1 files changed, 375 insertions, 0 deletions
diff --git a/xen-mapcache.c b/xen-mapcache.c
new file mode 100644
index 0000000000..349cc6221d
--- /dev/null
+++ b/xen-mapcache.c
@@ -0,0 +1,375 @@
+/*
+ * 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.
+ *
+ */
+
+#include "config.h"
+
+#include <sys/resource.h>
+
+#include "hw/xen_backend.h"
+#include "blockdev.h"
+#include "bitmap.h"
+
+#include <xen/hvm/params.h>
+#include <sys/mman.h>
+
+#include "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 defined(__i386__)
+#  define MCACHE_BUCKET_SHIFT 16
+#  define MCACHE_MAX_SIZE     (1UL<<31) /* 2GB Cap */
+#elif defined(__x86_64__)
+#  define MCACHE_BUCKET_SHIFT 20
+#  define MCACHE_MAX_SIZE     (1UL<<35) /* 32GB Cap */
+#endif
+#define MCACHE_BUCKET_SIZE (1UL << MCACHE_BUCKET_SHIFT)
+
+typedef struct MapCacheEntry {
+    target_phys_addr_t paddr_index;
+    uint8_t *vaddr_base;
+    DECLARE_BITMAP(valid_mapping, MCACHE_BUCKET_SIZE >> XC_PAGE_SHIFT);
+    uint8_t lock;
+    struct MapCacheEntry *next;
+} MapCacheEntry;
+
+typedef struct MapCacheRev {
+    uint8_t *vaddr_req;
+    target_phys_addr_t paddr_index;
+    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. */
+    target_phys_addr_t last_address_index;
+    uint8_t *last_address_vaddr;
+    unsigned long max_mcache_size;
+    unsigned int mcache_bucket_shift;
+} MapCache;
+
+static MapCache *mapcache;
+
+void qemu_map_cache_init(void)
+{
+    unsigned long size;
+    struct rlimit rlimit_as;
+
+    mapcache = qemu_mallocz(sizeof (MapCache));
+
+    QTAILQ_INIT(&mapcache->locked_entries);
+    mapcache->last_address_index = -1;
+
+    getrlimit(RLIMIT_AS, &rlimit_as);
+    if (rlimit_as.rlim_max < MCACHE_MAX_SIZE) {
+        rlimit_as.rlim_cur = rlimit_as.rlim_max;
+    } else {
+        rlimit_as.rlim_cur = MCACHE_MAX_SIZE;
+    }
+
+    setrlimit(RLIMIT_AS, &rlimit_as);
+    mapcache->max_mcache_size = rlimit_as.rlim_cur;
+
+    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("qemu_map_cache_init, nr_buckets = %lx size %lu\n", mapcache->nr_buckets, size);
+    mapcache->entry = qemu_mallocz(size);
+}
+
+static void qemu_remap_bucket(MapCacheEntry *entry,
+                              target_phys_addr_t size,
+                              target_phys_addr_t address_index)
+{
+    uint8_t *vaddr_base;
+    xen_pfn_t *pfns;
+    int *err;
+    unsigned int i;
+    target_phys_addr_t nb_pfn = size >> XC_PAGE_SHIFT;
+
+    trace_qemu_remap_bucket(address_index);
+
+    pfns = qemu_mallocz(nb_pfn * sizeof (xen_pfn_t));
+    err = qemu_mallocz(nb_pfn * sizeof (int));
+
+    if (entry->vaddr_base != NULL) {
+        if (munmap(entry->vaddr_base, size) != 0) {
+            perror("unmap fails");
+            exit(-1);
+        }
+    }
+
+    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;
+
+    bitmap_zero(entry->valid_mapping, nb_pfn);
+    for (i = 0; i < nb_pfn; i++) {
+        if (!err[i]) {
+            bitmap_set(entry->valid_mapping, i, 1);
+        }
+    }
+
+    qemu_free(pfns);
+    qemu_free(err);
+}
+
+uint8_t *qemu_map_cache(target_phys_addr_t phys_addr, target_phys_addr_t size, uint8_t lock)
+{
+    MapCacheEntry *entry, *pentry = NULL;
+    target_phys_addr_t address_index  = phys_addr >> MCACHE_BUCKET_SHIFT;
+    target_phys_addr_t address_offset = phys_addr & (MCACHE_BUCKET_SIZE - 1);
+
+    trace_qemu_map_cache(phys_addr);
+
+    if (address_index == mapcache->last_address_index && !lock) {
+        trace_qemu_map_cache_return(mapcache->last_address_vaddr + address_offset);
+        return mapcache->last_address_vaddr + address_offset;
+    }
+
+    entry = &mapcache->entry[address_index % mapcache->nr_buckets];
+
+    while (entry && entry->lock && entry->paddr_index != address_index && entry->vaddr_base) {
+        pentry = entry;
+        entry = entry->next;
+    }
+    if (!entry) {
+        entry = qemu_mallocz(sizeof (MapCacheEntry));
+        pentry->next = entry;
+        qemu_remap_bucket(entry, size ? : MCACHE_BUCKET_SIZE, address_index);
+    } else if (!entry->lock) {
+        if (!entry->vaddr_base || entry->paddr_index != address_index ||
+            !test_bit(address_offset >> XC_PAGE_SHIFT, entry->valid_mapping)) {
+            qemu_remap_bucket(entry, size ? : MCACHE_BUCKET_SIZE, address_index);
+        }
+    }
+
+    if (!test_bit(address_offset >> XC_PAGE_SHIFT, entry->valid_mapping)) {
+        mapcache->last_address_index = -1;
+        trace_qemu_map_cache_return(NULL);
+        return NULL;
+    }
+
+    mapcache->last_address_index = address_index;
+    mapcache->last_address_vaddr = entry->vaddr_base;
+    if (lock) {
+        MapCacheRev *reventry = qemu_mallocz(sizeof(MapCacheRev));
+        entry->lock++;
+        reventry->vaddr_req = mapcache->last_address_vaddr + address_offset;
+        reventry->paddr_index = mapcache->last_address_index;
+        QTAILQ_INSERT_HEAD(&mapcache->locked_entries, reventry, next);
+    }
+
+    trace_qemu_map_cache_return(mapcache->last_address_vaddr + address_offset);
+    return mapcache->last_address_vaddr + address_offset;
+}
+
+void qemu_map_cache_unlock(void *buffer)
+{
+    MapCacheEntry *entry = NULL, *pentry = NULL;
+    MapCacheRev *reventry;
+    target_phys_addr_t paddr_index;
+    int found = 0;
+
+    QTAILQ_FOREACH(reventry, &mapcache->locked_entries, next) {
+        if (reventry->vaddr_req == buffer) {
+            paddr_index = reventry->paddr_index;
+            found = 1;
+            break;
+        }
+    }
+    if (!found) {
+        return;
+    }
+    QTAILQ_REMOVE(&mapcache->locked_entries, reventry, next);
+    qemu_free(reventry);
+
+    entry = &mapcache->entry[paddr_index % mapcache->nr_buckets];
+    while (entry && entry->paddr_index != paddr_index) {
+        pentry = entry;
+        entry = entry->next;
+    }
+    if (!entry) {
+        return;
+    }
+    if (entry->lock > 0) {
+        entry->lock--;
+    }
+}
+
+ram_addr_t qemu_ram_addr_from_mapcache(void *ptr)
+{
+    MapCacheRev *reventry;
+    target_phys_addr_t paddr_index;
+    int found = 0;
+
+    QTAILQ_FOREACH(reventry, &mapcache->locked_entries, next) {
+        if (reventry->vaddr_req == ptr) {
+            paddr_index = reventry->paddr_index;
+            found = 1;
+            break;
+        }
+    }
+    if (!found) {
+        fprintf(stderr, "qemu_ram_addr_from_mapcache, could not find %p\n", 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;
+    }
+
+    return paddr_index << MCACHE_BUCKET_SHIFT;
+}
+
+void qemu_invalidate_entry(uint8_t *buffer)
+{
+    MapCacheEntry *entry = NULL, *pentry = NULL;
+    MapCacheRev *reventry;
+    target_phys_addr_t paddr_index;
+    int found = 0;
+
+    if (mapcache->last_address_vaddr == buffer) {
+        mapcache->last_address_index = -1;
+    }
+
+    QTAILQ_FOREACH(reventry, &mapcache->locked_entries, next) {
+        if (reventry->vaddr_req == buffer) {
+            paddr_index = reventry->paddr_index;
+            found = 1;
+            break;
+        }
+    }
+    if (!found) {
+        DPRINTF("qemu_invalidate_entry, could not find %p\n", 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);
+    qemu_free(reventry);
+
+    entry = &mapcache->entry[paddr_index % mapcache->nr_buckets];
+    while (entry && entry->paddr_index != paddr_index) {
+        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, MCACHE_BUCKET_SIZE) != 0) {
+        perror("unmap fails");
+        exit(-1);
+    }
+    qemu_free(entry);
+}
+
+void qemu_invalidate_map_cache(void)
+{
+    unsigned long i;
+    MapCacheRev *reventry;
+
+    /* Flush pending AIO before destroying the mapcache */
+    qemu_aio_flush();
+
+    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);
+    }
+
+    mapcache_lock();
+
+    for (i = 0; i < mapcache->nr_buckets; i++) {
+        MapCacheEntry *entry = &mapcache->entry[i];
+
+        if (entry->vaddr_base == NULL) {
+            continue;
+        }
+
+        if (munmap(entry->vaddr_base, MCACHE_BUCKET_SIZE) != 0) {
+            perror("unmap fails");
+            exit(-1);
+        }
+
+        entry->paddr_index = 0;
+        entry->vaddr_base = NULL;
+    }
+
+    mapcache->last_address_index = -1;
+    mapcache->last_address_vaddr = NULL;
+
+    mapcache_unlock();
+}
+
+uint8_t *xen_map_block(target_phys_addr_t phys_addr, target_phys_addr_t size)
+{
+    uint8_t *vaddr_base;
+    xen_pfn_t *pfns;
+    int *err;
+    unsigned int i;
+    target_phys_addr_t nb_pfn = size >> XC_PAGE_SHIFT;
+
+    trace_xen_map_block(phys_addr, size);
+    phys_addr >>= XC_PAGE_SHIFT;
+
+    pfns = qemu_mallocz(nb_pfn * sizeof (xen_pfn_t));
+    err = qemu_mallocz(nb_pfn * sizeof (int));
+
+    for (i = 0; i < nb_pfn; i++) {
+        pfns[i] = phys_addr + 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);
+    }
+
+    qemu_free(pfns);
+    qemu_free(err);
+
+    return vaddr_base;
+}