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/*
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* Copyright (C) 2011 Citrix Ltd.
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*
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* This work is licensed under the terms of the GNU GPL, version 2. See
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* the COPYING file in the top-level directory.
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*
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* Contributions after 2012-01-13 are licensed under the terms of the
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* GNU GPL, version 2 or (at your option) any later version.
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*/
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#include "config.h" |
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#include <sys/resource.h> |
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#include "hw/xen_backend.h" |
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#include "blockdev.h" |
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#include "bitmap.h" |
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#include <xen/hvm/params.h> |
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#include <sys/mman.h> |
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#include "xen-mapcache.h" |
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#include "trace.h" |
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//#define MAPCACHE_DEBUG
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#ifdef MAPCACHE_DEBUG
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# define DPRINTF(fmt, ...) do { \ |
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fprintf(stderr, "xen_mapcache: " fmt, ## __VA_ARGS__); \ |
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} while (0) |
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#else
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# define DPRINTF(fmt, ...) do { } while (0) |
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#endif
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#if defined(__i386__)
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# define MCACHE_BUCKET_SHIFT 16 |
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# define MCACHE_MAX_SIZE (1UL<<31) /* 2GB Cap */ |
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#elif defined(__x86_64__)
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# define MCACHE_BUCKET_SHIFT 20 |
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# define MCACHE_MAX_SIZE (1UL<<35) /* 32GB Cap */ |
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#endif
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#define MCACHE_BUCKET_SIZE (1UL << MCACHE_BUCKET_SHIFT) |
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/* This is the size of the virtual address space reserve to QEMU that will not
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* be use by MapCache.
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* From empirical tests I observed that qemu use 75MB more than the
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* max_mcache_size.
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*/
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#define NON_MCACHE_MEMORY_SIZE (80 * 1024 * 1024) |
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#define mapcache_lock() ((void)0) |
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#define mapcache_unlock() ((void)0) |
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typedef struct MapCacheEntry { |
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target_phys_addr_t paddr_index; |
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uint8_t *vaddr_base; |
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unsigned long *valid_mapping; |
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uint8_t lock; |
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target_phys_addr_t size; |
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struct MapCacheEntry *next;
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} MapCacheEntry; |
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typedef struct MapCacheRev { |
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uint8_t *vaddr_req; |
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target_phys_addr_t paddr_index; |
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target_phys_addr_t size; |
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QTAILQ_ENTRY(MapCacheRev) next; |
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} MapCacheRev; |
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typedef struct MapCache { |
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MapCacheEntry *entry; |
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unsigned long nr_buckets; |
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QTAILQ_HEAD(map_cache_head, MapCacheRev) locked_entries; |
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/* For most cases (>99.9%), the page address is the same. */
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target_phys_addr_t last_address_index; |
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uint8_t *last_address_vaddr; |
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unsigned long max_mcache_size; |
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unsigned int mcache_bucket_shift; |
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} MapCache; |
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static MapCache *mapcache;
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static inline int test_bits(int nr, int size, const unsigned long *addr) |
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{ |
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unsigned long res = find_next_zero_bit(addr, size + nr, nr); |
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if (res >= nr + size)
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return 1; |
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else
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return 0; |
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} |
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void xen_map_cache_init(void) |
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{ |
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unsigned long size; |
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struct rlimit rlimit_as;
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mapcache = g_malloc0(sizeof (MapCache));
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QTAILQ_INIT(&mapcache->locked_entries); |
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mapcache->last_address_index = -1;
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if (geteuid() == 0) { |
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rlimit_as.rlim_cur = RLIM_INFINITY; |
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rlimit_as.rlim_max = RLIM_INFINITY; |
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mapcache->max_mcache_size = MCACHE_MAX_SIZE; |
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} else {
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getrlimit(RLIMIT_AS, &rlimit_as); |
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rlimit_as.rlim_cur = rlimit_as.rlim_max; |
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if (rlimit_as.rlim_max != RLIM_INFINITY) {
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fprintf(stderr, "Warning: QEMU's maximum size of virtual"
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" memory is not infinity.\n");
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} |
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if (rlimit_as.rlim_max < MCACHE_MAX_SIZE + NON_MCACHE_MEMORY_SIZE) {
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mapcache->max_mcache_size = rlimit_as.rlim_max - |
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NON_MCACHE_MEMORY_SIZE; |
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} else {
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mapcache->max_mcache_size = MCACHE_MAX_SIZE; |
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} |
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} |
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setrlimit(RLIMIT_AS, &rlimit_as); |
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mapcache->nr_buckets = |
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(((mapcache->max_mcache_size >> XC_PAGE_SHIFT) + |
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(1UL << (MCACHE_BUCKET_SHIFT - XC_PAGE_SHIFT)) - 1) >> |
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(MCACHE_BUCKET_SHIFT - XC_PAGE_SHIFT)); |
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size = mapcache->nr_buckets * sizeof (MapCacheEntry);
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size = (size + XC_PAGE_SIZE - 1) & ~(XC_PAGE_SIZE - 1); |
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DPRINTF("%s, nr_buckets = %lx size %lu\n", __func__,
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mapcache->nr_buckets, size); |
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mapcache->entry = g_malloc0(size); |
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} |
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static void xen_remap_bucket(MapCacheEntry *entry, |
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target_phys_addr_t size, |
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target_phys_addr_t address_index) |
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{ |
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uint8_t *vaddr_base; |
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xen_pfn_t *pfns; |
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int *err;
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unsigned int i; |
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target_phys_addr_t nb_pfn = size >> XC_PAGE_SHIFT; |
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trace_xen_remap_bucket(address_index); |
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pfns = g_malloc0(nb_pfn * sizeof (xen_pfn_t));
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err = g_malloc0(nb_pfn * sizeof (int)); |
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if (entry->vaddr_base != NULL) { |
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if (munmap(entry->vaddr_base, entry->size) != 0) { |
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perror("unmap fails");
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exit(-1);
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} |
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} |
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if (entry->valid_mapping != NULL) { |
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g_free(entry->valid_mapping); |
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entry->valid_mapping = NULL;
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} |
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for (i = 0; i < nb_pfn; i++) { |
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pfns[i] = (address_index << (MCACHE_BUCKET_SHIFT-XC_PAGE_SHIFT)) + i; |
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} |
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vaddr_base = xc_map_foreign_bulk(xen_xc, xen_domid, PROT_READ|PROT_WRITE, |
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pfns, err, nb_pfn); |
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if (vaddr_base == NULL) { |
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perror("xc_map_foreign_bulk");
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exit(-1);
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} |
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entry->vaddr_base = vaddr_base; |
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entry->paddr_index = address_index; |
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entry->size = size; |
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entry->valid_mapping = (unsigned long *) g_malloc0(sizeof(unsigned long) * |
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BITS_TO_LONGS(size >> XC_PAGE_SHIFT)); |
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bitmap_zero(entry->valid_mapping, nb_pfn); |
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for (i = 0; i < nb_pfn; i++) { |
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if (!err[i]) {
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bitmap_set(entry->valid_mapping, i, 1);
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} |
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} |
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g_free(pfns); |
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g_free(err); |
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} |
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uint8_t *xen_map_cache(target_phys_addr_t phys_addr, target_phys_addr_t size, |
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uint8_t lock) |
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{ |
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MapCacheEntry *entry, *pentry = NULL;
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target_phys_addr_t address_index = phys_addr >> MCACHE_BUCKET_SHIFT; |
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target_phys_addr_t address_offset = phys_addr & (MCACHE_BUCKET_SIZE - 1);
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target_phys_addr_t __size = size; |
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trace_xen_map_cache(phys_addr); |
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if (address_index == mapcache->last_address_index && !lock && !__size) {
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trace_xen_map_cache_return(mapcache->last_address_vaddr + address_offset); |
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return mapcache->last_address_vaddr + address_offset;
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} |
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/* size is always a multiple of MCACHE_BUCKET_SIZE */
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if ((address_offset + (__size % MCACHE_BUCKET_SIZE)) > MCACHE_BUCKET_SIZE)
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__size += MCACHE_BUCKET_SIZE; |
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if (__size % MCACHE_BUCKET_SIZE)
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__size += MCACHE_BUCKET_SIZE - (__size % MCACHE_BUCKET_SIZE); |
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if (!__size)
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__size = MCACHE_BUCKET_SIZE; |
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entry = &mapcache->entry[address_index % mapcache->nr_buckets]; |
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while (entry && entry->lock && entry->vaddr_base &&
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(entry->paddr_index != address_index || entry->size != __size || |
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!test_bits(address_offset >> XC_PAGE_SHIFT, size >> XC_PAGE_SHIFT, |
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entry->valid_mapping))) { |
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pentry = entry; |
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entry = entry->next; |
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} |
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if (!entry) {
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entry = g_malloc0(sizeof (MapCacheEntry));
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pentry->next = entry; |
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xen_remap_bucket(entry, __size, address_index); |
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} else if (!entry->lock) { |
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if (!entry->vaddr_base || entry->paddr_index != address_index ||
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entry->size != __size || |
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!test_bits(address_offset >> XC_PAGE_SHIFT, size >> XC_PAGE_SHIFT, |
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entry->valid_mapping)) { |
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xen_remap_bucket(entry, __size, address_index); |
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} |
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} |
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if(!test_bits(address_offset >> XC_PAGE_SHIFT, size >> XC_PAGE_SHIFT,
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entry->valid_mapping)) { |
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mapcache->last_address_index = -1;
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trace_xen_map_cache_return(NULL);
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return NULL; |
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} |
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mapcache->last_address_index = address_index; |
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mapcache->last_address_vaddr = entry->vaddr_base; |
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if (lock) {
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MapCacheRev *reventry = g_malloc0(sizeof(MapCacheRev));
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entry->lock++; |
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reventry->vaddr_req = mapcache->last_address_vaddr + address_offset; |
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reventry->paddr_index = mapcache->last_address_index; |
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reventry->size = entry->size; |
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QTAILQ_INSERT_HEAD(&mapcache->locked_entries, reventry, next); |
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} |
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trace_xen_map_cache_return(mapcache->last_address_vaddr + address_offset); |
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return mapcache->last_address_vaddr + address_offset;
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} |
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ram_addr_t xen_ram_addr_from_mapcache(void *ptr)
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{ |
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MapCacheEntry *entry = NULL;
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MapCacheRev *reventry; |
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target_phys_addr_t paddr_index; |
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target_phys_addr_t size; |
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int found = 0; |
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QTAILQ_FOREACH(reventry, &mapcache->locked_entries, next) { |
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if (reventry->vaddr_req == ptr) {
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paddr_index = reventry->paddr_index; |
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size = reventry->size; |
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found = 1;
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break;
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} |
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} |
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if (!found) {
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fprintf(stderr, "%s, could not find %p\n", __func__, ptr);
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QTAILQ_FOREACH(reventry, &mapcache->locked_entries, next) { |
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DPRINTF(" "TARGET_FMT_plx" -> %p is present\n", reventry->paddr_index, |
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reventry->vaddr_req); |
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} |
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abort(); |
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return 0; |
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} |
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entry = &mapcache->entry[paddr_index % mapcache->nr_buckets]; |
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while (entry && (entry->paddr_index != paddr_index || entry->size != size)) {
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entry = entry->next; |
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} |
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if (!entry) {
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DPRINTF("Trying to find address %p that is not in the mapcache!\n", ptr);
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return 0; |
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} |
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return (reventry->paddr_index << MCACHE_BUCKET_SHIFT) +
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((unsigned long) ptr - (unsigned long) entry->vaddr_base); |
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} |
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void xen_invalidate_map_cache_entry(uint8_t *buffer)
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{ |
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MapCacheEntry *entry = NULL, *pentry = NULL; |
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MapCacheRev *reventry; |
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target_phys_addr_t paddr_index; |
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target_phys_addr_t size; |
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int found = 0; |
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if (mapcache->last_address_vaddr == buffer) {
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mapcache->last_address_index = -1;
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} |
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QTAILQ_FOREACH(reventry, &mapcache->locked_entries, next) { |
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if (reventry->vaddr_req == buffer) {
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paddr_index = reventry->paddr_index; |
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size = reventry->size; |
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found = 1;
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break;
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} |
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} |
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if (!found) {
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DPRINTF("%s, could not find %p\n", __func__, buffer);
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QTAILQ_FOREACH(reventry, &mapcache->locked_entries, next) { |
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DPRINTF(" "TARGET_FMT_plx" -> %p is present\n", reventry->paddr_index, reventry->vaddr_req); |
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} |
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return;
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} |
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QTAILQ_REMOVE(&mapcache->locked_entries, reventry, next); |
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g_free(reventry); |
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entry = &mapcache->entry[paddr_index % mapcache->nr_buckets]; |
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while (entry && (entry->paddr_index != paddr_index || entry->size != size)) {
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pentry = entry; |
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entry = entry->next; |
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} |
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if (!entry) {
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DPRINTF("Trying to unmap address %p that is not in the mapcache!\n", buffer);
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return;
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} |
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entry->lock--; |
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if (entry->lock > 0 || pentry == NULL) { |
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return;
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} |
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pentry->next = entry->next; |
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if (munmap(entry->vaddr_base, entry->size) != 0) { |
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perror("unmap fails");
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exit(-1);
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} |
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g_free(entry->valid_mapping); |
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g_free(entry); |
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} |
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void xen_invalidate_map_cache(void) |
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{ |
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unsigned long i; |
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MapCacheRev *reventry; |
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/* Flush pending AIO before destroying the mapcache */
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bdrv_drain_all(); |
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QTAILQ_FOREACH(reventry, &mapcache->locked_entries, next) { |
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DPRINTF("There should be no locked mappings at this time, "
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"but "TARGET_FMT_plx" -> %p is present\n", |
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reventry->paddr_index, reventry->vaddr_req); |
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} |
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mapcache_lock(); |
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for (i = 0; i < mapcache->nr_buckets; i++) { |
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MapCacheEntry *entry = &mapcache->entry[i]; |
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if (entry->vaddr_base == NULL) { |
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continue;
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} |
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if (munmap(entry->vaddr_base, entry->size) != 0) { |
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perror("unmap fails");
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exit(-1);
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} |
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entry->paddr_index = 0;
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entry->vaddr_base = NULL;
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entry->size = 0;
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g_free(entry->valid_mapping); |
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entry->valid_mapping = NULL;
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} |
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mapcache->last_address_index = -1;
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mapcache->last_address_vaddr = NULL;
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mapcache_unlock(); |
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} |