Message ID | 1470159012-7110-7-git-send-email-eric.auger@redhat.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Hi Eric, [auto build test ERROR on vfio/next] [also build test ERROR on v4.7] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system] url: https://github.com/0day-ci/linux/commits/Eric-Auger/KVM-PCIe-MSI-passthrough-on-ARM-ARM64-kernel-part-3-3-vfio-changes/20160803-122924 base: https://github.com/awilliam/linux-vfio.git next config: x86_64-randconfig-s1-08031247 (attached as .config) compiler: gcc-4.4 (Debian 4.4.7-8) 4.4.7 reproduce: # save the attached .config to linux build tree make ARCH=x86_64 All errors (new ones prefixed by >>): drivers/vfio/vfio_iommu_type1.c:39:29: error: linux/msi-iommu.h: No such file or directory >> drivers/vfio/vfio_iommu_type1.c:40:32: error: linux/msi-doorbell.h: No such file or directory drivers/vfio/vfio_iommu_type1.c: In function 'vfio_set_msi_aperture': drivers/vfio/vfio_iommu_type1.c:453: error: implicit declaration of function 'iommu_msi_set_aperture' drivers/vfio/vfio_iommu_type1.c: In function 'vfio_iommu_type1_attach_group': >> drivers/vfio/vfio_iommu_type1.c:933: error: implicit declaration of function 'msi_doorbell_safe' At top level: cc1: warning: unrecognized command line option "-Wno-maybe-uninitialized" vim +40 drivers/vfio/vfio_iommu_type1.c 33 #include <linux/rbtree.h> 34 #include <linux/sched.h> 35 #include <linux/slab.h> 36 #include <linux/uaccess.h> 37 #include <linux/vfio.h> 38 #include <linux/workqueue.h> > 39 #include <linux/msi-iommu.h> > 40 #include <linux/msi-doorbell.h> 41 42 #define DRIVER_VERSION "0.2" 43 #define DRIVER_AUTHOR "Alex Williamson <alex.williamson@redhat.com>" --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index 14dc9ef..7daab53 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/msi-iommu.h> +#include <linux/msi-doorbell.h> #define DRIVER_VERSION "0.2" #define DRIVER_AUTHOR "Alex Williamson <alex.williamson@redhat.com>" @@ -922,8 +923,14 @@ static int vfio_iommu_type1_attach_group(void *iommu_data, INIT_LIST_HEAD(&domain->group_list); list_add(&group->next, &domain->group_list); + /* + * to advertise safe interrupts either the IOMMU or the MSI controllers + * must support IRQ remapping (aka. interrupt translation), property + * exposed by their registered doorbells + */ if (!allow_unsafe_interrupts && - !iommu_capable(bus, IOMMU_CAP_INTR_REMAP)) { + (!iommu_capable(bus, IOMMU_CAP_INTR_REMAP) && + !msi_doorbell_safe())) { 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;
On x86 IRQ remapping is abstracted by the IOMMU. On ARM this is abstracted by the msi controller. Since we currently have no way to detect whether the MSI controller is upstream or downstream to the IOMMU we rely on the MSI doorbell information registered by the interrupt controllers. In case at least one doorbell does not implement proper isolation, we state the assignment is unsafe with regard to interrupts. This is a coase assessment but should allow to wait for a better system description. At this point ARM sMMU still advertises IOMMU_CAP_INTR_REMAP. This is removed in next patch. Signed-off-by: Eric Auger <eric.auger@redhat.com> --- v9 -> v10: - coarse safety assessment based on MSI doorbell info v3 -> v4: - rename vfio_msi_parent_irq_remapping_capable into vfio_safe_irq_domain and irq_remapping into safe_irq_domains v2 -> v3: - protect vfio_msi_parent_irq_remapping_capable with CONFIG_GENERIC_MSI_IRQ_DOMAIN --- drivers/vfio/vfio_iommu_type1.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)