Remove support for Xen PV domU kernels. Support for HVM domU kernels

remains.  Xen is planning to phase out support for PV upstream since it
is harder to maintain and has more overhead.  Modern x86 CPUs include
virtualization extensions that support HVM guests instead of PV guests.
In addition, the PV code was i386 only and not as well maintained recently
as the HVM code.
- Remove the i386-only NATIVE option that was used to disable certain
  components for PV kernels.  These components are now standard as they
  are on amd64.
- Remove !XENHVM bits from PV drivers.
- Remove various shims required for XEN (e.g. PT_UPDATES_FLUSH, LOAD_CR3,
  etc.)
- Remove duplicate copy of <xen/features.h>.
- Remove unused, i386-only xenstored.h.

Differential Revision:	https://reviews.freebsd.org/D2362
Reviewed by:	royger
Tested by:	royger (i386/amd64 HVM domU and amd64 PVH dom0)
Relnotes:	yes

1 files changed, 0 insertions, 9 deletions

diff --git a/sys/kern/subr_trap.c b/sys/kern/subr_trap.c
index 744c064f3a1c..93f7557aef63 100644
--- a/sys/kern/subr_trap.c
+++ b/sys/kern/subr_trap.c
@@ -80,12 +80,6 @@ __FBSDID("$FreeBSD$");
 #include <net/vnet.h>
 #endif
 
-#ifdef XEN
-#include <vm/vm.h>
-#include <vm/vm_param.h>
-#include <vm/pmap.h>
-#endif
-
 #ifdef	HWPMC_HOOKS
 #include <sys/pmckern.h>
 #endif
@@ -136,9 +130,6 @@ userret(struct thread *td, struct trapframe *frame)
 	 * Let the scheduler adjust our priority etc.
 	 */
 	sched_userret(td);
-#ifdef XEN
-	PT_UPDATES_FLUSH();
-#endif
 
 	/*
 	 * Check for misbehavior.