[PATCH v7 09/23] vfio: VFIO_IOMMU_BIND/UNBIND_MSI

Eric Auger
2019-04-08T12:18:57Z

This patch adds the VFIO_IOMMU_BIND/UNBIND_MSI ioctl which aim
to pass/withdraw the guest MSI binding to/from the host.

Signed-off-by: Eric Auger <eric.auger-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>

---
v6 -> v7:
- removed the dev arg

v3 -> v4:
- add UNBIND
- unwind on BIND error

v2 -> v3:
- adapt to new proto of bind_guest_msi
- directly use vfio_iommu_for_each_dev

v1 -> v2:
- s/vfio_iommu_type1_guest_msi_binding/vfio_iommu_type1_bind_guest_msi
---
drivers/vfio/vfio_iommu_type1.c | 64 +++++++++++++++++++++++++++++++++
include/uapi/linux/vfio.h | 29 +++++++++++++++
2 files changed, 93 insertions(+)

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 4a6b5a360a5e..6df72840fbd9 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -1718,6 +1718,42 @@ static int vfio_cache_inv_fn(struct device *dev, void *data)
return iommu_cache_invalidate(dc->domain, dev, &ustruct->info);
}

+static int
+vfio_bind_msi(struct vfio_iommu *iommu,
+ dma_addr_t giova, phys_addr_t gpa, size_t size)
+{
+ struct vfio_domain *d;
+ int ret = 0;
+
+ mutex_lock(&iommu->lock);
+
+ list_for_each_entry(d, &iommu->domain_list, next) {
+ ret = iommu_bind_guest_msi(d->domain, giova, gpa, size);
+ if (ret)
+ goto unwind;
+ }
+ goto unlock;
+unwind:
+ list_for_each_entry_continue_reverse(d, &iommu->domain_list, next) {
+ iommu_unbind_guest_msi(d->domain, giova);
+ }
+unlock:
+ mutex_unlock(&iommu->lock);
+ return ret;
+}
+
+static void
+vfio_unbind_msi(struct vfio_iommu *iommu, dma_addr_t giova)
+{
+ struct vfio_domain *d;
+
+ mutex_lock(&iommu->lock);
+ list_for_each_entry(d, &iommu->domain_list, next) {
+ iommu_unbind_guest_msi(d->domain, giova);
+ }
+ mutex_unlock(&iommu->lock);
+}
+
static long vfio_iommu_type1_ioctl(void *iommu_data,
unsigned int cmd, unsigned long arg)
{
@@ -1822,6 +1858,34 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
&ustruct);
mutex_unlock(&iommu->lock);
return ret;
+ } else if (cmd == VFIO_IOMMU_BIND_MSI) {
+ struct vfio_iommu_type1_bind_msi ustruct;
+
+ minsz = offsetofend(struct vfio_iommu_type1_bind_msi,
+ size);
+
+ if (copy_from_user(&ustruct, (void __user *)arg, minsz))
+ return -EFAULT;
+
+ if (ustruct.argsz < minsz || ustruct.flags)
+ return -EINVAL;
+
+ return vfio_bind_msi(iommu, ustruct.iova, ustruct.gpa,
+ ustruct.size);
+ } else if (cmd == VFIO_IOMMU_UNBIND_MSI) {
+ struct vfio_iommu_type1_unbind_msi ustruct;
+
+ minsz = offsetofend(struct vfio_iommu_type1_unbind_msi,
+ iova);
+
+ if (copy_from_user(&ustruct, (void __user *)arg, minsz))
+ return -EFAULT;
+
+ if (ustruct.argsz < minsz || ustruct.flags)
+ return -EINVAL;
+
+ vfio_unbind_msi(iommu, ustruct.iova);
+ return 0;
}

return -ENOTTY;
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index b5325552bae0..69775adda155 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -794,6 +794,35 @@ struct vfio_iommu_type1_cache_invalidate {
};
#define VFIO_IOMMU_CACHE_INVALIDATE _IO(VFIO_TYPE, VFIO_BASE + 24)

+/**
+ * VFIO_IOMMU_BIND_MSI - _IOWR(VFIO_TYPE, VFIO_BASE + 25,
+ * struct vfio_iommu_type1_bind_msi)
+ *
+ * Pass a stage 1 MSI doorbell mapping to the host so that this
+ * latter can build a nested stage2 mapping
+ */
+struct vfio_iommu_type1_bind_msi {
+ __u32 argsz;
+ __u32 flags;
+ __u64 iova;
+ __u64 gpa;
+ __u64 size;
+};
+#define VFIO_IOMMU_BIND_MSI _IO(VFIO_TYPE, VFIO_BASE + 25)
+
+/**
+ * VFIO_IOMMU_UNBIND_MSI - _IOWR(VFIO_TYPE, VFIO_BASE + 26,
+ * struct vfio_iommu_type1_unbind_msi)
+ *
+ * Unregister an MSI mapping
+ */
+struct vfio_iommu_type1_unbind_msi {
+ __u32 argsz;
+ __u32 flags;
+ __u64 iova;
+};
+#define VFIO_IOMMU_UNBIND_MSI _IO(VFIO_TYPE, VFIO_BASE + 26)
+
/* -------- Additional API for SPAPR TCE (Server POWERPC) IOMMU -------- */

/*
--
2.20.1