The commit is pushed to "work" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git after rh8-4.18.0-193.6.3.vz8.4.16 ------> commit b82cdbd9074b894fd5f0f6f098c017e5c5a64ba8 Author: Andrey Ryabinin <aryabi...@virtuozzo.com> Date: Fri Nov 6 17:11:44 2020 +0300
x86: don't enable cpuid faults if /proc/vz/cpuid_override unused #PSBM-121823 We don't need to enable cpuid faults if /proc/vz/cpuid_override was never used. If task was attached to ve before a write to 'cpuid_override' it will not get cpuid faults now. It shouldn't be a problem since the proper use of 'cpuid_override' requires stopping all containers. https://jira.sw.ru/browse/PSBM-121823 Signed-off-by: Andrey Ryabinin <aryabi...@virtuozzo.com> Reviewed-by: Kirill Tkhai <ktk...@virtuozzo.com> --- arch/x86/kernel/cpuid_fault.c | 21 ++------------------- include/linux/cpuid_override.h | 30 ++++++++++++++++++++++++++++++ kernel/ve/ve.c | 5 ++++- 3 files changed, 36 insertions(+), 20 deletions(-) diff --git a/arch/x86/kernel/cpuid_fault.c b/arch/x86/kernel/cpuid_fault.c index 1e8ffacc4412..cb6c2216fa8a 100644 --- a/arch/x86/kernel/cpuid_fault.c +++ b/arch/x86/kernel/cpuid_fault.c @@ -1,3 +1,4 @@ +#include <linux/cpuid_override.h> #include <linux/gfp.h> #include <linux/slab.h> #include <linux/spinlock.h> @@ -9,25 +10,7 @@ #include <linux/veowner.h> #include <linux/uaccess.h> -struct cpuid_override_entry { - unsigned int op; - unsigned int count; - bool has_count; - unsigned int eax; - unsigned int ebx; - unsigned int ecx; - unsigned int edx; -}; - -#define MAX_CPUID_OVERRIDE_ENTRIES 16 - -struct cpuid_override_table { - struct rcu_head rcu_head; - int size; - struct cpuid_override_entry entries[MAX_CPUID_OVERRIDE_ENTRIES]; -}; - -static struct cpuid_override_table __rcu *cpuid_override __read_mostly; +struct cpuid_override_table __rcu *cpuid_override __read_mostly; static DEFINE_SPINLOCK(cpuid_override_lock); static void cpuid_override_update(struct cpuid_override_table *new_table) diff --git a/include/linux/cpuid_override.h b/include/linux/cpuid_override.h new file mode 100644 index 000000000000..ea0fa7af3d3c --- /dev/null +++ b/include/linux/cpuid_override.h @@ -0,0 +1,30 @@ +#ifndef __CPUID_OVERRIDE_H +#define __CPUID_OVERRIDE_H + +#include <linux/rcupdate.h> + +struct cpuid_override_entry { + unsigned int op; + unsigned int count; + bool has_count; + unsigned int eax; + unsigned int ebx; + unsigned int ecx; + unsigned int edx; +}; + +#define MAX_CPUID_OVERRIDE_ENTRIES 16 + +struct cpuid_override_table { + struct rcu_head rcu_head; + int size; + struct cpuid_override_entry entries[MAX_CPUID_OVERRIDE_ENTRIES]; +}; + +extern struct cpuid_override_table __rcu *cpuid_override; + +static inline bool cpuid_override_on(void) +{ + return rcu_access_pointer(cpuid_override); +} +#endif diff --git a/kernel/ve/ve.c b/kernel/ve/ve.c index a6e3a145d51d..a9afefc5b9de 100644 --- a/kernel/ve/ve.c +++ b/kernel/ve/ve.c @@ -9,6 +9,7 @@ * 've.c' helper file performing VE sub-system initialization */ +#include <linux/cpuid_override.h> #include <linux/ctype.h> #include <linux/init.h> #include <linux/kernel.h> @@ -801,6 +802,7 @@ static void ve_attach(struct cgroup_taskset *tset) { struct cgroup_subsys_state *css; struct task_struct *task; + extern struct cpuid_override_table __rcu *cpuid_override; cgroup_taskset_for_each(task, css, tset) { struct ve_struct *ve = css_to_ve(css); @@ -816,7 +818,8 @@ static void ve_attach(struct cgroup_taskset *tset) /* Leave parent exec domain */ task->parent_exec_id--; - set_tsk_thread_flag(task, TIF_CPUID_OVERRIDE); + if (cpuid_override_on()) + set_tsk_thread_flag(task, TIF_CPUID_OVERRIDE); task->task_ve = ve; } } _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel