Re: [PATCH openEuler-1.0-LTS v2 8/9] mpam: Add support for group rmid modify

在 2021/9/26 16:00, Wang Xingang 写道:

From: Xingang Wang wangxingang5@huawei.com

ascend inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I49RB2 CVE: NA

---

The mpam driver controls the allocation of rmid, however there are some ocassions that the partid and pmg of a group might come from elsewhere. This add support for group rmid modify. The sysfs rmid file is set to write accessible, and this add a write interface to accept rmid from user. When the rmid from user is different and valid, update the group with new rmid.

Signed-off-by: Xingang Wang wangxingang5@huawei.com Signed-off-by: Shaobo Wang bobo.shaobowang@huawei.com

---

arch/arm64/kernel/mpam/mpam_resctrl.c | 98 ++++++++++++++++++++++++--- 1 file changed, 90 insertions(+), 8 deletions(-)

diff --git a/arch/arm64/kernel/mpam/mpam_resctrl.c b/arch/arm64/kernel/mpam/mpam_resctrl.c index a7fef0ac3..991af33f2 100644 --- a/arch/arm64/kernel/mpam/mpam_resctrl.c +++ b/arch/arm64/kernel/mpam/mpam_resctrl.c @@ -808,6 +808,11 @@ static void unset_rmid_remap_bmp_occ(unsigned long *bmp) set_bit(0, bmp); }

+static int is_rmid_remap_bmp_bdr_set(unsigned long *bmp, int b) +{

• return (test_bit(b + 1, bmp) == 0) ? 1 : 0;

+}

• static void rmid_remap_bmp_bdr_set(unsigned long *bmp, int b) { set_bit(b + 1, bmp);

@@ -914,11 +919,11 @@ static int rmid_to_partid_pmg(int rmid, int *partid, int *pmg) return 0; }

-static int __rmid_alloc(int partid) +static int __rmid_alloc(int partid, int pmg) { int stride = 0; int partid_sel = 0;

• int ret, pmg;

• int ret; int rmid[2] = {-1, -1}; unsigned long **cmp, **bmp;

@@ -933,10 +938,19 @@ static int __rmid_alloc(int partid) continue; set_rmid_remap_bmp_occ(*bmp);

• 	ret = rmid_remap_bmp_alloc_pmg(*bmp);
  

• 	if (ret < 0)
  

• 		goto out;
  

• 	pmg = ret;
  

• 	if (pmg >= 0) {
  

• 		if (is_rmid_remap_bmp_bdr_set(*bmp, pmg)) {
  

• 			ret = -EEXIST;
  

• 			goto out;
  

• 		}
  

• 		rmid_remap_bmp_bdr_clear(*bmp, pmg);
  

• 	} else {
  

• 		ret = rmid_remap_bmp_alloc_pmg(*bmp);
  

• 		if (ret < 0)
  

• 			goto out;
  

• 		pmg = ret;
  

• 	}
  

• rmid[stride] = to_rmid(partid + stride, pmg);
  if (STRIDE_INC_CHK(stride))
  	break;
  

@@ -976,7 +990,7 @@ static int __rmid_alloc(int partid)

int rmid_alloc(int partid) {

• return __rmid_alloc(partid);

• return __rmid_alloc(partid, -1); }

  void rmid_free(int rmid)

@@ -1851,6 +1865,73 @@ static int resctrl_group_rmid_show(struct kernfs_open_file *of, return ret; }

+static ssize_t resctrl_group_rmid_write(struct kernfs_open_file *of,

• char *buf, size_t nbytes, loff_t off)
  

+{

• struct rdtgroup *rdtgrp;
• int ret = 0;
• int partid;
• int pmg;
• int rmid;
• struct task_struct *p, *t;
• if (kstrtoint(strstrip(buf), 0, &rmid) || rmid < 0)

• return -EINVAL;
  

• rdtgrp = resctrl_group_kn_lock_live(of->kn);
• if (!rdtgrp) {

• ret = -ENOENT;
  

• goto unlock;
  

• }
• rdt_last_cmd_clear();
• ret = rmid_to_partid_pmg(rmid, &partid, &pmg);
• if (ret < 0) {

• ret = -EINVAL;
  

• goto unlock;
  

• }
• if (rmid == rdtgrp->mon.rmid)

• goto unlock;
  

• if (rdtgrp->type != RDTCTRL_GROUP ||

• 	!list_empty(&rdtgrp->mon.crdtgrp_list)) {
  

• rdt_last_cmd_puts("unsupported operation\n");
  

• goto unlock;
  

• }
• ret = __rmid_alloc(partid, pmg);
• if (ret < 0) {

• rdt_last_cmd_puts("set rmid failed\n");
  

• goto unlock;
  

• }
• /*

• * we use intpartid as group control, use reqpartid for config
  

• * synchronization and monitor, only update the reqpartid
  

• */
  

• rdtgrp->closid.reqpartid = partid;
• rdtgrp->mon.rmid = rmid;
• read_lock(&tasklist_lock);
• for_each_process_thread(p, t) {

• if (t->closid == rdtgrp->closid.intpartid)
  

• 	__resctrl_group_move_task(t, rdtgrp);
  

• }
• read_unlock(&tasklist_lock);
• update_closid_rmid(&rdtgrp->cpu_mask, rdtgrp);
• rmid_free(rdtgrp->mon.rmid);

这里释放的应该是旧的rmid吧，我看你后面一个补丁改了，最好这里直接改掉，免得后面误解

+unlock:

• resctrl_group_kn_unlock(of->kn);
• if (ret)

• return ret;
  

• return nbytes;

+}

• /* rdtgroup information files for one cache resource. */ static struct rftype res_specific_files[] = { {

@@ -1950,8 +2031,9 @@ static struct rftype res_specific_files[] = { }, { .name = "rmid",

• .mode		= 0444,
  

• .mode		= 0644,
  

  .kf_ops = &resctrl_group_kf_single_ops,

• .write		= resctrl_group_rmid_write,
  

  .seq_show = resctrl_group_rmid_show, .fflags = RFTYPE_BASE, },