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accdadce98
The policy of vART is that software in native can run in
VM too. And in native side, the relationship between the
ART hardware and TSC is:
pTSC = (pART * M) / N + pAdjust
The vART solution is:
- Present the ART capability to guest through CPUID leaf
15H for M/N which identical to the physical values.
- PT devices see the pART (vART = pART).
- Guest expect: vTSC = vART * M / N + vAdjust.
- VMCS.OFFSET = vTSC - pTSC = vAdjust - pAdjust.
So to support vART, we should do the following:
1. if vAdjust and vTSC are changed by guest, we should change
VMCS.OFFSET accordingly.
2. Make the assumption that the pAjust is never touched by ACRN.
For #1, commit "a958fea hv: emulate IA32_TSC_ADJUST MSR" has implementation
it. And for #2, acrn never touch pAdjust.
--
v2 -> v3:
- Add comment when handle guest TSC_ADJUST and TSC accessing.
- Initialize the VMCS.OFFSET = vAdjust - pAdjust.
v1 -> v2
Refine commit message to describe the whole vART solution.
Tracked-On: #3501
Signed-off-by: Kaige Fu <kaige.fu@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>