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path: root/hw/kvm/i8254.c
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2012-08-14kvm: i8254: Finish time conversion fixJan Kiszka1-4/+10
0cdd3d1444 fixed reading back the counter load time from the kernel while assuming the kernel would always update its load time on writing the state. That is only true for channel 1, and so pit_get_channel_info returned wrong output pin states for high counter values. Fix this by applying the offset also on kvm_pit_put. Now we also need to update the offset when we write the state while the VM is stopped as it keeps on changing in that state. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-14kvm: i8254: Cache kernel clock offset in KVMPITStateJan Kiszka1-14/+24
To prepare the final fix for clock calibration issues with the in-kernel PIT, we want to cache the offset between vmclock and the clock used by the in-kernel PIT. So far, we only need to update it when the VM state changes between running and stopped because we only read the in-kernel PIT state while the VM is running. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-06-11kvm: i8254: Fix conversion of in-kernel to userspace stateJan Kiszka1-5/+52
Due to a offset between the clock used to generate the in-kernel count_load_time (CLOCK_MONOTONIC) and the clock used for processing this in userspace (vm_clock), reading back the output of PIT channel 2 via port 0x61 was broken. One use cases that suffered from it was the CPU frequency calibration of SeaBIOS, which also affected IDE/AHCI timeouts. This fixes it by calibrating the offset between both clocks on kvm_pit_get and adjusting the kernel value before saving it in the userspace state. As the calibration only works while the vm_clock is running, we cache the in-kernel state across stopped phases. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-07kvm: x86: Add user space part for in-kernel i8254Jan Kiszka1-0/+254
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>