[Xen-changelog] [xen staging] mm / iommu: include need_iommu() test in iommu_use_hap_pt()

[patchbot@xxxxxxx]

commit 2916951c1bb943e79bf965cde66a78b0e841455b
Author:     Paul Durrant <paul.durrant@xxxxxxxxxx>
AuthorDate: Fri Oct 5 16:36:56 2018 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Fri Oct 5 16:36:56 2018 +0200

    mm / iommu: include need_iommu() test in iommu_use_hap_pt()
    
    The name 'iommu_use_hap_pt' suggests that that P2M table is in use as the
    domain's IOMMU pagetable which, prior to this patch, is not strictly true
    since the macro did not test whether the domain actually has IOMMU
    mappings.
    
    Signed-off-by: Paul Durrant <paul.durrant@xxxxxxxxxx>
    Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
    Acked-by: Julien Grall <julien.grall@xxxxxxx>
    Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
    Acked-by: George Dunlap <george.dunlap@xxxxxxxxxx>
---
 xen/arch/x86/mm/p2m-ept.c       | 6 +++---
 xen/arch/x86/mm/p2m-pt.c        | 6 +++---
 xen/arch/x86/mm/p2m.c           | 2 +-
 xen/drivers/passthrough/iommu.c | 2 +-
 xen/include/asm-arm/iommu.h     | 2 +-
 xen/include/asm-x86/iommu.h     | 5 +++--
 6 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/xen/arch/x86/mm/p2m-ept.c b/xen/arch/x86/mm/p2m-ept.c
index e0eb85bc3d..e3f1a8e111 100644
--- a/xen/arch/x86/mm/p2m-ept.c
+++ b/xen/arch/x86/mm/p2m-ept.c
@@ -874,12 +874,12 @@ out:
         ept_sync_domain(p2m);
 
     /* For host p2m, may need to change VT-d page table.*/
-    if ( rc == 0 && p2m_is_hostp2m(p2m) && need_iommu(d) &&
+    if ( rc == 0 && p2m_is_hostp2m(p2m) &&
          need_modify_vtd_table )
     {
-        if ( iommu_hap_pt_share )
+        if ( iommu_use_hap_pt(d) )
             rc = iommu_pte_flush(d, gfn, &ept_entry->epte, order, 
vtd_pte_present);
-        else
+        else if ( need_iommu(d) )
         {
             dfn_t dfn = _dfn(gfn);
 
diff --git a/xen/arch/x86/mm/p2m-pt.c b/xen/arch/x86/mm/p2m-pt.c
index 0569f1de80..50f7e72fc8 100644
--- a/xen/arch/x86/mm/p2m-pt.c
+++ b/xen/arch/x86/mm/p2m-pt.c
@@ -678,8 +678,8 @@ p2m_pt_set_entry(struct p2m_domain *p2m, gfn_t gfn_, mfn_t 
mfn,
          && (gfn + (1UL << page_order) - 1 > p2m->max_mapped_pfn) )
         p2m->max_mapped_pfn = gfn + (1UL << page_order) - 1;
 
-    if ( iommu_enabled && need_iommu(p2m->domain) &&
-         (iommu_old_flags != iommu_pte_flags || old_mfn != mfn_x(mfn)) )
+    if ( iommu_enabled && (iommu_old_flags != iommu_pte_flags ||
+                           old_mfn != mfn_x(mfn)) )
     {
         ASSERT(rc == 0);
 
@@ -688,7 +688,7 @@ p2m_pt_set_entry(struct p2m_domain *p2m, gfn_t gfn_, mfn_t 
mfn,
             if ( iommu_old_flags )
                 amd_iommu_flush_pages(p2m->domain, gfn, page_order);
         }
-        else
+        else if ( need_iommu(p2m->domain) )
         {
             dfn_t dfn = _dfn(gfn);
 
diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index e5c06e22c7..20e8f97d3c 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -2087,7 +2087,7 @@ static unsigned int mmio_order(const struct domain *d,
      * - exclude PV guests, should execution reach this code for such.
      * So be careful when altering this.
      */
-    if ( !need_iommu(d) || !iommu_use_hap_pt(d) ||
+    if ( !iommu_use_hap_pt(d) ||
          (start_fn & ((1UL << PAGE_ORDER_2M) - 1)) || !(nr >> PAGE_ORDER_2M) )
         return PAGE_ORDER_4K;
 
diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c
index 7eae31c7df..898950c63a 100644
--- a/xen/drivers/passthrough/iommu.c
+++ b/xen/drivers/passthrough/iommu.c
@@ -487,7 +487,7 @@ int iommu_do_domctl(
 
 void iommu_share_p2m_table(struct domain* d)
 {
-    if ( iommu_enabled && iommu_use_hap_pt(d) )
+    if ( iommu_use_hap_pt(d) )
         iommu_get_ops()->share_p2m(d);
 }
 
diff --git a/xen/include/asm-arm/iommu.h b/xen/include/asm-arm/iommu.h
index 57d9b1e14a..8d1506c6f7 100644
--- a/xen/include/asm-arm/iommu.h
+++ b/xen/include/asm-arm/iommu.h
@@ -21,7 +21,7 @@ struct arch_iommu
 };
 
 /* Always share P2M Table between the CPU and the IOMMU */
-#define iommu_use_hap_pt(d) (1)
+#define iommu_use_hap_pt(d) (need_iommu(d))
 
 const struct iommu_ops *iommu_get_ops(void);
 void __init iommu_set_ops(const struct iommu_ops *ops);
diff --git a/xen/include/asm-x86/iommu.h b/xen/include/asm-x86/iommu.h
index 0ed4a9e86d..7c3187c8ec 100644
--- a/xen/include/asm-x86/iommu.h
+++ b/xen/include/asm-x86/iommu.h
@@ -89,8 +89,9 @@ static inline int iommu_hardware_setup(void)
     return -ENODEV;
 }
 
-/* Does this domain have a P2M table we can use as its IOMMU pagetable? */
-#define iommu_use_hap_pt(d) (hap_enabled(d) && iommu_hap_pt_share)
+/* Are we using the domain P2M table as its IOMMU pagetable? */
+#define iommu_use_hap_pt(d) \
+    (hap_enabled(d) && need_iommu(d) && iommu_hap_pt_share)
 
 void iommu_update_ire_from_apic(unsigned int apic, unsigned int reg, unsigned 
int value);
 unsigned int iommu_read_apic_from_ire(unsigned int apic, unsigned int reg);
--
generated by git-patchbot for /home/xen/git/xen.git#staging

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