[PATCH 1/2] Clean up MADT Table Creation

[Beth Kon <eak@us.ibm.com>]

This patch is based on the recent patch from Vincent Minet. I split Vincent's
changes into 2 patches (to separate MADT and RSDT table cleanup, as suggested by
Marcelo) and added a bit to them. And to give credit where it is due, this
cleanup is also related to the patch Marcelo provided when the HPET addition 
tripped over the same problem. (Thanks again Marcelo :-) 

This patch moves all the table layout calculations to the same area of
acpi_bios_init. This prevents corruption problems when, in the middle of
filling in the tables, the MADT table size grows. The idea is to do all the 
layout in one section, then fill things in afterwards. It also corrects a 
problem where the madt table was memset to 0 before the final size of the 
table had been determined.

Signed-off-by: Beth Kon <eak@us.ibm.com>

diff --git a/kvm/bios/rombios32.c b/kvm/bios/rombios32.c
index cbd5f15..7f62e4f 100755
--- a/kvm/bios/rombios32.c
+++ b/kvm/bios/rombios32.c
@@ -1665,6 +1665,7 @@ void acpi_bios_init(void)
 
     addr = (addr + 7) & ~7;
     madt_addr = addr;
+    madt = (void *)(addr);
     madt_size = sizeof(*madt) +
         sizeof(struct madt_processor_apic) * MAX_CPUS +
 #ifdef BX_QEMU
@@ -1672,7 +1673,11 @@ void acpi_bios_init(void)
 #else
         sizeof(struct madt_io_apic);
 #endif
-    madt = (void *)(addr);
+    for ( i = 0; i < 16; i++ ) {
+        if ( PCI_ISA_IRQ_MASK & (1U << i) ) {
+            madt_size += sizeof(struct madt_int_override);
+        }
+    }
     addr += madt_size;
 
 #ifdef BX_QEMU
@@ -1786,7 +1791,6 @@ void acpi_bios_init(void)
                 continue;
             }
             int_override++;
-            madt_size += sizeof(struct madt_int_override);
         }
         acpi_build_table_header((struct acpi_table_header *)madt,
                                 "APIC", madt_size, 1);