This patch adds a new method to the VT-d IOMMU implementation to find the
MFN currently mapped by the specified DFN along with a wrapper function
in generic IOMMU code to call the implementation if it exists.
NOTE: This patch only adds a Xen-internal interface. This will be used by
a subsequent patch.
Another subsequent patch will add similar functionality for AMD
IOMMUs.
Signed-off-by: Paul Durrant <paul.durr...@citrix.com>
Reviewed-by: Jan Beulich <jbeul...@suse.com>
Reviewed-by: Kevin Tian <kevin.t...@intel.com>
---
Cc: Wei Liu <wei.l...@citrix.com>
Cc: George Dunlap <george.dun...@citrix.com>
v11:
- Fold in patch to change failure semantics (already ack-ed by Kevin).
v10:
- Adjust the locking comment.
v9:
- Add comment about locking in xen/iommu.h.
v8:
- Remove clean-up as this is now done by a prior patch.
- Make intel_iommu_lookup_page() return dfn value if using shared EPT
or iommu_passthrough is set, as requested by Kevin.
v7:
- Re-base and re-name BFN -> DFN.
- Add missing checks for shared EPT and iommu_passthrough.
- Remove unnecessary initializers and use array-style dereference.
- Drop Wei's R-b because of code churn.
v3:
- Addressed comments from George.
v2:
- Addressed some comments from Jan.
---
xen/drivers/passthrough/iommu.c | 11 ++++++++++
xen/drivers/passthrough/vtd/iommu.c | 41 +++++++++++++++++++++++++++++++++++++
xen/drivers/passthrough/vtd/iommu.h | 3 +++
xen/include/xen/iommu.h | 10 +++++++++
4 files changed, 65 insertions(+)
diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c
index c0dd8e494f..d51fffae40 100644
--- a/xen/drivers/passthrough/iommu.c
+++ b/xen/drivers/passthrough/iommu.c
@@ -327,6 +327,17 @@ int iommu_unmap_page(struct domain *d, dfn_t dfn)
return rc;
}
+int iommu_lookup_page(struct domain *d, dfn_t dfn, mfn_t *mfn,
+ unsigned int *flags)
+{
+ const struct domain_iommu *hd = dom_iommu(d);
+
+ if ( !iommu_enabled || !hd->platform_ops )
+ return -EOPNOTSUPP;
+
+ return hd->platform_ops->lookup_page(d, dfn, mfn, flags);
+}
+
static void iommu_free_pagetables(unsigned long unused)
{
do {
diff --git a/xen/drivers/passthrough/vtd/iommu.c
b/xen/drivers/passthrough/vtd/iommu.c
index 9187d50730..f94b522c73 100644
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -1833,6 +1833,46 @@ static int __must_check intel_iommu_unmap_page(struct
domain *d,
return dma_pte_clear_one(d, dfn_to_daddr(dfn));
}
+static int intel_iommu_lookup_page(struct domain *d, dfn_t dfn, mfn_t *mfn,
+ unsigned int *flags)
+{
+ struct domain_iommu *hd = dom_iommu(d);
+ struct dma_pte *page, val;
+ u64 pg_maddr;
+
+ /*
+ * If VT-d shares EPT page table or if the domain is the hardware
+ * domain and iommu_passthrough is set then pass back the dfn.
+ */
+ if ( iommu_use_hap_pt(d) ||
+ (iommu_hwdom_passthrough && is_hardware_domain(d)) )
+ return -EOPNOTSUPP;
+
+ spin_lock(&hd->arch.mapping_lock);
+
+ pg_maddr = addr_to_dma_page_maddr(d, dfn_to_daddr(dfn), 0);
+ if ( !pg_maddr )
+ {
+ spin_unlock(&hd->arch.mapping_lock);
+ return -ENOMEM;
+ }
+
+ page = map_vtd_domain_page(pg_maddr);
+ val = page[dfn_x(dfn) & LEVEL_MASK];
+
+ unmap_vtd_domain_page(page);
+ spin_unlock(&hd->arch.mapping_lock);
+
+ if ( !dma_pte_present(val) )
+ return -ENOENT;
+
+ *mfn = maddr_to_mfn(dma_pte_addr(val));
+ *flags = dma_pte_read(val) ? IOMMUF_readable : 0;
+ *flags |= dma_pte_write(val) ? IOMMUF_writable : 0;
+
+ return 0;
+}
+
int iommu_pte_flush(struct domain *d, uint64_t dfn, uint64_t *pte,
int order, int present)
{
@@ -2658,6 +2698,7 @@ const struct iommu_ops intel_iommu_ops = {
.teardown = iommu_domain_teardown,
.map_page = intel_iommu_map_page,
.unmap_page = intel_iommu_unmap_page,
+ .lookup_page = intel_iommu_lookup_page,
.free_page_table = iommu_free_page_table,
.reassign_device = reassign_device_ownership,
.get_device_group_id = intel_iommu_group_id,
diff --git a/xen/drivers/passthrough/vtd/iommu.h
b/xen/drivers/passthrough/vtd/iommu.h
index 72c1a2e3cd..47bdfcb5ea 100644
--- a/xen/drivers/passthrough/vtd/iommu.h
+++ b/xen/drivers/passthrough/vtd/iommu.h
@@ -272,6 +272,9 @@ struct dma_pte {
#define dma_set_pte_prot(p, prot) do { \
(p).val = ((p).val & ~DMA_PTE_PROT) | ((prot) & DMA_PTE_PROT); \
} while (0)
+#define dma_pte_prot(p) ((p).val & DMA_PTE_PROT)
+#define dma_pte_read(p) (dma_pte_prot(p) & DMA_PTE_READ)
+#define dma_pte_write(p) (dma_pte_prot(p) & DMA_PTE_WRITE)
#define dma_pte_addr(p) ((p).val & PADDR_MASK & PAGE_MASK_4K)
#define dma_set_pte_addr(p, addr) do {\
(p).val |= ((addr) & PAGE_MASK_4K); } while (0)
diff --git a/xen/include/xen/iommu.h b/xen/include/xen/iommu.h
index 7313957c81..9ae8321bb4 100644
--- a/xen/include/xen/iommu.h
+++ b/xen/include/xen/iommu.h
@@ -92,6 +92,8 @@ void iommu_teardown(struct domain *d);
int __must_check iommu_map_page(struct domain *d, dfn_t dfn,
mfn_t mfn, unsigned int flags);
int __must_check iommu_unmap_page(struct domain *d, dfn_t dfn);
+int __must_check iommu_lookup_page(struct domain *d, dfn_t dfn, mfn_t *mfn,
+ unsigned int *flags);
enum iommu_feature
{
@@ -179,9 +181,17 @@ struct iommu_ops {
#endif /* HAS_PCI */
void (*teardown)(struct domain *d);
+
+ /*
+ * This block of operations must be appropriately locked against each
+ * other by the caller in order to have meaningful results.
+ */
int __must_check (*map_page)(struct domain *d, dfn_t dfn, mfn_t mfn,
unsigned int flags);
int __must_check (*unmap_page)(struct domain *d, dfn_t dfn);
+ int __must_check (*lookup_page)(struct domain *d, dfn_t dfn, mfn_t *mfn,
+ unsigned int *flags);
+
void (*free_page_table)(struct page_info *);
#ifdef CONFIG_X86
void (*update_ire_from_apic)(unsigned int apic, unsigned int reg, unsigned
int value);
--
2.11.0
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