From 0fdb48ffe7a1a56745b999506bf572e260e8ae0a Mon Sep 17 00:00:00 2001 From: Paul Durrant Date: Tue, 8 Dec 2020 19:30:12 +0000 Subject: [PATCH] libxl: Make sure devices added by pci-attach are reflected in the config Currently libxl__device_pci_add_xenstore() is broken in that does not update the domain's configuration for the first device added (which causes creation of the overall backend area in xenstore). This can be easily observed by running 'xl list -l' after adding a single device: the device will be missing. This patch fixes the problem and adds a DEBUG log line to allow easy verification that the domain configuration is being modified. Also, the use of libxl__device_generic_add() is dropped as it leads to a confusing situation where only partial backend information is written under the xenstore '/libxl' path. For LIBXL__DEVICE_KIND_PCI devices the only definitive information in xenstore is under '/local/domain/0/backend' (the '0' being hard-coded). NOTE: This patch includes a whitespace in add_pcis_done(). Signed-off-by: Paul Durrant Reviewed-by: Oleksandr Andrushchenko Acked-by: Wei Liu --- tools/libs/light/libxl_pci.c | 87 +++++++++++++++++++----------------- 1 file changed, 45 insertions(+), 42 deletions(-) diff --git a/tools/libs/light/libxl_pci.c b/tools/libs/light/libxl_pci.c index d536702ac4..3f85f0d762 100644 --- a/tools/libs/light/libxl_pci.c +++ b/tools/libs/light/libxl_pci.c @@ -79,39 +79,55 @@ static void libxl__device_from_pci(libxl__gc *gc, uint32_t domid, device->kind = LIBXL__DEVICE_KIND_PCI; } -static int libxl__create_pci_backend(libxl__gc *gc, uint32_t domid, - const libxl_device_pci *pci, - int num) +static void libxl__create_pci_backend(libxl__gc *gc, xs_transaction_t t, + uint32_t domid, const libxl_device_pci *pci) { - flexarray_t *front = NULL; - flexarray_t *back = NULL; - libxl__device device; - int i; + libxl_ctx *ctx = libxl__gc_owner(gc); + flexarray_t *front, *back; + char *fe_path, *be_path; + struct xs_permissions fe_perms[2], be_perms[2]; + + LOGD(DEBUG, domid, "Creating pci backend"); front = flexarray_make(gc, 16, 1); back = flexarray_make(gc, 16, 1); - LOGD(DEBUG, domid, "Creating pci backend"); - - /* add pci device */ - libxl__device_from_pci(gc, domid, pci, &device); + fe_path = libxl__domain_device_frontend_path(gc, domid, 0, + LIBXL__DEVICE_KIND_PCI); + be_path = libxl__domain_device_backend_path(gc, 0, domid, 0, + LIBXL__DEVICE_KIND_PCI); + flexarray_append_pair(back, "frontend", fe_path); flexarray_append_pair(back, "frontend-id", GCSPRINTF("%d", domid)); - flexarray_append_pair(back, "online", "1"); + flexarray_append_pair(back, "online", GCSPRINTF("%d", 1)); flexarray_append_pair(back, "state", GCSPRINTF("%d", XenbusStateInitialising)); flexarray_append_pair(back, "domain", libxl__domid_to_name(gc, domid)); - for (i = 0; i < num; i++, pci++) - libxl_create_pci_backend_device(gc, back, i, pci); + be_perms[0].id = 0; + be_perms[0].perms = XS_PERM_NONE; + be_perms[1].id = domid; + be_perms[1].perms = XS_PERM_READ; + + xs_rm(ctx->xsh, t, be_path); + xs_mkdir(ctx->xsh, t, be_path); + xs_set_permissions(ctx->xsh, t, be_path, be_perms, + ARRAY_SIZE(be_perms)); + libxl__xs_writev(gc, t, be_path, libxl__xs_kvs_of_flexarray(gc, back)); - flexarray_append_pair(back, "num_devs", GCSPRINTF("%d", num)); + flexarray_append_pair(front, "backend", be_path); flexarray_append_pair(front, "backend-id", GCSPRINTF("%d", 0)); flexarray_append_pair(front, "state", GCSPRINTF("%d", XenbusStateInitialising)); - return libxl__device_generic_add(gc, XBT_NULL, &device, - libxl__xs_kvs_of_flexarray(gc, back), - libxl__xs_kvs_of_flexarray(gc, front), - NULL); + fe_perms[0].id = domid; + fe_perms[0].perms = XS_PERM_NONE; + fe_perms[1].id = 0; + fe_perms[1].perms = XS_PERM_READ; + + xs_rm(ctx->xsh, t, fe_path); + xs_mkdir(ctx->xsh, t, fe_path); + xs_set_permissions(ctx->xsh, t, fe_path, + fe_perms, ARRAY_SIZE(fe_perms)); + libxl__xs_writev(gc, t, fe_path, libxl__xs_kvs_of_flexarray(gc, front)); } static int libxl__device_pci_add_xenstore(libxl__gc *gc, @@ -135,8 +151,6 @@ static int libxl__device_pci_add_xenstore(libxl__gc *gc, be_path = libxl__domain_device_backend_path(gc, 0, domid, 0, LIBXL__DEVICE_KIND_PCI); num_devs = libxl__xs_read(gc, XBT_NULL, GCSPRINTF("%s/num_devs", be_path)); - if (!num_devs) - return libxl__create_pci_backend(gc, domid, pci, 1); libxl_domain_type domtype = libxl__domain_type(gc, domid); if (domtype == LIBXL_DOMAIN_TYPE_INVALID) @@ -150,17 +164,17 @@ static int libxl__device_pci_add_xenstore(libxl__gc *gc, back = flexarray_make(gc, 16, 1); LOGD(DEBUG, domid, "Adding new pci device to xenstore"); - num = atoi(num_devs); + num = num_devs ? atoi(num_devs) : 0; libxl_create_pci_backend_device(gc, back, num, pci); flexarray_append_pair(back, "num_devs", GCSPRINTF("%d", num + 1)); - if (!starting) + if (num && !starting) flexarray_append_pair(back, "state", GCSPRINTF("%d", XenbusStateReconfiguring)); /* * Stubdomin config is derived from its target domain, it doesn't have * its own file. */ - if (!is_stubdomain) { + if (!is_stubdomain && !starting) { lock = libxl__lock_domain_userdata(gc, domid); if (!lock) { rc = ERROR_LOCK_FAIL; @@ -170,6 +184,7 @@ static int libxl__device_pci_add_xenstore(libxl__gc *gc, rc = libxl__get_domain_configuration(gc, domid, &d_config); if (rc) goto out; + LOGD(DEBUG, domid, "Adding new pci device to config"); device_add_domain_config(gc, &d_config, &libxl__pci_devtype, pci); @@ -186,6 +201,10 @@ static int libxl__device_pci_add_xenstore(libxl__gc *gc, if (rc) goto out; } + /* This is the first device, so create the backend */ + if (!num_devs) + libxl__create_pci_backend(gc, t, domid, pci); + libxl__xs_writev(gc, t, be_path, libxl__xs_kvs_of_flexarray(gc, back)); rc = libxl__xs_transaction_commit(gc, &t); @@ -1437,7 +1456,7 @@ out_no_irq: } } - if (!starting && !libxl_get_stubdom_id(CTX, domid)) + if (!libxl_get_stubdom_id(CTX, domid)) rc = libxl__device_pci_add_xenstore(gc, domid, pci, starting); else rc = 0; @@ -1765,28 +1784,12 @@ static void libxl__add_pcis(libxl__egc *egc, libxl__ao *ao, uint32_t domid, } static void add_pcis_done(libxl__egc *egc, libxl__multidev *multidev, - int rc) + int rc) { EGC_GC; add_pcis_state *apds = CONTAINER_OF(multidev, *apds, multidev); - - /* Convenience aliases */ - libxl_domain_config *d_config = apds->d_config; - libxl_domid domid = apds->domid; libxl__ao_device *aodev = apds->outer_aodev; - if (rc) goto out; - - if (d_config->num_pcidevs > 0 && !libxl_get_stubdom_id(CTX, domid)) { - rc = libxl__create_pci_backend(gc, domid, d_config->pcidevs, - d_config->num_pcidevs); - if (rc < 0) { - LOGD(ERROR, domid, "libxl_create_pci_backend failed: %d", rc); - goto out; - } - } - -out: aodev->rc = rc; aodev->callback(egc, aodev); } -- 2.30.2