x86/vmware: Enable steal time accounting

Set paravirt_steal_rq_enabled if steal clock present.
paravirt_steal_rq_enabled is used in sched/core.c to adjust task
progress by offsetting stolen time. Use 'no-steal-acc' off switch (share
same name with KVM) to disable steal time accounting.

Signed-off-by: Alexey Makhalov <amakhalov@vmware.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200323195707.31242-5-amakhalov@vmware.com

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index c07815d..863b37d 100644 (file)
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -3174,7 +3174,7 @@
                        [X86,PV_OPS] Disable paravirtualized VMware scheduler
                        clock and use the default one.
 
-       no-steal-acc    [X86,KVM,ARM64] Disable paravirtualized steal time
+       no-steal-acc    [X86,PV_OPS,ARM64] Disable paravirtualized steal time
                        accounting. steal time is computed, but won't
                        influence scheduler behaviour
 

diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
index cc60461..e885f73 100644 (file)
--- a/arch/x86/kernel/cpu/vmware.c
+++ b/arch/x86/kernel/cpu/vmware.c
@@ -125,6 +125,7 @@ static struct cyc2ns_data vmware_cyc2ns __ro_after_init;
 static int vmw_sched_clock __initdata = 1;
 static DEFINE_PER_CPU_DECRYPTED(struct vmware_steal_time, vmw_steal_time) __aligned(64);
 static bool has_steal_clock;
+static bool steal_acc __initdata = true; /* steal time accounting */
 
 static __init int setup_vmw_sched_clock(char *s)
 {
@@ -133,6 +134,13 @@ static __init int setup_vmw_sched_clock(char *s)
 }
 early_param("no-vmw-sched-clock", setup_vmw_sched_clock);
 
+static __init int parse_no_stealacc(char *arg)
+{
+       steal_acc = false;
+       return 0;
+}
+early_param("no-steal-acc", parse_no_stealacc);
+
 static unsigned long long notrace vmware_sched_clock(void)
 {
        unsigned long long ns;
@@ -306,8 +314,11 @@ static int vmware_cpu_down_prepare(unsigned int cpu)
 
 static __init int activate_jump_labels(void)
 {
-       if (has_steal_clock)
+       if (has_steal_clock) {
                static_key_slow_inc(&paravirt_steal_enabled);
+               if (steal_acc)
+                       static_key_slow_inc(&paravirt_steal_rq_enabled);
+       }
 
        return 0;
 }