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mm.c
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/*
****************************************************************************
* (C) 2003 - Rolf Neugebauer - Intel Research Cambridge
* (C) 2005 - Grzegorz Milos - Intel Research Cambridge
****************************************************************************
*
* File: mm.c
* Author: Rolf Neugebauer ([email protected])
* Changes: Grzegorz Milos
*
* Date: Aug 2003, chages Aug 2005
*
* Environment: Xen Minimal OS
* Description: memory management related functions
* contains buddy page allocator from Xen.
*
****************************************************************************
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
#include <mini-os/os.h>
#include <mini-os/hypervisor.h>
#include <mini-os/mm.h>
#include <mini-os/types.h>
#include <mini-os/lib.h>
#include <mini-os/xmalloc.h>
#include <xen/memory.h>
#ifdef MM_DEBUG
#define DEBUG(_f, _a...) \
printk("MINI_OS(file=mm.c, line=%d) " _f "\n", __LINE__, ## _a)
#else
#define DEBUG(_f, _a...) ((void)0)
#endif
unsigned long *phys_to_machine_mapping;
unsigned long mfn_zero;
extern char stack[];
extern void page_walk(unsigned long va);
static unsigned long memory_size;
/*
* Make pt_pfn a new 'level' page table frame and hook it into the page
* table at offset in previous level MFN (pref_l_mfn). pt_pfn is a guest
* PFN.
*/
static void new_pt_frame(unsigned long *pt_pfn, unsigned long prev_l_mfn,
unsigned long offset, unsigned long level)
{
pgentry_t *tab = (pgentry_t *)start_info.pt_base;
unsigned long pt_page = (unsigned long)pfn_to_virt(*pt_pfn);
pgentry_t prot_e, prot_t;
mmu_update_t mmu_updates[1];
int rc;
prot_e = prot_t = 0;
DEBUG("Allocating new L%d pt frame for pfn=%lx, "
"prev_l_mfn=%lx, offset=%lx",
level, *pt_pfn, prev_l_mfn, offset);
/* We need to clear the page, otherwise we might fail to map it
as a page table page */
memset((void*) pt_page, 0, PAGE_SIZE);
switch ( level )
{
case L1_FRAME:
prot_e = L1_PROT;
prot_t = L2_PROT;
break;
case L2_FRAME:
prot_e = L2_PROT;
prot_t = L3_PROT;
break;
#if defined(__x86_64__)
case L3_FRAME:
prot_e = L3_PROT;
prot_t = L4_PROT;
break;
#endif
default:
printk("new_pt_frame() called with invalid level number %d\n", level);
do_exit();
break;
}
/* Make PFN a page table page */
#if defined(__x86_64__)
tab = pte_to_virt(tab[l4_table_offset(pt_page)]);
#endif
tab = pte_to_virt(tab[l3_table_offset(pt_page)]);
if (!xen_feature(XENFEAT_auto_translated_physmap)) {
mmu_updates[0].ptr = (tab[l2_table_offset(pt_page)] & PAGE_MASK) +
sizeof(pgentry_t) * l1_table_offset(pt_page);
mmu_updates[0].val = (pgentry_t)pfn_to_mfn(*pt_pfn) << PAGE_SHIFT |
(prot_e & ~_PAGE_RW);
if ( (rc = HYPERVISOR_mmu_update(mmu_updates, 1, NULL, DOMID_SELF)) < 0 )
{
printk("ERROR: PTE for new page table page could not be updated\n");
printk(" mmu_update failed with rc=%d\n", rc);
do_exit();
}
/* Hook the new page table page into the hierarchy */
mmu_updates[0].ptr =
((pgentry_t)prev_l_mfn << PAGE_SHIFT) + sizeof(pgentry_t) * offset;
mmu_updates[0].val = (pgentry_t)pfn_to_mfn(*pt_pfn) << PAGE_SHIFT | prot_t;
if ( (rc = HYPERVISOR_mmu_update(mmu_updates, 1, NULL, DOMID_SELF)) < 0 )
{
printk("ERROR: mmu_update failed with rc=%d\n", rc);
do_exit();
}
}
else {
/* Unlike auto-translated, we only need to set the previous-level page table
* due to no need to relinquish RW from L1 table pointing to it */
pgentry_t *prev_l_vaddr = mfn_to_virt(prev_l_mfn);
prev_l_vaddr[offset] = (pgentry_t)pfn_to_mfn(*pt_pfn) << PAGE_SHIFT | prot_t;
}
*pt_pfn += 1;
}
/*
* Checks if a pagetable frame is needed at 'level' to map a given
* address. Note, this function is specific to the initial page table
* building.
*/
static int need_pt_frame(unsigned long va, int level)
{
unsigned long hyp_virt_start = HYPERVISOR_VIRT_START;
#if defined(__x86_64__)
unsigned long hyp_virt_end = HYPERVISOR_VIRT_END;
#else
unsigned long hyp_virt_end = 0xffffffff;
#endif
/* In general frames will _not_ be needed if they were already
allocated to map the hypervisor into our VA space */
#if defined(__x86_64__)
if ( level == L3_FRAME )
{
if ( l4_table_offset(va) >=
l4_table_offset(hyp_virt_start) &&
l4_table_offset(va) <=
l4_table_offset(hyp_virt_end))
return 0;
return 1;
}
else
#endif
if ( level == L2_FRAME )
{
#if defined(__x86_64__)
if ( l4_table_offset(va) >=
l4_table_offset(hyp_virt_start) &&
l4_table_offset(va) <=
l4_table_offset(hyp_virt_end))
#endif
if ( l3_table_offset(va) >=
l3_table_offset(hyp_virt_start) &&
l3_table_offset(va) <=
l3_table_offset(hyp_virt_end))
return 0;
return 1;
}
else
/* Always need l1 frames */
if ( level == L1_FRAME )
return 1;
printk("ERROR: Unknown frame level %d, hypervisor %llx,%llx\n",
level, hyp_virt_start, hyp_virt_end);
return -1;
}
/*
* Build the initial pagetable.
*/
static void build_pagetable(unsigned long *start_pfn, unsigned long *max_pfn)
{
unsigned long start_address, end_address;
unsigned long pfn_to_map, pt_pfn = *start_pfn;
static mmu_update_t mmu_updates[L1_PAGETABLE_ENTRIES + 1];
pgentry_t *tab = (pgentry_t *)start_info.pt_base, page;
unsigned long pt_mfn = pfn_to_mfn(virt_to_pfn(start_info.pt_base));
unsigned long offset;
int count = 0;
int rc;
/* Be conservative: even if we know there will be more pages already
mapped, start the loop at the very beginning. */
pfn_to_map = *start_pfn;
if ( *max_pfn >= virt_to_pfn(HYPERVISOR_VIRT_START) )
{
printk("WARNING: Mini-OS trying to use Xen virtual space. "
"Truncating memory from %luMB to ",
((unsigned long)pfn_to_virt(*max_pfn) -
(unsigned long)&_text)>>20);
*max_pfn = virt_to_pfn(HYPERVISOR_VIRT_START - PAGE_SIZE);
printk("%luMB\n",
((unsigned long)pfn_to_virt(*max_pfn) -
(unsigned long)&_text)>>20);
}
start_address = (unsigned long)pfn_to_virt(pfn_to_map);
end_address = (unsigned long)pfn_to_virt(*max_pfn);
/* We worked out the virtual memory range to map, now mapping loop */
printk("Mapping memory range 0x%lx - 0x%lx\n", start_address, end_address);
while ( start_address < end_address )
{
tab = (pgentry_t *)start_info.pt_base;
pt_mfn = pfn_to_mfn(virt_to_pfn(start_info.pt_base));
#if defined(__x86_64__)
offset = l4_table_offset(start_address);
/* Need new L3 pt frame */
if ( !(tab[offset] & _PAGE_PRESENT) )
new_pt_frame(&pt_pfn, pt_mfn, offset, L3_FRAME);
page = tab[offset];
pt_mfn = pte_to_mfn(page);
tab = to_virt(mfn_to_pfn(pt_mfn) << PAGE_SHIFT);
#endif
offset = l3_table_offset(start_address);
/* Need new L2 pt frame */
if ( !(tab[offset] & _PAGE_PRESENT) )
new_pt_frame(&pt_pfn, pt_mfn, offset, L2_FRAME);
page = tab[offset];
pt_mfn = pte_to_mfn(page);
tab = to_virt(mfn_to_pfn(pt_mfn) << PAGE_SHIFT);
offset = l2_table_offset(start_address);
/* Need new L1 pt frame */
if ( !(tab[offset] & _PAGE_PRESENT) )
new_pt_frame(&pt_pfn, pt_mfn, offset, L1_FRAME);
page = tab[offset];
pt_mfn = pte_to_mfn(page);
tab = to_virt(mfn_to_pfn(pt_mfn) << PAGE_SHIFT);
offset = l1_table_offset(start_address);
if ( !(tab[offset] & _PAGE_PRESENT) )
{
mmu_updates[count].ptr =
((pgentry_t)pt_mfn << PAGE_SHIFT) + sizeof(pgentry_t) * offset;
mmu_updates[count].val =
(pgentry_t)pfn_to_mfn(pfn_to_map) << PAGE_SHIFT | L1_PROT;
count++;
}
pfn_to_map++;
if ( count == L1_PAGETABLE_ENTRIES ||
(count && pfn_to_map == *max_pfn) )
{
rc = HYPERVISOR_mmu_update(mmu_updates, count, NULL, DOMID_SELF);
if ( rc < 0 )
{
printk("ERROR: build_pagetable(): PTE could not be updated\n");
printk(" mmu_update failed with rc=%d\n", rc);
do_exit();
}
count = 0;
}
start_address += PAGE_SIZE;
}
*start_pfn = pt_pfn;
}
/*
* Mark portion of the address space read only.
*/
extern struct shared_info shared_info;
static void set_readonly(void *text, void *etext)
{
unsigned long start_address =
((unsigned long) text + PAGE_SIZE - 1) & PAGE_MASK;
unsigned long end_address = (unsigned long) etext;
static mmu_update_t mmu_updates[L1_PAGETABLE_ENTRIES + 1];
pgentry_t *tab = (pgentry_t *)start_info.pt_base, page;
unsigned long mfn = pfn_to_mfn(virt_to_pfn(start_info.pt_base));
unsigned long offset;
int count = 0;
int rc;
printk("setting %p-%p readonly\n", text, etext);
while ( start_address + PAGE_SIZE <= end_address )
{
tab = (pgentry_t *)start_info.pt_base;
mfn = pfn_to_mfn(virt_to_pfn(start_info.pt_base));
#if defined(__x86_64__)
offset = l4_table_offset(start_address);
page = tab[offset];
mfn = pte_to_mfn(page);
tab = to_virt(mfn_to_pfn(mfn) << PAGE_SHIFT);
#endif
offset = l3_table_offset(start_address);
page = tab[offset];
mfn = pte_to_mfn(page);
tab = to_virt(mfn_to_pfn(mfn) << PAGE_SHIFT);
offset = l2_table_offset(start_address);
page = tab[offset];
mfn = pte_to_mfn(page);
tab = to_virt(mfn_to_pfn(mfn) << PAGE_SHIFT);
offset = l1_table_offset(start_address);
if ( start_address != (unsigned long)&shared_info )
{
if (!xen_feature(XENFEAT_auto_translated_physmap)) {
mmu_updates[count].ptr =
((pgentry_t)mfn << PAGE_SHIFT) + sizeof(pgentry_t) * offset;
mmu_updates[count].val = tab[offset] & ~_PAGE_RW;
count++;
}
else
tab[offset] &= ~_PAGE_RW;
}
else
printk("skipped %p\n", start_address);
start_address += PAGE_SIZE;
if ( !xen_feature(XENFEAT_auto_translated_physmap) &&
(count == L1_PAGETABLE_ENTRIES ||
start_address + PAGE_SIZE > end_address) )
{
rc = HYPERVISOR_mmu_update(mmu_updates, count, NULL, DOMID_SELF);
if ( rc < 0 )
{
printk("ERROR: set_readonly(): PTE could not be updated\n");
do_exit();
}
count = 0;
}
}
flush_tlb_global();
}
/*
* A useful mem testing function. Write the address to every address in the
* range provided and read back the value. If verbose, print page walk to
* some VA
*
* If we get MEM_TEST_MAX_ERRORS we might as well stop
*/
#define MEM_TEST_MAX_ERRORS 10
int mem_test(unsigned long *start_va, unsigned long *end_va, int verbose)
{
unsigned long mask = 0x10000;
unsigned long *pointer;
int error_count = 0;
/* write values and print page walks */
if ( verbose && (((unsigned long)start_va) & 0xfffff) )
{
printk("MemTest Start: 0x%lx\n", start_va);
page_walk((unsigned long)start_va);
}
for ( pointer = start_va; pointer < end_va; pointer++ )
{
if ( verbose && !(((unsigned long)pointer) & 0xfffff) )
{
printk("Writing to %lx\n", pointer);
page_walk((unsigned long)pointer);
}
*pointer = (unsigned long)pointer & ~mask;
}
if ( verbose && (((unsigned long)end_va) & 0xfffff) )
{
printk("MemTest End: %lx\n", end_va-1);
page_walk((unsigned long)end_va-1);
}
/* verify values */
for ( pointer = start_va; pointer < end_va; pointer++ )
{
if ( ((unsigned long)pointer & ~mask) != *pointer )
{
printk("Read error at 0x%lx. Read: 0x%lx, should read 0x%lx\n",
(unsigned long)pointer, *pointer,
((unsigned long)pointer & ~mask));
error_count++;
if ( error_count >= MEM_TEST_MAX_ERRORS )
{
printk("mem_test: too many errors\n");
return -1;
}
}
}
return 0;
}
/*
* get the PTE for virtual address va if it exists. Otherwise NULL.
*/
static pgentry_t *get_pgt(unsigned long va)
{
unsigned long mfn;
pgentry_t *tab;
unsigned offset;
tab = (pgentry_t *)start_info.pt_base;
mfn = virt_to_mfn(start_info.pt_base);
#if defined(__x86_64__)
offset = l4_table_offset(va);
if ( !(tab[offset] & _PAGE_PRESENT) )
return NULL;
mfn = pte_to_mfn(tab[offset]);
tab = mfn_to_virt(mfn);
#endif
offset = l3_table_offset(va);
if ( !(tab[offset] & _PAGE_PRESENT) )
return NULL;
mfn = pte_to_mfn(tab[offset]);
tab = mfn_to_virt(mfn);
offset = l2_table_offset(va);
if ( !(tab[offset] & _PAGE_PRESENT) )
return NULL;
mfn = pte_to_mfn(tab[offset]);
tab = mfn_to_virt(mfn);
offset = l1_table_offset(va);
return &tab[offset];
}
/*
* return a valid PTE for a given virtual address. If PTE does not exist,
* allocate page-table pages.
*/
pgentry_t *need_pgt(unsigned long va)
{
unsigned long pt_mfn;
pgentry_t *tab;
unsigned long pt_pfn;
unsigned offset;
tab = (pgentry_t *)start_info.pt_base;
pt_mfn = virt_to_mfn(start_info.pt_base);
#if defined(__x86_64__)
offset = l4_table_offset(va);
if ( !(tab[offset] & _PAGE_PRESENT) )
{
pt_pfn = virt_to_pfn(alloc_page());
new_pt_frame(&pt_pfn, pt_mfn, offset, L3_FRAME);
}
ASSERT(tab[offset] & _PAGE_PRESENT);
pt_mfn = pte_to_mfn(tab[offset]);
tab = mfn_to_virt(pt_mfn);
#endif
offset = l3_table_offset(va);
if ( !(tab[offset] & _PAGE_PRESENT) )
{
pt_pfn = virt_to_pfn(alloc_page());
new_pt_frame(&pt_pfn, pt_mfn, offset, L2_FRAME);
}
ASSERT(tab[offset] & _PAGE_PRESENT);
pt_mfn = pte_to_mfn(tab[offset]);
tab = mfn_to_virt(pt_mfn);
offset = l2_table_offset(va);
if ( !(tab[offset] & _PAGE_PRESENT) )
{
pt_pfn = virt_to_pfn(alloc_page());
new_pt_frame(&pt_pfn, pt_mfn, offset, L1_FRAME);
}
ASSERT(tab[offset] & _PAGE_PRESENT);
pt_mfn = pte_to_mfn(tab[offset]);
tab = mfn_to_virt(pt_mfn);
offset = l1_table_offset(va);
return &tab[offset];
}
/*
* Reserve an area of virtual address space for mappings and Heap
*/
static unsigned long demand_map_area_start;
#ifdef __x86_64__
#define DEMAND_MAP_PAGES ((128ULL << 30) / PAGE_SIZE)
#else
#define DEMAND_MAP_PAGES ((2ULL << 30) / PAGE_SIZE)
#endif
#ifndef HAVE_LIBC
#define HEAP_PAGES 0
#else
unsigned long heap, brk, heap_mapped, heap_end;
#ifdef __x86_64__
#define HEAP_PAGES ((128ULL << 30) / PAGE_SIZE)
#else
#define HEAP_PAGES ((1ULL << 30) / PAGE_SIZE)
#endif
#endif
void arch_init_demand_mapping_area(unsigned long cur_pfn)
{
cur_pfn++;
demand_map_area_start = (unsigned long) pfn_to_virt(cur_pfn);
cur_pfn += DEMAND_MAP_PAGES;
printk("Demand map pfns at %lx-%lx.\n",
demand_map_area_start, pfn_to_virt(cur_pfn));
#ifdef HAVE_LIBC
cur_pfn++;
heap_mapped = brk = heap = (unsigned long) pfn_to_virt(cur_pfn);
cur_pfn += HEAP_PAGES;
heap_end = (unsigned long) pfn_to_virt(cur_pfn);
printk("Heap resides at %lx-%lx.\n", brk, heap_end);
#endif
}
unsigned long allocate_ondemand(unsigned long n, unsigned long alignment)
{
unsigned long x;
unsigned long y = 0;
/* Find a properly aligned run of n contiguous frames */
for ( x = 0;
x <= DEMAND_MAP_PAGES - n;
x = (x + y + 1 + alignment - 1) & ~(alignment - 1) )
{
unsigned long addr = demand_map_area_start + x * PAGE_SIZE;
pgentry_t *pgt = get_pgt(addr);
for ( y = 0; y < n; y++, addr += PAGE_SIZE )
{
if ( !(addr & L1_MASK) )
pgt = get_pgt(addr);
if ( pgt )
{
if ( *pgt & _PAGE_PRESENT )
break;
pgt++;
}
}
if ( y == n )
break;
}
if ( y != n )
{
printk("Failed to find %ld frames!\n", n);
return 0;
}
return demand_map_area_start + x * PAGE_SIZE;
}
/*
* Map an array of MFNs contiguously into virtual address space starting at
* va. map f[i*stride]+i*increment for i in 0..n-1.
*/
#define MAP_BATCH ((STACK_SIZE / 2) / sizeof(mmu_update_t))
void do_map_frames(unsigned long va,
const unsigned long *mfns, unsigned long n,
unsigned long stride, unsigned long incr,
domid_t id, int *err, unsigned long prot)
{
pgentry_t *pgt = NULL;
unsigned long done = 0;
unsigned long i;
int rc;
if ( !xen_feature(XENFEAT_auto_translated_physmap) && !mfns )
{
printk("do_map_frames: no mfns supplied\n");
return;
}
DEBUG("va=%p n=0x%lx, mfns[0]=0x%lx stride=0x%lx incr=0x%lx prot=0x%lx\n",
va, n, mfns ? mfns[0] : 0, stride, incr, prot);
if ( err )
memset(err, 0x00, n * sizeof(int));
while ( done < n )
{
unsigned long todo;
if ( err )
todo = 1;
else
todo = n - done;
if ( todo > MAP_BATCH )
todo = MAP_BATCH;
{
mmu_update_t mmu_updates[todo];
for ( i = 0; i < todo; i++, va += PAGE_SIZE, pgt++)
{
if ( !pgt || !(va & L1_MASK) )
pgt = need_pgt(va);
if (!xen_feature(XENFEAT_auto_translated_physmap)) {
mmu_updates[i].ptr = virt_to_mach(pgt) | MMU_NORMAL_PT_UPDATE;
mmu_updates[i].val = ((pgentry_t)(mfns[(done + i) * stride] +
(done + i) * incr)
<< PAGE_SHIFT) | prot;
}
else {
if (mfns)
*pgt = ((pgentry_t)(mfns[(done + i) * stride] +
(done + i) * incr) << PAGE_SHIFT) | prot;
else /* for grant table */
*pgt = (to_phys(va) & PAGE_MASK) | prot;
}
}
if (!xen_feature(XENFEAT_auto_translated_physmap)) {
rc = HYPERVISOR_mmu_update(mmu_updates, todo, NULL, id);
if ( rc < 0 )
{
if (err)
err[done * stride] = rc;
else {
printk("Map %ld (%lx, ...) at %p failed: %d.\n",
todo, mfns[done * stride] + done * incr, va, rc);
do_exit();
}
}
}
}
done += todo;
}
}
/*
* Map an array of MFNs contiguous into virtual address space. Virtual
* addresses are allocated from the on demand area.
*/
void *map_frames_ex(const unsigned long *mfns, unsigned long n,
unsigned long stride, unsigned long incr,
unsigned long alignment,
domid_t id, int *err, unsigned long prot)
{
unsigned long va = allocate_ondemand(n, alignment);
if ( !va )
return NULL;
do_map_frames(va, mfns, n, stride, incr, id, err, prot);
return (void *)va;
}
/*
* Unmap nun_frames frames mapped at virtual address va.
*/
#define UNMAP_BATCH ((STACK_SIZE / 2) / sizeof(multicall_entry_t))
int unmap_frames(unsigned long va, unsigned long num_frames)
{
int n = UNMAP_BATCH;
multicall_entry_t call[n];
int ret;
int i;
ASSERT(!((unsigned long)va & ~PAGE_MASK));
DEBUG("va=%p, num=0x%lx\n", va, num_frames);
while ( num_frames ) {
if ( n > num_frames )
n = num_frames;
for ( i = 0; i < n; i++ )
{
int arg = 0;
/* simply update the PTE for the VA and invalidate TLB */
call[i].op = __HYPERVISOR_update_va_mapping;
call[i].args[arg++] = va;
call[i].args[arg++] = 0;
#ifdef __i386__
call[i].args[arg++] = 0;
#endif
call[i].args[arg++] = UVMF_INVLPG;
va += PAGE_SIZE;
}
ret = HYPERVISOR_multicall(call, n);
if ( ret )
{
printk("update_va_mapping hypercall failed with rc=%d.\n", ret);
return -ret;
}
for ( i = 0; i < n; i++ )
{
if ( call[i].result )
{
printk("update_va_mapping failed for with rc=%d.\n", ret);
return -(call[i].result);
}
}
num_frames -= n;
}
return 0;
}
/*
* Maps num_frames frames from virtual address orig_va to va.
* The frame mapping at orig_va remains after the call.
* Returns 0 on success
*/
#define SHARE_BATCH ((STACK_SIZE / 8) / (sizeof(unsigned long) + sizeof(int)))
int share_frames(unsigned long va, unsigned long orig_va, unsigned long num_frames,
int readonly)
{
unsigned long shift;
unsigned long prot = readonly ? L1_PROT_RO : L1_PROT;
unsigned long n = SHARE_BATCH;
unsigned long i;
shift = 0;
while (num_frames) {
if (n > num_frames)
n = num_frames;
do {
unsigned long mfns[n];
int err[n];
DEBUG("add shared mapping to 0x%lx (VA):\n",
va + (shift * PAGE_SIZE));
for (i = 0; i < n; ++i) {
mfns[i] = virt_to_mfn(orig_va + ((i + shift) * PAGE_SIZE));
DEBUG(" orig 0x%lx (VA) / 0x%lx (MFN)\n",
orig_va + ((i + shift) * PAGE_SIZE), mfns[i]);
}
do_map_frames(va + (shift * PAGE_SIZE), mfns, n, 1, 0, DOMID_SELF, err, prot);
for (i = 0; i < n; ++i) {
if (err[i]) {
printk("share_frames failed on mfn 0x%lx with rc=%d.\n",
mfns[i], err[i]);
return -err[i];
}
}
shift += n;
num_frames -= n;
} while(0);
}
return 0;
}
/*
* Allocate pages which are contiguous in machine memory.
* Returns a VA to where they are mapped or 0 on failure.
*
* addr_bits indicates if the region has restrictions on where it is
* located. Typical values are 32 (if for example PCI devices can't access
* 64bit memory) or 0 for no restrictions.
*
* Allocated pages can be freed using the page allocators free_pages()
* function.
*
* based on Linux function xen_create_contiguous_region()
*/
#define MAX_CONTIG_ORDER 9 /* 2MB */
unsigned long alloc_contig_pages(int order, unsigned int addr_bits)
{
unsigned long in_va, va;
unsigned long in_frames[1UL << order], out_frames, mfn;
multicall_entry_t call[1UL << order];
unsigned int i, num_pages = 1UL << order;
int ret, exch_success;
/* pass in num_pages 'extends' of size 1 and
* request 1 extend of size 'order */
struct xen_memory_exchange exchange = {
.in = {
.nr_extents = num_pages,
.extent_order = 0,
.domid = DOMID_SELF
},
.out = {
.nr_extents = 1,
.extent_order = order,
.address_bits = addr_bits,
.domid = DOMID_SELF
},
.nr_exchanged = 0
};
if ( order > MAX_CONTIG_ORDER )
{
printk("alloc_contig_pages: order too large 0x%x > 0x%x\n",
order, MAX_CONTIG_ORDER);
return 0;
}
/* Allocate some potentially discontiguous pages */
in_va = alloc_pages(order);
if ( !in_va )
{
printk("alloc_contig_pages: could not get enough pages (order=0x%x\n",
order);
return 0;
}
/* set up arguments for exchange hyper call */
set_xen_guest_handle(exchange.in.extent_start, in_frames);
set_xen_guest_handle(exchange.out.extent_start, &out_frames);
/* unmap current frames, keep a list of MFNs */
for ( i = 0; i < num_pages; i++ )
{
int arg = 0;
va = in_va + (PAGE_SIZE * i);
in_frames[i] = virt_to_mfn(va);
/* update P2M mapping */
phys_to_machine_mapping[virt_to_pfn(va)] = INVALID_P2M_ENTRY;
/* build multi call */
call[i].op = __HYPERVISOR_update_va_mapping;
call[i].args[arg++] = va;
call[i].args[arg++] = 0;
#ifdef __i386__
call[i].args[arg++] = 0;
#endif
call[i].args[arg++] = UVMF_INVLPG;
}
ret = HYPERVISOR_multicall(call, i);
if ( ret )
{
printk("Odd, update_va_mapping hypercall failed with rc=%d.\n", ret);
return 0;
}
/* try getting a contig range of MFNs */
out_frames = virt_to_pfn(in_va); /* PFNs to populate */
ret = HYPERVISOR_memory_op(XENMEM_exchange, &exchange);
if ( ret ) {
printk("mem exchanged order=0x%x failed with rc=%d, nr_exchanged=%d\n",
order, ret, exchange.nr_exchanged);
/* we still need to return the allocated pages above to the pool
* ie. map them back into the 1:1 mapping etc. so we continue but
* in the end return the pages to the page allocator and return 0. */
exch_success = 0;
}
else
exch_success = 1;
/* map frames into 1:1 and update p2m */
for ( i = 0; i < num_pages; i++ )
{
int arg = 0;
pte_t pte;
va = in_va + (PAGE_SIZE * i);
mfn = i < exchange.nr_exchanged ? (out_frames + i) : in_frames[i];
pte = __pte(mfn << PAGE_SHIFT | L1_PROT);
/* update P2M mapping */
phys_to_machine_mapping[virt_to_pfn(va)] = mfn;
/* build multi call */
call[i].op = __HYPERVISOR_update_va_mapping;
call[i].args[arg++] = va;
#ifdef __x86_64__
call[i].args[arg++] = (pgentry_t)pte.pte;
#else
call[i].args[arg++] = pte.pte_low;
call[i].args[arg++] = pte.pte_high;
#endif
call[i].args[arg++] = UVMF_INVLPG;
}
ret = HYPERVISOR_multicall(call, i);
if ( ret )
{
printk("update_va_mapping hypercall no. 2 failed with rc=%d.\n", ret);
return 0;
}
if ( !exch_success )
{
/* since the exchanged failed we just free the pages as well */
free_pages((void *) in_va, order);
return 0;
}
return in_va;
}
/*
* Clear some of the bootstrap memory
*/
static void clear_bootstrap(void)
{
pte_t nullpte = { };
int rc;
/* Use first page as the CoW zero page */
memset(&_text, 0, PAGE_SIZE);
mfn_zero = virt_to_mfn((unsigned long) &_text);
if (!xen_feature(XENFEAT_auto_translated_physmap)) {
if ( (rc = HYPERVISOR_update_va_mapping(0, nullpte, UVMF_INVLPG)) )
printk("Unable to unmap NULL page. rc=%d\n", rc);
}
else {
pgentry_t *pgt = need_pgt(0);
*pgt = 0;
flush_tlb_single(0);
}
}
#ifdef __x86_64__
#define L1_P2M_SHIFT 9
#define L2_P2M_SHIFT 18
#define L3_P2M_SHIFT 27
#else
#define L1_P2M_SHIFT 10
#define L2_P2M_SHIFT 20
#define L3_P2M_SHIFT 30
#endif
#define L1_P2M_ENTRIES (1 << L1_P2M_SHIFT)
#define L2_P2M_ENTRIES (1 << (L2_P2M_SHIFT - L1_P2M_SHIFT))
#define L3_P2M_ENTRIES (1 << (L3_P2M_SHIFT - L2_P2M_SHIFT))
#define L1_P2M_MASK (L1_P2M_ENTRIES - 1)
#define L2_P2M_MASK (L2_P2M_ENTRIES - 1)
#define L3_P2M_MASK (L3_P2M_ENTRIES - 1)
static unsigned long _max_pfn;
static unsigned long *l3_list;
static unsigned long *l2_list_pages[L3_P2M_ENTRIES];
void arch_init_p2m(unsigned long max_pfn)
{
unsigned long *l2_list = NULL;
unsigned long pfn;
if (xen_feature(XENFEAT_auto_translated_physmap))
return;
_max_pfn = max_pfn;
l3_list = (unsigned long *)alloc_page();
for ( pfn=0; pfn<max_pfn; pfn += L1_P2M_ENTRIES )
{
if ( !(pfn % (L1_P2M_ENTRIES * L2_P2M_ENTRIES)) )
{
l2_list = (unsigned long*)alloc_page();
if ( (pfn >> L3_P2M_SHIFT) > 0 )
{
printk("Error: Too many pfns.\n");
do_exit();
}
l3_list[(pfn >> L2_P2M_SHIFT)] = virt_to_mfn(l2_list);
l2_list_pages[(pfn >> L2_P2M_SHIFT)] = l2_list;
}
l2_list[(pfn >> L1_P2M_SHIFT) & L2_P2M_MASK] =
virt_to_mfn(&(phys_to_machine_mapping[pfn]));
}
HYPERVISOR_shared_info->arch.pfn_to_mfn_frame_list_list =
virt_to_mfn(l3_list);
HYPERVISOR_shared_info->arch.max_pfn = max_pfn;
}
void arch_rebuild_p2m(void)
{
unsigned long pfn;
unsigned long *l2_list = NULL;
for ( pfn=0; pfn<_max_pfn; pfn += L1_P2M_ENTRIES )
{
if ( !(pfn % (L1_P2M_ENTRIES * L2_P2M_ENTRIES)) )
{
l2_list = l2_list_pages[pfn >> L2_P2M_SHIFT];
l3_list[pfn >> L2_P2M_SHIFT] = virt_to_mfn(l2_list);