From 637c53ffcb891ce8876183e6b593b8f0c3763ab1 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Thu, 12 May 2016 16:13:40 +0200 Subject: [PATCH] xen: write information about supported backends Add a Xenstore directory for each supported pv backend. This will allow Xen tools to decide which backend type to use in case there are multiple possibilities. The information is added under /local/domain//device-model//backends before the "running" state is written to Xenstore. Using a directory for each backend enables us to add parameters for specific backends in the future. This interface is documented in the Xen source repository in the file docs/misc/qemu-backends.txt In order to reuse the Xenstore directory creation already present in hw/xen/xen_devconfig.c move the related functions to hw/xen/xen_backend.c where they fit better. Signed-off-by: Juergen Gross Acked-by: Anthony PERARD Reviewed-by: Wei Liu Message-id: 1463062421-613-3-git-send-email-jgross@suse.com Signed-off-by: Gerd Hoffmann --- hw/xen/xen_backend.c | 63 ++++++++++++++++++++++++++++++++++++ hw/xen/xen_devconfig.c | 52 ++--------------------------- include/hw/xen/xen_backend.h | 2 ++ 3 files changed, 67 insertions(+), 50 deletions(-) diff --git a/hw/xen/xen_backend.c b/hw/xen/xen_backend.c index 60575ad38d..c63f9df38b 100644 --- a/hw/xen/xen_backend.c +++ b/hw/xen/xen_backend.c @@ -42,11 +42,36 @@ struct xs_handle *xenstore = NULL; const char *xen_protocol; /* private */ +struct xs_dirs { + char *xs_dir; + QTAILQ_ENTRY(xs_dirs) list; +}; +static QTAILQ_HEAD(xs_dirs_head, xs_dirs) xs_cleanup = + QTAILQ_HEAD_INITIALIZER(xs_cleanup); + static QTAILQ_HEAD(XenDeviceHead, XenDevice) xendevs = QTAILQ_HEAD_INITIALIZER(xendevs); static int debug = 0; /* ------------------------------------------------------------- */ +static void xenstore_cleanup_dir(char *dir) +{ + struct xs_dirs *d; + + d = g_malloc(sizeof(*d)); + d->xs_dir = dir; + QTAILQ_INSERT_TAIL(&xs_cleanup, d, list); +} + +void xen_config_cleanup(void) +{ + struct xs_dirs *d; + + QTAILQ_FOREACH(d, &xs_cleanup, list) { + xs_rm(xenstore, 0, d->xs_dir); + } +} + int xenstore_write_str(const char *base, const char *node, const char *val) { char abspath[XEN_BUFSIZE]; @@ -75,6 +100,30 @@ char *xenstore_read_str(const char *base, const char *node) return ret; } +int xenstore_mkdir(char *path, int p) +{ + struct xs_permissions perms[2] = { + { + .id = 0, /* set owner: dom0 */ + }, { + .id = xen_domid, + .perms = p, + } + }; + + if (!xs_mkdir(xenstore, 0, path)) { + xen_be_printf(NULL, 0, "xs_mkdir %s: failed\n", path); + return -1; + } + xenstore_cleanup_dir(g_strdup(path)); + + if (!xs_set_permissions(xenstore, 0, path, perms, 2)) { + xen_be_printf(NULL, 0, "xs_set_permissions %s: failed\n", path); + return -1; + } + return 0; +} + int xenstore_write_int(const char *base, const char *node, int ival) { char val[12]; @@ -726,6 +775,20 @@ err: int xen_be_register(const char *type, struct XenDevOps *ops) { + char path[50]; + int rc; + + if (ops->backend_register) { + rc = ops->backend_register(); + if (rc) { + return rc; + } + } + + snprintf(path, sizeof(path), "device-model/%u/backends/%s", xen_domid, + type); + xenstore_mkdir(path, XS_PERM_NONE); + return xenstore_scan(type, xen_domid, ops); } diff --git a/hw/xen/xen_devconfig.c b/hw/xen/xen_devconfig.c index 1f30fe4f5a..b7d290df6c 100644 --- a/hw/xen/xen_devconfig.c +++ b/hw/xen/xen_devconfig.c @@ -5,54 +5,6 @@ /* ------------------------------------------------------------- */ -struct xs_dirs { - char *xs_dir; - QTAILQ_ENTRY(xs_dirs) list; -}; -static QTAILQ_HEAD(xs_dirs_head, xs_dirs) xs_cleanup = QTAILQ_HEAD_INITIALIZER(xs_cleanup); - -static void xen_config_cleanup_dir(char *dir) -{ - struct xs_dirs *d; - - d = g_malloc(sizeof(*d)); - d->xs_dir = dir; - QTAILQ_INSERT_TAIL(&xs_cleanup, d, list); -} - -void xen_config_cleanup(void) -{ - struct xs_dirs *d; - - QTAILQ_FOREACH(d, &xs_cleanup, list) { - xs_rm(xenstore, 0, d->xs_dir); - } -} - -/* ------------------------------------------------------------- */ - -static int xen_config_dev_mkdir(char *dev, int p) -{ - struct xs_permissions perms[2] = {{ - .id = 0, /* set owner: dom0 */ - },{ - .id = xen_domid, - .perms = p, - }}; - - if (!xs_mkdir(xenstore, 0, dev)) { - xen_be_printf(NULL, 0, "xs_mkdir %s: failed\n", dev); - return -1; - } - xen_config_cleanup_dir(g_strdup(dev)); - - if (!xs_set_permissions(xenstore, 0, dev, perms, 2)) { - xen_be_printf(NULL, 0, "xs_set_permissions %s: failed\n", dev); - return -1; - } - return 0; -} - static int xen_config_dev_dirs(const char *ftype, const char *btype, int vdev, char *fe, char *be, int len) { @@ -66,8 +18,8 @@ static int xen_config_dev_dirs(const char *ftype, const char *btype, int vdev, snprintf(be, len, "%s/backend/%s/%d/%d", dom, btype, xen_domid, vdev); free(dom); - xen_config_dev_mkdir(fe, XS_PERM_READ | XS_PERM_WRITE); - xen_config_dev_mkdir(be, XS_PERM_READ); + xenstore_mkdir(fe, XS_PERM_READ | XS_PERM_WRITE); + xenstore_mkdir(be, XS_PERM_READ); return 0; } diff --git a/include/hw/xen/xen_backend.h b/include/hw/xen/xen_backend.h index b4b4ff0af2..63364f71d0 100644 --- a/include/hw/xen/xen_backend.h +++ b/include/hw/xen/xen_backend.h @@ -28,6 +28,7 @@ struct XenDevOps { int (*free)(struct XenDevice *xendev); void (*backend_changed)(struct XenDevice *xendev, const char *node); void (*frontend_changed)(struct XenDevice *xendev, const char *node); + int (*backend_register)(void); }; struct XenDevice { @@ -63,6 +64,7 @@ extern const char *xen_protocol; extern DeviceState *xen_sysdev; /* xenstore helper functions */ +int xenstore_mkdir(char *path, int p); int xenstore_write_str(const char *base, const char *node, const char *val); int xenstore_write_int(const char *base, const char *node, int ival); int xenstore_write_int64(const char *base, const char *node, int64_t ival);