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Message-Id: <1591877734-66527-7-git-send-email-yi.l.liu@intel.com>
Date: Thu, 11 Jun 2020 05:15:25 -0700
From: Liu Yi L <yi.l.liu@...el.com>
To: alex.williamson@...hat.com, eric.auger@...hat.com,
baolu.lu@...ux.intel.com, joro@...tes.org
Cc: kevin.tian@...el.com, jacob.jun.pan@...ux.intel.com,
ashok.raj@...el.com, yi.l.liu@...el.com, jun.j.tian@...el.com,
yi.y.sun@...el.com, jean-philippe@...aro.org, peterx@...hat.com,
hao.wu@...el.com, iommu@...ts.linux-foundation.org,
kvm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH v2 06/15] vfio/type1: Add VFIO_IOMMU_PASID_REQUEST (alloc/free)
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.tian@...el.com>
CC: Jacob Pan <jacob.jun.pan@...ux.intel.com>
Cc: Alex Williamson <alex.williamson@...hat.com>
Cc: Eric Auger <eric.auger@...hat.com>
Cc: Jean-Philippe Brucker <jean-philippe@...aro.org>
Cc: Joerg Roedel <joro@...tes.org>
Cc: Lu Baolu <baolu.lu@...ux.intel.com>
Signed-off-by: Liu Yi L <yi.l.liu@...el.com>
Signed-off-by: Yi Sun <yi.y.sun@...ux.intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@...ux.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 22432cf..a7b3a83 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -72,6 +72,7 @@ struct vfio_iommu {
bool v2;
bool nesting;
struct iommu_nesting_info *nesting_info;
+ struct vfio_mm *vmm;
};
struct vfio_domain {
@@ -1615,6 +1616,17 @@ 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)
{
@@ -1738,6 +1750,25 @@ 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 */
@@ -1841,7 +1872,8 @@ 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);
@@ -2040,7 +2072,8 @@ 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);
@@ -2363,6 +2396,63 @@ static int vfio_iommu_type1_unmap_dma(struct vfio_iommu *iommu,
}
+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)
{
@@ -2377,6 +2467,8 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
return vfio_iommu_type1_map_dma(iommu, arg);
case VFIO_IOMMU_UNMAP_DMA:
return vfio_iommu_type1_unmap_dma(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 104418a..76da56e 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -99,6 +99,7 @@ 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);
@@ -112,6 +113,11 @@ 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 26e3dce..24d1992 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -840,6 +840,42 @@ struct vfio_iommu_type1_dma_unmap {
#define VFIO_IOMMU_ENABLE _IO(VFIO_TYPE, VFIO_BASE + 15)
#define VFIO_IOMMU_DISABLE _IO(VFIO_TYPE, VFIO_BASE + 16)
+/**
+ * VFIO_IOMMU_PASID_REQUEST - _IOWR(VFIO_TYPE, VFIO_BASE + 22,
+ * 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 + 22)
+
/* -------- Additional API for SPAPR TCE (Server POWERPC) IOMMU -------- */
/*
--
2.7.4
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