[Xen-devel] [PATCH RFC 4/5] pvh: dom0 add rw mapping for dom0_iommu_rwmem boot opt

[Elena Ufimtseva <elena.ufimtseva@xxxxxxxxxx>]

Patch adds mapping for memory regions specified by dom0_iommu_rwmem
regions. These special regions are not described by ACPI as RMRRs
and have special memory type.
Condition need_modify_vtd_table to perform iommu mapping is changed
in order to take into account pte permission changes applied for
this regions.
Make set_typed_p2m_entry available for using in mapping routine.

See other patches in this series for details and discovery history.

Signed-off-by: Elena Ufimtseva <elena.ufimtseva@xxxxxxxxxx>
---
 xen/arch/x86/mm/p2m-ept.c           |    6 ++--
 xen/arch/x86/mm/p2m.c               |    2 +-
 xen/drivers/passthrough/iommu.c     |   55 ++++++++++++++++++++++++++++++++++-
 xen/drivers/passthrough/vtd/iommu.c |    7 +++++
 xen/include/asm-x86/p2m.h           |    3 +-
 5 files changed, 67 insertions(+), 6 deletions(-)

diff --git a/xen/arch/x86/mm/p2m-ept.c b/xen/arch/x86/mm/p2m-ept.c
index d7d8ad1..9643183 100644
--- a/xen/arch/x86/mm/p2m-ept.c
+++ b/xen/arch/x86/mm/p2m-ept.c
@@ -730,7 +730,7 @@ ept_set_entry(struct p2m_domain *p2m, unsigned long gfn, 
mfn_t mfn,
     }
 
     if ( mfn_valid(mfn_x(mfn)) || direct_mmio || p2m_is_paged(p2mt) ||
-         (p2mt == p2m_ram_paging_in) )
+         (p2mt == p2m_ram_paging_in) || (p2mt == p2m_sys_rw) )
     {
         int emt = epte_get_entry_emt(p2m->domain, gfn, mfn,
                                      i * EPT_TABLE_ORDER, &ipat, direct_mmio);
@@ -750,8 +750,8 @@ ept_set_entry(struct p2m_domain *p2m, unsigned long gfn, 
mfn_t mfn,
         new_entry.mfn = mfn_x(mfn);
 
         /* Safe to read-then-write because we hold the p2m lock */
-        if ( ept_entry->mfn == new_entry.mfn )
-             need_modify_vtd_table = 0;
+        if ( ept_entry->mfn == new_entry.mfn && ept_entry->sa_p2mt == 
new_entry.sa_p2mt )
+            need_modify_vtd_table = 0;
 
         ept_p2m_type_to_flags(&new_entry, p2mt, p2ma);
     }
diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index 6a06e9f..f9e55da 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -811,7 +811,7 @@ void p2m_change_type_range(struct domain *d,
 }
 
 /* Returns: 0 for success, -errno for failure */
-static int set_typed_p2m_entry(struct domain *d, unsigned long gfn, mfn_t mfn,
+int set_typed_p2m_entry(struct domain *d, unsigned long gfn, mfn_t mfn,
                                p2m_type_t gfn_p2mt, p2m_access_t access)
 {
     int rc = 0;
diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c
index cc12735..a7c7748 100644
--- a/xen/drivers/passthrough/iommu.c
+++ b/xen/drivers/passthrough/iommu.c
@@ -144,6 +144,59 @@ static void __hwdom_init check_hwdom_reqs(struct domain *d)
     iommu_dom0_strict = 1;
 }
 
+int rwmem_change_entry_type(struct domain *d, unsigned long gfn, unsigned long 
nr_gfns, p2m_type_t nt)
+{
+
+    p2m_type_t ot;
+    int rc = 0;
+    p2m_access_t a;
+    mfn_t omfn;
+    unsigned long i;
+    struct p2m_domain *p2m = p2m_get_hostp2m(d);
+
+    if ( !paging_mode_translate(d) )
+        return -EIO;
+
+    i = gfn;
+    while ( i <= gfn + nr_gfns ) {
+        omfn = p2m->get_entry(p2m, i, &ot, &a, 0, NULL);
+        rc = set_typed_p2m_entry(d, i, omfn, nt, 0);
+        if ( rc != 0 ) {
+            printk(XENLOG_ERR "Unable to set entry for %"PRIx64"\n", i);
+            break;
+        }
+        i++;
+    }
+    return rc;
+}
+
+static void rwmem_regions_map(struct domain *d)
+{
+    struct hvm_iommu *hd = domain_hvm_iommu(d);
+    struct rwmem_range *rwmem;
+    int rc = 0;
+
+    list_for_each_entry ( rwmem, &hd->arch.rwmem_ranges, list )
+    {
+        if ( rwmem->end >= rwmem->start )
+
+            rc = rwmem_change_entry_type(d, rwmem->start, rwmem->end - 
rwmem->start,
+                                         p2m_sys_rw);
+            if ( rc != 0 ) {
+                printk(XENLOG_ERR "Could not change type for region 
[%"PRIx64",%"PRIx64"]\n",
+                       rwmem->start, rwmem->end);
+                return;
+            }
+        }
+        else
+        {
+            printk(XENLOG_ERR "Bad RW memory region, %"PRIx64" > %"PRIx64"\n",
+                   rwmem->start, rwmem->end);
+            return;
+        }
+}
+}
+
 void __hwdom_init iommu_hwdom_init(struct domain *d)
 {
     struct hvm_iommu *hd = domain_hvm_iommu(d);
@@ -174,7 +227,7 @@ void __hwdom_init iommu_hwdom_init(struct domain *d)
                 process_pending_softirqs();
         }
     }
-
+    rwmem_regions_map(d);
     return hd->platform_ops->hwdom_init(d);
 }
 
diff --git a/xen/drivers/passthrough/vtd/iommu.c 
b/xen/drivers/passthrough/vtd/iommu.c
index 2e113d7..2d0546e 100644
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -1655,6 +1655,7 @@ static void iommu_domain_teardown(struct domain *d)
 {
     struct hvm_iommu *hd = domain_hvm_iommu(d);
     struct mapped_rmrr *mrmrr, *tmp;
+    struct rwmem_range *rwrange, *rwtmp;
 
     if ( list_empty(&acpi_drhd_units) )
         return;
@@ -1665,6 +1666,12 @@ static void iommu_domain_teardown(struct domain *d)
         xfree(mrmrr);
     }
 
+    list_for_each_entry_safe ( rwrange, rwtmp, &hd->arch.rwmem_ranges, list )
+    {
+        list_del(&rwrange->list);
+        xfree(rwrange);
+    }
+
     if ( iommu_use_hap_pt(d) )
         return;
 
diff --git a/xen/include/asm-x86/p2m.h b/xen/include/asm-x86/p2m.h
index a95521d..5872d0a 100644
--- a/xen/include/asm-x86/p2m.h
+++ b/xen/include/asm-x86/p2m.h
@@ -527,7 +527,8 @@ void p2m_memory_type_changed(struct domain *d);
 
 int p2m_is_logdirty_range(struct p2m_domain *, unsigned long start,
                           unsigned long end);
-
+int set_typed_p2m_entry(struct domain *d, unsigned long gfn, mfn_t mfn,
+                               p2m_type_t gfn_p2mt, p2m_access_t access);
 /* Set mmio addresses in the p2m table (for pass-through) */
 int set_mmio_p2m_entry(struct domain *d, unsigned long gfn, mfn_t mfn,
                        p2m_access_t access);
-- 
1.7.10.4


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