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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v7 6/6] vtd: add lookup_page method to iommu_ops
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.
This patch also cleans up the initializers in intel_iommu_map_page() and
uses array-style dereference there, for consistency. A missing check for
shared EPT is also added to intel_iommu_unmap_page().
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.durrant@xxxxxxxxxx>
---
Cc: Wei Liu <wei.liu2@xxxxxxxxxx>
Cc: Kevin Tian <kevin.tian@xxxxxxxxx>
Cc: Jan Beulich <jbeulich@xxxxxxxx>
Cc: George Dunlap <george.dunlap@xxxxxxxxxx>
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 | 52 +++++++++++++++++++++++++++++++++++--
xen/drivers/passthrough/vtd/iommu.h | 3 +++
xen/include/xen/iommu.h | 4 +++
4 files changed, 68 insertions(+), 2 deletions(-)
diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c
index a16f1a0c66..52e3f500c7 100644
--- a/xen/drivers/passthrough/iommu.c
+++ b/xen/drivers/passthrough/iommu.c
@@ -296,6 +296,17 @@ 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 0163bb949b..6622c2dd4c 100644
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -1770,7 +1770,7 @@ static int __must_check intel_iommu_map_page(struct
domain *d,
unsigned int flags)
{
struct domain_iommu *hd = dom_iommu(d);
- struct dma_pte *page = NULL, *pte = NULL, old, new = { 0 };
+ struct dma_pte *page, *pte, old, new = {};
u64 pg_maddr;
int rc = 0;
@@ -1790,9 +1790,11 @@ static int __must_check intel_iommu_map_page(struct
domain *d,
spin_unlock(&hd->arch.mapping_lock);
return -ENOMEM;
}
+
page = (struct dma_pte *)map_vtd_domain_page(pg_maddr);
- pte = page + (dfn_x(dfn) & LEVEL_MASK);
+ pte = &page[dfn_x(dfn) & LEVEL_MASK];
old = *pte;
+
dma_set_pte_addr(new, mfn_to_maddr(mfn));
dma_set_pte_prot(new,
((flags & IOMMUF_readable) ? DMA_PTE_READ : 0) |
@@ -1808,6 +1810,7 @@ static int __must_check intel_iommu_map_page(struct
domain *d,
unmap_vtd_domain_page(page);
return 0;
}
+
*pte = new;
iommu_flush_cache_entry(pte, sizeof(struct dma_pte));
@@ -1823,6 +1826,10 @@ static int __must_check intel_iommu_map_page(struct
domain *d,
static int __must_check intel_iommu_unmap_page(struct domain *d,
dfn_t dfn)
{
+ /* Do nothing if VT-d shares EPT page table */
+ if ( iommu_use_hap_pt(d) )
+ return 0;
+
/* Do nothing if hardware domain and iommu supports pass thru. */
if ( iommu_passthrough && is_hardware_domain(d) )
return 0;
@@ -1830,6 +1837,46 @@ 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;
+
+ /* Fail if VT-d shares EPT page table */
+ if ( iommu_use_hap_pt(d) )
+ return -ENOENT;
+
+ /* Fail if hardware domain and iommu supports pass thru. */
+ if ( iommu_passthrough && is_hardware_domain(d) )
+ return -ENOENT;
+
+ spin_lock(&hd->arch.mapping_lock);
+
+ pg_maddr = addr_to_dma_page_maddr(d, dfn_to_daddr(dfn), 0);
+ if ( pg_maddr == 0 )
+ {
+ 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)
{
@@ -2655,6 +2702,7 @@ 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 9e0b4e8638..bebddc2db4 100644
--- a/xen/include/xen/iommu.h
+++ b/xen/include/xen/iommu.h
@@ -100,6 +100,8 @@ 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
{
@@ -190,6 +192,8 @@ struct iommu_ops {
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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