[Xen-changelog] [xen master] xen: introduce arch_grant_(un)map_page_identity

[patchbot@xxxxxxx]

commit e25a5f4d8cf3b55718048abdd21c7d0de64ae54c
Author:     Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
AuthorDate: Fri Aug 1 15:45:24 2014 +0100
Commit:     Ian Campbell <ian.campbell@xxxxxxxxxx>
CommitDate: Tue Sep 9 11:47:08 2014 +0100

    xen: introduce arch_grant_(un)map_page_identity
    
    Introduce two arch specific functions to create a new p2m mapping of
    granted pages at pfn == mfn.
    We don't an x86 implementation as these functions should never be
    compiled on x86 (they are called from an if (0) statement).
    
    Base the implementation of arm_smmu_(un)map_page on
    arch_grant_(un)map_page_identity.
    
    Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
    Acked-by: Julien Grall <julien.grall@xxxxxxxxxx>
    Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
---
 xen/arch/arm/p2m.c                 |   26 ++++++++++++++++++++++++++
 xen/drivers/passthrough/arm/smmu.c |   13 ++-----------
 xen/include/asm-arm/p2m.h          |    4 ++++
 xen/include/asm-x86/p2m.h          |    4 ++++
 4 files changed, 36 insertions(+), 11 deletions(-)

diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
index fc8c0dd..a7dcdf5 100644
--- a/xen/arch/arm/p2m.c
+++ b/xen/arch/arm/p2m.c
@@ -927,6 +927,32 @@ void guest_physmap_remove_page(struct domain *d,
                       pfn_to_paddr(mfn), MATTR_MEM, p2m_invalid);
 }
 
+int arch_grant_map_page_identity(struct domain *d, unsigned long frame,
+                                 bool_t writeable)
+{
+    p2m_type_t t;
+
+    ASSERT(is_domain_direct_mapped(d));
+
+    /* This is not an IOMMU mapping but it is not a regular RAM p2m type
+     * either. We are using IOMMU p2m types here to prevent the pages
+     * from being used as grants. */
+    if ( writeable )
+        t = p2m_iommu_map_rw;
+    else
+        t = p2m_iommu_map_ro;
+
+    return guest_physmap_add_entry(d, frame, frame, 0, t);
+}
+
+int arch_grant_unmap_page_identity(struct domain *d, unsigned long frame)
+{
+    ASSERT(is_domain_direct_mapped(d));
+
+    guest_physmap_remove_page(d, frame, frame, 0);
+    return 0;
+}
+
 int p2m_alloc_table(struct domain *d)
 {
     struct p2m_domain *p2m = &d->arch.p2m;
diff --git a/xen/drivers/passthrough/arm/smmu.c 
b/xen/drivers/passthrough/arm/smmu.c
index f4eb2a2..fb0c694 100644
--- a/xen/drivers/passthrough/arm/smmu.c
+++ b/xen/drivers/passthrough/arm/smmu.c
@@ -1539,8 +1539,6 @@ static void arm_smmu_iommu_domain_teardown(struct domain 
*d)
 static int arm_smmu_map_page(struct domain *d, unsigned long gfn,
                              unsigned long mfn, unsigned int flags)
 {
-    p2m_type_t t;
-
     /* Grant mappings can be used for DMA requests. The dev_bus_addr returned 
by
      * the hypercall is the MFN (not the IPA). For device protected by
      * an IOMMU, Xen needs to add a 1:1 mapping in the domain p2m to
@@ -1555,12 +1553,7 @@ static int arm_smmu_map_page(struct domain *d, unsigned 
long gfn,
     if ( !(flags & (IOMMUF_readable | IOMMUF_writable)) )
         return -EINVAL;
 
-    t = (flags & IOMMUF_writable) ? p2m_iommu_map_rw : p2m_iommu_map_ro;
-
-    /* The function guest_physmap_add_entry replaces the current mapping
-     * if there is already one...
-     */
-    return guest_physmap_add_entry(d, gfn, mfn, 0, t);
+    return arch_grant_map_page_identity(d, mfn, flags & IOMMUF_writable);
 }
 
 static int arm_smmu_unmap_page(struct domain *d, unsigned long gfn)
@@ -1571,9 +1564,7 @@ static int arm_smmu_unmap_page(struct domain *d, unsigned 
long gfn)
     if ( !is_domain_direct_mapped(d) )
         return -EINVAL;
 
-    guest_physmap_remove_page(d, gfn, gfn, 0);
-
-    return 0;
+    return arch_grant_unmap_page_identity(d, gfn);
 }
 
 static const struct iommu_ops arm_smmu_iommu_ops = {
diff --git a/xen/include/asm-arm/p2m.h b/xen/include/asm-arm/p2m.h
index 08ce07b..97cbae4 100644
--- a/xen/include/asm-arm/p2m.h
+++ b/xen/include/asm-arm/p2m.h
@@ -194,6 +194,10 @@ static inline int get_page_and_type(struct page_info *page,
     return rc;
 }
 
+int arch_grant_map_page_identity(struct domain *d, unsigned long frame,
+                                 bool_t writeable);
+int arch_grant_unmap_page_identity(struct domain *d, unsigned long frame);
+
 #endif /* _XEN_P2M_H */
 
 /*
diff --git a/xen/include/asm-x86/p2m.h b/xen/include/asm-x86/p2m.h
index 39f235d..bae669e 100644
--- a/xen/include/asm-x86/p2m.h
+++ b/xen/include/asm-x86/p2m.h
@@ -719,6 +719,10 @@ static inline unsigned int p2m_get_iommu_flags(p2m_type_t 
p2mt)
     return flags;
 }
 
+extern int arch_grant_map_page_identity(struct domain *d, unsigned long frame,
+                                 bool_t writeable);
+extern int arch_grant_unmap_page_identity(struct domain *d, unsigned long 
frame);
+
 #endif /* _XEN_P2M_H */
 
 /*
--
generated by git-patchbot for /home/xen/git/xen.git#master

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