--- a/vboxdrv/include/iprt/time.h	2020-02-27 08:29:15.598443630 +0300
+++ a/vboxdrv/include/iprt/time.h	2020-02-27 09:11:28.528393987 +0300
@@ -366,6 +366,7 @@ 
  * @param   pTime       The time spec to interpret.
  * @param   pTimeval    Where to store the time as POSIX timeval.
  */
+#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 5, 99)
 DECLINLINE(struct timeval *) RTTimeSpecGetTimeval(PCRTTIMESPEC pTime, struct timeval *pTimeval)
 {
     int64_t i64 = RTTimeSpecGetMicro(pTime);
@@ -392,12 +393,14 @@ 
 {
     return RTTimeSpecAddMicro(RTTimeSpecSetSeconds(pTime, pTimeval->tv_sec), pTimeval->tv_usec);
 }
+#endif
 #endif /* various ways of detecting struct timeval */
 
 
 /* PORTME: Add struct timespec guard macro here. */
 #if defined(RTTIME_INCL_TIMESPEC) || defined(_STRUCT_TIMESPEC) || defined(_SYS__TIMESPEC_H_) || defined(TIMEVAL_TO_TIMESPEC) || defined(_TIMESPEC) \
  || (defined(RT_OS_NETBSD) && defined(_SYS_TIME_H_))
+#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 5, 99)
 /**
  * Gets the time as POSIX timespec.
  *
@@ -431,16 +434,17 @@ 
 {
     return RTTimeSpecAddNano(RTTimeSpecSetSeconds(pTime, pTimespec->tv_sec), pTimespec->tv_nsec);
 }
+#endif
 
 
+#endif /* various ways of detecting struct timespec */
+
 # ifdef _LINUX_TIME64_H
 DECLINLINE(PRTTIMESPEC) RTTimeSpecSetTimespec64(PRTTIMESPEC pTime, const struct timespec64 *pTimeval)
 {
     return RTTimeSpecAddNano(RTTimeSpecSetSeconds(pTime, pTimeval->tv_sec), pTimeval->tv_nsec);
 }
-# endif
-#endif /* various ways of detecting struct timespec */
-
+#endif
 
 
 /** The offset of the unix epoch and the base for NT time (in 100ns units).
--- a/vboxdrv/r0drv/linux/time-r0drv-linux.c	2020-02-27 08:29:15.608443629 +0300
+++ a/vboxdrv/r0drv/linux/time-r0drv-linux.c	2020-02-27 09:00:17.518407138 +0300
@@ -43,8 +43,8 @@ 
      * Use ktime_get_ts, this is also what clock_gettime(CLOCK_MONOTONIC,) is using.
      */
     uint64_t u64;
-    struct timespec Ts;
-    ktime_get_ts(&Ts);
+    struct timespec64 Ts;
+    ktime_get_ts64(&Ts);
     u64 = Ts.tv_sec * RT_NS_1SEC_64 + Ts.tv_nsec;
     return u64;
 
--- a/vboxnetadp/include/iprt/time.h	2020-02-27 08:29:15.598443630 +0300
+++ a/vboxnetadp/include/iprt/time.h	2020-02-27 09:11:28.528393987 +0300
@@ -366,6 +366,7 @@ 
  * @param   pTime       The time spec to interpret.
  * @param   pTimeval    Where to store the time as POSIX timeval.
  */
+#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 5, 99)
 DECLINLINE(struct timeval *) RTTimeSpecGetTimeval(PCRTTIMESPEC pTime, struct timeval *pTimeval)
 {
     int64_t i64 = RTTimeSpecGetMicro(pTime);
@@ -392,12 +393,14 @@ 
 {
     return RTTimeSpecAddMicro(RTTimeSpecSetSeconds(pTime, pTimeval->tv_sec), pTimeval->tv_usec);
 }
+#endif
 #endif /* various ways of detecting struct timeval */
 
 
 /* PORTME: Add struct timespec guard macro here. */
 #if defined(RTTIME_INCL_TIMESPEC) || defined(_STRUCT_TIMESPEC) || defined(_SYS__TIMESPEC_H_) || defined(TIMEVAL_TO_TIMESPEC) || defined(_TIMESPEC) \
  || (defined(RT_OS_NETBSD) && defined(_SYS_TIME_H_))
+#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 5, 99)
 /**
  * Gets the time as POSIX timespec.
  *
@@ -431,16 +434,17 @@ 
 {
     return RTTimeSpecAddNano(RTTimeSpecSetSeconds(pTime, pTimespec->tv_sec), pTimespec->tv_nsec);
 }
+#endif
 
 
+#endif /* various ways of detecting struct timespec */
+
 # ifdef _LINUX_TIME64_H
 DECLINLINE(PRTTIMESPEC) RTTimeSpecSetTimespec64(PRTTIMESPEC pTime, const struct timespec64 *pTimeval)
 {
     return RTTimeSpecAddNano(RTTimeSpecSetSeconds(pTime, pTimeval->tv_sec), pTimeval->tv_nsec);
 }
-# endif
-#endif /* various ways of detecting struct timespec */
-
+#endif
 
 
 /** The offset of the unix epoch and the base for NT time (in 100ns units).
--- a/vboxnetflt/include/iprt/time.h	2020-02-27 08:29:15.588443630 +0300
+++ a/vboxnetflt/include/iprt/time.h	2020-02-27 09:11:28.528393987 +0300
@@ -366,6 +366,7 @@ 
  * @param   pTime       The time spec to interpret.
  * @param   pTimeval    Where to store the time as POSIX timeval.
  */
+#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 5, 99)
 DECLINLINE(struct timeval *) RTTimeSpecGetTimeval(PCRTTIMESPEC pTime, struct timeval *pTimeval)
 {
     int64_t i64 = RTTimeSpecGetMicro(pTime);
@@ -392,12 +393,14 @@ 
 {
     return RTTimeSpecAddMicro(RTTimeSpecSetSeconds(pTime, pTimeval->tv_sec), pTimeval->tv_usec);
 }
+#endif
 #endif /* various ways of detecting struct timeval */
 
 
 /* PORTME: Add struct timespec guard macro here. */
 #if defined(RTTIME_INCL_TIMESPEC) || defined(_STRUCT_TIMESPEC) || defined(_SYS__TIMESPEC_H_) || defined(TIMEVAL_TO_TIMESPEC) || defined(_TIMESPEC) \
  || (defined(RT_OS_NETBSD) && defined(_SYS_TIME_H_))
+#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 5, 99)
 /**
  * Gets the time as POSIX timespec.
  *
@@ -431,16 +434,17 @@ 
 {
     return RTTimeSpecAddNano(RTTimeSpecSetSeconds(pTime, pTimespec->tv_sec), pTimespec->tv_nsec);
 }
+#endif
 
 
+#endif /* various ways of detecting struct timespec */
+
 # ifdef _LINUX_TIME64_H
 DECLINLINE(PRTTIMESPEC) RTTimeSpecSetTimespec64(PRTTIMESPEC pTime, const struct timespec64 *pTimeval)
 {
     return RTTimeSpecAddNano(RTTimeSpecSetSeconds(pTime, pTimeval->tv_sec), pTimeval->tv_nsec);
 }
-# endif
-#endif /* various ways of detecting struct timespec */
-
+#endif
 
 
 /** The offset of the unix epoch and the base for NT time (in 100ns units).
--- a/vboxdrv/r0drv/linux/memobj-r0drv-linux.c	
+++ a/vboxdrv/r0drv/linux/memobj-r0drv-linux.c	
@@ -1462,7 +1462,7 @@ 
              */
             Assert(pMemLnxToMap->Core.enmType == RTR0MEMOBJTYPE_PHYS && !pMemLnxToMap->Core.u.Phys.fAllocated);
             pMemLnx->Core.pv = pMemLnxToMap->Core.u.Phys.uCachePolicy == RTMEM_CACHE_POLICY_MMIO
-                             ? ioremap_nocache(pMemLnxToMap->Core.u.Phys.PhysBase + offSub, cbSub)
+                             ? ioremap_cache(pMemLnxToMap->Core.u.Phys.PhysBase + offSub, cbSub)
                              : ioremap(pMemLnxToMap->Core.u.Phys.PhysBase + offSub, cbSub);
             if (pMemLnx->Core.pv)
             {