hw/i386/pc: add max combined fw size as machine configuration option

At Hewlett Packard Inc. we have a need for increased fw size to enable testing of our custom fw.

Rebase v6 patch to d73c46e4

Signed-off-by: Erich McMillan <erich.mcmillan@hp.com>
Message-Id: <20201208155338.14-1-erich.mcmillan@hp.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 3 insertions, 12 deletions

diff --git a/hw/i386/pc_sysfw.c b/hw/i386/pc_sysfw.c
index b6c0822fe3..f8bd3a8b85 100644
--- a/hw/i386/pc_sysfw.c
+++ b/hw/i386/pc_sysfw.c
@@ -39,15 +39,6 @@
 #include "hw/block/flash.h"
 #include "sysemu/kvm.h"
 
-/*
- * We don't have a theoretically justifiable exact lower bound on the base
- * address of any flash mapping. In practice, the IO-APIC MMIO range is
- * [0xFEE00000..0xFEE01000] -- see IO_APIC_DEFAULT_ADDRESS --, leaving free
- * only 18MB-4KB below 4G. For now, restrict the cumulative mapping to 8MB in
- * size.
- */
-#define FLASH_SIZE_LIMIT (8 * MiB)
-
 #define FLASH_SECTOR_SIZE 4096
 
 static void pc_isa_bios_init(MemoryRegion *rom_memory,
@@ -140,7 +131,7 @@ void pc_system_flash_cleanup_unused(PCMachineState *pcms)
  * Stop at the first pcms->flash[0] lacking a block backend.
  * Set each flash's size from its block backend.  Fatal error if the
  * size isn't a non-zero multiple of 4KiB, or the total size exceeds
- * FLASH_SIZE_LIMIT.
+ * pcms->max_fw_size.
  *
  * If pcms->flash[0] has a block backend, its memory is passed to
  * pc_isa_bios_init().  Merging several flash devices for isa-bios is
@@ -182,10 +173,10 @@ static void pc_system_flash_map(PCMachineState *pcms,
         }
         if ((hwaddr)size != size
             || total_size > HWADDR_MAX - size
-            || total_size + size > FLASH_SIZE_LIMIT) {
+            || total_size + size > pcms->max_fw_size) {
             error_report("combined size of system firmware exceeds "
                          "%" PRIu64 " bytes",
-                         FLASH_SIZE_LIMIT);
+                         pcms->max_fw_size);
             exit(1);
         }