
3 changed files with 30 additions and 1 deletions
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18
hw/ppc/spapr_iommu.c
View file

@ -160,6 +160,19 @@ static uint64_t spapr_tce_get_min_page_size(IOMMUMemoryRegion *iommu)
return 1ULL << tcet->page_shift;
}
static int spapr_tce_get_attr(IOMMUMemoryRegion *iommu,
enum IOMMUMemoryRegionAttr attr, void *data)
{
sPAPRTCETable *tcet = container_of(iommu, sPAPRTCETable, iommu);
if (attr == IOMMU_ATTR_SPAPR_TCE_FD && kvmppc_has_cap_spapr_vfio()) {
*(int *) data = tcet->fd;
return 0;
}
return -EINVAL;
}
static void spapr_tce_notify_flag_changed(IOMMUMemoryRegion *iommu,
IOMMUNotifierFlag old,
IOMMUNotifierFlag new)
@ -284,6 +297,10 @@ void spapr_tce_set_need_vfio(sPAPRTCETable *tcet, bool need_vfio)
tcet->need_vfio = need_vfio;
if (!need_vfio || (tcet->fd != -1 && kvmppc_has_cap_spapr_vfio())) {
return;
}
oldtable = tcet->table;
tcet->table = spapr_tce_alloc_table(tcet->liobn,
@ -643,6 +660,7 @@ static void spapr_iommu_memory_region_class_init(ObjectClass *klass, void *data)
imrc->translate = spapr_tce_translate_iommu;
imrc->get_min_page_size = spapr_tce_get_min_page_size;
imrc->notify_flag_changed = spapr_tce_notify_flag_changed;
imrc->get_attr = spapr_tce_get_attr;
}
static const TypeInfo spapr_iommu_memory_region_info = {