[PATCH v1 3/8] vfio/type1: Report PASID alloc/free support to userspace

Liu, Yi L
2020-03-22T12:27:04Z

From: Liu Yi L <yi.l.liu@intel.com>

This patch reports PASID alloc/free availability to userspace (e.g. QEMU)
thus userspace could do a pre-check before utilizing this feature.

Cc: Kevin Tian <kevin.tian@intel.com>
CC: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Eric Auger <eric.auger@redhat.com>
Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
---
drivers/vfio/vfio_iommu_type1.c | 28 ++++++++++++++++++++++++++++
include/uapi/linux/vfio.h | 8 ++++++++
2 files changed, 36 insertions(+)

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index e40afc0..ddd1ffe 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -2234,6 +2234,30 @@ static int vfio_iommu_type1_pasid_free(struct vfio_iommu *iommu,
return ret;
}

+static int vfio_iommu_info_add_nesting_cap(struct vfio_iommu *iommu,
+ struct vfio_info_cap *caps)
+{
+ struct vfio_info_cap_header *header;
+ struct vfio_iommu_type1_info_cap_nesting *nesting_cap;
+
+ header = vfio_info_cap_add(caps, sizeof(*nesting_cap),
+ VFIO_IOMMU_TYPE1_INFO_CAP_NESTING, 1);
+ if (IS_ERR(header))
+ return PTR_ERR(header);
+
+ nesting_cap = container_of(header,
+ struct vfio_iommu_type1_info_cap_nesting,
+ header);
+
+ nesting_cap->nesting_capabilities = 0;
+ if (iommu->nesting) {
+ /* nesting iommu type supports PASID requests (alloc/free) */
+ nesting_cap->nesting_capabilities |= VFIO_IOMMU_PASID_REQS;
+ }
+
+ return 0;
+}
+
static long vfio_iommu_type1_ioctl(void *iommu_data,
unsigned int cmd, unsigned long arg)
{
@@ -2283,6 +2307,10 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
if (ret)
return ret;

+ ret = vfio_iommu_info_add_nesting_cap(iommu, &caps);
+ if (ret)
+ return ret;
+
if (caps.size) {
info.flags |= VFIO_IOMMU_INFO_CAPS;

diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 298ac80..8837219 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -748,6 +748,14 @@ struct vfio_iommu_type1_info_cap_iova_range {
struct vfio_iova_range iova_ranges[];
};

+#define VFIO_IOMMU_TYPE1_INFO_CAP_NESTING 2
+
+struct vfio_iommu_type1_info_cap_nesting {
+ struct vfio_info_cap_header header;
+#define VFIO_IOMMU_PASID_REQS (1 << 0)
+ __u32 nesting_capabilities;
+};
+
#define VFIO_IOMMU_GET_INFO _IO(VFIO_TYPE, VFIO_BASE + 12)

/**
--
2.7.4