The design of ACRN CPU performance management is to let hardware
do the autonomous frequency selection(or set to a fixed value),
and remove guest's ability to control CPU frequency.
This patch is to remove guest's ability to control CPU frequency by
removing the guests' HWP/EIST CPUIDs and blocking the related MSR
accesses. Including:
- Remove CPUID.06H:EAX[7..11] (HWP)
- Remove CPUID.01H:ECX[7] (EIST)
- Inject #GP(0) upon accesses to MSR_IA32_PM_ENABLE,
MSR_IA32_HWP_CAPABILITIES, MSR_IA32_HWP_REQUEST,
MSR_IA32_HWP_STATUS, MSR_IA32_HWP_INTERRUPT,
MSR_IA32_HWP_REQUEST_PKG
- Emulate MSR_IA32_PERF_CTL. Value written to MSR_IA32_PERF_CTL
is just stored for reading. This is like how the native
environment would behavior when EIST is disabled from BIOS.
- Emulate MSR_IA32_PERF_STATUS by filling it with base frequency
state. This is consistent with Windows, which displays current
frequency as base frequency when running in VM.
- Hide the IA32_MISC_ENABLE bit 16 (EIST enable) from guests.
This bit is dependent to CPUID.01H:ECX[7] according to SDM.
- Remove CPID.06H:ECX[0] (hardware coordination feedback)
- Inject #GP(0) upon accesses to IA32_MPERF, IA32_APERF
Also DM do not need to generate _PSS/_PPC for post-launched VMs
anymore. This is done by letting hypercall HC_PM_GET_CPU_STATE sub
command ACRN_PMCMD_GET_PX_CNT and ACRN_PMCMD_GET_PX_DATA return (-1).
Tracked-On: #8168
Signed-off-by: Wu Zhou <wu.zhou@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
6a430de814