[PATCH 2/4] iommu/x86: introduce a generic IVMD/RMRR range validity helper

[Roger Pau Monne <roger.pau@citrix.com>]

IVMD and RMRR ranges are functionally equivalent, and as so could use the same
validity checker.

Move the IVMD to x86 common IOMMU code and adjust the function to take a pair
of [start, end) mfn parameters.

So far only the AMD-Vi side is adjusted to use the newly introduced helper, the
VT-d side will be adjusted in a further change.

No functional change intended.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
---
 xen/arch/x86/include/asm/iommu.h         |  3 ++
 xen/drivers/passthrough/amd/iommu_acpi.c | 38 ++------------------
 xen/drivers/passthrough/x86/iommu.c      | 46 ++++++++++++++++++++++++
 3 files changed, 52 insertions(+), 35 deletions(-)

diff --git a/xen/arch/x86/include/asm/iommu.h b/xen/arch/x86/include/asm/iommu.h
index 15a848ddc329..5c7e37331aad 100644
--- a/xen/arch/x86/include/asm/iommu.h
+++ b/xen/arch/x86/include/asm/iommu.h
@@ -135,6 +135,9 @@ struct page_info *__must_check iommu_alloc_pgtable(struct domain_iommu *hd,
                                                    uint64_t contig_mask);
 void iommu_queue_free_pgtable(struct domain_iommu *hd, struct page_info *pg);
 
+/* Check [start, end) unity map range for correctness. */
+bool iommu_unity_region_ok(mfn_t start, mfn_t end);
+
 #endif /* !__ARCH_X86_IOMMU_H__ */
 /*
  * Local variables:
diff --git a/xen/drivers/passthrough/amd/iommu_acpi.c b/xen/drivers/passthrough/amd/iommu_acpi.c
index ca70f4f3ae2c..40468dbbccf3 100644
--- a/xen/drivers/passthrough/amd/iommu_acpi.c
+++ b/xen/drivers/passthrough/amd/iommu_acpi.c
@@ -405,41 +405,9 @@ static int __init parse_ivmd_block(const struct acpi_ivrs_memory *ivmd_block)
         return 0;
     }
 
-    if ( !e820_all_mapped(base, limit + PAGE_SIZE, E820_RESERVED) )
-    {
-        paddr_t addr;
-
-        AMD_IOMMU_WARN("IVMD: [%lx,%lx) is not (entirely) in reserved memory\n",
-                       base, limit + PAGE_SIZE);
-
-        for ( addr = base; addr <= limit; addr += PAGE_SIZE )
-        {
-            unsigned int type = page_get_ram_type(maddr_to_mfn(addr));
-
-            if ( type == RAM_TYPE_UNKNOWN )
-            {
-                if ( e820_add_range(addr, addr + PAGE_SIZE,
-                                    E820_RESERVED) )
-                    continue;
-                AMD_IOMMU_ERROR("IVMD: page at %lx couldn't be reserved\n",
-                                addr);
-                return -EIO;
-            }
-
-            /*
-             * Types which aren't RAM are considered good enough.
-             * Note that a page being partially RESERVED, ACPI or UNUSABLE will
-             * force Xen into assuming the whole page as having that type in
-             * practice.
-             */
-            if ( type & (RAM_TYPE_RESERVED | RAM_TYPE_ACPI |
-                         RAM_TYPE_UNUSABLE) )
-                continue;
-
-            AMD_IOMMU_ERROR("IVMD: page at %lx can't be converted\n", addr);
-            return -EIO;
-        }
-    }
+    if ( !iommu_unity_region_ok(maddr_to_mfn(base),
+                                maddr_to_mfn(limit + PAGE_SIZE)) )
+        return -EIO;
 
     if ( ivmd_block->header.flags & ACPI_IVMD_EXCLUSION_RANGE )
         exclusion = true;
diff --git a/xen/drivers/passthrough/x86/iommu.c b/xen/drivers/passthrough/x86/iommu.c
index c90755ff58fa..63d4cb898218 100644
--- a/xen/drivers/passthrough/x86/iommu.c
+++ b/xen/drivers/passthrough/x86/iommu.c
@@ -792,6 +792,52 @@ static int __init cf_check adjust_irq_affinities(void)
 }
 __initcall(adjust_irq_affinities);
 
+bool __init iommu_unity_region_ok(mfn_t start, mfn_t end)
+{
+    mfn_t addr;
+
+    if ( e820_all_mapped(mfn_to_maddr(start), mfn_to_maddr(end),
+                         E820_RESERVED) )
+        return true;
+
+    printk(XENLOG_WARNING "IOMMU: [%#" PRI_mfn " ,%#" PRI_mfn
+           ") is not (entirely) in reserved memory\n",
+           mfn_x(start), mfn_x(end));
+
+    for ( addr = start; !mfn_eq(addr, end); mfn_add(addr, 1) )
+    {
+        unsigned int type = page_get_ram_type(addr);
+
+        if ( type == RAM_TYPE_UNKNOWN )
+        {
+            if ( e820_add_range(mfn_to_maddr(addr),
+                                mfn_to_maddr(addr) + PAGE_SIZE, E820_RESERVED) )
+                continue;
+            printk(XENLOG_WARNING
+                   "IOMMU: page at %#" PRI_mfn " couldn't be reserved\n",
+                   mfn_x(addr));
+            return false;
+        }
+
+        /*
+         * Types which aren't RAM are considered good enough.
+         * Note that a page being partially RESERVED, ACPI or UNUSABLE will
+         * force Xen into assuming the whole page as having that type in
+         * practice.
+         */
+        if ( type & (RAM_TYPE_RESERVED | RAM_TYPE_ACPI |
+                     RAM_TYPE_UNUSABLE) )
+            continue;
+
+        printk(XENLOG_WARNING
+               "IOMMU: page at %#" PRI_mfn " can't be converted\n",
+               mfn_x(addr));
+        return false;
+    }
+
+    return true;
+}
+
 /*
  * Local variables:
  * mode: C
-- 
2.43.0