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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v6 11/14] x86: add iommu_op to enable modification of IOMMU mappings
This patch adds an iommu_op which checks whether it is possible or
safe for a domain to modify its own IOMMU mappings and, if so, creates
a rangeset to track modifications.
The op passes back a capabilities mask. There is only one bit currently
defined for this mask: XEN_IOMMU_CAP_per_device_mappings. This bit is
always left clear by the current implementation but may be set in future
if the implementation is enhance to support per-device IOMMU mappings.
NOTE: The actual map and unmap operations are introduced by subsequent
patches.
Signed-off-by: Paul Durrant <paul.durrant@xxxxxxxxxx>
---
Cc: Jan Beulich <jbeulich@xxxxxxxx>
Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Cc: George Dunlap <George.Dunlap@xxxxxxxxxxxxx>
Cc: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
Cc: Julien Grall <julien.grall@xxxxxxx>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx>
Cc: Tim Deegan <tim@xxxxxxx>
Cc: Wei Liu <wei.liu2@xxxxxxxxxx>
v6:
- Add struct xen_iommu_op_enable_modification to hold the capabilities
mask.
v4:
- Set sync_iommu_pt to false instead of need_iommu.
v2:
- New in v2.
---
xen/common/iommu_op.c | 53 +++++++++++++++++++++++++++++++++++++++++
xen/drivers/passthrough/iommu.c | 2 +-
xen/drivers/passthrough/pci.c | 4 ++--
xen/include/public/iommu_op.h | 20 ++++++++++++++++
xen/include/xen/iommu.h | 3 +++
xen/include/xlat.lst | 1 +
6 files changed, 80 insertions(+), 3 deletions(-)
diff --git a/xen/common/iommu_op.c b/xen/common/iommu_op.c
index bcfcd49102..ccbb9b6340 100644
--- a/xen/common/iommu_op.c
+++ b/xen/common/iommu_op.c
@@ -78,6 +78,51 @@ static int iommu_op_query_reserved(struct
xen_iommu_op_query_reserved *op)
return 0;
}
+static int iommu_op_enable_modification(
+ struct xen_iommu_op_enable_modification *op)
+{
+ struct domain *currd = current->domain;
+ struct domain_iommu *iommu = dom_iommu(currd);
+ const struct iommu_ops *ops = iommu->platform_ops;
+
+ if ( op->cap || op->pad )
+ return -EINVAL;
+
+ /*
+ * XEN_IOMMU_CAP_per_device_mappings is not supported yet so we can
+ * leave op->cap alone.
+ */
+
+ /* Has modification already been enabled? */
+ if ( iommu->iommu_op_ranges )
+ return 0;
+
+ /*
+ * The IOMMU mappings cannot be modified if:
+ * - the IOMMU is not enabled or,
+ * - the current domain is dom0 and tranlsation is disabled or,
+ * - HAP is enabled and the IOMMU shares the mappings.
+ */
+ if ( !iommu_enabled ||
+ (is_hardware_domain(currd) && iommu_passthrough) ||
+ iommu_use_hap_pt(currd) )
+ return -EACCES;
+
+ /*
+ * The IOMMU implementation must provide the lookup method if
+ * modification of the mappings is to be supported.
+ */
+ if ( !ops->lookup_page )
+ return -EOPNOTSUPP;
+
+ iommu->iommu_op_ranges = rangeset_new(currd, NULL, 0);
+ if ( !iommu->iommu_op_ranges )
+ return -ENOMEM;
+
+ iommu->need_sync = false; /* Disable synchronization */
+ return 0;
+}
+
static void iommu_op(xen_iommu_op_t *op)
{
switch ( op->op )
@@ -86,6 +131,10 @@ static void iommu_op(xen_iommu_op_t *op)
op->status = iommu_op_query_reserved(&op->u.query_reserved);
break;
+ case XEN_IOMMUOP_enable_modification:
+ op->status = iommu_op_enable_modification(&op->u.enable_modification);
+ break;
+
default:
op->status = -EOPNOTSUPP;
break;
@@ -98,6 +147,7 @@ int do_one_iommu_op(xen_iommu_op_buf_t *buf)
size_t offset;
static const size_t op_size[] = {
[XEN_IOMMUOP_query_reserved] = sizeof(struct
xen_iommu_op_query_reserved),
+ [XEN_IOMMUOP_enable_modification] = sizeof(struct
xen_iommu_op_enable_modification),
};
size_t size;
int rc;
@@ -184,6 +234,7 @@ int compat_one_iommu_op(compat_iommu_op_buf_t *buf)
size_t offset;
static const size_t op_size[] = {
[XEN_IOMMUOP_query_reserved] = sizeof(struct
compat_iommu_op_query_reserved),
+ [XEN_IOMMUOP_enable_modification] = sizeof(struct
compat_iommu_op_enable_modification),
};
size_t size;
xen_iommu_op_t nat;
@@ -221,6 +272,7 @@ int compat_one_iommu_op(compat_iommu_op_buf_t *buf)
* we need to fix things up here.
*/
#define XLAT_iommu_op_u_query_reserved XEN_IOMMUOP_query_reserved
+#define XLAT_iommu_op_u_enable_modification XEN_IOMMUOP_enable_modification
u = cmp.op;
#define XLAT_iommu_op_query_reserved_HNDL_ranges(_d_, _s_) \
@@ -280,6 +332,7 @@ int compat_one_iommu_op(compat_iommu_op_buf_t *buf)
&cmp, status) )
return -EFAULT;
+#undef XLAT_iommu_op_u_enable_modification
#undef XLAT_iommu_op_u_query_reserved
return 0;
diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c
index 848d6c7d69..30b800c97b 100644
--- a/xen/drivers/passthrough/iommu.c
+++ b/xen/drivers/passthrough/iommu.c
@@ -26,7 +26,6 @@ static void iommu_dump_p2m_table(unsigned char key);
unsigned int __read_mostly iommu_dev_iotlb_timeout = 1000;
integer_param("iommu_dev_iotlb_timeout", iommu_dev_iotlb_timeout);
-
/*
* The 'iommu' parameter enables the IOMMU. Optional comma separated
* value may contain:
@@ -280,6 +279,7 @@ void iommu_domain_destroy(struct domain *d)
arch_iommu_domain_destroy(d);
rangeset_destroy(hd->reserved_ranges);
+ rangeset_destroy(hd->iommu_op_ranges);
}
int iommu_map_page(struct domain *d, bfn_t bfn, mfn_t mfn,
diff --git a/xen/drivers/passthrough/pci.c b/xen/drivers/passthrough/pci.c
index e10f0bba1c..91de8b2784 100644
--- a/xen/drivers/passthrough/pci.c
+++ b/xen/drivers/passthrough/pci.c
@@ -1460,7 +1460,7 @@ static int assign_device(struct domain *d, u16 seg, u8
bus, u8 devfn, u32 flag)
}
done:
- if ( !has_arch_pdevs(d) && has_iommu_pt(d) )
+ if ( !has_arch_pdevs(d) && has_iommu_pt(d) && !hd->iommu_op_ranges )
iommu_teardown(d);
pcidevs_unlock();
@@ -1510,7 +1510,7 @@ int deassign_device(struct domain *d, u16 seg, u8 bus, u8
devfn)
pdev->fault.count = 0;
- if ( !has_arch_pdevs(d) && has_iommu_pt(d) )
+ if ( !has_arch_pdevs(d) && has_iommu_pt(d) && !hd->iommu_op_ranges )
iommu_teardown(d);
return ret;
diff --git a/xen/include/public/iommu_op.h b/xen/include/public/iommu_op.h
index ade404a877..9b98b5cf89 100644
--- a/xen/include/public/iommu_op.h
+++ b/xen/include/public/iommu_op.h
@@ -61,6 +61,25 @@ struct xen_iommu_op_query_reserved {
XEN_GUEST_HANDLE(xen_iommu_reserved_range_t) ranges;
};
+/*
+ * XEN_IOMMUOP_enable_modification: Enable operations that modify IOMMU
+ * mappings.
+ */
+#define XEN_IOMMUOP_enable_modification 2
+
+struct xen_iommu_op_enable_modification {
+ /*
+ * OUT - On successful return this is set to the bitwise OR of capabilities
+ * defined below. On entry this must be set to zero.
+ */
+ unsigned int cap;
+ unsigned int pad;
+
+ /* Does the implementation support per-device mappings? */
+#define _XEN_IOMMU_CAP_per_device_mappings 0
+#define XEN_IOMMU_CAP_per_device_mappings (1u <<
_XEN_IOMMU_CAP_per_device_mappings)
+};
+
struct xen_iommu_op {
uint16_t op; /* op type */
uint16_t pad;
@@ -68,6 +87,7 @@ struct xen_iommu_op {
/* 0 for success otherwise, negative errno */
union {
struct xen_iommu_op_query_reserved query_reserved;
+ struct xen_iommu_op_enable_modification enable_modification;
} u;
};
typedef struct xen_iommu_op xen_iommu_op_t;
diff --git a/xen/include/xen/iommu.h b/xen/include/xen/iommu.h
index 37052e033f..14186ae8e4 100644
--- a/xen/include/xen/iommu.h
+++ b/xen/include/xen/iommu.h
@@ -147,6 +147,9 @@ struct domain_iommu {
* include/xen/mm.h).
*/
bool need_sync;
+
+ /* Ranges under the control of PV IOMMU interface */
+ struct rangeset *iommu_op_ranges;
};
#define dom_iommu(d) (&(d)->iommu)
diff --git a/xen/include/xlat.lst b/xen/include/xlat.lst
index d2f9b1034b..c1b27e0349 100644
--- a/xen/include/xlat.lst
+++ b/xen/include/xlat.lst
@@ -79,6 +79,7 @@
? vcpu_hvm_x86_64 hvm/hvm_vcpu.h
! iommu_op iommu_op.h
! iommu_op_buf iommu_op.h
+! iommu_op_enable_modification iommu_op.h
! iommu_op_query_reserved iommu_op.h
? iommu_reserved_range iommu_op.h
? kexec_exec kexec.h
--
2.11.0
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