For physical RTC is monotonic growth, ensure vRTC monotonicity.
Periodical calibration and physical RTC modification may have
impact. Check it before reading
Tracked-On: #7440
Signed-off-by: Yuanyuan Zhao <yuanyuan.zhao@linux.intel.com>
Reviewed-by: Junjie Mao <junjie.mao@intel.com>
VRTC for hv used to ignore writes to vRTC register.
This patch add time modification to vRTC.
Add base RTC time and TSC offset to get the current time. Convert
current time to vRTC register values (`struct rtcdev`). Then
modify a register, and calculate a new time. Get RTC offset by
substrcting new time from current time.
Thereafter, add RTC offset also when get current time. Then user
can get the modified time.
Tracked-On: #7440
Signed-off-by: Yuanyuan Zhao <yuanyuan.zhao@linux.intel.com>
Reviewed-by: Junjie Mao <junjie.mao@intel.com>
Current code would read physical RTC register and return it directly to guest.
This patch would read a base physical RTC time and a base physical TSC time
at initialize stage. Then when guest tries to read vRTC time, ACRN HV would
read the real TSC time and use the TSC offset to calculate the real RTC time.
This patch only support BIN data mode and 24 hour mode.
BCD data mode and 12 hour mode will add in other patch.
The accuracy of clock provided by this patch is limited by TSC, and will
be improved in a following patch also.
Tracked-On: #7440
Signed-off-by: Yuanyuan Zhao <yuanyuan.zhao@linux.intel.com>
Reviewed-by: Junjie Mao <junjie.mao@intel.com>
Yuanyuan Zhao