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Diffstat (limited to 'hw/i386/pc_piix.c')
-rw-r--r--hw/i386/pc_piix.c19
1 files changed, 17 insertions, 2 deletions
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 4e0dae7981..276641436e 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -61,6 +61,11 @@ static const int ide_irq[MAX_IDE_BUS] = { 14, 15 };
static bool has_pci_info;
static bool has_acpi_build = true;
static bool smbios_type1_defaults = true;
+/* Make sure that guest addresses aligned at 1Gbyte boundaries get mapped to
+ * host addresses aligned at 1Gbyte boundaries. This way we can use 1GByte
+ * pages in the host.
+ */
+static bool gigabyte_align = true;
/* PC hardware initialisation */
static void pc_init1(QEMUMachineInitArgs *args,
@@ -106,9 +111,17 @@ static void pc_init1(QEMUMachineInitArgs *args,
kvmclock_create();
}
+ /* Check whether RAM fits below 4G (leaving 1/2 GByte for IO memory).
+ * If it doesn't, we need to split it in chunks below and above 4G.
+ * In any case, try to make sure that guest addresses aligned at
+ * 1G boundaries get mapped to host addresses aligned at 1G boundaries.
+ * For old machine types, use whatever split we used historically to avoid
+ * breaking migration.
+ */
if (args->ram_size >= 0xe0000000) {
- above_4g_mem_size = args->ram_size - 0xe0000000;
- below_4g_mem_size = 0xe0000000;
+ ram_addr_t lowmem = gigabyte_align ? 0xc0000000 : 0xe0000000;
+ above_4g_mem_size = args->ram_size - lowmem;
+ below_4g_mem_size = lowmem;
} else {
above_4g_mem_size = 0;
below_4g_mem_size = args->ram_size;
@@ -157,6 +170,7 @@ static void pc_init1(QEMUMachineInitArgs *args,
if (pci_enabled) {
pci_bus = i440fx_init(&i440fx_state, &piix3_devfn, &isa_bus, gsi,
system_memory, system_io, args->ram_size,
+ below_4g_mem_size,
above_4g_mem_size,
pci_memory, ram_memory);
} else {
@@ -245,6 +259,7 @@ static void pc_init_pci(QEMUMachineInitArgs *args)
static void pc_compat_1_7(QEMUMachineInitArgs *args)
{
smbios_type1_defaults = false;
+ gigabyte_align = false;
}
static void pc_compat_1_6(QEMUMachineInitArgs *args)