Subject:[PATCH 1/2] Clean up MADT Table Creation

[Beth Kon <eak@xxxxxxxxxx>]

This patch is also based on the patch by Vincent Minet. It corrects the size
calculation of the RSDT, and checks for overflow of MAX_RSDT_ENTRIES, 
assuming that the external table entry count is contained within
MAX_RSDT_ENTRIES.

Signed-off-by: Beth Kon <eak@xxxxxxxxxx>

diff --git a/kvm/bios/rombios32.c b/kvm/bios/rombios32.c
index 7f62e4f..ac8f9c5 100755
--- a/kvm/bios/rombios32.c
+++ b/kvm/bios/rombios32.c
@@ -1626,7 +1626,7 @@ void acpi_bios_init(void)
     addr = base_addr = ram_size - ACPI_DATA_SIZE;
     rsdt_addr = addr;
     rsdt = (void *)(addr);
-    rsdt_size = sizeof(*rsdt) + external_tables * 4;
+    rsdt_size = sizeof(*rsdt);
     addr += rsdt_size;
 
     fadt_addr = addr;
@@ -1873,16 +1873,6 @@ void acpi_bios_init(void)
                              "HPET", sizeof(*hpet), 1);
 #endif
 
-    acpi_additional_tables(); /* resets cfg to required entry */
-    for(i = 0; i < external_tables; i++) {
-        uint16_t len;
-        if(acpi_load_table(i, addr, &len) < 0)
-            BX_PANIC("Failed to load ACPI table from QEMU\n");
-        rsdt->table_offset_entry[nb_rsdt_entries++] = cpu_to_le32(addr);
-        addr += len;
-        if(addr >= ram_size)
-            BX_PANIC("ACPI table overflow\n");
-    }
 #endif
 
     /* RSDT */
@@ -1895,6 +1885,19 @@ void acpi_bios_init(void)
 //  rsdt->table_offset_entry[nb_rsdt_entries++] = cpu_to_le32(hpet_addr);
     if (nb_numa_nodes > 0)
         rsdt->table_offset_entry[nb_rsdt_entries++] = cpu_to_le32(srat_addr);
+    acpi_additional_tables(); /* resets cfg to required entry */
+    /* external_tables load must occur last to 
+     * properly check for MAX_RSDT_ENTRIES overflow.
+     */
+    for(i = 0; i < external_tables; i++) {
+        uint16_t len;
+        if(acpi_load_table(i, addr, &len) < 0)
+            BX_PANIC("Failed to load ACPI table from QEMU\n");
+        rsdt->table_offset_entry[nb_rsdt_entries++] = cpu_to_le32(addr);
+        addr += len;
+        if((addr >= ram_size) || (nb_rsdt_entries > MAX_RSDT_ENTRIES))     
+            BX_PANIC("ACPI table overflow\n");
+    }
 #endif
     rsdt_size -= MAX_RSDT_ENTRIES * 4;
     rsdt_size += nb_rsdt_entries * 4;
--
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