[PATCH 3/4] Add the code to send the consigned time from the host to the guest

Michael Wolf
2013-02-05T21:49:47Z

Change the paravirt calls that retrieve the steal-time information
from the host. Add to it getting the consigned value as well as
the steal time.

Signed-off-by: Michael Wolf <mjw@linux.vnet.ibm.com>
---
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/include/asm/paravirt.h | 4 ++--
arch/x86/include/uapi/asm/kvm_para.h | 3 ++-
arch/x86/kernel/kvm.c | 3 ++-
arch/x86/kernel/paravirt.c | 4 ++--
arch/x86/kvm/x86.c | 2 ++
include/linux/kernel_stat.h | 1 +
kernel/sched/cputime.c | 21 +++++++++++++++++++--
kernel/sched/sched.h | 2 ++
9 files changed, 33 insertions(+), 8 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index dc87b65..fe5a37b 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -428,6 +428,7 @@ struct kvm_vcpu_arch {
u64 msr_val;
u64 last_steal;
u64 accum_steal;
+ u64 accum_consigned;
struct gfn_to_hva_cache stime;
struct kvm_steal_time steal;
} st;
diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index 9b753ea..77f05e7 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -196,9 +196,9 @@ struct static_key;
extern struct static_key paravirt_steal_enabled;
extern struct static_key paravirt_steal_rq_enabled;

-static inline void paravirt_steal_clock(int cpu, u64 *steal)
+static inline void paravirt_steal_clock(int cpu, u64 *steal, u64 *consigned)
{
- PVOP_VCALL2(pv_time_ops.steal_clock, cpu, steal);
+ PVOP_VCALL3(pv_time_ops.steal_clock, cpu, steal, consigned);
}

static inline unsigned long long paravirt_read_pmc(int counter)
diff --git a/arch/x86/include/uapi/asm/kvm_para.h b/arch/x86/include/uapi/asm/kvm_para.h
index 06fdbd9..55d617f 100644
--- a/arch/x86/include/uapi/asm/kvm_para.h
+++ b/arch/x86/include/uapi/asm/kvm_para.h
@@ -42,9 +42,10 @@

struct kvm_steal_time {
__u64 steal;
+ __u64 consigned;
__u32 version;
__u32 flags;
- __u32 pad[12];
+ __u32 pad[10];
};

#define KVM_STEAL_ALIGNMENT_BITS 5
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 89e5468..fb52f8a 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -386,7 +386,7 @@ static struct notifier_block kvm_pv_reboot_nb = {
.notifier_call = kvm_pv_reboot_notify,
};

-static void kvm_steal_clock(int cpu, u64 *steal)
+static void kvm_steal_clock(int cpu, u64 *steal, u64 *consigned)
{
struct kvm_steal_time *src;
int version;
@@ -396,6 +396,7 @@ static void kvm_steal_clock(int cpu, u64 *steal)
version = src->version;
rmb();
*steal = src->steal;
+ *consigned = src->consigned;
rmb();
} while ((version & 1) || (version != src->version));
}
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index 17fff18..3797683 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -207,9 +207,9 @@ static void native_flush_tlb_single(unsigned long addr)
struct static_key paravirt_steal_enabled;
struct static_key paravirt_steal_rq_enabled;

-static u64 native_steal_clock(int cpu)
+static void native_steal_clock(int cpu, u64 *steal, u64 *consigned)
{
- return 0;
+ *steal = *consigned = 0;
}

/* These are in entry.S */
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c243b81..51b63d1 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1867,8 +1867,10 @@ static void record_steal_time(struct kvm_vcpu *vcpu)
return;

vcpu->arch.st.steal.steal += vcpu->arch.st.accum_steal;
+ vcpu->arch.st.steal.consigned += vcpu->arch.st.accum_consigned;
vcpu->arch.st.steal.version += 2;
vcpu->arch.st.accum_steal = 0;
+ vcpu->arch.st.accum_consigned = 0;

kvm_write_guest_cached(vcpu->kvm, &vcpu->arch.st.stime,
&vcpu->arch.st.steal, sizeof(struct kvm_steal_time));
diff --git a/include/linux/kernel_stat.h b/include/linux/kernel_stat.h
index e352052..f58ed0f 100644
--- a/include/linux/kernel_stat.h
+++ b/include/linux/kernel_stat.h
@@ -126,6 +126,7 @@ extern unsigned long long task_delta_exec(struct task_struct *);
extern void account_user_time(struct task_struct *, cputime_t, cputime_t);
extern void account_system_time(struct task_struct *, int, cputime_t, cputime_t);
extern void account_steal_time(cputime_t);
+extern void account_consigned_time(cputime_t);
extern void account_idle_time(cputime_t);

#ifdef CONFIG_VIRT_CPU_ACCOUNTING
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index 0b4f1ec..2a2d4be 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -244,6 +244,18 @@ void account_system_time(struct task_struct *p, int hardirq_offset,
}

/*
+ * This accounts for the time that is split out of steal time.
+ * Consigned time represents the amount of time that the cpu was
+ * expected to be somewhere else.
+ */
+void account_consigned_time(cputime_t cputime)
+{
+ u64 *cpustat = kcpustat_this_cpu->cpustat;
+
+ cpustat[CPUTIME_CONSIGN] += (__force u64) cputime;
+}
+
+/*
* Account for involuntary wait time.
* @cputime: the cpu time spent in involuntary wait
*/
@@ -274,15 +286,20 @@ static __always_inline bool steal_account_process_tick(void)
#ifdef CONFIG_PARAVIRT
if (static_key_false(&paravirt_steal_enabled)) {
u64 steal, st = 0;
+ u64 consigned, cs = 0;

- paravirt_steal_clock(smp_processor_id(), &steal);
+ paravirt_steal_clock(smp_processor_id(), &steal, &consigned);
steal -= this_rq()->prev_steal_time;
+ consigned -= this_rq()->prev_consigned_time;

st = steal_ticks(steal);
+ cs = steal_ticks(consigned);
this_rq()->prev_steal_time += st * TICK_NSEC;
+ this_rq()->prev_consigned_time += cs * TICK_NSEC;

account_steal_time(st);
- return st;
+ account_consigned_time(cs);
+ return st || cs;
}
#endif
return false;
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index fc88644..73a9ef2 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -442,9 +442,11 @@ struct rq {
#endif
#ifdef CONFIG_PARAVIRT
u64 prev_steal_time;
+ u64 prev_consigned_time;
#endif
#ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
u64 prev_steal_time_rq;
+ u64 prev_consigned_time_rq;
#endif

/* calc_load related fields */