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

8 files changed, 5 insertions, 88 deletions

diff --git a/sys/x86/include/segments.h b/sys/x86/include/segments.h
index a5c1ea4..65b5870 100644
--- a/sys/x86/include/segments.h
+++ b/sys/x86/include/segments.h
@@ -46,11 +46,7 @@
  */
 #define	SEL_RPL_MASK	3		/* requester priv level */
 #define	ISPL(s)		((s)&3)		/* priority level of a selector */
-#ifdef XEN
-#define	SEL_KPL		1		/* kernel priority level */
-#else
 #define	SEL_KPL		0		/* kernel priority level */
-#endif
 #define	SEL_UPL		3		/* user priority level */
 #define	ISLDT(s)	((s)&SEL_LDT)	/* is it local or global */
 #define	SEL_LDT		4		/* local descriptor table */
@@ -244,11 +240,7 @@ union descriptor {
 #define	GBIOSUTIL_SEL	16	/* BIOS interface (Utility) */
 #define	GBIOSARGS_SEL	17	/* BIOS interface (Arguments) */
 #define	GNDIS_SEL	18	/* For the NDIS layer */
-#ifdef XEN
-#define	NGDT		9
-#else
 #define	NGDT		19
-#endif
 
 /*
  * Entries in the Local Descriptor Table (LDT)
diff --git a/sys/x86/x86/busdma_bounce.c b/sys/x86/x86/busdma_bounce.c
index f5c1b92..dcdeafa 100644
--- a/sys/x86/x86/busdma_bounce.c
+++ b/sys/x86/x86/busdma_bounce.c
@@ -147,11 +147,6 @@ static void _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
 static int _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 				     int flags);
 
-#ifdef XEN
-#undef pmap_kextract
-#define pmap_kextract pmap_kextract_ma
-#endif
-
 /*
  * Allocate a device specific dma_tag.
  */
diff --git a/sys/x86/x86/cpu_machdep.c b/sys/x86/x86/cpu_machdep.c
index 846a123..f8d1f08 100644
--- a/sys/x86/x86/cpu_machdep.c
+++ b/sys/x86/x86/cpu_machdep.c
@@ -100,15 +100,6 @@ __FBSDID("$FreeBSD$");
 #include <vm/vm_pager.h>
 #include <vm/vm_param.h>
 
-#ifdef XEN
-/* XEN includes */
-#include <xen/xen-os.h>
-#include <xen/hypervisor.h>
-#include <machine/xen/xenvar.h>
-#include <machine/xen/xenfunc.h>
-#include <xen/xen_intr.h>
-#endif
-
 /*
  * Machine dependent boot() routine
  *
@@ -193,33 +184,6 @@ cpu_est_clockrate(int cpu_id, uint64_t *rate)
 	return (0);
 }
 
-#if defined(__i386__) && defined(XEN)
-
-static void
-idle_block(void)
-{
-
-	HYPERVISOR_sched_op(SCHEDOP_block, 0);
-}
-
-void
-cpu_halt(void)
-{
-	HYPERVISOR_shutdown(SHUTDOWN_poweroff);
-}
-
-int scheduler_running;
-
-static void
-cpu_idle_hlt(sbintime_t sbt)
-{
-
-	scheduler_running = 1;
-	enable_intr();
-	idle_block();
-}
-
-#else
 /*
  * Shutdown the CPU as much as possible
  */
@@ -230,8 +194,6 @@ cpu_halt(void)
 		halt();
 }
 
-#endif
-
 void (*cpu_idle_hook)(sbintime_t) = NULL;	/* ACPI idle hook. */
 static int	cpu_ident_amdc1e = 0;	/* AMD C1E supported. */
 static int	idle_mwait = 1;		/* Use MONITOR/MWAIT for short idle. */
@@ -263,7 +225,6 @@ cpu_idle_acpi(sbintime_t sbt)
 }
 #endif /* !PC98 */
 
-#if !defined(__i386__) || !defined(XEN)
 static void
 cpu_idle_hlt(sbintime_t sbt)
 {
@@ -295,7 +256,6 @@ cpu_idle_hlt(sbintime_t sbt)
 		__asm __volatile("sti; hlt");
 	*state = STATE_RUNNING;
 }
-#endif
 
 static void
 cpu_idle_mwait(sbintime_t sbt)
@@ -370,7 +330,7 @@ cpu_probe_amdc1e(void)
 	}
 }
 
-#if defined(__i386__) && (defined(PC98) || defined(XEN))
+#if defined(__i386__) && defined(PC98)
 void (*cpu_idle_fn)(sbintime_t) = cpu_idle_hlt;
 #else
 void (*cpu_idle_fn)(sbintime_t) = cpu_idle_acpi;
@@ -379,17 +339,15 @@ void (*cpu_idle_fn)(sbintime_t) = cpu_idle_acpi;
 void
 cpu_idle(int busy)
 {
-#if !defined(__i386__) || !defined(XEN)
 	uint64_t msr;
-#endif
 	sbintime_t sbt = -1;
 
 	CTR2(KTR_SPARE2, "cpu_idle(%d) at %d",
 	    busy, curcpu);
-#if defined(MP_WATCHDOG) && (!defined(__i386__) || !defined(XEN))
+#ifdef MP_WATCHDOG
 	ap_watchdog(PCPU_GET(cpuid));
 #endif
-#if !defined(__i386__) || !defined(XEN)
+
 	/* If we are busy - try to use fast methods. */
 	if (busy) {
 		if ((cpu_feature2 & CPUID2_MON) && idle_mwait) {
@@ -397,7 +355,6 @@ cpu_idle(int busy)
 			goto out;
 		}
 	}
-#endif
 
 	/* If we have time - switch timers into idle mode. */
 	if (!busy) {
@@ -405,14 +362,12 @@ cpu_idle(int busy)
 		sbt = cpu_idleclock();
 	}
 
-#if !defined(__i386__) || !defined(XEN)
 	/* Apply AMD APIC timer C1E workaround. */
 	if (cpu_ident_amdc1e && cpu_disable_c3_sleep) {
 		msr = rdmsr(MSR_AMDK8_IPM);
 		if (msr & AMDK8_CMPHALT)
 			wrmsr(MSR_AMDK8_IPM, msr & ~AMDK8_CMPHALT);
 	}
-#endif
 
 	/* Call main idle method. */
 	cpu_idle_fn(sbt);
@@ -422,9 +377,7 @@ cpu_idle(int busy)
 		cpu_activeclock();
 		critical_exit();
 	}
-#if !defined(__i386__) || !defined(XEN)
 out:
-#endif
 	CTR2(KTR_SPARE2, "cpu_idle(%d) at %d done",
 	    busy, curcpu);
 }
diff --git a/sys/x86/x86/identcpu.c b/sys/x86/x86/identcpu.c
index ca2b5ca..9f39d1c 100644
--- a/sys/x86/x86/identcpu.c
+++ b/sys/x86/x86/identcpu.c
@@ -1190,7 +1190,6 @@ hook_tsc_freq(void *arg __unused)
 
 SYSINIT(hook_tsc_freq, SI_SUB_CONFIGURE, SI_ORDER_ANY, hook_tsc_freq, NULL);
 
-#ifndef XEN
 static const char *const vm_bnames[] = {
 	"QEMU",				/* QEMU */
 	"Plex86",			/* Plex86 */
@@ -1281,7 +1280,6 @@ identify_hypervisor(void)
 		freeenv(p);
 	}
 }
-#endif
 
 /*
  * Final stage of CPU identification.
@@ -1314,9 +1312,7 @@ identify_cpu(void)
 	cpu_feature2 = regs[2];
 #endif
 
-#ifndef XEN
 	identify_hypervisor();
-#endif
 	cpu_vendor_id = find_cpu_vendor_id();
 
 	/*
diff --git a/sys/x86/x86/intr_machdep.c b/sys/x86/x86/intr_machdep.c
index b27df4a..d81c913 100644
--- a/sys/x86/x86/intr_machdep.c
+++ b/sys/x86/x86/intr_machdep.c
@@ -532,13 +532,6 @@ intr_shuffle_irqs(void *arg __unused)
 	struct intsrc *isrc;
 	int i;
 
-#ifdef XEN
-	/*
-	 * Doesn't work yet
-	 */
-	return;
-#endif
-
 	/* Don't bother on UP. */
 	if (mp_ncpus == 1)
 		return;
diff --git a/sys/x86/x86/local_apic.c b/sys/x86/x86/local_apic.c
index e0656ef..d75a452 100644
--- a/sys/x86/x86/local_apic.c
+++ b/sys/x86/x86/local_apic.c
@@ -1579,17 +1579,13 @@ apic_setup_io(void *dummy __unused)
 	 * Local APIC must be registered before other PICs and pseudo PICs
 	 * for proper suspend/resume order.
 	 */
-#ifndef XEN
 	intr_register_pic(&lapic_pic);
-#endif
 
 	retval = best_enum->apic_setup_io();
 	if (retval != 0)
 		printf("%s: Failed to setup I/O APICs: returned %d\n",
 		    best_enum->apic_name, retval);
-#ifdef XEN
-	return;
-#endif
+
 	/*
 	 * Finish setting up the local APIC on the BSP once we know
 	 * how to properly program the LINT pins.  In particular, this
diff --git a/sys/x86/xen/xen_intr.c b/sys/x86/xen/xen_intr.c
index 64979b1..3bc4b43 100644
--- a/sys/x86/xen/xen_intr.c
+++ b/sys/x86/xen/xen_intr.c
@@ -1,7 +1,7 @@
 /******************************************************************************
  * xen_intr.c
  *
- * Xen event and interrupt services for x86 PV and HVM guests.
+ * Xen event and interrupt services for x86 HVM guests.
  *
  * Copyright (c) 2002-2005, K A Fraser
  * Copyright (c) 2005, Intel Corporation <xiaofeng.ling@intel.com>
@@ -864,10 +864,8 @@ xen_intr_assign_cpu(struct intsrc *base_isrc, u_int apic_id)
 	u_int to_cpu, vcpu_id;
 	int error, masked;
 
-#ifdef XENHVM
 	if (xen_vector_callback_enabled == 0)
 		return (EOPNOTSUPP);
-#endif
 
 	to_cpu = apic_cpuid(apic_id);
 	vcpu_id = pcpu_find(to_cpu)->pc_vcpu_id;
diff --git a/sys/x86/xen/xen_nexus.c b/sys/x86/xen/xen_nexus.c
index f25f970..73506fc 100644
--- a/sys/x86/xen/xen_nexus.c
+++ b/sys/x86/xen/xen_nexus.c
@@ -66,14 +66,11 @@ static int
 nexus_xen_attach(device_t dev)
 {
 	int error;
-#ifndef XEN
 	device_t acpi_dev = NULL;
-#endif
 
 	nexus_init_resources();
 	bus_generic_probe(dev);
 
-#ifndef XEN
 	if (xen_initial_domain()) {
 		/* Disable some ACPI devices that are not usable by Dom0 */
 		acpi_cpu_disabled = true;
@@ -84,13 +81,10 @@ nexus_xen_attach(device_t dev)
 		if (acpi_dev == NULL)
 			panic("Unable to add ACPI bus to Xen Dom0");
 	}
-#endif
 
 	error = bus_generic_attach(dev);
-#ifndef XEN
 	if (xen_initial_domain() && (error == 0))
 		acpi_install_wakeup_handler(device_get_softc(acpi_dev));
-#endif
 
 	return (error);
 }