hvmloader: Move acpi_info structure out from low memory.

This avoids a conflict with SeaBIOS's memory management. Moreover
there is no reason that acp_info must live below 1MB, and moving it
out actually simplifies our code.

Signed-off-by: Keir Fraser <keir@xen.org>

6 files changed, 24 insertions, 54 deletions

diff --git a/tools/firmware/hvmloader/acpi/build.c b/tools/firmware/hvmloader/acpi/build.c
index c902885080..02cdf14ad1 100644
--- a/tools/firmware/hvmloader/acpi/build.c
+++ b/tools/firmware/hvmloader/acpi/build.c
@@ -276,7 +276,7 @@ static int construct_secondary_tables(unsigned long *table_ptrs,
 
 void acpi_build_tables(struct acpi_config *config, unsigned int physical)
 {
-    struct acpi_info *acpi_info = (struct acpi_info *)ACPI_INFO_PHYSICAL_ADDRESS;
+    struct acpi_info *acpi_info;
     struct acpi_20_rsdp *rsdp;
     struct acpi_20_rsdt *rsdt;
     struct acpi_20_xsdt *xsdt;
@@ -287,6 +287,9 @@ void acpi_build_tables(struct acpi_config *config, unsigned int physical)
     unsigned long        secondary_tables[16];
     int                  nr_secondaries, i;
 
+    /* Allocate and initialise the acpi info area. */
+    mem_hole_populate_ram(ACPI_INFO_PHYSICAL_ADDRESS >> PAGE_SHIFT, 1);
+    acpi_info = (struct acpi_info *)ACPI_INFO_PHYSICAL_ADDRESS;
     memset(acpi_info, 0, sizeof(*acpi_info));
 
     /*
diff --git a/tools/firmware/hvmloader/acpi/dsdt.asl b/tools/firmware/hvmloader/acpi/dsdt.asl
index 0549d7b607..8ae90db2b1 100644
--- a/tools/firmware/hvmloader/acpi/dsdt.asl
+++ b/tools/firmware/hvmloader/acpi/dsdt.asl
@@ -61,8 +61,8 @@ DefinitionBlock ("DSDT.aml", "DSDT", 2, "Xen", "HVM", 0)
 
     Scope (\_SB)
     {
-       /* ACPI_INFO_PHYSICAL_ADDRESS == 0x9F000 */
-       OperationRegion(BIOS, SystemMemory, 0x9F000, 24)
+       /* ACPI_INFO_PHYSICAL_ADDRESS == 0xFC000000 */
+       OperationRegion(BIOS, SystemMemory, 0xFC000000, 24)
        Field(BIOS, ByteAcc, NoLock, Preserve) {
            UAR1, 1,
            UAR2, 1,
diff --git a/tools/firmware/hvmloader/config.h b/tools/firmware/hvmloader/config.h
index 079416613e..d911352e82 100644
--- a/tools/firmware/hvmloader/config.h
+++ b/tools/firmware/hvmloader/config.h
@@ -54,18 +54,17 @@ extern struct bios_config seabios_config;
 #define PCI_MEM_END         0xfc000000
 extern unsigned long pci_mem_start, pci_mem_end;
 
-/* Reserved for special BIOS mappings, etc. */
-#define RESERVED_MEMBASE    0xfc000000
 
 /* Memory map. */
 #define SCRATCH_PHYSICAL_ADDRESS      0x00010000
 #define HYPERCALL_PHYSICAL_ADDRESS    0x00080000
-#define ACPI_INFO_PHYSICAL_ADDRESS    0x0009F000
 #define VGABIOS_PHYSICAL_ADDRESS      0x000C0000
 #define HVMLOADER_PHYSICAL_ADDRESS    0x00100000
-
-#define ACPI_INFO_SIZE                     0xC00
-#define ACPI_INFO_PHYSICAL_END (ACPI_INFO_PHYSICAL_ADDRESS + ACPI_INFO_SIZE)
+/* Special BIOS mappings, etc. are allocated from here upwards... */
+#define RESERVED_MEMBASE              0xFC000000
+/* NB. ACPI_INFO_PHYSICAL_ADDRESS *MUST* match definition in acpi/dsdt.asl! */
+#define ACPI_INFO_PHYSICAL_ADDRESS    0xFC000000
+#define RESERVED_MEMORY_DYNAMIC       0xFC001000
 
 extern unsigned long scratch_start;
 
diff --git a/tools/firmware/hvmloader/e820.c b/tools/firmware/hvmloader/e820.c
index 8e68e8c9a3..3b50dd015d 100644
--- a/tools/firmware/hvmloader/e820.c
+++ b/tools/firmware/hvmloader/e820.c
@@ -81,55 +81,24 @@ int build_e820_table(struct e820entry *e820,
     /* Lowmem must be at least 512K to keep Windows happy) */
     ASSERT ( lowmem_reserved_base > 512<<10 );
 
+    ASSERT ( bios_image_base < 0x100000 );
+
     /*
-     * Lowmem reservation must either cover the ACPI info region
-     * entirely or not at all. Sitting half way through suggests
-     * something funny is going on.
+     * 0x0-lowmem_reserved_base: Ordinary RAM.
      */
-    ASSERT ( lowmem_reserved_base < ACPI_INFO_PHYSICAL_ADDRESS ||
-             lowmem_reserved_base > ACPI_INFO_PHYSICAL_END );
-
-    ASSERT ( bios_image_base < 0x100000 );
+    e820[nr].addr = 0x00000;
+    e820[nr].size = lowmem_reserved_base;
+    e820[nr].type = E820_RAM;
+    nr++;
 
-    if ( lowmem_reserved_base < ACPI_INFO_PHYSICAL_ADDRESS )
-    {
-        /*
-         * 0x0-lowmem_reserved_base: Ordinary RAM.
-         */
-        e820[nr].addr = 0x00000;
-        e820[nr].size = lowmem_reserved_base;
-        e820[nr].type = E820_RAM;
-        nr++;
-    }
-    else
+    /* lowmem_reserved_base-0xA0000: reserved by BIOS implementation. */
+    if ( lowmem_reserved_base < 0xA0000 )
     {
-        /* 0x0-ACPI_INFO: Ordinary RAM. */
-        e820[nr].addr = 0x00000;
-        e820[nr].size = ACPI_INFO_PHYSICAL_ADDRESS;
-        e820[nr].type = E820_RAM;
-        nr++;
-
-        /* ACPI INFO: Reserved. */
-        e820[nr].addr = ACPI_INFO_PHYSICAL_ADDRESS;
-        e820[nr].size = ACPI_INFO_SIZE;
+        /* Reserved for internal use. */
+        e820[nr].addr = lowmem_reserved_base;
+        e820[nr].size = 0xA0000-lowmem_reserved_base;
         e820[nr].type = E820_RESERVED;
         nr++;
-
-        /* ACPI_INFO-lowmem_reserved_base: Ordinary RAM. */
-        e820[nr].addr = ACPI_INFO_PHYSICAL_END;
-        e820[nr].size = lowmem_reserved_base - ACPI_INFO_PHYSICAL_END;
-        e820[nr].type = E820_RAM;
-        nr++;
-    }
-
-    /* lowmem_reserved_base-0xa00000: reserved by BIOS implementation. */
-    if ( lowmem_reserved_base < 0xA0000 )
-    {
-            /* Reserved for internal use. */
-            e820[nr].addr = lowmem_reserved_base;
-            e820[nr].size = 0xA0000-lowmem_reserved_base;
-            e820[nr].type = E820_RESERVED;
-            nr++;
     }
 
     /*
diff --git a/tools/firmware/hvmloader/rombios.c b/tools/firmware/hvmloader/rombios.c
index fa38014354..d5831aa9cf 100644
--- a/tools/firmware/hvmloader/rombios.c
+++ b/tools/firmware/hvmloader/rombios.c
@@ -47,7 +47,6 @@ static void rombios_setup_e820(void)
 {
     /*
      * 0x9E000-0x09F000: Stack.
-     * 0x9F000-0x09C000: ACPI info.
      * 0x9FC00-0x0A0000: Extended BIOS Data Area (EBDA).
      * ...
      * 0xE0000-0x0F0000: PC-specific area. We place various tables here.
diff --git a/tools/firmware/hvmloader/util.c b/tools/firmware/hvmloader/util.c
index 0801fb6aac..c2ba855c4a 100644
--- a/tools/firmware/hvmloader/util.c
+++ b/tools/firmware/hvmloader/util.c
@@ -343,7 +343,7 @@ void mem_hole_populate_ram(xen_pfn_t mfn, uint32_t nr_mfns)
     }
 }
 
-static uint32_t reserve = RESERVED_MEMBASE - 1;
+static uint32_t reserve = RESERVED_MEMORY_DYNAMIC - 1;
 
 xen_pfn_t mem_hole_alloc(uint32_t nr_mfns)
 {