Merge branch 'for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup changes from Tejun Heo:
 "The only notable change is Vipin's new misc cgroup controller.

  This implements generic support for resources which can be controlled
  by simply counting and limiting the number of resource instances - ie
  there's X number of these on the system and this cgroup subtree can
  have upto Y of those.

  The first user is the address space IDs used for virtual machine
  memory encryption and expected future usages are similar - niche
  hardware features with concrete resource limits and simple usage
  models"

* 'for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: use tsk->in_iowait instead of delayacct_is_task_waiting_on_io()
  cgroup/cpuset: fix typos in comments
  cgroup: misc: mark dummy misc_cg_res_total_usage() static inline
  svm/sev: Register SEV and SEV-ES ASIDs to the misc controller
  cgroup: Miscellaneous cgroup documentation.
  cgroup: Add misc cgroup controller

Author: torvalds

Documentation/admin-guide/cgroup-v1/index.rst

@@ -17,6 +17,7 @@ Control Groups version 1
     hugetlb
     memcg_test
     memory
+    misc
     net_cls
     net_prio
     pids

Documentation/admin-guide/cgroup-v1/misc.rst

@@ -0,0 +1,4 @@
+===============
+Misc controller
+===============
+Please refer "Misc" documentation in Documentation/admin-guide/cgroup-v2.rst

Documentation/admin-guide/cgroup-v2.rst

@@ -65,8 +65,11 @@ v1 is available under :ref:`Documentation/admin-guide/cgroup-v1/index.rst <cgrou
        5-7-1. RDMA Interface Files
      5-8. HugeTLB
        5.8-1. HugeTLB Interface Files
-     5-8. Misc
-       5-8-1. perf_event
+     5-9. Misc
+       5.9-1 Miscellaneous cgroup Interface Files
+       5.9-2 Migration and Ownership
+     5-10. Others
+       5-10-1. perf_event
      5-N. Non-normative information
        5-N-1. CPU controller root cgroup process behaviour
        5-N-2. IO controller root cgroup process behaviour
@@ -2171,6 +2174,72 @@ HugeTLB Interface Files
 Misc
 ----
 
+The Miscellaneous cgroup provides the resource limiting and tracking
+mechanism for the scalar resources which cannot be abstracted like the other
+cgroup resources. Controller is enabled by the CONFIG_CGROUP_MISC config
+option.
+
+A resource can be added to the controller via enum misc_res_type{} in the
+include/linux/misc_cgroup.h file and the corresponding name via misc_res_name[]
+in the kernel/cgroup/misc.c file. Provider of the resource must set its
+capacity prior to using the resource by calling misc_cg_set_capacity().
+
+Once a capacity is set then the resource usage can be updated using charge and
+uncharge APIs. All of the APIs to interact with misc controller are in
+include/linux/misc_cgroup.h.
+
+Misc Interface Files
+~~~~~~~~~~~~~~~~~~~~
+
+Miscellaneous controller provides 3 interface files. If two misc resources (res_a and res_b) are registered then:
+
+  misc.capacity
+        A read-only flat-keyed file shown only in the root cgroup.  It shows
+        miscellaneous scalar resources available on the platform along with
+        their quantities::
+
+	  $ cat misc.capacity
+	  res_a 50
+	  res_b 10
+
+  misc.current
+        A read-only flat-keyed file shown in the non-root cgroups.  It shows
+        the current usage of the resources in the cgroup and its children.::
+
+	  $ cat misc.current
+	  res_a 3
+	  res_b 0
+
+  misc.max
+        A read-write flat-keyed file shown in the non root cgroups. Allowed
+        maximum usage of the resources in the cgroup and its children.::
+
+	  $ cat misc.max
+	  res_a max
+	  res_b 4
+
+	Limit can be set by::
+
+	  # echo res_a 1 > misc.max
+
+	Limit can be set to max by::
+
+	  # echo res_a max > misc.max
+
+        Limits can be set higher than the capacity value in the misc.capacity
+        file.
+
+Migration and Ownership
+~~~~~~~~~~~~~~~~~~~~~~~
+
+A miscellaneous scalar resource is charged to the cgroup in which it is used
+first, and stays charged to that cgroup until that resource is freed. Migrating
+a process to a different cgroup does not move the charge to the destination
+cgroup where the process has moved.
+
+Others
+------
+
 perf_event
 ~~~~~~~~~~
 

arch/x86/kvm/svm/sev.c

@@ -14,6 +14,7 @@
 #include <linux/psp-sev.h>
 #include <linux/pagemap.h>
 #include <linux/swap.h>
+#include <linux/misc_cgroup.h>
 #include <linux/processor.h>
 #include <linux/trace_events.h>
 #include <asm/fpu/internal.h>
@@ -28,6 +29,21 @@
 
 #define __ex(x) __kvm_handle_fault_on_reboot(x)
 
+#ifndef CONFIG_KVM_AMD_SEV
+/*
+ * When this config is not defined, SEV feature is not supported and APIs in
+ * this file are not used but this file still gets compiled into the KVM AMD
+ * module.
+ *
+ * We will not have MISC_CG_RES_SEV and MISC_CG_RES_SEV_ES entries in the enum
+ * misc_res_type {} defined in linux/misc_cgroup.h.
+ *
+ * Below macros allow compilation to succeed.
+ */
+#define MISC_CG_RES_SEV MISC_CG_RES_TYPES
+#define MISC_CG_RES_SEV_ES MISC_CG_RES_TYPES
+#endif
+
 static u8 sev_enc_bit;
 static int sev_flush_asids(void);
 static DECLARE_RWSEM(sev_deactivate_lock);
@@ -89,8 +105,19 @@ static bool __sev_recycle_asids(int min_asid, int max_asid)
 
 static int sev_asid_new(struct kvm_sev_info *sev)
 {
-	int pos, min_asid, max_asid;
+	int pos, min_asid, max_asid, ret;
 	bool retry = true;
+	enum misc_res_type type;
+
+	type = sev->es_active ? MISC_CG_RES_SEV_ES : MISC_CG_RES_SEV;
+	WARN_ON(sev->misc_cg);
+	sev->misc_cg = get_current_misc_cg();
+	ret = misc_cg_try_charge(type, sev->misc_cg, 1);
+	if (ret) {
+		put_misc_cg(sev->misc_cg);
+		sev->misc_cg = NULL;
+		return ret;
+	}
 
 	mutex_lock(&sev_bitmap_lock);
 
@@ -108,14 +135,20 @@ static int sev_asid_new(struct kvm_sev_info *sev)
 			goto again;
 		}
 		mutex_unlock(&sev_bitmap_lock);
-		return -EBUSY;
+		ret = -EBUSY;
+		goto e_uncharge;
 	}
 
 	__set_bit(pos, sev_asid_bitmap);
 
 	mutex_unlock(&sev_bitmap_lock);
 
 	return pos + 1;
+e_uncharge:
+	misc_cg_uncharge(type, sev->misc_cg, 1);
+	put_misc_cg(sev->misc_cg);
+	sev->misc_cg = NULL;
+	return ret;
 }
 
 static int sev_get_asid(struct kvm *kvm)
@@ -125,14 +158,15 @@ static int sev_get_asid(struct kvm *kvm)
 	return sev->asid;
 }
 
-static void sev_asid_free(int asid)
+static void sev_asid_free(struct kvm_sev_info *sev)
 {
 	struct svm_cpu_data *sd;
 	int cpu, pos;
+	enum misc_res_type type;
 
 	mutex_lock(&sev_bitmap_lock);
 
-	pos = asid - 1;
+	pos = sev->asid - 1;
 	__set_bit(pos, sev_reclaim_asid_bitmap);
 
 	for_each_possible_cpu(cpu) {
@@ -141,6 +175,11 @@ static void sev_asid_free(int asid)
 	}
 
 	mutex_unlock(&sev_bitmap_lock);
+
+	type = sev->es_active ? MISC_CG_RES_SEV_ES : MISC_CG_RES_SEV;
+	misc_cg_uncharge(type, sev->misc_cg, 1);
+	put_misc_cg(sev->misc_cg);
+	sev->misc_cg = NULL;
 }
 
 static void sev_unbind_asid(struct kvm *kvm, unsigned int handle)
@@ -188,19 +227,20 @@ static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp)
 	asid = sev_asid_new(sev);
 	if (asid < 0)
 		return ret;
+	sev->asid = asid;
 
 	ret = sev_platform_init(&argp->error);
 	if (ret)
 		goto e_free;
 
 	sev->active = true;
-	sev->asid = asid;
 	INIT_LIST_HEAD(&sev->regions_list);
 
 	return 0;
 
 e_free:
-	sev_asid_free(asid);
+	sev_asid_free(sev);
+	sev->asid = 0;
 	return ret;
 }
 
@@ -1315,12 +1355,12 @@ void sev_vm_destroy(struct kvm *kvm)
 	mutex_unlock(&kvm->lock);
 
 	sev_unbind_asid(kvm, sev->handle);
-	sev_asid_free(sev->asid);
+	sev_asid_free(sev);
 }
 
 void __init sev_hardware_setup(void)
 {
-	unsigned int eax, ebx, ecx, edx;
+	unsigned int eax, ebx, ecx, edx, sev_asid_count, sev_es_asid_count;
 	bool sev_es_supported = false;
 	bool sev_supported = false;
 
@@ -1352,7 +1392,11 @@ void __init sev_hardware_setup(void)
 	if (!sev_reclaim_asid_bitmap)
 		goto out;
 
-	pr_info("SEV supported: %u ASIDs\n", max_sev_asid - min_sev_asid + 1);
+	sev_asid_count = max_sev_asid - min_sev_asid + 1;
+	if (misc_cg_set_capacity(MISC_CG_RES_SEV, sev_asid_count))
+		goto out;
+
+	pr_info("SEV supported: %u ASIDs\n", sev_asid_count);
 	sev_supported = true;
 
 	/* SEV-ES support requested? */
@@ -1367,7 +1411,11 @@ void __init sev_hardware_setup(void)
 	if (min_sev_asid == 1)
 		goto out;
 
-	pr_info("SEV-ES supported: %u ASIDs\n", min_sev_asid - 1);
+	sev_es_asid_count = min_sev_asid - 1;
+	if (misc_cg_set_capacity(MISC_CG_RES_SEV_ES, sev_es_asid_count))
+		goto out;
+
+	pr_info("SEV-ES supported: %u ASIDs\n", sev_es_asid_count);
 	sev_es_supported = true;
 
 out:
@@ -1382,6 +1430,8 @@ void sev_hardware_teardown(void)
 
 	bitmap_free(sev_asid_bitmap);
 	bitmap_free(sev_reclaim_asid_bitmap);
+	misc_cg_set_capacity(MISC_CG_RES_SEV, 0);
+	misc_cg_set_capacity(MISC_CG_RES_SEV_ES, 0);
 
 	sev_flush_asids();
 }

arch/x86/kvm/svm/svm.h

@@ -65,6 +65,7 @@ struct kvm_sev_info {
 	unsigned long pages_locked; /* Number of pages locked */
 	struct list_head regions_list;  /* List of registered regions */
 	u64 ap_jump_table;	/* SEV-ES AP Jump Table address */
+	struct misc_cg *misc_cg; /* For misc cgroup accounting */
 };
 
 struct kvm_svm {

include/linux/cgroup_subsys.h

@@ -61,6 +61,10 @@ SUBSYS(pids)
 SUBSYS(rdma)
 #endif
 
+#if IS_ENABLED(CONFIG_CGROUP_MISC)
+SUBSYS(misc)
+#endif
+
 /*
  * The following subsystems are not supported on the default hierarchy.
  */