[libvirt] [RFC] RFC: Reimplement cache allocation for a VM

This is a RFC patch for the reimplement of `support cache tune(CAT) in libvirt`[1]. There are already patch sets[2] to address it, and functional works, but people doesn't like it cause it has global variable, and missing unit test case for new added capabilites, etc. Martin has proposed a test infra to do vircaps2xmltest, and I extened it on top of it to extend resctrl control[3], this is kinds of new desiged apart from [2], so I propose this RFC patch to do some rework on it. [] https://www.redhat.com/archives/libvir-list/2017-January/msg00683.html [] https://www.redhat.com/archives/libvir-list/2017-March/msg00181.html [] https://www.redhat.com/archives/libvir-list/2017-April/msg00516.html --- src/util/virresctrl.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++++ src/util/virresctrl.h | 86 +++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 167 insertions(+) create mode 100644 src/util/virresctrl.c create mode 100644 src/util/virresctrl.h diff --git a/src/util/virresctrl.c b/src/util/virresctrl.c new file mode 100644 index 0000000..f555eb8 --- /dev/null +++ b/src/util/virresctrl.c @@ -0,0 +1,81 @@ +/* + * virresctrl.c: methods for managing resource control + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library. If not, see + * <http://www.gnu.org/licenses/>;. + * + * Authors: + * Eli Qiao <liyong.qiao(a)intel.com&gt; + */ + +#include <config.h> +#include <fcntl.h> +#include <sys/file.h> +#include <sys/stat.h> +#include <sys/types.h> + +#include "virresctrl.h" +#include "viralloc.h" +#include "virerror.h" +#include "virfile.h" +#include "virhostcpu.h" +#include "virlog.h" +#include "virstring.h" +#include "virarch.h" + +VIR_LOG_INIT("util.resctrl"); + +#define VIR_FROM_THIS VIR_FROM_RESCTRL + +VIR_ENUM_IMPL(virResctrl, VIR_RESCTRL_TYPE_LAST, + "L3", + "L3CODE", + "L3DATA", + "L2") + +/** + * a virResctrlDomain represents a resource control group, it's a directory + * under /sys/fs/resctrl. + * eg: /sys/fs/resctrl/CG1 + * |-- cpus + * |-- schemata + * `-- tasks + * # cat schemata + * L3DATA:0=fffff;1=fffff + * L3CODE:0=fffff;1=fffff + * + * Besides, it can also represent the default resource control group of the + * host. + */ + +typedef struct _virResctrlGroup virResctrlGroup; +typedef virResctrlGroup *virResctrlGroupPtr; +struct _virResctrlGroup { + char *name; /* resource group name, eg: CG1. If it represent host's + default resource group name, should be a NULL pointer */ + size_t n_tasks; /* number of task assigned to the resource group */ + char **tasks; /* task list which contains task id eg: 77454 */ + + size_t n_schematas; /* number of schemata the resource group contains, + eg: 2 */ + virResctrlSchemataPtr *schematas; /* scheamta list */ +}; + +/* All resource control groups on this host, including default resource group */ +typedef struct _virResCtrlDomain virResCtrlDomain; +typedef virResCtrlDomain *virResCtrlDomainPtr; +struct _virResCtrlDomain { + size_t n_groups; /* number of resource control group */ + virResctrlGroupPtr groups; /* list of resource control group */ +}; diff --git a/src/util/virresctrl.h b/src/util/virresctrl.h new file mode 100644 index 0000000..da89542 --- /dev/null +++ b/src/util/virresctrl.h @@ -0,0 +1,86 @@ +/* + * virresctrl.h: header for managing resctrl control + * + * Copyright (C) 2016 Intel, Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library. If not, see + * <http://www.gnu.org/licenses/>;. + * + * Authors: + * Eli Qiao <liyong.qiao(a)intel.com&gt; + */ + +#ifndef __VIR_RESCTRL_H__ +# define __VIR_RESCTRL_H__ + +typedef enum { + VIR_RESCTRL_TYPE_L3, + VIR_RESCTRL_TYPE_L3_CODE, + VIR_RESCTRL_TYPE_L3_DATA, + VIR_RESCTRL_TYPE_L2, + + VIR_RESCTRL_TYPE_LAST +} virResctrlType; + +VIR_ENUM_DECL(virResctrl); + +/* + * a virResctrlSchemataItem represents one of schemata object in a + * resource control group. + * eg: 0=f + */ +typedef struct _virResCtrlSchemataItem virResctrlSchemataItem; +typedef virResctrlSchemataItem *virResctrlSchemataItemPtr; +struct _virResctrlSchemataItem { + unsigned int cache_id; /* cache resource id, eg: 0 */ + unsigned int continuous_schemata; /* schemata, should be a continuous bits, + eg: f, this schemata can be persisted + to sysfs */ + unsigned int schemata; /* schemata eg: f0f, a schemata which is calculated + at running time */ + unsigned long long size; /* the cache size schemata represented in B, + eg: (min * bits of continuous_schemata) */ +}; + +/* + * a virResctrlSchemata represents schemata objects of specific type of + * resource in a resource control group. + * eg: L3:0=f,1=ff + */ +typedef struct _virResctrlSchemata virResctrlSchemata; +typedef virResctrlSchemata *virResctrlSchemataPtr; +struct _virResctrlSchemata { + virResctrlType type; /* resource control type, eg: L3 */ + size_t n_schemata_items; /* number of schemata item, eg: 2 */ + virResctrlSchemataItemPtr *schemata_items; /* pointer list of schemata item */ +}; + +/* Get free cache of the host, result saved in schemata */ +int virResctrlGetFreeCache(virResctrlType type, + virResctrlSchemataPtr *schemata); + +/* Get free cache of specific cache id of the host, result saved in + schemataitem */ +int virResctrlGetFreeCacheByCacheId(virResctrlType type, + virResctrlSchemataItemPtr *schemataitem); + +/* Set cache allocation for a VM domain */ +int virResctrlSetCacheBanks(virDomainCachetunePtr cachetune, + unsigned char *group_name, + size_t n_pids, + pid_t *pids); + +/* remove cache allocation for a VM domain */ +int virResctrlRemoveCacheBanks(unsigned char *group_name); +#endif -- 1.9.1