[PATCH 1/2] vfio/type1: Cope with hardware MSI reserved regions
From: Alex Williamson <hidden>
Date: 2017-08-10 19:16:23
Also in:
kvm, lkml
On Thu, 27 Jul 2017 15:54:13 +0100 Robin Murphy [off-list ref] wrote:
For ARM-based systems with a GICv3 ITS to provide interrupt isolation, but hardware limitations which are worked around by having MSIs bypass SMMU translation (e.g. HiSilicon Hip06/Hip07), VFIO neglects to check for the IRQ_DOMAIN_FLAG_MSI_REMAP capability, (and thus erroneously demands unsafe_interrupts) if a software-managed MSI region is absent. Fix this by always checking for isolation capability at both the IRQ domain and IOMMU domain levels, rather than predicating that on whether MSIs require an IOMMU mapping (which was always slightly tenuous logic). Signed-off-by: Robin Murphy <robin.murphy@arm.com> --- drivers/vfio/vfio_iommu_type1.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
I've pushed these to my next branch with Eric's R-b and Shameerali's T-b for v4.14. Thanks, Alex
quoted hunk ↗ jump to hunk
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index 8549cb111627..2328be628f21 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c@@ -1265,8 +1265,8 @@ static int vfio_iommu_type1_attach_group(void *iommu_data, INIT_LIST_HEAD(&domain->group_list); list_add(&group->next, &domain->group_list); - msi_remap = resv_msi ? irq_domain_check_msi_remap() : - iommu_capable(bus, IOMMU_CAP_INTR_REMAP); + msi_remap = 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",