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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v4 12/15] 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.
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>
v4:
- Set sync_iommu_pt to false instead of need_iommu.
v2:
- New in v2.
---
xen/arch/x86/iommu_op.c | 42 +++++++++++++++++++++++++++++++++++++++++
xen/drivers/passthrough/iommu.c | 2 +-
xen/drivers/passthrough/pci.c | 4 ++--
xen/include/public/iommu_op.h | 6 ++++++
xen/include/xen/iommu.h | 3 +++
5 files changed, 54 insertions(+), 3 deletions(-)
diff --git a/xen/arch/x86/iommu_op.c b/xen/arch/x86/iommu_op.c
index bcfcd49102..b29547bffd 100644
--- a/xen/arch/x86/iommu_op.c
+++ b/xen/arch/x86/iommu_op.c
@@ -78,6 +78,42 @@ static int iommu_op_query_reserved(struct
xen_iommu_op_query_reserved *op)
return 0;
}
+static int iommu_op_enable_modification(void)
+{
+ struct domain *currd = current->domain;
+ struct domain_iommu *iommu = dom_iommu(currd);
+ const struct iommu_ops *ops = iommu->platform_ops;
+
+ /* 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;
+
+ currd->sync_iommu_pt = 0; /* Disable synchronization */
+ return 0;
+}
+
static void iommu_op(xen_iommu_op_t *op)
{
switch ( op->op )
@@ -86,6 +122,10 @@ 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();
+ break;
+
default:
op->status = -EOPNOTSUPP;
break;
@@ -98,6 +138,7 @@ 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] = 0,
};
size_t size;
int rc;
@@ -184,6 +225,7 @@ 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] = 0,
};
size_t size;
xen_iommu_op_t nat;
diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c
index caf3d125ae..8f635a5cdb 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:
@@ -265,6 +264,7 @@ 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 3d3ad484e7..d4033af41a 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..9bf74bd007 100644
--- a/xen/include/public/iommu_op.h
+++ b/xen/include/public/iommu_op.h
@@ -61,6 +61,12 @@ 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 {
uint16_t op; /* op type */
uint16_t pad;
diff --git a/xen/include/xen/iommu.h b/xen/include/xen/iommu.h
index 7c5d46df81..08b163cbcb 100644
--- a/xen/include/xen/iommu.h
+++ b/xen/include/xen/iommu.h
@@ -130,6 +130,9 @@ struct domain_iommu {
* must not be modified after initialization.
*/
struct rangeset *reserved_ranges;
+
+ /* Ranges under the control of iommu_op */
+ struct rangeset *iommu_op_ranges;
};
#define dom_iommu(d) (&(d)->iommu)
--
2.11.0
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