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