iommu/x86: introduce a generic IVMD/RMRR range validity helper

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>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

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(const char *prefix, mfn_t start, mfn_t end);
+
 #endif /* !__ARCH_X86_IOMMU_H__ */
 /*
  * Local variables:

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("IVMD", maddr_to_mfn(base),
+                                maddr_to_mfn(limit)) )
+        return -EIO;
 
     if ( ivmd_block->header.flags & ACPI_IVMD_EXCLUSION_RANGE )
         exclusion = true;

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(const char *prefix, mfn_t start, mfn_t end)
+{
+    mfn_t addr;
+
+    if ( e820_all_mapped(mfn_to_maddr(start), mfn_to_maddr(end) + PAGE_SIZE,
+                         E820_RESERVED) )
+        return true;
+
+    printk(XENLOG_WARNING
+           "%s: [%#" PRI_mfn " ,%#" PRI_mfn "] is not (entirely) in reserved memory\n",
+           prefix, mfn_x(start), mfn_x(end));
+
+    for ( addr = start; mfn_x(addr) <= mfn_x(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_ERR
+                   "%s: page at %#" PRI_mfn " couldn't be reserved\n",
+                   prefix, 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_ERR
+               "%s: page at %#" PRI_mfn " can't be converted\n",
+               prefix, mfn_x(addr));
+        return false;
+    }
+
+    return true;
+}
+
 /*
  * Local variables:
  * mode: C