[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v6 16/18] xen: automatically create XenBlockDevice-s
> -----Original Message----- > From: Anthony PERARD [mailto:anthony.perard@xxxxxxxxxx] > Sent: 19 December 2018 12:39 > To: Paul Durrant <Paul.Durrant@xxxxxxxxxx> > Cc: qemu-devel@xxxxxxxxxx; qemu-block@xxxxxxxxxx; xen- > devel@xxxxxxxxxxxxxxxxxxxx; Kevin Wolf <kwolf@xxxxxxxxxx>; Max Reitz > <mreitz@xxxxxxxxxx>; Stefano Stabellini <sstabellini@xxxxxxxxxx> > Subject: Re: [PATCH v6 16/18] xen: automatically create XenBlockDevice-s > > On Mon, Dec 17, 2018 at 01:30:09PM +0000, Paul Durrant wrote: > > +static char *xen_block_blockdev_add(const char *id, QDict *qdict, > > + Error **errp) > > +{ > > + const char *driver = qdict_get_try_str(qdict, "driver"); > > + BlockdevOptions *options = NULL; > > + Error *local_err = NULL; > > + char *str = NULL; > > + char *node_name; > > + Visitor *v; > > + > > + if (!driver) { > > + error_setg(errp, "no 'driver' parameter"); > > + return NULL; > > + } > > + > > + node_name = g_strdup_printf("%s-%s", id, driver); > > + qdict_put_str(qdict, "node-name", node_name); > > + > > + qdict_iter(qdict, add_item, &str); > > + > > + trace_xen_block_blockdev_add(str); > > + g_free(str); > > + > > + v = qobject_input_visitor_new_flat_confused(qdict, errp); > > Kevin seems to say that this could be done without the _flat_confused > version. The flat_confused version seems to be useful just because > the key "cache.direct" is used earlier, and because everything in qdict > is a string. It could be, but there's a good reason for wanting everything as a string, and that is so that I can do a qdict_iter to generate my trace message. Also I really don't want to get too elaborate here... this is supposed to be mimicking what would normally come via a json blob, and that would start out as strings. Paul > > I think instead, qobject_input_visitor_new could be used. You would just > need to replace > qdict_put_str(qdict, "cache.direct", "on"); > by > QDict *cache = qdict_new(); > qdict_put_str(cache, "direct", "on"); > qdict_put_obj(qdict, "cache", QOBJECT(cache)); > > And also the property "read-only" which seems to be a bool as well. I've > check all property in the qdict, and I think that the only two that > needs to be changes. And then, we can use: > v = qobject_input_visitor_new(qdict); which never fails. > > You'll just need "qapi/qobject-input-visitor.h" instead of "block/qdict.h" > > > + if (!v) { > > + goto fail; > > + } > > + > > + visit_type_BlockdevOptions(v, NULL, &options, &local_err); > > + visit_free(v); > > + > > + if (local_err) { > > + error_propagate(errp, local_err); > > + goto fail; > > + } > > + > > + qmp_blockdev_add(options, &local_err); > > + > > + if (local_err) { > > + error_propagate(errp, local_err); > > + goto fail; > > + } > > + > > + qapi_free_BlockdevOptions(options); > > + > > + return node_name; > > + > > +fail: > > + if (options) { > > + qapi_free_BlockdevOptions(options); > > + } > > + g_free(node_name); > > + > > + return NULL; > > +} > [...] > > +static XenBlockDrive *xen_block_drive_create(const char *id, > > + const char *device_type, > > + QDict *opts, Error **errp) > > +{ > > + const char *params = qdict_get_try_str(opts, "params"); > > + const char *mode = qdict_get_try_str(opts, "mode"); > > + const char *direct_io_safe = qdict_get_try_str(opts, "direct-io- > safe"); > > + const char *discard_enable = qdict_get_try_str(opts, "discard- > enable"); > > + char *driver = NULL; > > + char *filename = NULL; > > + XenBlockDrive *drive = NULL; > > + Error *local_err = NULL; > > + QDict *qdict; > > + > > + if (params) { > > + char **v = g_strsplit(params, ":", 2); > > + > > + if (v[1] == NULL) { > > + filename = g_strdup(v[0]); > > + driver = g_strdup("file"); > > + } else { > > + if (strcmp(v[0], "aio") == 0) { > > + driver = g_strdup("file"); > > + } else if (strcmp(v[0], "vhd") == 0) { > > + driver = g_strdup("vpc"); > > + } else { > > + driver = g_strdup(v[0]); > > + } > > + filename = g_strdup(v[1]); > > + } > > + > > + g_strfreev(v); > > + } > > + > > + if (!filename) { > > + error_setg(errp, "no filename"); > > + goto done; > > + } > > + assert(driver); > > + > > + drive = g_new0(XenBlockDrive, 1); > > + drive->id = g_strdup(id); > > + > > + qdict = qdict_new(); > > + > > + qdict_put_str(qdict, "driver", "file"); > > + qdict_put_str(qdict, "filename", filename); > > + > > + if (mode && *mode != 'w') { > > + qdict_put_str(qdict, "read-only", "on"); > > + } > > + > > + if (direct_io_safe) { > > + unsigned long value; > > + > > + if (!qemu_strtoul(direct_io_safe, NULL, 2, &value) && !!value) > { > > + qdict_put_str(qdict, "cache.direct", "on"); > > + qdict_put_str(qdict, "aio", "native"); > > + } > > + } > > + > > + if (discard_enable) { > > + unsigned long value; > > + > > + if (!qemu_strtoul(discard_enable, NULL, 2, &value) && !!value) > { > > + qdict_put_str(qdict, "discard", "unmap"); > > + } > > + } > > + > > + /* > > + * It is necessary to turn file locking off as an emulated device > > + * may have already opened the same image file. > > + */ > > + qdict_put_str(qdict, "locking", "off"); > > + > > + xen_block_drive_layer_add(drive, qdict, &local_err); > > + qobject_unref(qdict); > > + > > + if (local_err) { > > + error_propagate(errp, local_err); > > + goto done; > > + } > > + > > + /* If the image is a raw file then we are done */ > > I don't think that is true, as I have this warning in QEMU: > qemu-system-i386: warning: Opening a block device as a file using the > 'file' driver is deprecated > > We would need a "raw" driver. > > > + if (!strcmp(driver, "file")) { > > + goto done; > > + } > > + > > + qdict = qdict_new(); > > + > > + qdict_put_str(qdict, "driver", driver); > > + > > + xen_block_drive_layer_add(drive, qdict, &local_err); > > + qobject_unref(qdict); > > + > > +done: > > + g_free(driver); > > + g_free(filename); > > + > > + if (local_err) { > > + xen_block_drive_destroy(drive, NULL); > > + return NULL; > > + } > > + > > + return drive; > > +} > > -- > Anthony PERARD _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/mailman/listinfo/xen-devel
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