604 lines
16 KiB
C
604 lines
16 KiB
C
/*
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* Machine specific setup for xen
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*
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* Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
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*/
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/pm.h>
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#include <linux/memblock.h>
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#include <linux/cpuidle.h>
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#include <linux/cpufreq.h>
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#include <asm/elf.h>
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#include <asm/vdso.h>
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#include <asm/e820.h>
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#include <asm/setup.h>
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#include <asm/acpi.h>
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#include <asm/numa.h>
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#include <asm/xen/hypervisor.h>
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#include <asm/xen/hypercall.h>
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#include <xen/xen.h>
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#include <xen/page.h>
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#include <xen/interface/callback.h>
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#include <xen/interface/memory.h>
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#include <xen/interface/physdev.h>
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#include <xen/features.h>
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#include "xen-ops.h"
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#include "vdso.h"
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/* These are code, but not functions. Defined in entry.S */
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extern const char xen_hypervisor_callback[];
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extern const char xen_failsafe_callback[];
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#ifdef CONFIG_X86_64
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extern const char nmi[];
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#endif
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extern void xen_sysenter_target(void);
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extern void xen_syscall_target(void);
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extern void xen_syscall32_target(void);
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/* Amount of extra memory space we add to the e820 ranges */
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struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata;
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/* Number of pages released from the initial allocation. */
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unsigned long xen_released_pages;
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/*
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* The maximum amount of extra memory compared to the base size. The
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* main scaling factor is the size of struct page. At extreme ratios
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* of base:extra, all the base memory can be filled with page
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* structures for the extra memory, leaving no space for anything
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* else.
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*
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* 10x seems like a reasonable balance between scaling flexibility and
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* leaving a practically usable system.
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*/
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#define EXTRA_MEM_RATIO (10)
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static void __init xen_add_extra_mem(u64 start, u64 size)
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{
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unsigned long pfn;
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int i;
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for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
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/* Add new region. */
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if (xen_extra_mem[i].size == 0) {
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xen_extra_mem[i].start = start;
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xen_extra_mem[i].size = size;
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break;
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}
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/* Append to existing region. */
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if (xen_extra_mem[i].start + xen_extra_mem[i].size == start) {
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xen_extra_mem[i].size += size;
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break;
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}
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}
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if (i == XEN_EXTRA_MEM_MAX_REGIONS)
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printk(KERN_WARNING "Warning: not enough extra memory regions\n");
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memblock_reserve(start, size);
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xen_max_p2m_pfn = PFN_DOWN(start + size);
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for (pfn = PFN_DOWN(start); pfn < xen_max_p2m_pfn; pfn++) {
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unsigned long mfn = pfn_to_mfn(pfn);
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if (WARN(mfn == pfn, "Trying to over-write 1-1 mapping (pfn: %lx)\n", pfn))
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continue;
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WARN(mfn != INVALID_P2M_ENTRY, "Trying to remove %lx which has %lx mfn!\n",
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pfn, mfn);
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__set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
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}
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}
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static unsigned long __init xen_do_chunk(unsigned long start,
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unsigned long end, bool release)
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{
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struct xen_memory_reservation reservation = {
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.address_bits = 0,
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.extent_order = 0,
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.domid = DOMID_SELF
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};
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unsigned long len = 0;
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unsigned long pfn;
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int ret;
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for (pfn = start; pfn < end; pfn++) {
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unsigned long frame;
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unsigned long mfn = pfn_to_mfn(pfn);
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if (release) {
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/* Make sure pfn exists to start with */
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if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn)
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continue;
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frame = mfn;
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} else {
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if (mfn != INVALID_P2M_ENTRY)
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continue;
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frame = pfn;
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}
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set_xen_guest_handle(reservation.extent_start, &frame);
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reservation.nr_extents = 1;
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ret = HYPERVISOR_memory_op(release ? XENMEM_decrease_reservation : XENMEM_populate_physmap,
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&reservation);
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WARN(ret != 1, "Failed to %s pfn %lx err=%d\n",
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release ? "release" : "populate", pfn, ret);
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if (ret == 1) {
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if (!early_set_phys_to_machine(pfn, release ? INVALID_P2M_ENTRY : frame)) {
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if (release)
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break;
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set_xen_guest_handle(reservation.extent_start, &frame);
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reservation.nr_extents = 1;
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ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation,
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&reservation);
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break;
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}
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len++;
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} else
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break;
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}
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if (len)
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printk(KERN_INFO "%s %lx-%lx pfn range: %lu pages %s\n",
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release ? "Freeing" : "Populating",
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start, end, len,
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release ? "freed" : "added");
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return len;
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}
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static unsigned long __init xen_release_chunk(unsigned long start,
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unsigned long end)
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{
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return xen_do_chunk(start, end, true);
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}
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static unsigned long __init xen_populate_chunk(
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const struct e820entry *list, size_t map_size,
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unsigned long max_pfn, unsigned long *last_pfn,
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unsigned long credits_left)
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{
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const struct e820entry *entry;
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unsigned int i;
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unsigned long done = 0;
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unsigned long dest_pfn;
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for (i = 0, entry = list; i < map_size; i++, entry++) {
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unsigned long s_pfn;
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unsigned long e_pfn;
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unsigned long pfns;
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long capacity;
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if (credits_left <= 0)
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break;
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if (entry->type != E820_RAM)
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continue;
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e_pfn = PFN_DOWN(entry->addr + entry->size);
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/* We only care about E820 after the xen_start_info->nr_pages */
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if (e_pfn <= max_pfn)
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continue;
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s_pfn = PFN_UP(entry->addr);
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/* If the E820 falls within the nr_pages, we want to start
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* at the nr_pages PFN.
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* If that would mean going past the E820 entry, skip it
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*/
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if (s_pfn <= max_pfn) {
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capacity = e_pfn - max_pfn;
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dest_pfn = max_pfn;
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} else {
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capacity = e_pfn - s_pfn;
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dest_pfn = s_pfn;
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}
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if (credits_left < capacity)
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capacity = credits_left;
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pfns = xen_do_chunk(dest_pfn, dest_pfn + capacity, false);
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done += pfns;
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*last_pfn = (dest_pfn + pfns);
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if (pfns < capacity)
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break;
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credits_left -= pfns;
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}
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return done;
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}
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static void __init xen_set_identity_and_release_chunk(
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unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages,
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unsigned long *released, unsigned long *identity)
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{
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unsigned long pfn;
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/*
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* If the PFNs are currently mapped, clear the mappings
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* (except for the ISA region which must be 1:1 mapped) to
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* release the refcounts (in Xen) on the original frames.
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*/
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for (pfn = start_pfn; pfn <= max_pfn_mapped && pfn < end_pfn; pfn++) {
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pte_t pte = __pte_ma(0);
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if (pfn < PFN_UP(ISA_END_ADDRESS))
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pte = mfn_pte(pfn, PAGE_KERNEL_IO);
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(void)HYPERVISOR_update_va_mapping(
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(unsigned long)__va(pfn << PAGE_SHIFT), pte, 0);
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}
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if (start_pfn < nr_pages)
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*released += xen_release_chunk(
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start_pfn, min(end_pfn, nr_pages));
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*identity += set_phys_range_identity(start_pfn, end_pfn);
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}
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static unsigned long __init xen_set_identity_and_release(
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const struct e820entry *list, size_t map_size, unsigned long nr_pages)
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{
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phys_addr_t start = 0;
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unsigned long released = 0;
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unsigned long identity = 0;
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const struct e820entry *entry;
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int i;
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/*
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* Combine non-RAM regions and gaps until a RAM region (or the
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* end of the map) is reached, then set the 1:1 map and
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* release the pages (if available) in those non-RAM regions.
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*
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* The combined non-RAM regions are rounded to a whole number
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* of pages so any partial pages are accessible via the 1:1
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* mapping. This is needed for some BIOSes that put (for
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* example) the DMI tables in a reserved region that begins on
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* a non-page boundary.
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*/
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for (i = 0, entry = list; i < map_size; i++, entry++) {
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phys_addr_t end = entry->addr + entry->size;
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if (entry->type == E820_RAM || i == map_size - 1) {
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unsigned long start_pfn = PFN_DOWN(start);
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unsigned long end_pfn = PFN_UP(end);
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if (entry->type == E820_RAM)
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end_pfn = PFN_UP(entry->addr);
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if (start_pfn < end_pfn)
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xen_set_identity_and_release_chunk(
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start_pfn, end_pfn, nr_pages,
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&released, &identity);
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start = end;
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}
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}
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if (released)
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printk(KERN_INFO "Released %lu pages of unused memory\n", released);
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if (identity)
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printk(KERN_INFO "Set %ld page(s) to 1-1 mapping\n", identity);
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return released;
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}
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static unsigned long __init xen_get_max_pages(void)
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{
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unsigned long max_pages = MAX_DOMAIN_PAGES;
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domid_t domid = DOMID_SELF;
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int ret;
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/*
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* For the initial domain we use the maximum reservation as
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* the maximum page.
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*
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* For guest domains the current maximum reservation reflects
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* the current maximum rather than the static maximum. In this
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* case the e820 map provided to us will cover the static
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* maximum region.
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*/
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if (xen_initial_domain()) {
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ret = HYPERVISOR_memory_op(XENMEM_maximum_reservation, &domid);
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if (ret > 0)
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max_pages = ret;
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}
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return min(max_pages, MAX_DOMAIN_PAGES);
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}
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static void xen_align_and_add_e820_region(u64 start, u64 size, int type)
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{
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u64 end = start + size;
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/* Align RAM regions to page boundaries. */
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if (type == E820_RAM) {
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start = PAGE_ALIGN(start);
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end &= ~((u64)PAGE_SIZE - 1);
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}
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e820_add_region(start, end - start, type);
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}
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void xen_ignore_unusable(struct e820entry *list, size_t map_size)
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{
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struct e820entry *entry;
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unsigned int i;
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for (i = 0, entry = list; i < map_size; i++, entry++) {
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if (entry->type == E820_UNUSABLE)
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entry->type = E820_RAM;
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}
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}
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/**
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* machine_specific_memory_setup - Hook for machine specific memory setup.
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**/
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char * __init xen_memory_setup(void)
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{
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static struct e820entry map[E820MAX] __initdata;
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unsigned long max_pfn = xen_start_info->nr_pages;
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unsigned long long mem_end;
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int rc;
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struct xen_memory_map memmap;
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unsigned long max_pages;
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unsigned long last_pfn = 0;
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unsigned long extra_pages = 0;
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unsigned long populated;
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int i;
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int op;
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max_pfn = min(MAX_DOMAIN_PAGES, max_pfn);
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mem_end = PFN_PHYS(max_pfn);
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memmap.nr_entries = E820MAX;
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set_xen_guest_handle(memmap.buffer, map);
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op = xen_initial_domain() ?
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XENMEM_machine_memory_map :
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XENMEM_memory_map;
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rc = HYPERVISOR_memory_op(op, &memmap);
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if (rc == -ENOSYS) {
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BUG_ON(xen_initial_domain());
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memmap.nr_entries = 1;
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map[0].addr = 0ULL;
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map[0].size = mem_end;
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/* 8MB slack (to balance backend allocations). */
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map[0].size += 8ULL << 20;
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map[0].type = E820_RAM;
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rc = 0;
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}
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BUG_ON(rc);
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/*
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* Xen won't allow a 1:1 mapping to be created to UNUSABLE
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* regions, so if we're using the machine memory map leave the
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* region as RAM as it is in the pseudo-physical map.
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*
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* UNUSABLE regions in domUs are not handled and will need
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* a patch in the future.
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*/
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if (xen_initial_domain())
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xen_ignore_unusable(map, memmap.nr_entries);
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/* Make sure the Xen-supplied memory map is well-ordered. */
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sanitize_e820_map(map, memmap.nr_entries, &memmap.nr_entries);
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max_pages = xen_get_max_pages();
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if (max_pages > max_pfn)
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extra_pages += max_pages - max_pfn;
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/*
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* Set P2M for all non-RAM pages and E820 gaps to be identity
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* type PFNs. Any RAM pages that would be made inaccesible by
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* this are first released.
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*/
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xen_released_pages = xen_set_identity_and_release(
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map, memmap.nr_entries, max_pfn);
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/*
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* Populate back the non-RAM pages and E820 gaps that had been
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* released. */
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populated = xen_populate_chunk(map, memmap.nr_entries,
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max_pfn, &last_pfn, xen_released_pages);
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xen_released_pages -= populated;
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extra_pages += xen_released_pages;
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if (last_pfn > max_pfn) {
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max_pfn = min(MAX_DOMAIN_PAGES, last_pfn);
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mem_end = PFN_PHYS(max_pfn);
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}
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/*
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* Clamp the amount of extra memory to a EXTRA_MEM_RATIO
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* factor the base size. On non-highmem systems, the base
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* size is the full initial memory allocation; on highmem it
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* is limited to the max size of lowmem, so that it doesn't
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* get completely filled.
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*
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* In principle there could be a problem in lowmem systems if
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* the initial memory is also very large with respect to
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* lowmem, but we won't try to deal with that here.
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*/
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extra_pages = min(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)),
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extra_pages);
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i = 0;
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while (i < memmap.nr_entries) {
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u64 addr = map[i].addr;
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u64 size = map[i].size;
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u32 type = map[i].type;
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if (type == E820_RAM) {
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if (addr < mem_end) {
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size = min(size, mem_end - addr);
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} else if (extra_pages) {
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size = min(size, (u64)extra_pages * PAGE_SIZE);
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extra_pages -= size / PAGE_SIZE;
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xen_add_extra_mem(addr, size);
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} else
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type = E820_UNUSABLE;
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}
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xen_align_and_add_e820_region(addr, size, type);
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map[i].addr += size;
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map[i].size -= size;
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if (map[i].size == 0)
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i++;
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}
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/*
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* In domU, the ISA region is normal, usable memory, but we
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* reserve ISA memory anyway because too many things poke
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* about in there.
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*/
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e820_add_region(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS,
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E820_RESERVED);
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/*
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* Reserve Xen bits:
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* - mfn_list
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* - xen_start_info
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* See comment above "struct start_info" in <xen/interface/xen.h>
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* We tried to make the the memblock_reserve more selective so
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* that it would be clear what region is reserved. Sadly we ran
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* in the problem wherein on a 64-bit hypervisor with a 32-bit
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* initial domain, the pt_base has the cr3 value which is not
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* neccessarily where the pagetable starts! As Jan put it: "
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* Actually, the adjustment turns out to be correct: The page
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* tables for a 32-on-64 dom0 get allocated in the order "first L1",
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* "first L2", "first L3", so the offset to the page table base is
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* indeed 2. When reading xen/include/public/xen.h's comment
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* very strictly, this is not a violation (since there nothing is said
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* that the first thing in the page table space is pointed to by
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* pt_base; I admit that this seems to be implied though, namely
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* do I think that it is implied that the page table space is the
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* range [pt_base, pt_base + nt_pt_frames), whereas that
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* range here indeed is [pt_base - 2, pt_base - 2 + nt_pt_frames),
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* which - without a priori knowledge - the kernel would have
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* difficulty to figure out)." - so lets just fall back to the
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* easy way and reserve the whole region.
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*/
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memblock_reserve(__pa(xen_start_info->mfn_list),
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xen_start_info->pt_base - xen_start_info->mfn_list);
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sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
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return "Xen";
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}
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/*
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* Set the bit indicating "nosegneg" library variants should be used.
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* We only need to bother in pure 32-bit mode; compat 32-bit processes
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* can have un-truncated segments, so wrapping around is allowed.
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*/
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static void __init fiddle_vdso(void)
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{
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|
#ifdef CONFIG_X86_32
|
|
u32 *mask;
|
|
mask = VDSO32_SYMBOL(&vdso32_int80_start, NOTE_MASK);
|
|
*mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
|
|
mask = VDSO32_SYMBOL(&vdso32_sysenter_start, NOTE_MASK);
|
|
*mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
|
|
#endif
|
|
}
|
|
|
|
static int register_callback(unsigned type, const void *func)
|
|
{
|
|
struct callback_register callback = {
|
|
.type = type,
|
|
.address = XEN_CALLBACK(__KERNEL_CS, func),
|
|
.flags = CALLBACKF_mask_events,
|
|
};
|
|
|
|
return HYPERVISOR_callback_op(CALLBACKOP_register, &callback);
|
|
}
|
|
|
|
void xen_enable_sysenter(void)
|
|
{
|
|
int ret;
|
|
unsigned sysenter_feature;
|
|
|
|
#ifdef CONFIG_X86_32
|
|
sysenter_feature = X86_FEATURE_SEP;
|
|
#else
|
|
sysenter_feature = X86_FEATURE_SYSENTER32;
|
|
#endif
|
|
|
|
if (!boot_cpu_has(sysenter_feature))
|
|
return;
|
|
|
|
ret = register_callback(CALLBACKTYPE_sysenter, xen_sysenter_target);
|
|
if(ret != 0)
|
|
setup_clear_cpu_cap(sysenter_feature);
|
|
}
|
|
|
|
void xen_enable_syscall(void)
|
|
{
|
|
#ifdef CONFIG_X86_64
|
|
int ret;
|
|
|
|
ret = register_callback(CALLBACKTYPE_syscall, xen_syscall_target);
|
|
if (ret != 0) {
|
|
printk(KERN_ERR "Failed to set syscall callback: %d\n", ret);
|
|
/* Pretty fatal; 64-bit userspace has no other
|
|
mechanism for syscalls. */
|
|
}
|
|
|
|
if (boot_cpu_has(X86_FEATURE_SYSCALL32)) {
|
|
ret = register_callback(CALLBACKTYPE_syscall32,
|
|
xen_syscall32_target);
|
|
if (ret != 0)
|
|
setup_clear_cpu_cap(X86_FEATURE_SYSCALL32);
|
|
}
|
|
#endif /* CONFIG_X86_64 */
|
|
}
|
|
void __cpuinit xen_enable_nmi(void)
|
|
{
|
|
#ifdef CONFIG_X86_64
|
|
if (register_callback(CALLBACKTYPE_nmi, nmi))
|
|
BUG();
|
|
#endif
|
|
}
|
|
void __init xen_arch_setup(void)
|
|
{
|
|
xen_panic_handler_init();
|
|
|
|
HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments);
|
|
HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables);
|
|
|
|
if (!xen_feature(XENFEAT_auto_translated_physmap))
|
|
HYPERVISOR_vm_assist(VMASST_CMD_enable,
|
|
VMASST_TYPE_pae_extended_cr3);
|
|
|
|
if (register_callback(CALLBACKTYPE_event, xen_hypervisor_callback) ||
|
|
register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback))
|
|
BUG();
|
|
|
|
xen_enable_sysenter();
|
|
xen_enable_syscall();
|
|
xen_enable_nmi();
|
|
#ifdef CONFIG_ACPI
|
|
if (!(xen_start_info->flags & SIF_INITDOMAIN)) {
|
|
printk(KERN_INFO "ACPI in unprivileged domain disabled\n");
|
|
disable_acpi();
|
|
}
|
|
#endif
|
|
|
|
memcpy(boot_command_line, xen_start_info->cmd_line,
|
|
MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ?
|
|
COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE);
|
|
|
|
/* Set up idle, making sure it calls safe_halt() pvop */
|
|
disable_cpuidle();
|
|
disable_cpufreq();
|
|
WARN_ON(xen_set_default_idle());
|
|
fiddle_vdso();
|
|
#ifdef CONFIG_NUMA
|
|
numa_off = 1;
|
|
#endif
|
|
}
|