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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH v2 09/24] 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 f9f8374d7d36..ff37dc5b5921 100644
--- a/tools/libs/light/libxl_pci.c
+++ b/tools/libs/light/libxl_pci.c
@@ -317,50 +317,6 @@ 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)
{
@@ -408,19 +364,58 @@ 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) {
@@ -436,9 +431,6 @@ 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;
@@ -448,6 +440,10 @@ 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)++;
}
@@ -718,48 +714,6 @@ 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)
@@ -1575,6 +1529,9 @@ 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);
@@ -1702,6 +1659,7 @@ 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);
@@ -2279,6 +2237,9 @@ 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);
}
--
2.20.1
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