kvm: x86: Add user space part for in-kernel i8254

This provides the required user space stubs to enable the in-kernel
i8254 emulation of KVM.

The in-kernel model supports lost tick compensation according to the
"delay" policy. This is enabled by default and can be switched off via a
device property.

Depending on the feature set of the host kernel (before 2.6.32), we may
have to disable the HPET or lack sound output from the PC speaker.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Jan Kiszka 2012-03-02 20:28:49 +01:00 committed by Avi Kivity
parent 8a7c73932e
commit 5d17c0d2df
4 changed files with 278 additions and 3 deletions

14
hw/pc.c
View file

@ -1096,7 +1096,13 @@ void pc_basic_device_init(ISABus *isa_bus, qemu_irq *gsi,
register_ioport_write(0xf0, 1, 1, ioportF0_write, NULL);
if (!no_hpet) {
/*
* Check if an HPET shall be created.
*
* Without KVM_CAP_PIT_STATE2, we cannot switch off the in-kernel PIT
* when the HPET wants to take over. Thus we have to disable the latter.
*/
if (!no_hpet && (!kvm_irqchip_in_kernel() || kvm_has_pit_state2())) {
hpet = sysbus_try_create_simple("hpet", HPET_BASE, NULL);
if (hpet) {
@ -1112,7 +1118,11 @@ void pc_basic_device_init(ISABus *isa_bus, qemu_irq *gsi,
qemu_register_boot_set(pc_boot_set, *rtc_state);
pit = pit_init(isa_bus, 0x40, pit_isa_irq, pit_alt_irq);
if (kvm_irqchip_in_kernel()) {
pit = kvm_pit_init(isa_bus, 0x40);
} else {
pit = pit_init(isa_bus, 0x40, pit_isa_irq, pit_alt_irq);
}
if (hpet) {
/* connect PIT to output control line of the HPET */
qdev_connect_gpio_out(hpet, 0, qdev_get_gpio_in(&pit->qdev, 0));