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8.10.4. frequency, mode, and present
The
frequency attribute is used to set a fixed frequency, and is measured in Hz. This attribute is only relevant when the name element has a value of tsc. All other timers operate at a fixed frequency (pit, rtc).
mode determines how the time source is exposed to the guest virtual machine. This attribute is only relevant for a name value of tsc. All other timers are always emulated. Command is as follows: <timer name='tsc' frequency='NNN' mode='auto|native|emulate|smpsafe'/>. Mode definitions are given in the table.
Table 8.5. mode attribute values
| Value | Description |
|---|---|
| auto | Native if TSC is unstable, otherwise allow native TSC access. |
| native | Always allow native TSC access. |
| emulate | Always emulate TSC. |
| smpsafe | Always emulate TSC and interlock SMP |
present is used to override the default set of timers visible to the guest virtual machine..
Table 8.6. present attribute values
| Value | Description |
|---|---|
| yes | Force this timer to the visible to the guest virtual machine. |
| no | Force this timer to not be visible to the guest virtual machine. |