This patch allows user space to request PASID allocation/free, e.g. when
serving the request from the guest.
PASIDs that are not freed by userspace are automatically freed when the
IOASID set is destroyed when process exits.
Cc: Kevin Tian <kevin.t...@intel.com>
CC: Jacob Pan <jacob.jun....@linux.intel.com>
Cc: Alex Williamson <alex.william...@redhat.com>
Cc: Eric Auger <eric.au...@redhat.com>
Cc: Jean-Philippe Brucker <jean-phili...@linaro.org>
Cc: Joerg Roedel <j...@8bytes.org>
Cc: Lu Baolu <baolu...@linux.intel.com>
Signed-off-by: Liu Yi L <yi.l....@intel.com>
Signed-off-by: Yi Sun <yi.y....@linux.intel.com>
Signed-off-by: Jacob Pan <jacob.jun....@linux.intel.com>
---
v1 -> v2:
*) move the vfio_mm related code to be a seprate module
*) use a single structure for alloc/free, could support a range of PASIDs
*) fetch vfio_mm at group_attach time instead of at iommu driver open time
---
drivers/vfio/Kconfig | 1 +
drivers/vfio/vfio_iommu_type1.c | 96 ++++++++++++++++++++++++++++++++++++++++-
drivers/vfio/vfio_pasid.c | 10 +++++
include/linux/vfio.h | 6 +++
include/uapi/linux/vfio.h | 36 ++++++++++++++++
5 files changed, 147 insertions(+), 2 deletions(-)
diff --git a/drivers/vfio/Kconfig b/drivers/vfio/Kconfig
index 3d8a108..95d90c6 100644
--- a/drivers/vfio/Kconfig
+++ b/drivers/vfio/Kconfig
@@ -2,6 +2,7 @@
config VFIO_IOMMU_TYPE1
tristate
depends on VFIO
+ select VFIO_PASID if (X86)
default n
config VFIO_IOMMU_SPAPR_TCE
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 8c143d5..d0891c5 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -73,6 +73,7 @@ struct vfio_iommu {
bool v2;
bool nesting;
struct iommu_nesting_info *nesting_info;
+ struct vfio_mm *vmm;
bool dirty_page_tracking;
bool pinned_page_dirty_scope;
};
@@ -1933,6 +1934,17 @@ static void vfio_iommu_iova_insert_copy(struct
vfio_iommu *iommu,
list_splice_tail(iova_copy, iova);
}
+
+static void vfio_iommu_release_nesting_info(struct vfio_iommu *iommu)
+{
+ if (iommu->vmm) {
+ vfio_mm_put(iommu->vmm);
+ iommu->vmm = NULL;
+ }
+
+ kfree(iommu->nesting_info);
+}
+
static int vfio_iommu_type1_attach_group(void *iommu_data,
struct iommu_group *iommu_group)
{
@@ -2067,6 +2079,25 @@ static int vfio_iommu_type1_attach_group(void
*iommu_data,
goto out_detach;
}
iommu->nesting_info = info;
+
+ if (info->features & IOMMU_NESTING_FEAT_SYSWIDE_PASID) {
+ struct vfio_mm *vmm;
+ int sid;
+
+ vmm = vfio_mm_get_from_task(current);
+ if (IS_ERR(vmm)) {
+ ret = PTR_ERR(vmm);
+ goto out_detach;
+ }
+ iommu->vmm = vmm;
+
+ sid = vfio_mm_ioasid_sid(vmm);
+ ret = iommu_domain_set_attr(domain->domain,
+ DOMAIN_ATTR_IOASID_SID,
+ &sid);
+ if (ret)
+ goto out_detach;
+ }
}
/* Get aperture info */
@@ -2178,7 +2209,8 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
return 0;
out_detach:
- kfree(iommu->nesting_info);
+ if (iommu->nesting_info)
+ vfio_iommu_release_nesting_info(iommu);
vfio_iommu_detach_group(domain, group);
out_domain:
iommu_domain_free(domain->domain);
@@ -2380,7 +2412,8 @@ static void vfio_iommu_type1_detach_group(void
*iommu_data,
else
vfio_iommu_unmap_unpin_reaccount(iommu);
- kfree(iommu->nesting_info);
+ if (iommu->nesting_info)
+ vfio_iommu_release_nesting_info(iommu);
}
iommu_domain_free(domain->domain);
list_del(&domain->next);
@@ -2852,6 +2885,63 @@ static int vfio_iommu_type1_dirty_pages(struct
vfio_iommu *iommu,
return -EINVAL;
}
+static int vfio_iommu_type1_pasid_alloc(struct vfio_iommu *iommu,
+ unsigned int min,
+ unsigned int max)
+{
+ int ret = -ENOTSUPP;
+
+ mutex_lock(&iommu->lock);
+ if (iommu->vmm)
+ ret = vfio_pasid_alloc(iommu->vmm, min, max);
+ mutex_unlock(&iommu->lock);
+ return ret;
+}
+
+static int vfio_iommu_type1_pasid_free(struct vfio_iommu *iommu,
+ unsigned int min,
+ unsigned int max)
+{
+ int ret = -ENOTSUPP;
+
+ mutex_lock(&iommu->lock);
+ if (iommu->vmm) {
+ vfio_pasid_free_range(iommu->vmm, min, max);
+ ret = 0;
+ }
+ mutex_unlock(&iommu->lock);
+ return ret;
+}
+
+static int vfio_iommu_type1_pasid_request(struct vfio_iommu *iommu,
+ unsigned long arg)
+{
+ struct vfio_iommu_type1_pasid_request req;
+ unsigned long minsz;
+
+ minsz = offsetofend(struct vfio_iommu_type1_pasid_request, range);
+
+ if (copy_from_user(&req, (void __user *)arg, minsz))
+ return -EFAULT;
+
+ if (req.argsz < minsz || (req.flags & ~VFIO_PASID_REQUEST_MASK))
+ return -EINVAL;
+
+ if (req.range.min > req.range.max)
+ return -EINVAL;
+
+ switch (req.flags & VFIO_PASID_REQUEST_MASK) {
+ case VFIO_IOMMU_ALLOC_PASID:
+ return vfio_iommu_type1_pasid_alloc(iommu,
+ req.range.min, req.range.max);
+ case VFIO_IOMMU_FREE_PASID:
+ return vfio_iommu_type1_pasid_free(iommu,
+ req.range.min, req.range.max);
+ default:
+ return -EINVAL;
+ }
+}
+
static long vfio_iommu_type1_ioctl(void *iommu_data,
unsigned int cmd, unsigned long arg)
{
@@ -2868,6 +2958,8 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
return vfio_iommu_type1_unmap_dma(iommu, arg);
case VFIO_IOMMU_DIRTY_PAGES:
return vfio_iommu_type1_dirty_pages(iommu, arg);
+ case VFIO_IOMMU_PASID_REQUEST:
+ return vfio_iommu_type1_pasid_request(iommu, arg);
}
return -ENOTTY;
diff --git a/drivers/vfio/vfio_pasid.c b/drivers/vfio/vfio_pasid.c
index dd5b6d1..2ea9f1a 100644
--- a/drivers/vfio/vfio_pasid.c
+++ b/drivers/vfio/vfio_pasid.c
@@ -54,6 +54,7 @@ void vfio_mm_put(struct vfio_mm *vmm)
{
kref_put_mutex(&vmm->kref, vfio_mm_release, &vfio_pasid.vfio_mm_lock);
}
+EXPORT_SYMBOL_GPL(vfio_mm_put);
static void vfio_mm_get(struct vfio_mm *vmm)
{
@@ -103,6 +104,13 @@ struct vfio_mm *vfio_mm_get_from_task(struct task_struct
*task)
mmput(mm);
return vmm;
}
+EXPORT_SYMBOL_GPL(vfio_mm_get_from_task);
+
+int vfio_mm_ioasid_sid(struct vfio_mm *vmm)
+{
+ return vmm->ioasid_sid;
+}
+EXPORT_SYMBOL_GPL(vfio_mm_ioasid_sid);
int vfio_pasid_alloc(struct vfio_mm *vmm, int min, int max)
{
@@ -112,6 +120,7 @@ int vfio_pasid_alloc(struct vfio_mm *vmm, int min, int max)
return (pasid == INVALID_IOASID) ? -ENOSPC : pasid;
}
+EXPORT_SYMBOL_GPL(vfio_pasid_alloc);
void vfio_pasid_free_range(struct vfio_mm *vmm,
ioasid_t min, ioasid_t max)
@@ -129,6 +138,7 @@ void vfio_pasid_free_range(struct vfio_mm *vmm,
for (; pasid <= max; pasid++)
ioasid_free(pasid);
}
+EXPORT_SYMBOL_GPL(vfio_pasid_free_range);
static int __init vfio_pasid_init(void)
{
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index 74e077d..8e60a32 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -101,6 +101,7 @@ struct vfio_mm;
#if IS_ENABLED(CONFIG_VFIO_PASID)
extern struct vfio_mm *vfio_mm_get_from_task(struct task_struct *task);
extern void vfio_mm_put(struct vfio_mm *vmm);
+int vfio_mm_ioasid_sid(struct vfio_mm *vmm);
extern int vfio_pasid_alloc(struct vfio_mm *vmm, int min, int max);
extern void vfio_pasid_free_range(struct vfio_mm *vmm,
ioasid_t min, ioasid_t max);
@@ -114,6 +115,11 @@ static inline void vfio_mm_put(struct vfio_mm *vmm)
{
}
+static inline int vfio_mm_ioasid_sid(struct vfio_mm *vmm)
+{
+ return -ENOTTY;
+}
+
static inline int vfio_pasid_alloc(struct vfio_mm *vmm, int min, int max)
{
return -ENOTTY;
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index f1f39e1..657b2db 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -1162,6 +1162,42 @@ struct vfio_iommu_type1_dirty_bitmap_get {
#define VFIO_IOMMU_DIRTY_PAGES _IO(VFIO_TYPE, VFIO_BASE + 17)
+/**
+ * VFIO_IOMMU_PASID_REQUEST - _IOWR(VFIO_TYPE, VFIO_BASE + 18,
+ * struct vfio_iommu_type1_pasid_request)
+ *
+ * PASID (Processor Address Space ID) is a PCIe concept for tagging
+ * address spaces in DMA requests. When system-wide PASID allocation
+ * is required by underlying iommu driver (e.g. Intel VT-d), this
+ * provides an interface for userspace to request pasid alloc/free
+ * for its assigned devices. Userspace should check the availability
+ * of this API through VFIO_IOMMU_GET_INFO.
+ *
+ * @flags=VFIO_IOMMU_ALLOC_PASID, allocate a single PASID within @range.
+ * @flags=VFIO_IOMMU_FREE_PASID, free the PASIDs within @range.
+ * @range is [min, max], which means both @min and @max are inclusive.
+ * ALLOC_PASID and FREE_PASID are mutually exclusive.
+ *
+ * returns: allocated PASID value on success, -errno on failure for
+ * ALLOC_PASID;
+ * 0 for FREE_PASID operation;
+ */
+struct vfio_iommu_type1_pasid_request {
+ __u32 argsz;
+#define VFIO_IOMMU_ALLOC_PASID (1 << 0)
+#define VFIO_IOMMU_FREE_PASID (1 << 1)
+ __u32 flags;
+ struct {
+ __u32 min;
+ __u32 max;
+ } range;
+};
+
+#define VFIO_PASID_REQUEST_MASK (VFIO_IOMMU_ALLOC_PASID | \
+ VFIO_IOMMU_FREE_PASID)
+
+#define VFIO_IOMMU_PASID_REQUEST _IO(VFIO_TYPE, VFIO_BASE + 18)
+
/* -------- Additional API for SPAPR TCE (Server POWERPC) IOMMU -------- */
/*
--
2.7.4
