[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH v4 10/23] libxl: remove get_all_assigned_devices() from libxl_pci.c
From: Paul Durrant <pdurrant@xxxxxxxxxx> Use of this function is a very inefficient way to check whether a device has already been assigned. This patch adds code that saves the domain id in xenstore at the point of assignment, and removes it again when the device id de-assigned (or the domain is destroyed). It is then straightforward to check whether a device has been assigned by checking whether a device has a saved domain id. NOTE: To facilitate the xenstore check it is necessary to move the pci_info_xs_read() earlier in libxl_pci.c. To keep related functions together, the rest of the pci_info_xs_XXX() functions are moved too. Signed-off-by: Paul Durrant <pdurrant@xxxxxxxxxx> --- Cc: Ian Jackson <iwj@xxxxxxxxxxxxxx> Cc: Wei Liu <wl@xxxxxxx> --- tools/libs/light/libxl_pci.c | 149 ++++++++++++++++--------------------------- 1 file changed, 55 insertions(+), 94 deletions(-) diff --git a/tools/libs/light/libxl_pci.c b/tools/libs/light/libxl_pci.c index ec101f255f..d3c7a547c3 100644 --- a/tools/libs/light/libxl_pci.c +++ b/tools/libs/light/libxl_pci.c @@ -336,50 +336,6 @@ retry_transaction2: return 0; } -static int get_all_assigned_devices(libxl__gc *gc, libxl_device_pci **list, int *num) -{ - char **domlist; - unsigned int nd = 0, i; - - *list = NULL; - *num = 0; - - domlist = libxl__xs_directory(gc, XBT_NULL, "/local/domain", &nd); - for(i = 0; i < nd; i++) { - char *path, *num_devs; - - path = GCSPRINTF("/local/domain/0/backend/%s/%s/0/num_devs", - libxl__device_kind_to_string(LIBXL__DEVICE_KIND_PCI), - domlist[i]); - num_devs = libxl__xs_read(gc, XBT_NULL, path); - if ( num_devs ) { - int ndev = atoi(num_devs), j; - char *devpath, *bdf; - - for(j = 0; j < ndev; j++) { - devpath = GCSPRINTF("/local/domain/0/backend/%s/%s/0/dev-%u", - libxl__device_kind_to_string(LIBXL__DEVICE_KIND_PCI), - domlist[i], j); - bdf = libxl__xs_read(gc, XBT_NULL, devpath); - if ( bdf ) { - unsigned dom, bus, dev, func; - if ( sscanf(bdf, PCI_BDF, &dom, &bus, &dev, &func) != 4 ) - continue; - - *list = realloc(*list, sizeof(libxl_device_pci) * ((*num) + 1)); - if (*list == NULL) - return ERROR_NOMEM; - pci_struct_fill(*list + *num, dom, bus, dev, func, 0); - (*num)++; - } - } - } - } - libxl__ptr_add(gc, *list); - - return 0; -} - static int is_pci_in_array(libxl_device_pci *assigned, int num_assigned, int dom, int bus, int dev, int func) { @@ -427,19 +383,58 @@ static int sysfs_write_bdf(libxl__gc *gc, const char * sysfs_path, return 0; } +#define PCI_INFO_PATH "/libxl/pci" + +static char *pci_info_xs_path(libxl__gc *gc, libxl_device_pci *pci, + const char *node) +{ + return node ? + GCSPRINTF(PCI_INFO_PATH"/"PCI_BDF_XSPATH"/%s", + pci->domain, pci->bus, pci->dev, pci->func, + node) : + GCSPRINTF(PCI_INFO_PATH"/"PCI_BDF_XSPATH, + pci->domain, pci->bus, pci->dev, pci->func); +} + + +static int pci_info_xs_write(libxl__gc *gc, libxl_device_pci *pci, + const char *node, const char *val) +{ + char *path = pci_info_xs_path(gc, pci, node); + int rc = libxl__xs_printf(gc, XBT_NULL, path, "%s", val); + + if (rc) LOGE(WARN, "Write of %s to node %s failed.", val, path); + + return rc; +} + +static char *pci_info_xs_read(libxl__gc *gc, libxl_device_pci *pci, + const char *node) +{ + char *path = pci_info_xs_path(gc, pci, node); + + return libxl__xs_read(gc, XBT_NULL, path); +} + +static void pci_info_xs_remove(libxl__gc *gc, libxl_device_pci *pci, + const char *node) +{ + char *path = pci_info_xs_path(gc, pci, node); + libxl_ctx *ctx = libxl__gc_owner(gc); + + /* Remove the xenstore entry */ + xs_rm(ctx->xsh, XBT_NULL, path); +} + libxl_device_pci *libxl_device_pci_assignable_list(libxl_ctx *ctx, int *num) { GC_INIT(ctx); - libxl_device_pci *pcis = NULL, *new, *assigned; + libxl_device_pci *pcis = NULL, *new; struct dirent *de; DIR *dir; - int r, num_assigned; *num = 0; - r = get_all_assigned_devices(gc, &assigned, &num_assigned); - if (r) goto out; - dir = opendir(SYSFS_PCIBACK_DRIVER); if (NULL == dir) { if (errno == ENOENT) { @@ -455,9 +450,6 @@ libxl_device_pci *libxl_device_pci_assignable_list(libxl_ctx *ctx, int *num) if (sscanf(de->d_name, PCI_BDF, &dom, &bus, &dev, &func) != 4) continue; - if (is_pci_in_array(assigned, num_assigned, dom, bus, dev, func)) - continue; - new = realloc(pcis, ((*num) + 1) * sizeof(*new)); if (NULL == new) continue; @@ -467,6 +459,10 @@ libxl_device_pci *libxl_device_pci_assignable_list(libxl_ctx *ctx, int *num) memset(new, 0, sizeof(*new)); pci_struct_fill(new, dom, bus, dev, func, 0); + + if (pci_info_xs_read(gc, new, "domid")) /* already assigned */ + continue; + (*num)++; } @@ -737,48 +733,6 @@ static int pciback_dev_unassign(libxl__gc *gc, libxl_device_pci *pci) return 0; } -#define PCI_INFO_PATH "/libxl/pci" - -static char *pci_info_xs_path(libxl__gc *gc, libxl_device_pci *pci, - const char *node) -{ - return node ? - GCSPRINTF(PCI_INFO_PATH"/"PCI_BDF_XSPATH"/%s", - pci->domain, pci->bus, pci->dev, pci->func, - node) : - GCSPRINTF(PCI_INFO_PATH"/"PCI_BDF_XSPATH, - pci->domain, pci->bus, pci->dev, pci->func); -} - - -static void pci_info_xs_write(libxl__gc *gc, libxl_device_pci *pci, - const char *node, const char *val) -{ - char *path = pci_info_xs_path(gc, pci, node); - - if ( libxl__xs_printf(gc, XBT_NULL, path, "%s", val) < 0 ) { - LOGE(WARN, "Write of %s to node %s failed.", val, path); - } -} - -static char *pci_info_xs_read(libxl__gc *gc, libxl_device_pci *pci, - const char *node) -{ - char *path = pci_info_xs_path(gc, pci, node); - - return libxl__xs_read(gc, XBT_NULL, path); -} - -static void pci_info_xs_remove(libxl__gc *gc, libxl_device_pci *pci, - const char *node) -{ - char *path = pci_info_xs_path(gc, pci, node); - libxl_ctx *ctx = libxl__gc_owner(gc); - - /* Remove the xenstore entry */ - xs_rm(ctx->xsh, XBT_NULL, path); -} - static int libxl__device_pci_assignable_add(libxl__gc *gc, libxl_device_pci *pci, int rebind) @@ -1594,6 +1548,9 @@ void libxl__device_pci_add(libxl__egc *egc, uint32_t domid, goto out; } + rc = pci_info_xs_write(gc, pci, "domid", GCSPRINTF("%u", domid)); + if (rc) goto out; + libxl__device_pci_reset(gc, pci->domain, pci->bus, pci->dev, pci->func); stubdomid = libxl_get_stubdom_id(ctx, domid); @@ -1721,6 +1678,7 @@ static void device_pci_add_done(libxl__egc *egc, "PCI device %x:%x:%x.%x (rc %d)", pci->domain, pci->bus, pci->dev, pci->func, rc); + pci_info_xs_remove(gc, pci, "domid"); } aodev->rc = rc; aodev->callback(egc, aodev); @@ -2282,6 +2240,9 @@ out: libxl__xswait_stop(gc, &prs->xswait); libxl__ev_time_deregister(gc, &prs->timeout); libxl__ev_time_deregister(gc, &prs->retry_timer); + + if (!rc) pci_info_xs_remove(gc, pci, "domid"); + aodev->rc = rc; aodev->callback(egc, aodev); } -- 2.11.0
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