HVM firmware passthrough ACPI processing

ACPI table passthrough support allowing additional static tables and
SSDTs (AML code) to be loaded. These additional tables are added at
the end of the secondary table list in the RSDT/XSDT tables.

Signed-off-by: Ross Philipson <ross.philipson@citrix.com>
Committed-by: Keir Fraser <keir@xen.org>

tools/firmware/hvmloader/acpi/build.c

@@ -23,6 +23,9 @@
 #include "ssdt_pm.h"
 #include "../config.h"
 #include "../util.h"
+#include <xen/hvm/hvm_xs_strings.h>
+
+#define ACPI_MAX_SECONDARY_TABLES 16
 
 #define align16(sz)        (((sz) + 15) & ~15)
 #define fixed_strcpy(d, s) strncpy((d), (s), sizeof(d))
@@ -198,6 +201,52 @@ static struct acpi_20_waet *construct_waet(void)
     return waet;
 }
 
+static int construct_passthrough_tables(unsigned long *table_ptrs,
+                                        int nr_tables)
+{
+    const char *s;
+    uint8_t *acpi_pt_addr;
+    uint32_t acpi_pt_length;
+    struct acpi_header *header;
+    int nr_added;
+    int nr_max = (ACPI_MAX_SECONDARY_TABLES - nr_tables - 1);
+    uint32_t total = 0;
+    uint8_t *buffer;
+
+    s = xenstore_read(HVM_XS_ACPI_PT_ADDRESS, NULL);
+    if ( s == NULL )
+        return 0;    
+
+    acpi_pt_addr = (uint8_t*)(uint32_t)strtoll(s, NULL, 0);
+    if ( acpi_pt_addr == NULL )
+        return 0;
+
+    s = xenstore_read(HVM_XS_ACPI_PT_LENGTH, NULL);
+    if ( s == NULL )
+        return 0;
+
+    acpi_pt_length = (uint32_t)strtoll(s, NULL, 0);
+
+    for ( nr_added = 0; nr_added < nr_max; nr_added++ )
+    {        
+        if ( (acpi_pt_length - total) < sizeof(struct acpi_header) )
+            break;
+
+        header = (struct acpi_header*)acpi_pt_addr;
+
+        buffer = mem_alloc(header->length, 16);
+        if ( buffer == NULL )
+            break;
+        memcpy(buffer, header, header->length);
+
+        table_ptrs[nr_tables++] = (unsigned long)buffer;
+        total += header->length;
+        acpi_pt_addr += header->length;
+    }
+
+    return nr_added;
+}
+
 static int construct_secondary_tables(unsigned long *table_ptrs,
                                       struct acpi_info *info)
 {
@@ -293,6 +342,9 @@ static int construct_secondary_tables(unsigned long *table_ptrs,
         }
     }
 
+    /* Load any additional tables passed through. */
+    nr_tables += construct_passthrough_tables(table_ptrs, nr_tables);
+
     table_ptrs[nr_tables] = 0;
     return nr_tables;
 }
@@ -327,7 +379,7 @@ void acpi_build_tables(struct acpi_config *config, unsigned int physical)
     struct acpi_10_fadt *fadt_10;
     struct acpi_20_facs *facs;
     unsigned char       *dsdt;
-    unsigned long        secondary_tables[16];
+    unsigned long        secondary_tables[ACPI_MAX_SECONDARY_TABLES];
     int                  nr_secondaries, i;
     unsigned long        vm_gid_addr;