Commit 5e72179b authored by Anthony Liguori's avatar Anthony Liguori
Browse files

Merge remote-tracking branch 'sstabellini/xen-2013-01-14' into staging 



* sstabellini/xen-2013-01-14:
  xen_disk: implement BLKIF_OP_FLUSH_DISKCACHE, remove BLKIF_OP_WRITE_BARRIER
  xen_disk: add persistent grant support to xen_disk backend
  xen_disk: fix memory leak

Signed-off-by: default avatarAnthony Liguori <aliguori@us.ibm.com>
parents cf7c3f0c 7e7b7cba

hw/xen_disk.c

+184 −24
Original line number Diff line number Diff line
@@ -51,6 +51,13 @@ static int max_requests = 32; 
#define BLOCK_SIZE  512

#define IOCB_COUNT  (BLKIF_MAX_SEGMENTS_PER_REQUEST + 2)



struct PersistentGrant {

    void *page;

    struct XenBlkDev *blkdev;

};



typedef struct PersistentGrant PersistentGrant;



struct ioreq {

    blkif_request_t     req;

    int16_t             status;
@@ -68,6 +75,7 @@ struct ioreq { 
    int                 prot;

    void                *page[BLKIF_MAX_SEGMENTS_PER_REQUEST];

    void                *pages;

    int                 num_unmap;



    /* aio status */

    int                 aio_inflight;
@@ -104,6 +112,12 @@ struct XenBlkDev { 
    int                 requests_inflight;

    int                 requests_finished;



    /* Persistent grants extension */

    gboolean            feature_persistent;

    GTree               *persistent_gnts;

    unsigned int        persistent_gnt_count;

    unsigned int        max_grants;



    /* qemu block driver */

    DriveInfo           *dinfo;

    BlockDriverState    *bs;
@@ -112,6 +126,54 @@ struct XenBlkDev { 


/* ------------------------------------------------------------- */



static void ioreq_reset(struct ioreq *ioreq)

{

    memset(&ioreq->req, 0, sizeof(ioreq->req));

    ioreq->status = 0;

    ioreq->start = 0;

    ioreq->presync = 0;

    ioreq->postsync = 0;

    ioreq->mapped = 0;



    memset(ioreq->domids, 0, sizeof(ioreq->domids));

    memset(ioreq->refs, 0, sizeof(ioreq->refs));

    ioreq->prot = 0;

    memset(ioreq->page, 0, sizeof(ioreq->page));

    ioreq->pages = NULL;



    ioreq->aio_inflight = 0;

    ioreq->aio_errors = 0;



    ioreq->blkdev = NULL;

    memset(&ioreq->list, 0, sizeof(ioreq->list));

    memset(&ioreq->acct, 0, sizeof(ioreq->acct));



    qemu_iovec_reset(&ioreq->v);

}



static gint int_cmp(gconstpointer a, gconstpointer b, gpointer user_data)

{

    uint ua = GPOINTER_TO_UINT(a);

    uint ub = GPOINTER_TO_UINT(b);

    return (ua > ub) - (ua < ub);

}



static void destroy_grant(gpointer pgnt)

{

    PersistentGrant *grant = pgnt;

    XenGnttab gnt = grant->blkdev->xendev.gnttabdev;



    if (xc_gnttab_munmap(gnt, grant->page, 1) != 0) {

        xen_be_printf(&grant->blkdev->xendev, 0,

                      "xc_gnttab_munmap failed: %s\n",

                      strerror(errno));

    }

    grant->blkdev->persistent_gnt_count--;

    xen_be_printf(&grant->blkdev->xendev, 3,

                  "unmapped grant %p\n", grant->page);

    g_free(grant);

}



static struct ioreq *ioreq_start(struct XenBlkDev *blkdev)

{

    struct ioreq *ioreq = NULL;
@@ -129,7 +191,6 @@ static struct ioreq *ioreq_start(struct XenBlkDev *blkdev) 
        /* get one from freelist */

        ioreq = QLIST_FIRST(&blkdev->freelist);

        QLIST_REMOVE(ioreq, list);

        qemu_iovec_reset(&ioreq->v);

    }

    QLIST_INSERT_HEAD(&blkdev->inflight, ioreq, list);

    blkdev->requests_inflight++;
@@ -153,7 +214,7 @@ static void ioreq_release(struct ioreq *ioreq, bool finish) 
    struct XenBlkDev *blkdev = ioreq->blkdev;



    QLIST_REMOVE(ioreq, list);

    memset(ioreq, 0, sizeof(*ioreq));

    ioreq_reset(ioreq);

    ioreq->blkdev = blkdev;

    QLIST_INSERT_HEAD(&blkdev->freelist, ioreq, list);

    if (finish) {
@@ -182,12 +243,11 @@ static int ioreq_parse(struct ioreq *ioreq) 
    case BLKIF_OP_READ:

        ioreq->prot = PROT_WRITE; /* to memory */

        break;

    case BLKIF_OP_WRITE_BARRIER:

        if (!ioreq->req.nr_segments) {

    case BLKIF_OP_FLUSH_DISKCACHE:

        ioreq->presync = 1;

        if (!ioreq->req.nr_segments) {

            return 0;

        }

        ioreq->presync = ioreq->postsync = 1;

        /* fall through */

    case BLKIF_OP_WRITE:

        ioreq->prot = PROT_READ; /* from memory */
@@ -241,21 +301,21 @@ static void ioreq_unmap(struct ioreq *ioreq) 
    XenGnttab gnt = ioreq->blkdev->xendev.gnttabdev;

    int i;



    if (ioreq->v.niov == 0 || ioreq->mapped == 0) {

    if (ioreq->num_unmap == 0 || ioreq->mapped == 0) {

        return;

    }

    if (batch_maps) {

        if (!ioreq->pages) {

            return;

        }

        if (xc_gnttab_munmap(gnt, ioreq->pages, ioreq->v.niov) != 0) {

        if (xc_gnttab_munmap(gnt, ioreq->pages, ioreq->num_unmap) != 0) {

            xen_be_printf(&ioreq->blkdev->xendev, 0, "xc_gnttab_munmap failed: %s\n",

                          strerror(errno));

        }

        ioreq->blkdev->cnt_map -= ioreq->v.niov;

        ioreq->blkdev->cnt_map -= ioreq->num_unmap;

        ioreq->pages = NULL;

    } else {

        for (i = 0; i < ioreq->v.niov; i++) {

        for (i = 0; i < ioreq->num_unmap; i++) {

            if (!ioreq->page[i]) {

                continue;

            }
@@ -273,41 +333,120 @@ static void ioreq_unmap(struct ioreq *ioreq) 
static int ioreq_map(struct ioreq *ioreq)

{

    XenGnttab gnt = ioreq->blkdev->xendev.gnttabdev;

    int i;

    uint32_t domids[BLKIF_MAX_SEGMENTS_PER_REQUEST];

    uint32_t refs[BLKIF_MAX_SEGMENTS_PER_REQUEST];

    void *page[BLKIF_MAX_SEGMENTS_PER_REQUEST];

    int i, j, new_maps = 0;

    PersistentGrant *grant;

    /* domids and refs variables will contain the information necessary

     * to map the grants that are needed to fulfill this request.

     *

     * After mapping the needed grants, the page array will contain the

     * memory address of each granted page in the order specified in ioreq

     * (disregarding if it's a persistent grant or not).

     */



    if (ioreq->v.niov == 0 || ioreq->mapped == 1) {

        return 0;

    }

    if (batch_maps) {

    if (ioreq->blkdev->feature_persistent) {

        for (i = 0; i < ioreq->v.niov; i++) {

            grant = g_tree_lookup(ioreq->blkdev->persistent_gnts,

                                    GUINT_TO_POINTER(ioreq->refs[i]));



            if (grant != NULL) {

                page[i] = grant->page;

                xen_be_printf(&ioreq->blkdev->xendev, 3,

                              "using persistent-grant %" PRIu32 "\n",

                              ioreq->refs[i]);

            } else {

                    /* Add the grant to the list of grants that

                     * should be mapped

                     */

                    domids[new_maps] = ioreq->domids[i];

                    refs[new_maps] = ioreq->refs[i];

                    page[i] = NULL;

                    new_maps++;

            }

        }

        /* Set the protection to RW, since grants may be reused later

         * with a different protection than the one needed for this request

         */

        ioreq->prot = PROT_WRITE | PROT_READ;

    } else {

        /* All grants in the request should be mapped */

        memcpy(refs, ioreq->refs, sizeof(refs));

        memcpy(domids, ioreq->domids, sizeof(domids));

        memset(page, 0, sizeof(page));

        new_maps = ioreq->v.niov;

    }



    if (batch_maps && new_maps) {

        ioreq->pages = xc_gnttab_map_grant_refs

            (gnt, ioreq->v.niov, ioreq->domids, ioreq->refs, ioreq->prot);

            (gnt, new_maps, domids, refs, ioreq->prot);

        if (ioreq->pages == NULL) {

            xen_be_printf(&ioreq->blkdev->xendev, 0,

                          "can't map %d grant refs (%s, %d maps)\n",

                          ioreq->v.niov, strerror(errno), ioreq->blkdev->cnt_map);

                          new_maps, strerror(errno), ioreq->blkdev->cnt_map);

            return -1;

        }

        for (i = 0; i < ioreq->v.niov; i++) {

            ioreq->v.iov[i].iov_base = ioreq->pages + i * XC_PAGE_SIZE +

                (uintptr_t)ioreq->v.iov[i].iov_base;

        for (i = 0, j = 0; i < ioreq->v.niov; i++) {

            if (page[i] == NULL) {

                page[i] = ioreq->pages + (j++) * XC_PAGE_SIZE;

            }

        ioreq->blkdev->cnt_map += ioreq->v.niov;

    } else  {

        for (i = 0; i < ioreq->v.niov; i++) {

        }

        ioreq->blkdev->cnt_map += new_maps;

    } else if (new_maps)  {

        for (i = 0; i < new_maps; i++) {

            ioreq->page[i] = xc_gnttab_map_grant_ref

                (gnt, ioreq->domids[i], ioreq->refs[i], ioreq->prot);

                (gnt, domids[i], refs[i], ioreq->prot);

            if (ioreq->page[i] == NULL) {

                xen_be_printf(&ioreq->blkdev->xendev, 0,

                              "can't map grant ref %d (%s, %d maps)\n",

                              ioreq->refs[i], strerror(errno), ioreq->blkdev->cnt_map);

                              refs[i], strerror(errno), ioreq->blkdev->cnt_map);

                ioreq_unmap(ioreq);

                return -1;

            }

            ioreq->v.iov[i].iov_base = ioreq->page[i] + (uintptr_t)ioreq->v.iov[i].iov_base;

            ioreq->blkdev->cnt_map++;

        }

        for (i = 0, j = 0; i < ioreq->v.niov; i++) {

            if (page[i] == NULL) {

                page[i] = ioreq->page[j++];

            }

        }

    }

    if (ioreq->blkdev->feature_persistent) {

        while ((ioreq->blkdev->persistent_gnt_count < ioreq->blkdev->max_grants)

              && new_maps) {

            /* Go through the list of newly mapped grants and add as many

             * as possible to the list of persistently mapped grants.

             *

             * Since we start at the end of ioreq->page(s), we only need

             * to decrease new_maps to prevent this granted pages from

             * being unmapped in ioreq_unmap.

             */

            grant = g_malloc0(sizeof(*grant));

            new_maps--;

            if (batch_maps) {

                grant->page = ioreq->pages + (new_maps) * XC_PAGE_SIZE;

            } else {

                grant->page = ioreq->page[new_maps];

            }

            grant->blkdev = ioreq->blkdev;

            xen_be_printf(&ioreq->blkdev->xendev, 3,

                          "adding grant %" PRIu32 " page: %p\n",

                          refs[new_maps], grant->page);

            g_tree_insert(ioreq->blkdev->persistent_gnts,

                          GUINT_TO_POINTER(refs[new_maps]),

                          grant);

            ioreq->blkdev->persistent_gnt_count++;

        }

    }

    for (i = 0; i < ioreq->v.niov; i++) {

        ioreq->v.iov[i].iov_base += (uintptr_t)page[i];

    }

    ioreq->mapped = 1;

    ioreq->num_unmap = new_maps;

    return 0;

}
@@ -369,7 +508,7 @@ static int ioreq_runio_qemu_aio(struct ioreq *ioreq) 
                       qemu_aio_complete, ioreq);

        break;

    case BLKIF_OP_WRITE:

    case BLKIF_OP_WRITE_BARRIER:

    case BLKIF_OP_FLUSH_DISKCACHE:

        if (!ioreq->req.nr_segments) {

            break;

        }
@@ -654,7 +793,8 @@ static int blk_init(struct XenDevice *xendev) 
                  blkdev->file_size, blkdev->file_size >> 20);



    /* fill info */

    xenstore_write_be_int(&blkdev->xendev, "feature-barrier", 1);

    xenstore_write_be_int(&blkdev->xendev, "feature-flush-cache", 1);

    xenstore_write_be_int(&blkdev->xendev, "feature-persistent", 1);

    xenstore_write_be_int(&blkdev->xendev, "info",            info);

    xenstore_write_be_int(&blkdev->xendev, "sector-size",     blkdev->file_blk);

    xenstore_write_be_int(&blkdev->xendev, "sectors",
@@ -678,6 +818,7 @@ out_error: 
static int blk_connect(struct XenDevice *xendev)

{

    struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev);

    int pers;



    if (xenstore_read_fe_int(&blkdev->xendev, "ring-ref", &blkdev->ring_ref) == -1) {

        return -1;
@@ -686,6 +827,11 @@ static int blk_connect(struct XenDevice *xendev) 
                             &blkdev->xendev.remote_port) == -1) {

        return -1;

    }

    if (xenstore_read_fe_int(&blkdev->xendev, "feature-persistent", &pers)) {

        blkdev->feature_persistent = FALSE;

    } else {

        blkdev->feature_persistent = !!pers;

    }



    blkdev->protocol = BLKIF_PROTOCOL_NATIVE;

    if (blkdev->xendev.protocol) {
@@ -729,6 +875,15 @@ static int blk_connect(struct XenDevice *xendev) 
    }

    }



    if (blkdev->feature_persistent) {

        /* Init persistent grants */

        blkdev->max_grants = max_requests * BLKIF_MAX_SEGMENTS_PER_REQUEST;

        blkdev->persistent_gnts = g_tree_new_full((GCompareDataFunc)int_cmp,

                                             NULL, NULL,

                                             (GDestroyNotify)destroy_grant);

        blkdev->persistent_gnt_count = 0;

    }



    xen_be_bind_evtchn(&blkdev->xendev);



    xen_be_printf(&blkdev->xendev, 1, "ok: proto %s, ring-ref %d, "
@@ -769,6 +924,11 @@ static int blk_free(struct XenDevice *xendev) 
        blk_disconnect(xendev);

    }



    /* Free persistent grants */

    if (blkdev->feature_persistent) {

        g_tree_destroy(blkdev->persistent_gnts);

    }



    while (!QLIST_EMPTY(&blkdev->freelist)) {

        ioreq = QLIST_FIRST(&blkdev->freelist);

        QLIST_REMOVE(ioreq, list);