diff options
Diffstat (limited to 'hw/i386')
| -rw-r--r-- | hw/i386/pc_piix.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c index acb9445362..832e20c226 100644 --- a/hw/i386/pc_piix.c +++ b/hw/i386/pc_piix.c @@ -61,6 +61,10 @@ 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 */ @@ -107,6 +111,13 @@ 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) { ram_addr_t lowmem = gigabyte_align ? 0xc0000000 : 0xe0000000; above_4g_mem_size = args->ram_size - lowmem; |