When running QEMU without -cpu parameter, the user usually wants a sane
default. So far, we're using the qemu64/qemu32 CPU type, which basically
means the maximum TCG can emulate.
That's a really good default when using TCG, but when running with KVM
we much rather want a default saying the maximum performance I can get.
Fortunately we just added an option that gives us the best performance
while still staying safe on the testability side of things: -cpu best.
So all we need to do is make -cpu best the default when the user doesn't
explicitly specify a CPU type.
This fixes a lot of subtile breakage in the GNU toolchain (libgmp) which
hicks up on QEMU's non-existent CPU models.
This patch also adds a new pc-1.2 machine type to stay backwards compatible
with older versions of QEMU.
Signed-off-by: Alexander Graf ag...@suse.de
---
v1 - v2:
- rebase
---
hw/pc_piix.c | 45 -
1 files changed, 36 insertions(+), 9 deletions(-)
diff --git a/hw/pc_piix.c b/hw/pc_piix.c
index eae258c..eafd383 100644
--- a/hw/pc_piix.c
+++ b/hw/pc_piix.c
@@ -127,7 +127,8 @@ static void pc_init1(MemoryRegion *system_memory,
const char *initrd_filename,
const char *cpu_model,
int pci_enabled,
- int kvmclock_enabled)
+ int kvmclock_enabled,
+ int may_cpu_best)
{
int i;
ram_addr_t below_4g_mem_size, above_4g_mem_size;
@@ -149,6 +150,9 @@ static void pc_init1(MemoryRegion *system_memory,
MemoryRegion *rom_memory;
void *fw_cfg = NULL;
+if (!cpu_model kvm_enabled() may_cpu_best) {
+cpu_model = best;
+}
pc_cpus_init(cpu_model);
if (kvmclock_enabled) {
@@ -298,7 +302,21 @@ static void pc_init_pci(ram_addr_t ram_size,
get_system_io(),
ram_size, boot_device,
kernel_filename, kernel_cmdline,
- initrd_filename, cpu_model, 1, 1);
+ initrd_filename, cpu_model, 1, 1, 1);
+}
+
+static void pc_init_pci_oldcpu(ram_addr_t ram_size,
+ const char *boot_device,
+ const char *kernel_filename,
+ const char *kernel_cmdline,
+ const char *initrd_filename,
+ const char *cpu_model)
+{
+pc_init1(get_system_memory(),
+ get_system_io(),
+ ram_size, boot_device,
+ kernel_filename, kernel_cmdline,
+ initrd_filename, cpu_model, 1, 1, 0);
}
static void pc_init_pci_no_kvmclock(ram_addr_t ram_size,
@@ -312,7 +330,7 @@ static void pc_init_pci_no_kvmclock(ram_addr_t ram_size,
get_system_io(),
ram_size, boot_device,
kernel_filename, kernel_cmdline,
- initrd_filename, cpu_model, 1, 0);
+ initrd_filename, cpu_model, 1, 0, 0);
}
static void pc_init_isa(ram_addr_t ram_size,
@@ -328,7 +346,7 @@ static void pc_init_isa(ram_addr_t ram_size,
get_system_io(),
ram_size, boot_device,
kernel_filename, kernel_cmdline,
- initrd_filename, cpu_model, 0, 1);
+ initrd_filename, cpu_model, 0, 1, 0);
}
#ifdef CONFIG_XEN
@@ -349,8 +367,8 @@ static void pc_xen_hvm_init(ram_addr_t ram_size,
}
#endif
-static QEMUMachine pc_machine_v1_1 = {
-.name = pc-1.1,
+static QEMUMachine pc_machine_v1_2 = {
+.name = pc-1.2,
.alias = pc,
.desc = Standard PC,
.init = pc_init_pci,
@@ -358,6 +376,14 @@ static QEMUMachine pc_machine_v1_1 = {
.is_default = 1,
};
+static QEMUMachine pc_machine_v1_1 = {
+.name = pc-1.1,
+.desc = Standard PC,
+.init = pc_init_pci_oldcpu,
+.max_cpus = 255,
+.is_default = 1,
+};
+
#define PC_COMPAT_1_0 \
{\
.driver = pc-sysfw,\
@@ -384,7 +410,7 @@ static QEMUMachine pc_machine_v1_1 = {
static QEMUMachine pc_machine_v1_0 = {
.name = pc-1.0,
.desc = Standard PC,
-.init = pc_init_pci,
+.init = pc_init_pci_oldcpu,
.max_cpus = 255,
.compat_props = (GlobalProperty[]) {
PC_COMPAT_1_0,
@@ -399,7 +425,7 @@ static QEMUMachine pc_machine_v1_0 = {
static QEMUMachine pc_machine_v0_15 = {
.name = pc-0.15,
.desc = Standard PC,
-.init = pc_init_pci,
+.init = pc_init_pci_oldcpu,
.max_cpus = 255,
.compat_props = (GlobalProperty[]) {
PC_COMPAT_0_15,
@@ -431,7 +457,7 @@ static QEMUMachine pc_machine_v0_15 = {
static QEMUMachine pc_machine_v0_14 = {
.name = pc-0.14,
.desc = Standard PC,
-.init = pc_init_pci,
+.init = pc_init_pci_oldcpu,
.max_cpus = 255,
.compat_props = (GlobalProperty[]) {
PC_COMPAT_0_14,
@@ -612,6 +638,7 @@ static QEMUMachine xenfv_machine = {
static void pc_machine_init(void)
{
+qemu_register_machine(pc_machine_v1_2);
