path: root/tools/libxc/xc_dom_x86.c

/*
 * Xen domain builder -- i386 and x86_64 bits.
 *
 * Most architecture-specific code for x86 goes here.
 *   - prepare page tables.
 *   - fill architecture-specific structs.
 *
 * This code is licenced under the GPL.
 * written 2006 by Gerd Hoffmann <kraxel@suse.de>.
 *
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <inttypes.h>

#include <xen/xen.h>
#include <xen/foreign/x86_32.h>
#include <xen/foreign/x86_64.h>
#include <xen/hvm/hvm_info_table.h>
#include <xen/hvm/e820.h>

#include "xg_private.h"
#include "xc_dom.h"

/* ------------------------------------------------------------------------ */

#define bits_to_mask(bits)       (((xen_vaddr_t)1 << (bits))-1)
#define round_down(addr, mask)   ((addr) & ~(mask))
#define round_up(addr, mask)     ((addr) | (mask))

static inline unsigned long
nr_page_tables(xen_vaddr_t start, xen_vaddr_t end, unsigned long bits)
{
    xen_vaddr_t mask = bits_to_mask(bits);
    int tables;

    if (0 == bits)
	return 0;		/* unused */

    if (8 * sizeof(unsigned long) == bits)
    {
	/* must be pgd, need one */
	start = 0;
	end = -1;
	tables = 1;
    }
    else
    {
	start = round_down(start, mask);
	end = round_up(end, mask);
	tables = ((end - start) >> bits) + 1;
    }

    xc_dom_printf("%s: 0x%016" PRIx64 "/%ld: 0x%016" PRIx64
		  " -> 0x%016" PRIx64 ", %d table(s)\n",
		  __FUNCTION__, mask, bits, start, end, tables);
    return tables;
}

static int count_pgtables(struct xc_dom_image *dom, int pae,
			  int l4_bits, int l3_bits, int l2_bits, int l1_bits)
{
    int pages, extra_pages;
    xen_vaddr_t try_virt_end;

    extra_pages = dom->alloc_bootstack ? 1 : 0;
    extra_pages += dom->extra_pages;
    pages = extra_pages;
    for (;;)
    {
	try_virt_end = round_up(dom->virt_alloc_end + pages * PAGE_SIZE_X86,
				bits_to_mask(l1_bits));
	dom->pg_l4 =
	    nr_page_tables(dom->parms.virt_base, try_virt_end, l4_bits);
	dom->pg_l3 =
	    nr_page_tables(dom->parms.virt_base, try_virt_end, l3_bits);
	dom->pg_l2 =
	    nr_page_tables(dom->parms.virt_base, try_virt_end, l2_bits);
	dom->pg_l1 =
	    nr_page_tables(dom->parms.virt_base, try_virt_end, l1_bits);
	if (pae && try_virt_end < 0xc0000000)
	{
	    xc_dom_printf("%s: PAE: extra l2 page table for l3#3\n", __FUNCTION__);
	    dom->pg_l2++;
	}
	dom->pgtables = dom->pg_l4 + dom->pg_l3 + dom->pg_l2 + dom->pg_l1;
	pages = dom->pgtables + extra_pages;
	if (dom->virt_alloc_end + pages * PAGE_SIZE_X86 <= try_virt_end + 1)
	    break;
    }
    dom->virt_pgtab_end = try_virt_end + 1;
    return 0;
}

/* ------------------------------------------------------------------------ */
/* i386 pagetables                                                          */

#define L1_PROT (_PAGE_PRESENT|_PAGE_RW|_PAGE_ACCESSED)
#define L2_PROT (_PAGE_PRESENT|_PAGE_RW|_PAGE_ACCESSED|_PAGE_DIRTY|_PAGE_USER)
#define L3_PROT (_PAGE_PRESENT)

static int count_pgtables_x86_32(struct xc_dom_image *dom)
{
    return count_pgtables(dom, 0, 0, 0, 32, L2_PAGETABLE_SHIFT_I386);
}

static int count_pgtables_x86_32_pae(struct xc_dom_image *dom)
{
    return count_pgtables(dom, 1, 0, 32,
			  L3_PAGETABLE_SHIFT_PAE, L2_PAGETABLE_SHIFT_PAE);
}

#define pfn_to_paddr(pfn) ((xen_paddr_t)(pfn) << PAGE_SHIFT_X86)

static int setup_pgtables_x86_32(struct xc_dom_image *dom)
{
    xen_pfn_t l2pfn = dom->pgtables_seg.pfn;
    xen_pfn_t l1pfn = dom->pgtables_seg.pfn + dom->pg_l2;
    l2_pgentry_32_t *l2tab = xc_dom_pfn_to_ptr(dom, l2pfn, 1);
    l1_pgentry_32_t *l1tab = NULL;
    unsigned long l2off, l1off;
    xen_vaddr_t addr;
    xen_pfn_t pgpfn;

    for (addr = dom->parms.virt_base; addr < dom->virt_pgtab_end;
	 addr += PAGE_SIZE_X86)
    {
	if (NULL == l1tab)
	{
	    /* get L1 tab, make L2 entry */
	    l1tab = xc_dom_pfn_to_ptr(dom, l1pfn, 1);
	    l2off = l2_table_offset_i386(addr);
	    l2tab[l2off] =
		pfn_to_paddr(xc_dom_p2m_guest(dom, l1pfn)) | L2_PROT;
	    l1pfn++;
	}

	/* make L1 entry */
	l1off = l1_table_offset_i386(addr);
	pgpfn = (addr - dom->parms.virt_base) >> PAGE_SHIFT_X86;
	l1tab[l1off] =
	    pfn_to_paddr(xc_dom_p2m_guest(dom, pgpfn)) | L1_PROT;
	if (addr >= dom->pgtables_seg.vstart && addr < dom->pgtables_seg.vend)
	    l1tab[l1off] &= ~_PAGE_RW;	/* page tables are r/o */
	if (L1_PAGETABLE_ENTRIES_I386 - 1 == l1off)
	    l1tab = NULL;
    }
    return 0;
}

static int setup_pgtables_x86_32_pae(struct xc_dom_image *dom)
{
    xen_pfn_t l3pfn = dom->pgtables_seg.pfn;
    xen_pfn_t l2pfn = dom->pgtables_seg.pfn + dom->pg_l3;
    xen_pfn_t l1pfn = dom->pgtables_seg.pfn + dom->pg_l3 + dom->pg_l2;
    l3_pgentry_64_t *l3tab = xc_dom_pfn_to_ptr(dom, l3pfn, 1);
    l2_pgentry_64_t *l2tab = NULL;
    l1_pgentry_64_t *l1tab = NULL;
    unsigned long l3off, l2off, l1off;
    xen_vaddr_t addr;
    xen_pfn_t pgpfn;

    for (addr = dom->parms.virt_base; addr < dom->virt_pgtab_end;
	 addr += PAGE_SIZE_X86)
    {
	if (NULL == l2tab)
	{
	    /* get L2 tab, make L3 entry */
	    l2tab = xc_dom_pfn_to_ptr(dom, l2pfn, 1);
	    l3off = l3_table_offset_pae(addr);
	    l3tab[l3off] =
		pfn_to_paddr(xc_dom_p2m_guest(dom, l2pfn)) | L3_PROT;
	    l2pfn++;
	}

	if (NULL == l1tab)
	{
	    /* get L1 tab, make L2 entry */
	    l1tab = xc_dom_pfn_to_ptr(dom, l1pfn, 1);
	    l2off = l2_table_offset_pae(addr);
	    l2tab[l2off] =
		pfn_to_paddr(xc_dom_p2m_guest(dom, l1pfn)) | L2_PROT;
	    if (L2_PAGETABLE_ENTRIES_PAE - 1 == l2off)
		l2tab = NULL;
	    l1pfn++;
	}

	/* make L1 entry */
	l1off = l1_table_offset_pae(addr);
	pgpfn = (addr - dom->parms.virt_base) >> PAGE_SHIFT_X86;
	l1tab[l1off] =
	    pfn_to_paddr(xc_dom_p2m_guest(dom, pgpfn)) | L1_PROT;
	if (addr >= dom->pgtables_seg.vstart && addr < dom->pgtables_seg.vend)
	    l1tab[l1off] &= ~_PAGE_RW;	/* page tables are r/o */
	if (L1_PAGETABLE_ENTRIES_PAE - 1 == l1off)
	    l1tab = NULL;
    }

    if (dom->virt_pgtab_end <= 0xc0000000)
    {
	xc_dom_printf("%s: PAE: extra l2 page table for l3#3\n", __FUNCTION__);
	l3tab[3] = pfn_to_paddr(xc_dom_p2m_guest(dom, l2pfn)) | L3_PROT;
    }
    return 0;
}

#undef L1_PROT
#undef L2_PROT
#undef L3_PROT

/* ------------------------------------------------------------------------ */
/* x86_64 pagetables                                                        */

static int count_pgtables_x86_64(struct xc_dom_image *dom)
{
    return count_pgtables(dom, 0,
			  L4_PAGETABLE_SHIFT_X86_64 + 9,
			  L4_PAGETABLE_SHIFT_X86_64,
			  L3_PAGETABLE_SHIFT_X86_64, L2_PAGETABLE_SHIFT_X86_64);
}

#define L1_PROT (_PAGE_PRESENT|_PAGE_RW|_PAGE_ACCESSED)
#define L2_PROT (_PAGE_PRESENT|_PAGE_RW|_PAGE_ACCESSED|_PAGE_DIRTY|_PAGE_USER)
#define L3_PROT (_PAGE_PRESENT|_PAGE_RW|_PAGE_ACCESSED|_PAGE_DIRTY|_PAGE_USER)
#define L4_PROT (_PAGE_PRESENT|_PAGE_RW|_PAGE_ACCESSED|_PAGE_DIRTY|_PAGE_USER)

static int setup_pgtables_x86_64(struct xc_dom_image *dom)
{
    xen_pfn_t l4pfn = dom->pgtables_seg.pfn;
    xen_pfn_t l3pfn = dom->pgtables_seg.pfn + dom->pg_l4;
    xen_pfn_t l2pfn = dom->pgtables_seg.pfn + dom->pg_l4 + dom->pg_l3;
    xen_pfn_t l1pfn =
	dom->pgtables_seg.pfn + dom->pg_l4 + dom->pg_l3 + dom->pg_l2;
    l4_pgentry_64_t *l4tab = xc_dom_pfn_to_ptr(dom, l4pfn, 1);
    l3_pgentry_64_t *l3tab = NULL;
    l2_pgentry_64_t *l2tab = NULL;
    l1_pgentry_64_t *l1tab = NULL;
    uint64_t l4off, l3off, l2off, l1off;
    uint64_t addr;
    xen_pfn_t pgpfn;

    for (addr = dom->parms.virt_base; addr < dom->virt_pgtab_end;
	 addr += PAGE_SIZE_X86)
    {
	if (NULL == l3tab)
	{
	    /* get L3 tab, make L4 entry */
	    l3tab = xc_dom_pfn_to_ptr(dom, l3pfn, 1);
	    l4off = l4_table_offset_x86_64(addr);
	    l4tab[l4off] =
		pfn_to_paddr(xc_dom_p2m_guest(dom, l3pfn)) | L4_PROT;
	    l3pfn++;
	}

	if (NULL == l2tab)
	{
	    /* get L2 tab, make L3 entry */
	    l2tab = xc_dom_pfn_to_ptr(dom, l2pfn, 1);
	    l3off = l3_table_offset_x86_64(addr);
	    l3tab[l3off] =
		pfn_to_paddr(xc_dom_p2m_guest(dom, l2pfn)) | L3_PROT;
	    if (L3_PAGETABLE_ENTRIES_X86_64 - 1 == l3off)
		l3tab = NULL;
	    l2pfn++;
	}

	if (NULL == l1tab)
	{
	    /* get L1 tab, make L2 entry */
	    l1tab = xc_dom_pfn_to_ptr(dom, l1pfn, 1);
	    l2off = l2_table_offset_x86_64(addr);
	    l2tab[l2off] =
		pfn_to_paddr(xc_dom_p2m_guest(dom, l1pfn)) | L2_PROT;
	    if (L2_PAGETABLE_ENTRIES_X86_64 - 1 == l2off)
		l2tab = NULL;
	    l1pfn++;
	}

	/* make L1 entry */
	l1off = l1_table_offset_x86_64(addr);
	pgpfn = (addr - dom->parms.virt_base) >> PAGE_SHIFT_X86;
	l1tab[l1off] =
	    pfn_to_paddr(xc_dom_p2m_guest(dom, pgpfn)) | L1_PROT;
	if (addr >= dom->pgtables_seg.vstart && addr < dom->pgtables_seg.vend)
	    l1tab[l1off] &= ~_PAGE_RW;	/* page tables are r/o */
	if (L1_PAGETABLE_ENTRIES_X86_64 - 1 == l1off)
	    l1tab = NULL;
    }
    return 0;
}

#undef L1_PROT
#undef L2_PROT
#undef L3_PROT
#undef L4_PROT

/* ------------------------------------------------------------------------ */

static int alloc_magic_pages(struct xc_dom_image *dom)
{
    size_t p2m_size = dom->total_pages * dom->arch_hooks->sizeof_pfn;

    /* allocate phys2mach table */
    if (0 != xc_dom_alloc_segment(dom, &dom->p2m_seg, "phys2mach", 0, p2m_size))
	return -1;
    dom->p2m_guest = xc_dom_seg_to_ptr(dom, &dom->p2m_seg);

    /* allocate special pages */
    dom->start_info_pfn = xc_dom_alloc_page(dom, "start info");
    dom->xenstore_pfn = xc_dom_alloc_page(dom, "xenstore");
    dom->console_pfn = xc_dom_alloc_page(dom, "console");
    if (xc_dom_feature_translated(dom))
	dom->shared_info_pfn = xc_dom_alloc_page(dom, "shared info");
    dom->alloc_bootstack = 1;
    return 0;
}

/* ------------------------------------------------------------------------ */

static int start_info_x86_32(struct xc_dom_image *dom)
{
    start_info_x86_32_t *start_info =
	xc_dom_pfn_to_ptr(dom, dom->start_info_pfn, 1);
    xen_pfn_t shinfo =
	xc_dom_feature_translated(dom) ? dom->shared_info_pfn : dom->
	shared_info_mfn;

    xc_dom_printf("%s: called\n", __FUNCTION__);

    sprintf(start_info->magic, dom->guest_type);
    start_info->nr_pages = dom->total_pages;
    start_info->shared_info = shinfo << PAGE_SHIFT_X86;
    start_info->pt_base = dom->pgtables_seg.vstart;
    start_info->nr_pt_frames = dom->pgtables;
    start_info->mfn_list = dom->p2m_seg.vstart;

    start_info->flags = dom->flags;
    start_info->store_mfn = xc_dom_p2m_guest(dom, dom->xenstore_pfn);
    start_info->store_evtchn = dom->xenstore_evtchn;
    start_info->console.domU.mfn = xc_dom_p2m_guest(dom, dom->console_pfn);
    start_info->console.domU.evtchn = dom->console_evtchn;

    if (dom->ramdisk_blob)
    {
	start_info->mod_start = dom->ramdisk_seg.vstart;
	start_info->mod_len = dom->ramdisk_seg.vend - dom->ramdisk_seg.vstart;
    }
    if (dom->cmdline)
    {
	strncpy((char *)start_info->cmd_line, dom->cmdline, MAX_GUEST_CMDLINE);
	start_info->cmd_line[MAX_GUEST_CMDLINE - 1] = '\0';
    }
    return 0;
}

static int start_info_x86_64(struct xc_dom_image *dom)
{
    start_info_x86_64_t *start_info =
	xc_dom_pfn_to_ptr(dom, dom->start_info_pfn, 1);
    xen_pfn_t shinfo =
	xc_dom_feature_translated(dom) ? dom->shared_info_pfn : dom->
	shared_info_mfn;

    xc_dom_printf("%s: called\n", __FUNCTION__);

    sprintf(start_info->magic, dom->guest_type);
    start_info->nr_pages = dom->total_pages;
    start_info->shared_info = shinfo << PAGE_SHIFT_X86;
    start_info->pt_base = dom->pgtables_seg.vstart;
    start_info->nr_pt_frames = dom->pgtables;
    start_info->mfn_list = dom->p2m_seg.vstart;

    start_info->flags = dom->flags;
    start_info->store_mfn = xc_dom_p2m_guest(dom, dom->xenstore_pfn);
    start_info->store_evtchn = dom->xenstore_evtchn;
    start_info->console.domU.mfn = xc_dom_p2m_guest(dom, dom->console_pfn);
    start_info->console.domU.evtchn = dom->console_evtchn;

    if (dom->ramdisk_blob)
    {
	start_info->mod_start = dom->ramdisk_seg.vstart;
	start_info->mod_len = dom->ramdisk_seg.vend - dom->ramdisk_seg.vstart;
    }
    if (dom->cmdline)
    {
	strncpy((char *)start_info->cmd_line, dom->cmdline, MAX_GUEST_CMDLINE);
	start_info->cmd_line[MAX_GUEST_CMDLINE - 1] = '\0';
    }
    return 0;
}

static int shared_info_x86_32(struct xc_dom_image *dom, void *ptr)
{
    shared_info_x86_32_t *shared_info = ptr;
    int i;

    xc_dom_printf("%s: called\n", __FUNCTION__);

    memset(shared_info, 0, sizeof(*shared_info));
    for (i = 0; i < MAX_VIRT_CPUS; i++)
	shared_info->vcpu_info[i].evtchn_upcall_mask = 1;
    return 0;
}

static int shared_info_x86_64(struct xc_dom_image *dom, void *ptr)
{
    shared_info_x86_64_t *shared_info = ptr;
    int i;

    xc_dom_printf("%s: called\n", __FUNCTION__);

    memset(shared_info, 0, sizeof(*shared_info));
    for (i = 0; i < MAX_VIRT_CPUS; i++)
	shared_info->vcpu_info[i].evtchn_upcall_mask = 1;
    return 0;
}

/* ------------------------------------------------------------------------ */

static int vcpu_x86_32(struct xc_dom_image *dom, void *ptr)
{
    vcpu_guest_context_x86_32_t *ctxt = ptr;
    xen_pfn_t cr3_pfn;
    int i;

    xc_dom_printf("%s: called\n", __FUNCTION__);

    /* clear everything */
    memset(ctxt, 0, sizeof(*ctxt));

    /* Virtual IDT is empty at start-of-day. */
    for (i = 0; i < 256; i++)
    {
	ctxt->trap_ctxt[i].vector = i;
	ctxt->trap_ctxt[i].cs = FLAT_KERNEL_CS_X86_32;
    }

    /* No callback handlers. */
    ctxt->event_callback_cs = FLAT_KERNEL_CS_X86_32;
    ctxt->failsafe_callback_cs = FLAT_KERNEL_CS_X86_32;

    ctxt->user_regs.ds = FLAT_KERNEL_DS_X86_32;
    ctxt->user_regs.es = FLAT_KERNEL_DS_X86_32;
    ctxt->user_regs.fs = FLAT_KERNEL_DS_X86_32;
    ctxt->user_regs.gs = FLAT_KERNEL_DS_X86_32;
    ctxt->user_regs.ss = FLAT_KERNEL_SS_X86_32;
    ctxt->user_regs.cs = FLAT_KERNEL_CS_X86_32;
    ctxt->user_regs.eip = dom->parms.virt_entry;
    ctxt->user_regs.esp =
	dom->parms.virt_base + (dom->bootstack_pfn + 1) * PAGE_SIZE_X86;
    ctxt->user_regs.esi =
	dom->parms.virt_base + (dom->start_info_pfn) * PAGE_SIZE_X86;
    ctxt->user_regs.eflags = 1 << 9;	/* Interrupt Enable */

    ctxt->kernel_ss = FLAT_KERNEL_SS_X86_32;
    ctxt->kernel_sp =
	dom->parms.virt_base + (dom->bootstack_pfn + 1) * PAGE_SIZE_X86;

    ctxt->flags = VGCF_in_kernel_X86_32;
    if (dom->parms.pae == 2 /* extended_cr3 */ ||
	dom->parms.pae == 3 /* bimodal */)
	ctxt->vm_assist |= (1UL << VMASST_TYPE_pae_extended_cr3);

    cr3_pfn = xc_dom_p2m_guest(dom, dom->pgtables_seg.pfn);
    ctxt->ctrlreg[3] = xen_pfn_to_cr3_x86_32(cr3_pfn);
    xc_dom_printf("%s: cr3: pfn 0x%" PRIpfn " mfn 0x%" PRIpfn "\n",
		  __FUNCTION__, dom->pgtables_seg.pfn, cr3_pfn);

    return 0;
}

static int vcpu_x86_64(struct xc_dom_image *dom, void *ptr)
{
    vcpu_guest_context_x86_64_t *ctxt = ptr;
    xen_pfn_t cr3_pfn;
    int i;

    xc_dom_printf("%s: called\n", __FUNCTION__);

    /* clear everything */
    memset(ctxt, 0, sizeof(*ctxt));

    /* Virtual IDT is empty at start-of-day. */
    for (i = 0; i < 256; i++)
    {
	ctxt->trap_ctxt[i].vector = i;
	ctxt->trap_ctxt[i].cs = FLAT_KERNEL_CS_X86_64;
    }

    ctxt->user_regs.ds = FLAT_KERNEL_DS_X86_64;
    ctxt->user_regs.es = FLAT_KERNEL_DS_X86_64;
    ctxt->user_regs.fs = FLAT_KERNEL_DS_X86_64;
    ctxt->user_regs.gs = FLAT_KERNEL_DS_X86_64;
    ctxt->user_regs.ss = FLAT_KERNEL_SS_X86_64;
    ctxt->user_regs.cs = FLAT_KERNEL_CS_X86_64;
    ctxt->user_regs.rip = dom->parms.virt_entry;
    ctxt->user_regs.rsp =
	dom->parms.virt_base + (dom->bootstack_pfn + 1) * PAGE_SIZE_X86;
    ctxt->user_regs.rsi =
	dom->parms.virt_base + (dom->start_info_pfn) * PAGE_SIZE_X86;
    ctxt->user_regs.rflags = 1 << 9;	/* Interrupt Enable */

    ctxt->kernel_ss = FLAT_KERNEL_SS_X86_64;
    ctxt->kernel_sp =
	dom->parms.virt_base + (dom->bootstack_pfn + 1) * PAGE_SIZE_X86;

    ctxt->flags = VGCF_in_kernel_X86_64;
    cr3_pfn = xc_dom_p2m_guest(dom, dom->pgtables_seg.pfn);
    ctxt->ctrlreg[3] = xen_pfn_to_cr3_x86_64(cr3_pfn);
    xc_dom_printf("%s: cr3: pfn 0x%" PRIpfn " mfn 0x%" PRIpfn "\n",
		  __FUNCTION__, dom->pgtables_seg.pfn, cr3_pfn);

    return 0;
}

/* ------------------------------------------------------------------------ */

static struct xc_dom_arch xc_dom_32 = {
    .guest_type = "xen-3.0-x86_32",
    .page_shift = PAGE_SHIFT_X86,
    .sizeof_pfn = 4,
    .alloc_magic_pages = alloc_magic_pages,
    .count_pgtables = count_pgtables_x86_32,
    .setup_pgtables = setup_pgtables_x86_32,
    .start_info = start_info_x86_32,
    .shared_info = shared_info_x86_32,
    .vcpu = vcpu_x86_32,
};
static struct xc_dom_arch xc_dom_32_pae = {
    .guest_type = "xen-3.0-x86_32p",
    .page_shift = PAGE_SHIFT_X86,
    .sizeof_pfn = 4,
    .alloc_magic_pages = alloc_magic_pages,
    .count_pgtables = count_pgtables_x86_32_pae,
    .setup_pgtables = setup_pgtables_x86_32_pae,
    .start_info = start_info_x86_32,
    .shared_info = shared_info_x86_32,
    .vcpu = vcpu_x86_32,
};

static struct xc_dom_arch xc_dom_64 = {
    .guest_type = "xen-3.0-x86_64",
    .page_shift = PAGE_SHIFT_X86,
    .sizeof_pfn = 8,
    .alloc_magic_pages = alloc_magic_pages,
    .count_pgtables = count_pgtables_x86_64,
    .setup_pgtables = setup_pgtables_x86_64,
    .start_info = start_info_x86_64,
    .shared_info = shared_info_x86_64,
    .vcpu = vcpu_x86_64,
};

static void __init register_arch_hooks(void)
{
    xc_dom_register_arch_hooks(&xc_dom_32);
    xc_dom_register_arch_hooks(&xc_dom_32_pae);
    xc_dom_register_arch_hooks(&xc_dom_64);
}