freebsd-dev/sys/i386/xen/xen_machdep.c

/*
 *
 * Copyright (c) 2004 Christian Limpach.
 * Copyright (c) 2004-2006,2008 Kip Macy
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Christian Limpach.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/ktr.h>
#include <sys/lock.h>
#include <sys/mount.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/reboot.h>
#include <sys/rwlock.h>
#include <sys/sysproto.h>

#include <xen/xen-os.h>

#include <vm/vm.h>
#include <vm/pmap.h>
#include <machine/segments.h>
#include <machine/pcb.h>
#include <machine/stdarg.h>
#include <machine/vmparam.h>
#include <machine/cpu.h>
#include <machine/intr_machdep.h>
#include <machine/md_var.h>
#include <machine/asmacros.h>



#include <xen/hypervisor.h>
#include <machine/xen/xenvar.h>
#include <machine/xen/xenfunc.h>
#include <machine/xen/xenpmap.h>
#include <machine/xen/xenfunc.h>
#include <xen/interface/memory.h>
#include <machine/xen/features.h>
#ifdef SMP
#include <machine/privatespace.h>
#endif


#include <vm/vm_page.h>


#define	IDTVEC(name)	__CONCAT(X,name)

extern inthand_t
IDTVEC(div), IDTVEC(dbg), IDTVEC(nmi), IDTVEC(bpt), IDTVEC(ofl),
	IDTVEC(bnd), IDTVEC(ill), IDTVEC(dna), IDTVEC(fpusegm),
	IDTVEC(tss), IDTVEC(missing), IDTVEC(stk), IDTVEC(prot),
	IDTVEC(page), IDTVEC(mchk), IDTVEC(rsvd), IDTVEC(fpu), IDTVEC(align),
	IDTVEC(xmm), IDTVEC(lcall_syscall), IDTVEC(int0x80_syscall);


int xendebug_flags; 
start_info_t *xen_start_info;
shared_info_t *HYPERVISOR_shared_info;
xen_pfn_t *xen_machine_phys = machine_to_phys_mapping;
xen_pfn_t *xen_phys_machine;
xen_pfn_t *xen_pfn_to_mfn_frame_list[16];
xen_pfn_t *xen_pfn_to_mfn_frame_list_list;
int preemptable, init_first;
extern unsigned int avail_space;
int xen_vector_callback_enabled = 0;
enum xen_domain_type xen_domain_type = XEN_PV_DOMAIN;

void ni_cli(void);
void ni_sti(void);


void
ni_cli(void)
{
	CTR0(KTR_SPARE2, "ni_cli disabling interrupts");
	__asm__("pushl %edx;"
		"pushl %eax;"
		);
	__cli();
	__asm__("popl %eax;"
		"popl %edx;"
		);
}


void
ni_sti(void)
{
	__asm__("pushl %edx;"
		"pushl %esi;"
		"pushl %eax;"
		);
	__sti();
	__asm__("popl %eax;"
		"popl %esi;"
		"popl %edx;"
		);
}

void
force_evtchn_callback(void)
{
    (void)HYPERVISOR_xen_version(0, NULL);
}

/*
 * Modify the cmd_line by converting ',' to NULLs so that it is in a  format 
 * suitable for the static env vars.
 */
char *
xen_setbootenv(char *cmd_line)
{
	char *cmd_line_next;
    
        /* Skip leading spaces */
        for (; *cmd_line == ' '; cmd_line++);

	xc_printf("xen_setbootenv(): cmd_line='%s'\n", cmd_line);

	for (cmd_line_next = cmd_line; strsep(&cmd_line_next, ",") != NULL;);
	return cmd_line;
}

static struct 
{
	const char	*ev;
	int		mask;
} howto_names[] = {
	{"boot_askname",	RB_ASKNAME},
	{"boot_single",	RB_SINGLE},
	{"boot_nosync",	RB_NOSYNC},
	{"boot_halt",	RB_ASKNAME},
	{"boot_serial",	RB_SERIAL},
	{"boot_cdrom",	RB_CDROM},
	{"boot_gdb",	RB_GDB},
	{"boot_gdb_pause",	RB_RESERVED1},
	{"boot_verbose",	RB_VERBOSE},
	{"boot_multicons",	RB_MULTIPLE},
	{NULL,	0}
};

int 
xen_boothowto(char *envp)
{
	int i, howto = 0;

	/* get equivalents from the environment */
	for (i = 0; howto_names[i].ev != NULL; i++)
		if (getenv(howto_names[i].ev) != NULL)
			howto |= howto_names[i].mask;
	return howto;
}

#define XC_PRINTF_BUFSIZE 1024
void
xc_printf(const char *fmt, ...)
{
        __va_list ap;
        int retval;
        static char buf[XC_PRINTF_BUFSIZE];

        va_start(ap, fmt);
        retval = vsnprintf(buf, XC_PRINTF_BUFSIZE - 1, fmt, ap);
        va_end(ap);
        buf[retval] = 0;
        (void)HYPERVISOR_console_write(buf, retval);
}


#define XPQUEUE_SIZE 128

struct mmu_log {
	char *file;
	int line;
};

#ifdef SMP
/* per-cpu queues and indices */
#ifdef INVARIANTS
static struct mmu_log xpq_queue_log[XEN_LEGACY_MAX_VCPUS][XPQUEUE_SIZE];
#endif

static int xpq_idx[XEN_LEGACY_MAX_VCPUS];
static mmu_update_t xpq_queue[XEN_LEGACY_MAX_VCPUS][XPQUEUE_SIZE];

#define	XPQ_QUEUE_LOG xpq_queue_log[vcpu]
#define	XPQ_QUEUE xpq_queue[vcpu]
#define	XPQ_IDX xpq_idx[vcpu]
#define	SET_VCPU() int vcpu = smp_processor_id()
#else
	
static mmu_update_t xpq_queue[XPQUEUE_SIZE];
#ifdef INVARIANTS
static struct mmu_log xpq_queue_log[XPQUEUE_SIZE];
#endif
static int xpq_idx = 0;

#define	XPQ_QUEUE_LOG xpq_queue_log
#define	XPQ_QUEUE xpq_queue
#define	XPQ_IDX xpq_idx
#define	SET_VCPU()
#endif /* !SMP */

#define XPQ_IDX_INC atomic_add_int(&XPQ_IDX, 1);

#if 0
static void
xen_dump_queue(void)
{
	int _xpq_idx = XPQ_IDX;
	int i;

	if (_xpq_idx <= 1)
		return;

	xc_printf("xen_dump_queue(): %u entries\n", _xpq_idx);
	for (i = 0; i < _xpq_idx; i++) {
		xc_printf(" val: %llx ptr: %llx\n", XPQ_QUEUE[i].val,
		    XPQ_QUEUE[i].ptr);
	}
}
#endif


static __inline void
_xen_flush_queue(void)
{
	SET_VCPU();
	int _xpq_idx = XPQ_IDX;
	int error, i;

#ifdef INVARIANTS
	if (__predict_true(gdtset))
		CRITICAL_ASSERT(curthread);
#endif

	XPQ_IDX = 0;
	/* Make sure index is cleared first to avoid double updates. */
	error = HYPERVISOR_mmu_update((mmu_update_t *)&XPQ_QUEUE,
				      _xpq_idx, NULL, DOMID_SELF);
    
#if 0
	if (__predict_true(gdtset))
	for (i = _xpq_idx; i > 0;) {
		if (i >= 3) {
			CTR6(KTR_PMAP, "mmu:val: %lx ptr: %lx val: %lx "
			    "ptr: %lx val: %lx ptr: %lx",
			    (XPQ_QUEUE[i-1].val & 0xffffffff),
			    (XPQ_QUEUE[i-1].ptr & 0xffffffff),
			    (XPQ_QUEUE[i-2].val & 0xffffffff),
			    (XPQ_QUEUE[i-2].ptr & 0xffffffff),
			    (XPQ_QUEUE[i-3].val & 0xffffffff),
			    (XPQ_QUEUE[i-3].ptr & 0xffffffff));
			    i -= 3;
		} else if (i == 2) {
			CTR4(KTR_PMAP, "mmu: val: %lx ptr: %lx val: %lx ptr: %lx",
			    (XPQ_QUEUE[i-1].val & 0xffffffff),
			    (XPQ_QUEUE[i-1].ptr & 0xffffffff),
			    (XPQ_QUEUE[i-2].val & 0xffffffff),
			    (XPQ_QUEUE[i-2].ptr & 0xffffffff));
			i = 0;
		} else {
			CTR2(KTR_PMAP, "mmu: val: %lx ptr: %lx", 
			    (XPQ_QUEUE[i-1].val & 0xffffffff),
			    (XPQ_QUEUE[i-1].ptr & 0xffffffff));
			i = 0;
		}
	}
#endif	
	if (__predict_false(error < 0)) {
		for (i = 0; i < _xpq_idx; i++)
			printf("val: %llx ptr: %llx\n",
			    XPQ_QUEUE[i].val, XPQ_QUEUE[i].ptr);
		panic("Failed to execute MMU updates: %d", error);
	}

}

void
xen_flush_queue(void)
{
	SET_VCPU();

	if (__predict_true(gdtset))
		critical_enter();
	if (XPQ_IDX != 0) _xen_flush_queue();
	if (__predict_true(gdtset))
		critical_exit();
}

static __inline void
xen_increment_idx(void)
{
	SET_VCPU();

	XPQ_IDX++;
	if (__predict_false(XPQ_IDX == XPQUEUE_SIZE))
		xen_flush_queue();
}

void
xen_check_queue(void)
{
#ifdef INVARIANTS
	SET_VCPU();
	
	KASSERT(XPQ_IDX == 0, ("pending operations XPQ_IDX=%d", XPQ_IDX));
#endif
}

void
xen_invlpg(vm_offset_t va)
{
	struct mmuext_op op;
	op.cmd = MMUEXT_INVLPG_ALL;
	op.arg1.linear_addr = va & ~PAGE_MASK;
	PANIC_IF(HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF) < 0);
}

void
xen_load_cr3(u_int val)
{
	struct mmuext_op op;
#ifdef INVARIANTS
	SET_VCPU();
	
	KASSERT(XPQ_IDX == 0, ("pending operations XPQ_IDX=%d", XPQ_IDX));
#endif
	op.cmd = MMUEXT_NEW_BASEPTR;
	op.arg1.mfn = xpmap_ptom(val) >> PAGE_SHIFT;
	PANIC_IF(HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF) < 0);
}

#ifdef KTR
static __inline u_int
rebp(void)
{
	u_int	data;

	__asm __volatile("movl 4(%%ebp),%0" : "=r" (data));	
	return (data);
}
#endif

u_int
read_eflags(void)
{
        vcpu_info_t *_vcpu;
	u_int eflags;

	eflags = _read_eflags();
        _vcpu = &HYPERVISOR_shared_info->vcpu_info[smp_processor_id()]; 
	if (_vcpu->evtchn_upcall_mask)
		eflags &= ~PSL_I;

	return (eflags);
}

void
write_eflags(u_int eflags)
{
	u_int intr;

	CTR2(KTR_SPARE2, "%x xen_restore_flags eflags %x", rebp(), eflags);
	intr = ((eflags & PSL_I) == 0);
	__restore_flags(intr);
	_write_eflags(eflags);
}

void
xen_cli(void)
{
	CTR1(KTR_SPARE2, "%x xen_cli disabling interrupts", rebp());
	__cli();
}

void
xen_sti(void)
{
	CTR1(KTR_SPARE2, "%x xen_sti enabling interrupts", rebp());
	__sti();
}

u_int
xen_rcr2(void)
{

	return (HYPERVISOR_shared_info->vcpu_info[curcpu].arch.cr2);
}

void
_xen_machphys_update(vm_paddr_t mfn, vm_paddr_t pfn, char *file, int line)
{
	SET_VCPU();
	
	if (__predict_true(gdtset))
		critical_enter();
	XPQ_QUEUE[XPQ_IDX].ptr = (mfn << PAGE_SHIFT) | MMU_MACHPHYS_UPDATE;
	XPQ_QUEUE[XPQ_IDX].val = pfn;
#ifdef INVARIANTS
	XPQ_QUEUE_LOG[XPQ_IDX].file = file;
	XPQ_QUEUE_LOG[XPQ_IDX].line = line;	
#endif		
	xen_increment_idx();
	if (__predict_true(gdtset))
		critical_exit();
}

extern struct rwlock pvh_global_lock;

void
_xen_queue_pt_update(vm_paddr_t ptr, vm_paddr_t val, char *file, int line)
{
	SET_VCPU();

	if (__predict_true(gdtset))	
		rw_assert(&pvh_global_lock, RA_WLOCKED);

	KASSERT((ptr & 7) == 0, ("misaligned update"));
	
	if (__predict_true(gdtset))
		critical_enter();
	
	XPQ_QUEUE[XPQ_IDX].ptr = ((uint64_t)ptr) | MMU_NORMAL_PT_UPDATE;
	XPQ_QUEUE[XPQ_IDX].val = (uint64_t)val;
#ifdef INVARIANTS
	XPQ_QUEUE_LOG[XPQ_IDX].file = file;
	XPQ_QUEUE_LOG[XPQ_IDX].line = line;	
#endif	
	xen_increment_idx();
	if (__predict_true(gdtset))
		critical_exit();
}

void 
xen_pgdpt_pin(vm_paddr_t ma)
{
	struct mmuext_op op;
	op.cmd = MMUEXT_PIN_L3_TABLE;
	op.arg1.mfn = ma >> PAGE_SHIFT;
	xen_flush_queue();
	PANIC_IF(HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF) < 0);
}

void 
xen_pgd_pin(vm_paddr_t ma)
{
	struct mmuext_op op;
	op.cmd = MMUEXT_PIN_L2_TABLE;
	op.arg1.mfn = ma >> PAGE_SHIFT;
	xen_flush_queue();
	PANIC_IF(HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF) < 0);
}

void 
xen_pgd_unpin(vm_paddr_t ma)
{
	struct mmuext_op op;
	op.cmd = MMUEXT_UNPIN_TABLE;
	op.arg1.mfn = ma >> PAGE_SHIFT;
	xen_flush_queue();
	PANIC_IF(HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF) < 0);
}

void 
xen_pt_pin(vm_paddr_t ma)
{
	struct mmuext_op op;
	op.cmd = MMUEXT_PIN_L1_TABLE;
	op.arg1.mfn = ma >> PAGE_SHIFT;
	xen_flush_queue();
	PANIC_IF(HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF) < 0);
}

void 
xen_pt_unpin(vm_paddr_t ma)
{
	struct mmuext_op op;
	op.cmd = MMUEXT_UNPIN_TABLE;
	op.arg1.mfn = ma >> PAGE_SHIFT;
	xen_flush_queue();
	PANIC_IF(HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF) < 0);
}

void 
xen_set_ldt(vm_paddr_t ptr, unsigned long len)
{
	struct mmuext_op op;
	op.cmd = MMUEXT_SET_LDT;
	op.arg1.linear_addr = ptr;
	op.arg2.nr_ents = len;
	xen_flush_queue();
	PANIC_IF(HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF) < 0);
}

void xen_tlb_flush(void)
{
	struct mmuext_op op;
	op.cmd = MMUEXT_TLB_FLUSH_LOCAL;
	xen_flush_queue();
	PANIC_IF(HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF) < 0);
}

void
xen_update_descriptor(union descriptor *table, union descriptor *entry)
{
	vm_paddr_t pa;
	pt_entry_t *ptp;

	ptp = vtopte((vm_offset_t)table);
	pa = (*ptp & PG_FRAME) | ((vm_offset_t)table & PAGE_MASK);
	if (HYPERVISOR_update_descriptor(pa, *(uint64_t *)entry))
		panic("HYPERVISOR_update_descriptor failed\n");
}


#if 0
/*
 * Bitmap is indexed by page number. If bit is set, the page is part of a
 * xen_create_contiguous_region() area of memory.
 */
unsigned long *contiguous_bitmap;

static void 
contiguous_bitmap_set(unsigned long first_page, unsigned long nr_pages)
{
	unsigned long start_off, end_off, curr_idx, end_idx;

	curr_idx  = first_page / BITS_PER_LONG;
	start_off = first_page & (BITS_PER_LONG-1);
	end_idx   = (first_page + nr_pages) / BITS_PER_LONG;
	end_off   = (first_page + nr_pages) & (BITS_PER_LONG-1);

	if (curr_idx == end_idx) {
		contiguous_bitmap[curr_idx] |=
			((1UL<<end_off)-1) & -(1UL<<start_off);
	} else {
		contiguous_bitmap[curr_idx] |= -(1UL<<start_off);
		while ( ++curr_idx < end_idx )
			contiguous_bitmap[curr_idx] = ~0UL;
		contiguous_bitmap[curr_idx] |= (1UL<<end_off)-1;
	}
}

static void 
contiguous_bitmap_clear(unsigned long first_page, unsigned long nr_pages)
{
	unsigned long start_off, end_off, curr_idx, end_idx;

	curr_idx  = first_page / BITS_PER_LONG;
	start_off = first_page & (BITS_PER_LONG-1);
	end_idx   = (first_page + nr_pages) / BITS_PER_LONG;
	end_off   = (first_page + nr_pages) & (BITS_PER_LONG-1);

	if (curr_idx == end_idx) {
		contiguous_bitmap[curr_idx] &=
			-(1UL<<end_off) | ((1UL<<start_off)-1);
	} else {
		contiguous_bitmap[curr_idx] &= (1UL<<start_off)-1;
		while ( ++curr_idx != end_idx )
			contiguous_bitmap[curr_idx] = 0;
		contiguous_bitmap[curr_idx] &= -(1UL<<end_off);
	}
}
#endif

/* Ensure multi-page extents are contiguous in machine memory. */
int 
xen_create_contiguous_region(vm_page_t pages, int npages)
{
	unsigned long  mfn, i, flags;
	int order;
	struct xen_memory_reservation reservation = {
		.nr_extents   = 1,
		.extent_order = 0,
		.domid        = DOMID_SELF
	};
	set_xen_guest_handle(reservation.extent_start, &mfn);
	
	balloon_lock(flags);

	/* can currently only handle power of two allocation */
	PANIC_IF(ffs(npages) != fls(npages));

	/* 0. determine order */
	order = (ffs(npages) == fls(npages)) ? fls(npages) - 1 : fls(npages);
	
	/* 1. give away machine pages. */
	for (i = 0; i < (1 << order); i++) {
		int pfn;
		pfn = VM_PAGE_TO_PHYS(&pages[i]) >> PAGE_SHIFT;
		mfn = PFNTOMFN(pfn);
		PFNTOMFN(pfn) = INVALID_P2M_ENTRY;
		PANIC_IF(HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation) != 1);
	}


	/* 2. Get a new contiguous memory extent. */
	reservation.extent_order = order;
	/* xenlinux hardcodes this because of aacraid - maybe set to 0 if we're not 
	 * running with a broxen driver XXXEN
	 */
	reservation.address_bits = 31; 
	if (HYPERVISOR_memory_op(XENMEM_increase_reservation, &reservation) != 1)
		goto fail;

	/* 3. Map the new extent in place of old pages. */
	for (i = 0; i < (1 << order); i++) {
		int pfn;
		pfn = VM_PAGE_TO_PHYS(&pages[i]) >> PAGE_SHIFT;
		xen_machphys_update(mfn+i, pfn);
		PFNTOMFN(pfn) = mfn+i;
	}

	xen_tlb_flush();

#if 0
	contiguous_bitmap_set(VM_PAGE_TO_PHYS(&pages[0]) >> PAGE_SHIFT, 1UL << order);
#endif

	balloon_unlock(flags);

	return 0;

 fail:
	reservation.extent_order = 0;
	reservation.address_bits = 0;

	for (i = 0; i < (1 << order); i++) {
		int pfn;
		pfn = VM_PAGE_TO_PHYS(&pages[i]) >> PAGE_SHIFT;
		PANIC_IF(HYPERVISOR_memory_op(
			XENMEM_increase_reservation, &reservation) != 1);
		xen_machphys_update(mfn, pfn);
		PFNTOMFN(pfn) = mfn;
	}

	xen_tlb_flush();

	balloon_unlock(flags);

	return ENOMEM;
}

void 
xen_destroy_contiguous_region(void *addr, int npages)
{
	unsigned long  mfn, i, flags, order, pfn0;
	struct xen_memory_reservation reservation = {
		.nr_extents   = 1,
		.extent_order = 0,
		.domid        = DOMID_SELF
	};
	set_xen_guest_handle(reservation.extent_start, &mfn);
	
	pfn0 = vtophys(addr) >> PAGE_SHIFT;
#if 0
	scrub_pages(vstart, 1 << order);
#endif
	/* can currently only handle power of two allocation */
	PANIC_IF(ffs(npages) != fls(npages));

	/* 0. determine order */
	order = (ffs(npages) == fls(npages)) ? fls(npages) - 1 : fls(npages);

	balloon_lock(flags);

#if 0
	contiguous_bitmap_clear(vtophys(addr) >> PAGE_SHIFT, 1UL << order);
#endif

	/* 1. Zap current PTEs, giving away the underlying pages. */
	for (i = 0; i < (1 << order); i++) {
		int pfn;
		uint64_t new_val = 0;
		pfn = vtomach((char *)addr + i*PAGE_SIZE) >> PAGE_SHIFT;

		PANIC_IF(HYPERVISOR_update_va_mapping((vm_offset_t)((char *)addr + (i * PAGE_SIZE)), new_val, 0));
		PFNTOMFN(pfn) = INVALID_P2M_ENTRY;
		PANIC_IF(HYPERVISOR_memory_op(
			XENMEM_decrease_reservation, &reservation) != 1);
	}

	/* 2. Map new pages in place of old pages. */
	for (i = 0; i < (1 << order); i++) {
		int pfn;
		uint64_t new_val;
		pfn = pfn0 + i;
		PANIC_IF(HYPERVISOR_memory_op(XENMEM_increase_reservation, &reservation) != 1);
		
		new_val = mfn << PAGE_SHIFT;
		PANIC_IF(HYPERVISOR_update_va_mapping((vm_offset_t)addr + (i * PAGE_SIZE), 
						      new_val, PG_KERNEL));
		xen_machphys_update(mfn, pfn);
		PFNTOMFN(pfn) = mfn;
	}

	xen_tlb_flush();

	balloon_unlock(flags);
}

extern  vm_offset_t	proc0kstack;
extern int vm86paddr, vm86phystk;
char *bootmem_start, *bootmem_current, *bootmem_end;

pteinfo_t *pteinfo_list;
void initvalues(start_info_t *startinfo);

struct xenstore_domain_interface;
extern struct xenstore_domain_interface *xen_store;

char *console_page;

void *
bootmem_alloc(unsigned int size) 
{
	char *retptr;
	
	retptr = bootmem_current;
	PANIC_IF(retptr + size > bootmem_end);
	bootmem_current += size;

	return retptr;
}

void 
bootmem_free(void *ptr, unsigned int size) 
{
	char *tptr;
	
	tptr = ptr;
	PANIC_IF(tptr != bootmem_current - size ||
		bootmem_current - size < bootmem_start);	

	bootmem_current -= size;
}

#if 0
static vm_paddr_t
xpmap_mtop2(vm_paddr_t mpa)
{
        return ((machine_to_phys_mapping[mpa >> PAGE_SHIFT] << PAGE_SHIFT)
            ) | (mpa & ~PG_FRAME);
}

static pd_entry_t 
xpmap_get_bootpde(vm_paddr_t va)
{

        return ((pd_entry_t *)xen_start_info->pt_base)[va >> 22];
}

static pd_entry_t
xpmap_get_vbootpde(vm_paddr_t va)
{
        pd_entry_t pde;

        pde = xpmap_get_bootpde(va);
        if ((pde & PG_V) == 0)
                return (pde & ~PG_FRAME);
        return (pde & ~PG_FRAME) |
                (xpmap_mtop2(pde & PG_FRAME) + KERNBASE);
}

static pt_entry_t 8*
xpmap_get_bootptep(vm_paddr_t va)
{
        pd_entry_t pde;

        pde = xpmap_get_vbootpde(va);
        if ((pde & PG_V) == 0)
                return (void *)-1;
#define PT_MASK         0x003ff000      /* page table address bits */
        return &(((pt_entry_t *)(pde & PG_FRAME))[(va & PT_MASK) >> PAGE_SHIFT]);
}

static pt_entry_t
xpmap_get_bootpte(vm_paddr_t va)
{

        return xpmap_get_bootptep(va)[0];
}
#endif


#ifdef ADD_ISA_HOLE
static void
shift_phys_machine(unsigned long *phys_machine, int nr_pages)
{

        unsigned long *tmp_page, *current_page, *next_page;
	int i;

	tmp_page = bootmem_alloc(PAGE_SIZE);
	current_page = phys_machine + nr_pages - (PAGE_SIZE/sizeof(unsigned long));  
	next_page = current_page - (PAGE_SIZE/sizeof(unsigned long));  
	bcopy(phys_machine, tmp_page, PAGE_SIZE);

	while (current_page > phys_machine) { 
	        /*  save next page */
	        bcopy(next_page, tmp_page, PAGE_SIZE);
	        /* shift down page */
		bcopy(current_page, next_page, PAGE_SIZE);
	        /*  finish swap */
	        bcopy(tmp_page, current_page, PAGE_SIZE);
	  
		current_page -= (PAGE_SIZE/sizeof(unsigned long));
		next_page -= (PAGE_SIZE/sizeof(unsigned long));
	}
	bootmem_free(tmp_page, PAGE_SIZE);	
	
	for (i = 0; i < nr_pages; i++) {
	        xen_machphys_update(phys_machine[i], i);
	}
	memset(phys_machine, INVALID_P2M_ENTRY, PAGE_SIZE);

}
#endif /* ADD_ISA_HOLE */

/*
 * Build a directory of the pages that make up our Physical to Machine
 * mapping table. The Xen suspend/restore code uses this to find our
 * mapping table.
 */
static void
init_frame_list_list(void *arg)
{
	unsigned long nr_pages = xen_start_info->nr_pages;
#define FPP	(PAGE_SIZE/sizeof(xen_pfn_t))
	int i, j, k;

	xen_pfn_to_mfn_frame_list_list = malloc(PAGE_SIZE, M_DEVBUF, M_WAITOK);
	for (i = 0, j = 0, k = -1; i < nr_pages;
	     i += FPP, j++) {
		if ((j & (FPP - 1)) == 0) {
			k++;
			xen_pfn_to_mfn_frame_list[k] =
				malloc(PAGE_SIZE, M_DEVBUF, M_WAITOK);
			xen_pfn_to_mfn_frame_list_list[k] =
				VTOMFN(xen_pfn_to_mfn_frame_list[k]);
			j = 0;
		}
		xen_pfn_to_mfn_frame_list[k][j] = 
			VTOMFN(&xen_phys_machine[i]);
	}

	HYPERVISOR_shared_info->arch.max_pfn = nr_pages;
	HYPERVISOR_shared_info->arch.pfn_to_mfn_frame_list_list
		= VTOMFN(xen_pfn_to_mfn_frame_list_list);
}	
SYSINIT(init_fll, SI_SUB_DEVFS, SI_ORDER_ANY, init_frame_list_list, NULL);

extern unsigned long physfree;

int pdir, curoffset;
extern int nkpt;

extern uint32_t kernbase;

void
initvalues(start_info_t *startinfo)
{ 
	vm_offset_t cur_space, cur_space_pt;
	struct physdev_set_iopl set_iopl;
	
	int l3_pages, l2_pages, l1_pages, offset;
	vm_paddr_t console_page_ma, xen_store_ma;
	vm_offset_t tmpva;
	vm_paddr_t shinfo;
#ifdef PAE
	vm_paddr_t IdlePDPTma, IdlePDPTnewma;
	vm_paddr_t IdlePTDnewma[4];
	pd_entry_t *IdlePDPTnew, *IdlePTDnew;
	vm_paddr_t IdlePTDma[4];
#else
	vm_paddr_t IdlePTDma[1];
#endif
	unsigned long i;
	int ncpus = MAXCPU;

	nkpt = min(
		min(
			max((startinfo->nr_pages >> NPGPTD_SHIFT), nkpt),
		    NPGPTD*NPDEPG - KPTDI),
		    (HYPERVISOR_VIRT_START - KERNBASE) >> PDRSHIFT);

	HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments);	
#ifdef notyet
	/*
	 * need to install handler
	 */
	HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments_notify);	
#endif	
	xen_start_info = startinfo;
	xen_phys_machine = (xen_pfn_t *)startinfo->mfn_list;

	IdlePTD = (pd_entry_t *)((uint8_t *)startinfo->pt_base + PAGE_SIZE);
	l1_pages = 0;
	
#ifdef PAE
	l3_pages = 1;
	l2_pages = 0;
	IdlePDPT = (pd_entry_t *)startinfo->pt_base;
	IdlePDPTma = VTOM(startinfo->pt_base);
	for (i = (KERNBASE >> 30);
	     (i < 4) && (IdlePDPT[i] != 0); i++)
			l2_pages++;
	/*
	 * Note that only one page directory has been allocated at this point.
	 * Thus, if KERNBASE
	 */
	for (i = 0; i < l2_pages; i++)
		IdlePTDma[i] = VTOM(IdlePTD + i*PAGE_SIZE);

	l2_pages = (l2_pages == 0) ? 1 : l2_pages;
#else	
	l3_pages = 0;
	l2_pages = 1;
#endif
	for (i = (((KERNBASE>>18) & PAGE_MASK)>>PAGE_SHIFT);
	     (i<l2_pages*NPDEPG) && (i<(VM_MAX_KERNEL_ADDRESS>>PDRSHIFT)); i++) {
		
		if (IdlePTD[i] == 0)
			break;
		l1_pages++;
	}

	/* number of pages allocated after the pts + 1*/;
	cur_space = xen_start_info->pt_base +
	    (l3_pages + l2_pages + l1_pages + 1)*PAGE_SIZE;

	xc_printf("initvalues(): wooh - availmem=%x,%x\n", avail_space,
	    cur_space);

	xc_printf("KERNBASE=%x,pt_base=%x, VTOPFN(base)=%x, nr_pt_frames=%x\n",
	    KERNBASE,xen_start_info->pt_base, VTOPFN(xen_start_info->pt_base),
	    xen_start_info->nr_pt_frames);
	xendebug_flags = 0; /* 0xffffffff; */

#ifdef ADD_ISA_HOLE
	shift_phys_machine(xen_phys_machine, xen_start_info->nr_pages);
#endif
	XENPRINTF("IdlePTD %p\n", IdlePTD);
	XENPRINTF("nr_pages: %ld shared_info: 0x%lx flags: 0x%lx pt_base: 0x%lx "
		  "mod_start: 0x%lx mod_len: 0x%lx\n",
		  xen_start_info->nr_pages, xen_start_info->shared_info, 
		  xen_start_info->flags, xen_start_info->pt_base, 
		  xen_start_info->mod_start, xen_start_info->mod_len);

#ifdef PAE
	IdlePDPTnew = (pd_entry_t *)cur_space; cur_space += PAGE_SIZE;
	bzero(IdlePDPTnew, PAGE_SIZE);

	IdlePDPTnewma =  VTOM(IdlePDPTnew);
	IdlePTDnew = (pd_entry_t *)cur_space; cur_space += 4*PAGE_SIZE;
	bzero(IdlePTDnew, 4*PAGE_SIZE);

	for (i = 0; i < 4; i++) 
		IdlePTDnewma[i] = VTOM((uint8_t *)IdlePTDnew + i*PAGE_SIZE);
	/*
	 * L3
	 *
	 * Copy the 4 machine addresses of the new PTDs in to the PDPT
	 * 
	 */
	for (i = 0; i < 4; i++)
		IdlePDPTnew[i] = IdlePTDnewma[i] | PG_V;

	__asm__("nop;");
	/*
	 *
	 * re-map the new PDPT read-only
	 */
	PT_SET_MA(IdlePDPTnew, IdlePDPTnewma | PG_V);
	/*
	 * 
	 * Unpin the current PDPT
	 */
	xen_pt_unpin(IdlePDPTma);

#endif  /* PAE */

	/* Map proc0's KSTACK */
	proc0kstack = cur_space; cur_space += (KSTACK_PAGES * PAGE_SIZE);
	xc_printf("proc0kstack=%u\n", proc0kstack);

	/* vm86/bios stack */
	cur_space += PAGE_SIZE;

	/* Map space for the vm86 region */
	vm86paddr = (vm_offset_t)cur_space;
	cur_space += (PAGE_SIZE * 3);

	/* allocate 4 pages for bootmem allocator */
	bootmem_start = bootmem_current = (char *)cur_space;
	cur_space += (4 * PAGE_SIZE);
	bootmem_end = (char *)cur_space;
	
	/* allocate pages for gdt */
	gdt = (union descriptor *)cur_space;
	cur_space += PAGE_SIZE*ncpus;

        /* allocate page for ldt */
	ldt = (union descriptor *)cur_space; cur_space += PAGE_SIZE;
	cur_space += PAGE_SIZE;
	
	/* unmap remaining pages from initial chunk
	 *
	 */
	for (tmpva = cur_space; tmpva < (((uint32_t)&kernbase) + (l1_pages<<PDRSHIFT));
	     tmpva += PAGE_SIZE) {
		bzero((char *)tmpva, PAGE_SIZE);
		PT_SET_MA(tmpva, (vm_paddr_t)0);
	}

	PT_UPDATES_FLUSH();

	memcpy(((uint8_t *)IdlePTDnew) + ((unsigned int)(KERNBASE >> 18)),
	    ((uint8_t *)IdlePTD) + ((KERNBASE >> 18) & PAGE_MASK),
	    l1_pages*sizeof(pt_entry_t));

	for (i = 0; i < 4; i++) {
		PT_SET_MA((uint8_t *)IdlePTDnew + i*PAGE_SIZE,
		    IdlePTDnewma[i] | PG_V);
	}
	xen_load_cr3(VTOP(IdlePDPTnew));
	xen_pgdpt_pin(VTOM(IdlePDPTnew));

	/* allocate remainder of nkpt pages */
	cur_space_pt = cur_space;
	for (offset = (KERNBASE >> PDRSHIFT), i = l1_pages; i < nkpt;
	     i++, cur_space += PAGE_SIZE) {
		pdir = (offset + i) / NPDEPG;
		curoffset = ((offset + i) % NPDEPG);
		if (((offset + i) << PDRSHIFT) == VM_MAX_KERNEL_ADDRESS)
			break;

		/*
		 * make sure that all the initial page table pages
		 * have been zeroed
		 */
		PT_SET_MA(cur_space, VTOM(cur_space) | PG_V | PG_RW);
		bzero((char *)cur_space, PAGE_SIZE);
		PT_SET_MA(cur_space, (vm_paddr_t)0);
		xen_pt_pin(VTOM(cur_space));
		xen_queue_pt_update((vm_paddr_t)(IdlePTDnewma[pdir] +
			curoffset*sizeof(vm_paddr_t)), 
		    VTOM(cur_space) | PG_KERNEL);
		PT_UPDATES_FLUSH();
	}
	
	for (i = 0; i < 4; i++) {
		pdir = (PTDPTDI + i) / NPDEPG;
		curoffset = (PTDPTDI + i) % NPDEPG;

		xen_queue_pt_update((vm_paddr_t)(IdlePTDnewma[pdir] +
			curoffset*sizeof(vm_paddr_t)), 
		    IdlePTDnewma[i] | PG_V);
	}

	PT_UPDATES_FLUSH();
	
	IdlePTD = IdlePTDnew;
	IdlePDPT = IdlePDPTnew;
	IdlePDPTma = IdlePDPTnewma;
	
	HYPERVISOR_shared_info = (shared_info_t *)cur_space;
	cur_space += PAGE_SIZE;

	xen_store = (struct xenstore_domain_interface *)cur_space;
	cur_space += PAGE_SIZE;

	console_page = (char *)cur_space;
	cur_space += PAGE_SIZE;
	
	/*
	 * shared_info is an unsigned long so this will randomly break if
	 * it is allocated above 4GB - I guess people are used to that
	 * sort of thing with Xen ... sigh
	 */
	shinfo = xen_start_info->shared_info;
	PT_SET_MA(HYPERVISOR_shared_info, shinfo | PG_KERNEL);
	
	xc_printf("#4\n");

	xen_store_ma = (((vm_paddr_t)xen_start_info->store_mfn) << PAGE_SHIFT);
	PT_SET_MA(xen_store, xen_store_ma | PG_KERNEL);
	console_page_ma = (((vm_paddr_t)xen_start_info->console.domU.mfn) << PAGE_SHIFT);
	PT_SET_MA(console_page, console_page_ma | PG_KERNEL);

	xc_printf("#5\n");

	set_iopl.iopl = 1;
	PANIC_IF(HYPERVISOR_physdev_op(PHYSDEVOP_SET_IOPL, &set_iopl));
	xc_printf("#6\n");
#if 0
	/* add page table for KERNBASE */
	xen_queue_pt_update(IdlePTDma + KPTDI*sizeof(vm_paddr_t), 
			    VTOM(cur_space) | PG_KERNEL);
	xen_flush_queue();
#ifdef PAE	
	xen_queue_pt_update(pdir_shadow_ma[3] + KPTDI*sizeof(vm_paddr_t), 
			    VTOM(cur_space) | PG_V | PG_A);
#else
	xen_queue_pt_update(pdir_shadow_ma + KPTDI*sizeof(vm_paddr_t), 
			    VTOM(cur_space) | PG_V | PG_A);
#endif	
	xen_flush_queue();
	cur_space += PAGE_SIZE;
	xc_printf("#6\n");
#endif /* 0 */	
#ifdef notyet
	if (xen_start_info->flags & SIF_INITDOMAIN) {
		/* Map first megabyte */
		for (i = 0; i < (256 << PAGE_SHIFT); i += PAGE_SIZE) 
			PT_SET_MA(KERNBASE + i, i | PG_KERNEL | PG_NC_PCD);
		xen_flush_queue();
	}
#endif
	/*
	 * re-map kernel text read-only
	 *
	 */
	for (i = (((vm_offset_t)&btext) & ~PAGE_MASK);
	     i < (((vm_offset_t)&etext) & ~PAGE_MASK); i += PAGE_SIZE)
		PT_SET_MA(i, VTOM(i) | PG_V | PG_A);
	
	xc_printf("#7\n");
	physfree = VTOP(cur_space);
	init_first = physfree >> PAGE_SHIFT;
	IdlePTD = (pd_entry_t *)VTOP(IdlePTD);
	IdlePDPT = (pd_entry_t *)VTOP(IdlePDPT);
	setup_xen_features();
	xc_printf("#8, proc0kstack=%u\n", proc0kstack);
}


trap_info_t trap_table[] = {
	{ 0,   0, GSEL(GCODE_SEL, SEL_KPL), (unsigned long) &IDTVEC(div)},
	{ 1,   0|4, GSEL(GCODE_SEL, SEL_KPL), (unsigned long) &IDTVEC(dbg)},
	{ 3,   3|4, GSEL(GCODE_SEL, SEL_KPL), (unsigned long) &IDTVEC(bpt)},
	{ 4,   3, GSEL(GCODE_SEL, SEL_KPL), (unsigned long) &IDTVEC(ofl)},
	/* This is UPL on Linux and KPL on BSD */
	{ 5,   3, GSEL(GCODE_SEL, SEL_KPL), (unsigned long) &IDTVEC(bnd)},
	{ 6,   0, GSEL(GCODE_SEL, SEL_KPL), (unsigned long) &IDTVEC(ill)},
	{ 7,   0|4, GSEL(GCODE_SEL, SEL_KPL), (unsigned long) &IDTVEC(dna)},
	/*
	 * { 8,   0, GSEL(GCODE_SEL, SEL_KPL), (unsigned long) &IDTVEC(XXX)},
	 *   no handler for double fault
	 */
	{ 9,   0, GSEL(GCODE_SEL, SEL_KPL), (unsigned long) &IDTVEC(fpusegm)},
	{10,   0, GSEL(GCODE_SEL, SEL_KPL), (unsigned long) &IDTVEC(tss)},
	{11,   0, GSEL(GCODE_SEL, SEL_KPL), (unsigned long) &IDTVEC(missing)},
	{12,   0, GSEL(GCODE_SEL, SEL_KPL), (unsigned long) &IDTVEC(stk)},
	{13,   0, GSEL(GCODE_SEL, SEL_KPL), (unsigned long) &IDTVEC(prot)},
	{14,   0|4, GSEL(GCODE_SEL, SEL_KPL), (unsigned long) &IDTVEC(page)},
	{15,   0, GSEL(GCODE_SEL, SEL_KPL), (unsigned long) &IDTVEC(rsvd)},
	{16,   0, GSEL(GCODE_SEL, SEL_KPL), (unsigned long) &IDTVEC(fpu)},
	{17,   0, GSEL(GCODE_SEL, SEL_KPL), (unsigned long) &IDTVEC(align)},
	{18,   0, GSEL(GCODE_SEL, SEL_KPL), (unsigned long) &IDTVEC(mchk)},
	{19,   0, GSEL(GCODE_SEL, SEL_KPL), (unsigned long) &IDTVEC(xmm)},
	{0x80, 3, GSEL(GCODE_SEL, SEL_KPL), (unsigned long) &IDTVEC(int0x80_syscall)},
	{  0, 0,           0, 0 }
};

/* Perform a multicall and check that individual calls succeeded. */
int
HYPERVISOR_multicall(struct multicall_entry * call_list, int nr_calls)
{
	int ret = 0;
	int i;

	/* Perform the multicall. */
	PANIC_IF(_HYPERVISOR_multicall(call_list, nr_calls));

	/* Check the results of individual hypercalls. */
	for (i = 0; i < nr_calls; i++)
		if (__predict_false(call_list[i].result < 0))
			ret++;
	if (__predict_false(ret > 0))
		panic("%d multicall(s) failed: cpu %d\n",
		    ret, smp_processor_id());

	/* If we didn't panic already, everything succeeded. */
	return (0);
}

/********** CODE WORTH KEEPING ABOVE HERE *****************/ 

void xen_failsafe_handler(void);

void
xen_failsafe_handler(void)
{

	panic("xen_failsafe_handler called!\n");
}

void xen_handle_thread_switch(struct pcb *pcb);

/* This is called by cpu_switch() when switching threads. */
/* The pcb arg refers to the process control block of the */
/* next thread which is to run */
void
xen_handle_thread_switch(struct pcb *pcb)
{
    uint32_t *a = (uint32_t *)&PCPU_GET(fsgs_gdt)[0];
    uint32_t *b = (uint32_t *)&pcb->pcb_fsd;
    multicall_entry_t mcl[3];
    int i = 0;

    /* Notify Xen of task switch */
    mcl[i].op = __HYPERVISOR_stack_switch;
    mcl[i].args[0] = GSEL(GDATA_SEL, SEL_KPL);
    mcl[i++].args[1] = (unsigned long)pcb;

    /* Check for update of fsd */
    if (*a != *b || *(a+1) != *(b+1)) {
        mcl[i].op = __HYPERVISOR_update_descriptor;
        *(uint64_t *)&mcl[i].args[0] = vtomach((vm_offset_t)a);
        *(uint64_t *)&mcl[i++].args[2] = *(uint64_t *)b;
    }    

    a += 2;
    b += 2;

    /* Check for update of gsd */
    if (*a != *b || *(a+1) != *(b+1)) {
        mcl[i].op = __HYPERVISOR_update_descriptor;
        *(uint64_t *)&mcl[i].args[0] = vtomach((vm_offset_t)a);
        *(uint64_t *)&mcl[i++].args[2] = *(uint64_t *)b;
    }    

    (void)HYPERVISOR_multicall(mcl, i);
}