Commit 86a6a9bf authored by Paolo Bonzini's avatar Paolo Bonzini Committed by Stefano Stabellini
Browse files

xen: add a lock for the mapcache 



Extend the existing dummy mapcache_lock/unlock macros to cover all of
xen-mapcache.c.  This prepares for unlocked memory access, when parts
of exec.c will not be protected by the BQL.

Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarStefano Stabellini <stefano.stabellini@eu.citrix.com>
parent 9b6d7b36

xen-mapcache.c

+43 −11
Original line number Diff line number Diff line
@@ -49,9 +49,6 @@ 
 */

#define NON_MCACHE_MEMORY_SIZE (80 * 1024 * 1024)



#define mapcache_lock()   ((void)0)

#define mapcache_unlock() ((void)0)



typedef struct MapCacheEntry {

    hwaddr paddr_index;

    uint8_t *vaddr_base;
@@ -79,11 +76,22 @@ typedef struct MapCache { 
    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);
@@ -102,6 +110,7 @@ void xen_map_cache_init(phys_offset_to_gaddr_t f, void *opaque) 


    mapcache->phys_offset_to_gaddr = f;

    mapcache->opaque = opaque;

    qemu_mutex_init(&mapcache->lock);



    QTAILQ_INIT(&mapcache->locked_entries);
@@ -193,7 +202,7 @@ static void xen_remap_bucket(MapCacheEntry *entry, 
    g_free(err);

}



uint8_t *xen_map_cache(hwaddr phys_addr, hwaddr size,

static uint8_t *xen_map_cache_unlocked(hwaddr phys_addr, hwaddr size,

                                       uint8_t lock)

{

    MapCacheEntry *entry, *pentry = NULL;
@@ -291,14 +300,27 @@ tryagain: 
    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;
@@ -323,13 +345,16 @@ ram_addr_t xen_ram_addr_from_mapcache(void *ptr) 
    }

    if (!entry) {

        DPRINTF("Trying to find address %p that is not in the mapcache!\n", ptr);

        return 0;

    }

    return (reventry->paddr_index << MCACHE_BUCKET_SHIFT) +

        raddr = 0;

    } else {

        raddr = (reventry->paddr_index << MCACHE_BUCKET_SHIFT) +

             ((unsigned long) ptr - (unsigned long) entry->vaddr_base);

    }

    mapcache_unlock();

    return raddr;

}



void xen_invalidate_map_cache_entry(uint8_t *buffer)

static void xen_invalidate_map_cache_entry_unlocked(uint8_t *buffer)

{

    MapCacheEntry *entry = NULL, *pentry = NULL;

    MapCacheRev *reventry;
@@ -383,6 +408,13 @@ void xen_invalidate_map_cache_entry(uint8_t *buffer) 
    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;
@@ -391,14 +423,14 @@ void xen_invalidate_map_cache(void) 
    /* 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);

    }



    mapcache_lock();



    for (i = 0; i < mapcache->nr_buckets; i++) {

        MapCacheEntry *entry = &mapcache->entry[i];