KVM: ppc: Implement in-kernel exit timing statistics
Existing KVM statistics are either just counters (kvm_stat) reported for
KVM generally or trace based aproaches like kvm_trace.
For KVM on powerpc we had the need to track the timings of the different exit
types. While this could be achieved parsing data created with a kvm_trace
extension this adds too much overhead (at least on embedded PowerPC) slowing
down the workloads we wanted to measure.
Therefore this patch adds a in-kernel exit timing statistic to the powerpc kvm
code. These statistic is available per vm&vcpu under the kvm debugfs directory.
As this statistic is low, but still some overhead it can be enabled via a
.config entry and should be off by default.
Since this patch touched all powerpc kvm_stat code anyway this code is now
merged and simplified together with the exit timing statistic code (still
working with exit timing disabled in .config).
Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index a4a7d5e..2f5b49f 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -71,6 +71,49 @@
u32 word2;
};
+enum kvm_exit_types {
+ MMIO_EXITS,
+ DCR_EXITS,
+ SIGNAL_EXITS,
+ ITLB_REAL_MISS_EXITS,
+ ITLB_VIRT_MISS_EXITS,
+ DTLB_REAL_MISS_EXITS,
+ DTLB_VIRT_MISS_EXITS,
+ SYSCALL_EXITS,
+ ISI_EXITS,
+ DSI_EXITS,
+ EMULATED_INST_EXITS,
+ EMULATED_MTMSRWE_EXITS,
+ EMULATED_WRTEE_EXITS,
+ EMULATED_MTSPR_EXITS,
+ EMULATED_MFSPR_EXITS,
+ EMULATED_MTMSR_EXITS,
+ EMULATED_MFMSR_EXITS,
+ EMULATED_TLBSX_EXITS,
+ EMULATED_TLBWE_EXITS,
+ EMULATED_RFI_EXITS,
+ DEC_EXITS,
+ EXT_INTR_EXITS,
+ HALT_WAKEUP,
+ USR_PR_INST,
+ FP_UNAVAIL,
+ DEBUG_EXITS,
+ TIMEINGUEST,
+ __NUMBER_OF_KVM_EXIT_TYPES
+};
+
+#ifdef CONFIG_KVM_EXIT_TIMING
+/* allow access to big endian 32bit upper/lower parts and 64bit var */
+struct exit_timing {
+ union {
+ u64 tv64;
+ struct {
+ u32 tbu, tbl;
+ } tv32;
+ };
+};
+#endif
+
struct kvm_arch {
};
@@ -130,6 +173,19 @@
u32 dbcr0;
u32 dbcr1;
+#ifdef CONFIG_KVM_EXIT_TIMING
+ struct exit_timing timing_exit;
+ struct exit_timing timing_last_enter;
+ u32 last_exit_type;
+ u32 timing_count_type[__NUMBER_OF_KVM_EXIT_TYPES];
+ u64 timing_sum_duration[__NUMBER_OF_KVM_EXIT_TYPES];
+ u64 timing_sum_quad_duration[__NUMBER_OF_KVM_EXIT_TYPES];
+ u64 timing_min_duration[__NUMBER_OF_KVM_EXIT_TYPES];
+ u64 timing_max_duration[__NUMBER_OF_KVM_EXIT_TYPES];
+ u64 timing_last_exit;
+ struct dentry *debugfs_exit_timing;
+#endif
+
u32 last_inst;
ulong fault_dear;
ulong fault_esr;
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index ba39526..9937fe4 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -383,5 +383,16 @@
DEFINE(PTE_T_LOG2, PTE_T_LOG2);
#endif
+#ifdef CONFIG_KVM_EXIT_TIMING
+ DEFINE(VCPU_TIMING_EXIT_TBU, offsetof(struct kvm_vcpu,
+ arch.timing_exit.tv32.tbu));
+ DEFINE(VCPU_TIMING_EXIT_TBL, offsetof(struct kvm_vcpu,
+ arch.timing_exit.tv32.tbl));
+ DEFINE(VCPU_TIMING_LAST_ENTER_TBU, offsetof(struct kvm_vcpu,
+ arch.timing_last_enter.tv32.tbu));
+ DEFINE(VCPU_TIMING_LAST_ENTER_TBL, offsetof(struct kvm_vcpu,
+ arch.timing_last_enter.tv32.tbl));
+#endif
+
return 0;
}
diff --git a/arch/powerpc/kvm/44x_emulate.c b/arch/powerpc/kvm/44x_emulate.c
index 9ef79c7..69f88d53 100644
--- a/arch/powerpc/kvm/44x_emulate.c
+++ b/arch/powerpc/kvm/44x_emulate.c
@@ -22,6 +22,7 @@
#include <asm/dcr-regs.h>
#include <asm/disassemble.h>
#include <asm/kvm_44x.h>
+#include "timing.h"
#include "booke.h"
#include "44x_tlb.h"
@@ -58,11 +59,11 @@
int ws;
switch (get_op(inst)) {
-
case OP_RFI:
switch (get_xop(inst)) {
case XOP_RFI:
kvmppc_emul_rfi(vcpu);
+ kvmppc_set_exit_type(vcpu, EMULATED_RFI_EXITS);
*advance = 0;
break;
@@ -78,10 +79,12 @@
case XOP_MFMSR:
rt = get_rt(inst);
vcpu->arch.gpr[rt] = vcpu->arch.msr;
+ kvmppc_set_exit_type(vcpu, EMULATED_MFMSR_EXITS);
break;
case XOP_MTMSR:
rs = get_rs(inst);
+ kvmppc_set_exit_type(vcpu, EMULATED_MTMSR_EXITS);
kvmppc_set_msr(vcpu, vcpu->arch.gpr[rs]);
break;
@@ -89,11 +92,13 @@
rs = get_rs(inst);
vcpu->arch.msr = (vcpu->arch.msr & ~MSR_EE)
| (vcpu->arch.gpr[rs] & MSR_EE);
+ kvmppc_set_exit_type(vcpu, EMULATED_WRTEE_EXITS);
break;
case XOP_WRTEEI:
vcpu->arch.msr = (vcpu->arch.msr & ~MSR_EE)
| (inst & MSR_EE);
+ kvmppc_set_exit_type(vcpu, EMULATED_WRTEE_EXITS);
break;
case XOP_MFDCR:
@@ -127,6 +132,7 @@
run->dcr.is_write = 0;
vcpu->arch.io_gpr = rt;
vcpu->arch.dcr_needed = 1;
+ account_exit(vcpu, DCR_EXITS);
emulated = EMULATE_DO_DCR;
}
@@ -146,6 +152,7 @@
run->dcr.data = vcpu->arch.gpr[rs];
run->dcr.is_write = 1;
vcpu->arch.dcr_needed = 1;
+ account_exit(vcpu, DCR_EXITS);
emulated = EMULATE_DO_DCR;
}
@@ -276,6 +283,7 @@
return EMULATE_FAIL;
}
+ kvmppc_set_exit_type(vcpu, EMULATED_MTSPR_EXITS);
return EMULATE_DONE;
}
@@ -357,6 +365,7 @@
return EMULATE_FAIL;
}
+ kvmppc_set_exit_type(vcpu, EMULATED_MFSPR_EXITS);
return EMULATE_DONE;
}
diff --git a/arch/powerpc/kvm/44x_tlb.c b/arch/powerpc/kvm/44x_tlb.c
index ff16d0e..9a34b8e 100644
--- a/arch/powerpc/kvm/44x_tlb.c
+++ b/arch/powerpc/kvm/44x_tlb.c
@@ -27,6 +27,7 @@
#include <asm/mmu-44x.h>
#include <asm/kvm_ppc.h>
#include <asm/kvm_44x.h>
+#include "timing.h"
#include "44x_tlb.h"
@@ -470,6 +471,7 @@
KVMTRACE_5D(GTLB_WRITE, vcpu, gtlb_index, tlbe->tid, tlbe->word0,
tlbe->word1, tlbe->word2, handler);
+ kvmppc_set_exit_type(vcpu, EMULATED_TLBWE_EXITS);
return EMULATE_DONE;
}
@@ -493,5 +495,6 @@
}
vcpu->arch.gpr[rt] = gtlb_index;
+ kvmppc_set_exit_type(vcpu, EMULATED_TLBSX_EXITS);
return EMULATE_DONE;
}
diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig
index e4ab1c7..6dbdc48 100644
--- a/arch/powerpc/kvm/Kconfig
+++ b/arch/powerpc/kvm/Kconfig
@@ -32,6 +32,17 @@
If unsure, say N.
+config KVM_EXIT_TIMING
+ bool "Detailed exit timing"
+ depends on KVM
+ ---help---
+ Calculate elapsed time for every exit/enter cycle. A per-vcpu
+ report is available in debugfs kvm/vm#_vcpu#_timing.
+ The overhead is relatively small, however it is not recommended for
+ production environments.
+
+ If unsure, say N.
+
config KVM_TRACE
bool "KVM trace support"
depends on KVM && MARKERS && SYSFS
diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile
index f045fad..df7ba59 100644
--- a/arch/powerpc/kvm/Makefile
+++ b/arch/powerpc/kvm/Makefile
@@ -9,6 +9,7 @@
common-objs-$(CONFIG_KVM_TRACE) += $(addprefix ../../../virt/kvm/, kvm_trace.o)
kvm-objs := $(common-objs-y) powerpc.o emulate.o
+obj-$(CONFIG_KVM_EXIT_TIMING) += timing.o
obj-$(CONFIG_KVM) += kvm.o
AFLAGS_booke_interrupts.o := -I$(obj)
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index eb24383..0f17124 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -28,6 +28,7 @@
#include <asm/cputable.h>
#include <asm/uaccess.h>
#include <asm/kvm_ppc.h>
+#include "timing.h"
#include <asm/cacheflush.h>
#include <asm/kvm_44x.h>
@@ -185,6 +186,9 @@
enum emulation_result er;
int r = RESUME_HOST;
+ /* update before a new last_exit_type is rewritten */
+ kvmppc_update_timing_stats(vcpu);
+
local_irq_enable();
run->exit_reason = KVM_EXIT_UNKNOWN;
@@ -198,7 +202,7 @@
break;
case BOOKE_INTERRUPT_EXTERNAL:
- vcpu->stat.ext_intr_exits++;
+ account_exit(vcpu, EXT_INTR_EXITS);
if (need_resched())
cond_resched();
r = RESUME_GUEST;
@@ -208,8 +212,7 @@
/* Since we switched IVPR back to the host's value, the host
* handled this interrupt the moment we enabled interrupts.
* Now we just offer it a chance to reschedule the guest. */
-
- vcpu->stat.dec_exits++;
+ account_exit(vcpu, DEC_EXITS);
if (need_resched())
cond_resched();
r = RESUME_GUEST;
@@ -222,20 +225,21 @@
vcpu->arch.esr = vcpu->arch.fault_esr;
kvmppc_booke_queue_irqprio(vcpu, BOOKE_IRQPRIO_PROGRAM);
r = RESUME_GUEST;
+ account_exit(vcpu, USR_PR_INST);
break;
}
er = kvmppc_emulate_instruction(run, vcpu);
switch (er) {
case EMULATE_DONE:
+ /* don't overwrite subtypes, just account kvm_stats */
+ account_exit_stat(vcpu, EMULATED_INST_EXITS);
/* Future optimization: only reload non-volatiles if
* they were actually modified by emulation. */
- vcpu->stat.emulated_inst_exits++;
r = RESUME_GUEST_NV;
break;
case EMULATE_DO_DCR:
run->exit_reason = KVM_EXIT_DCR;
- vcpu->stat.dcr_exits++;
r = RESUME_HOST;
break;
case EMULATE_FAIL:
@@ -255,6 +259,7 @@
case BOOKE_INTERRUPT_FP_UNAVAIL:
kvmppc_booke_queue_irqprio(vcpu, BOOKE_IRQPRIO_FP_UNAVAIL);
+ account_exit(vcpu, FP_UNAVAIL);
r = RESUME_GUEST;
break;
@@ -262,20 +267,20 @@
vcpu->arch.dear = vcpu->arch.fault_dear;
vcpu->arch.esr = vcpu->arch.fault_esr;
kvmppc_booke_queue_irqprio(vcpu, BOOKE_IRQPRIO_DATA_STORAGE);
- vcpu->stat.dsi_exits++;
+ account_exit(vcpu, DSI_EXITS);
r = RESUME_GUEST;
break;
case BOOKE_INTERRUPT_INST_STORAGE:
vcpu->arch.esr = vcpu->arch.fault_esr;
kvmppc_booke_queue_irqprio(vcpu, BOOKE_IRQPRIO_INST_STORAGE);
- vcpu->stat.isi_exits++;
+ account_exit(vcpu, ISI_EXITS);
r = RESUME_GUEST;
break;
case BOOKE_INTERRUPT_SYSCALL:
kvmppc_booke_queue_irqprio(vcpu, BOOKE_IRQPRIO_SYSCALL);
- vcpu->stat.syscall_exits++;
+ account_exit(vcpu, SYSCALL_EXITS);
r = RESUME_GUEST;
break;
@@ -294,7 +299,7 @@
kvmppc_booke_queue_irqprio(vcpu, BOOKE_IRQPRIO_DTLB_MISS);
vcpu->arch.dear = vcpu->arch.fault_dear;
vcpu->arch.esr = vcpu->arch.fault_esr;
- vcpu->stat.dtlb_real_miss_exits++;
+ account_exit(vcpu, DTLB_REAL_MISS_EXITS);
r = RESUME_GUEST;
break;
}
@@ -312,13 +317,13 @@
* invoking the guest. */
kvmppc_mmu_map(vcpu, eaddr, vcpu->arch.paddr_accessed, gtlbe->tid,
gtlbe->word2, get_tlb_bytes(gtlbe), gtlb_index);
- vcpu->stat.dtlb_virt_miss_exits++;
+ account_exit(vcpu, DTLB_VIRT_MISS_EXITS);
r = RESUME_GUEST;
} else {
/* Guest has mapped and accessed a page which is not
* actually RAM. */
r = kvmppc_emulate_mmio(run, vcpu);
- vcpu->stat.mmio_exits++;
+ account_exit(vcpu, MMIO_EXITS);
}
break;
@@ -340,11 +345,11 @@
if (gtlb_index < 0) {
/* The guest didn't have a mapping for it. */
kvmppc_booke_queue_irqprio(vcpu, BOOKE_IRQPRIO_ITLB_MISS);
- vcpu->stat.itlb_real_miss_exits++;
+ account_exit(vcpu, ITLB_REAL_MISS_EXITS);
break;
}
- vcpu->stat.itlb_virt_miss_exits++;
+ account_exit(vcpu, ITLB_VIRT_MISS_EXITS);
gtlbe = &vcpu_44x->guest_tlb[gtlb_index];
gpaddr = tlb_xlate(gtlbe, eaddr);
@@ -378,6 +383,7 @@
mtspr(SPRN_DBSR, dbsr);
run->exit_reason = KVM_EXIT_DEBUG;
+ account_exit(vcpu, DEBUG_EXITS);
r = RESUME_HOST;
break;
}
@@ -398,7 +404,7 @@
if (signal_pending(current)) {
run->exit_reason = KVM_EXIT_INTR;
r = (-EINTR << 2) | RESUME_HOST | (r & RESUME_FLAG_NV);
- vcpu->stat.signal_exits++;
+ account_exit(vcpu, SIGNAL_EXITS);
}
}
@@ -418,6 +424,8 @@
* before it's programmed its own IVPR. */
vcpu->arch.ivpr = 0x55550000;
+ kvmppc_init_timing_stats(vcpu);
+
return kvmppc_core_vcpu_setup(vcpu);
}
diff --git a/arch/powerpc/kvm/booke.h b/arch/powerpc/kvm/booke.h
index 48d905f..cf7c94c 100644
--- a/arch/powerpc/kvm/booke.h
+++ b/arch/powerpc/kvm/booke.h
@@ -22,6 +22,7 @@
#include <linux/types.h>
#include <linux/kvm_host.h>
+#include "timing.h"
/* interrupt priortity ordering */
#define BOOKE_IRQPRIO_DATA_STORAGE 0
@@ -50,8 +51,10 @@
vcpu->arch.msr = new_msr;
- if (vcpu->arch.msr & MSR_WE)
+ if (vcpu->arch.msr & MSR_WE) {
kvm_vcpu_block(vcpu);
+ kvmppc_set_exit_type(vcpu, EMULATED_MTMSRWE_EXITS);
+ };
}
#endif /* __KVM_BOOKE_H__ */
diff --git a/arch/powerpc/kvm/booke_interrupts.S b/arch/powerpc/kvm/booke_interrupts.S
index eb21868..084ebcd 100644
--- a/arch/powerpc/kvm/booke_interrupts.S
+++ b/arch/powerpc/kvm/booke_interrupts.S
@@ -107,6 +107,18 @@
li r6, 1
slw r6, r6, r5
+#ifdef CONFIG_KVM_EXIT_TIMING
+ /* save exit time */
+1:
+ mfspr r7, SPRN_TBRU
+ mfspr r8, SPRN_TBRL
+ mfspr r9, SPRN_TBRU
+ cmpw r9, r7
+ bne 1b
+ stw r8, VCPU_TIMING_EXIT_TBL(r4)
+ stw r9, VCPU_TIMING_EXIT_TBU(r4)
+#endif
+
/* Save the faulting instruction and all GPRs for emulation. */
andi. r7, r6, NEED_INST_MASK
beq ..skip_inst_copy
@@ -375,6 +387,18 @@
lwz r3, VCPU_SPRG7(r4)
mtspr SPRN_SPRG7, r3
+#ifdef CONFIG_KVM_EXIT_TIMING
+ /* save enter time */
+1:
+ mfspr r6, SPRN_TBRU
+ mfspr r7, SPRN_TBRL
+ mfspr r8, SPRN_TBRU
+ cmpw r8, r6
+ bne 1b
+ stw r7, VCPU_TIMING_LAST_ENTER_TBL(r4)
+ stw r8, VCPU_TIMING_LAST_ENTER_TBU(r4)
+#endif
+
/* Finish loading guest volatiles and jump to guest. */
lwz r3, VCPU_CTR(r4)
mtctr r3
diff --git a/arch/powerpc/kvm/emulate.c b/arch/powerpc/kvm/emulate.c
index 4c30fa0..d1d38da 100644
--- a/arch/powerpc/kvm/emulate.c
+++ b/arch/powerpc/kvm/emulate.c
@@ -28,6 +28,7 @@
#include <asm/byteorder.h>
#include <asm/kvm_ppc.h>
#include <asm/disassemble.h>
+#include "timing.h"
void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
{
@@ -73,6 +74,9 @@
enum emulation_result emulated = EMULATE_DONE;
int advance = 1;
+ /* this default type might be overwritten by subcategories */
+ kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);
+
switch (get_op(inst)) {
case 3: /* trap */
vcpu->arch.esr |= ESR_PTR;
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 7ad150e..1deda37 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -28,9 +28,9 @@
#include <asm/uaccess.h>
#include <asm/kvm_ppc.h>
#include <asm/tlbflush.h>
+#include "timing.h"
#include "../mm/mmu_decl.h"
-
gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn)
{
return gfn;
@@ -171,11 +171,15 @@
struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
{
- return kvmppc_core_vcpu_create(kvm, id);
+ struct kvm_vcpu *vcpu;
+ vcpu = kvmppc_core_vcpu_create(kvm, id);
+ kvmppc_create_vcpu_debugfs(vcpu, id);
+ return vcpu;
}
void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
{
+ kvmppc_remove_vcpu_debugfs(vcpu);
kvmppc_core_vcpu_free(vcpu);
}
diff --git a/arch/powerpc/kvm/timing.c b/arch/powerpc/kvm/timing.c
new file mode 100644
index 0000000..f42d272
--- /dev/null
+++ b/arch/powerpc/kvm/timing.c
@@ -0,0 +1,262 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * Copyright IBM Corp. 2007
+ *
+ * Authors: Hollis Blanchard <hollisb@us.ibm.com>
+ * Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
+ */
+
+#include <linux/kvm_host.h>
+#include <linux/fs.h>
+#include <linux/seq_file.h>
+#include <linux/debugfs.h>
+#include <linux/uaccess.h>
+
+#include "timing.h"
+#include <asm/time.h>
+#include <asm-generic/div64.h>
+
+void kvmppc_init_timing_stats(struct kvm_vcpu *vcpu)
+{
+ int i;
+
+ /* pause guest execution to avoid concurrent updates */
+ local_irq_disable();
+ mutex_lock(&vcpu->mutex);
+
+ vcpu->arch.last_exit_type = 0xDEAD;
+ for (i = 0; i < __NUMBER_OF_KVM_EXIT_TYPES; i++) {
+ vcpu->arch.timing_count_type[i] = 0;
+ vcpu->arch.timing_max_duration[i] = 0;
+ vcpu->arch.timing_min_duration[i] = 0xFFFFFFFF;
+ vcpu->arch.timing_sum_duration[i] = 0;
+ vcpu->arch.timing_sum_quad_duration[i] = 0;
+ }
+ vcpu->arch.timing_last_exit = 0;
+ vcpu->arch.timing_exit.tv64 = 0;
+ vcpu->arch.timing_last_enter.tv64 = 0;
+
+ mutex_unlock(&vcpu->mutex);
+ local_irq_enable();
+}
+
+static void add_exit_timing(struct kvm_vcpu *vcpu,
+ u64 duration, int type)
+{
+ u64 old;
+
+ do_div(duration, tb_ticks_per_usec);
+ if (unlikely(duration > 0xFFFFFFFF)) {
+ printk(KERN_ERR"%s - duration too big -> overflow"
+ " duration %lld type %d exit #%d\n",
+ __func__, duration, type,
+ vcpu->arch.timing_count_type[type]);
+ return;
+ }
+
+ vcpu->arch.timing_count_type[type]++;
+
+ /* sum */
+ old = vcpu->arch.timing_sum_duration[type];
+ vcpu->arch.timing_sum_duration[type] += duration;
+ if (unlikely(old > vcpu->arch.timing_sum_duration[type])) {
+ printk(KERN_ERR"%s - wrap adding sum of durations"
+ " old %lld new %lld type %d exit # of type %d\n",
+ __func__, old, vcpu->arch.timing_sum_duration[type],
+ type, vcpu->arch.timing_count_type[type]);
+ }
+
+ /* square sum */
+ old = vcpu->arch.timing_sum_quad_duration[type];
+ vcpu->arch.timing_sum_quad_duration[type] += (duration*duration);
+ if (unlikely(old > vcpu->arch.timing_sum_quad_duration[type])) {
+ printk(KERN_ERR"%s - wrap adding sum of squared durations"
+ " old %lld new %lld type %d exit # of type %d\n",
+ __func__, old,
+ vcpu->arch.timing_sum_quad_duration[type],
+ type, vcpu->arch.timing_count_type[type]);
+ }
+
+ /* set min/max */
+ if (unlikely(duration < vcpu->arch.timing_min_duration[type]))
+ vcpu->arch.timing_min_duration[type] = duration;
+ if (unlikely(duration > vcpu->arch.timing_max_duration[type]))
+ vcpu->arch.timing_max_duration[type] = duration;
+}
+
+void kvmppc_update_timing_stats(struct kvm_vcpu *vcpu)
+{
+ u64 exit = vcpu->arch.timing_last_exit;
+ u64 enter = vcpu->arch.timing_last_enter.tv64;
+
+ /* save exit time, used next exit when the reenter time is known */
+ vcpu->arch.timing_last_exit = vcpu->arch.timing_exit.tv64;
+
+ if (unlikely(vcpu->arch.last_exit_type == 0xDEAD || exit == 0))
+ return; /* skip incomplete cycle (e.g. after reset) */
+
+ /* update statistics for average and standard deviation */
+ add_exit_timing(vcpu, (enter - exit), vcpu->arch.last_exit_type);
+ /* enter -> timing_last_exit is time spent in guest - log this too */
+ add_exit_timing(vcpu, (vcpu->arch.timing_last_exit - enter),
+ TIMEINGUEST);
+}
+
+static const char *kvm_exit_names[__NUMBER_OF_KVM_EXIT_TYPES] = {
+ [MMIO_EXITS] = "MMIO",
+ [DCR_EXITS] = "DCR",
+ [SIGNAL_EXITS] = "SIGNAL",
+ [ITLB_REAL_MISS_EXITS] = "ITLBREAL",
+ [ITLB_VIRT_MISS_EXITS] = "ITLBVIRT",
+ [DTLB_REAL_MISS_EXITS] = "DTLBREAL",
+ [DTLB_VIRT_MISS_EXITS] = "DTLBVIRT",
+ [SYSCALL_EXITS] = "SYSCALL",
+ [ISI_EXITS] = "ISI",
+ [DSI_EXITS] = "DSI",
+ [EMULATED_INST_EXITS] = "EMULINST",
+ [EMULATED_MTMSRWE_EXITS] = "EMUL_WAIT",
+ [EMULATED_WRTEE_EXITS] = "EMUL_WRTEE",
+ [EMULATED_MTSPR_EXITS] = "EMUL_MTSPR",
+ [EMULATED_MFSPR_EXITS] = "EMUL_MFSPR",
+ [EMULATED_MTMSR_EXITS] = "EMUL_MTMSR",
+ [EMULATED_MFMSR_EXITS] = "EMUL_MFMSR",
+ [EMULATED_TLBSX_EXITS] = "EMUL_TLBSX",
+ [EMULATED_TLBWE_EXITS] = "EMUL_TLBWE",
+ [EMULATED_RFI_EXITS] = "EMUL_RFI",
+ [DEC_EXITS] = "DEC",
+ [EXT_INTR_EXITS] = "EXTINT",
+ [HALT_WAKEUP] = "HALT",
+ [USR_PR_INST] = "USR_PR_INST",
+ [FP_UNAVAIL] = "FP_UNAVAIL",
+ [DEBUG_EXITS] = "DEBUG",
+ [TIMEINGUEST] = "TIMEINGUEST"
+};
+
+static int kvmppc_exit_timing_show(struct seq_file *m, void *private)
+{
+ struct kvm_vcpu *vcpu = m->private;
+ int i;
+ u64 min, max;
+
+ for (i = 0; i < __NUMBER_OF_KVM_EXIT_TYPES; i++) {
+ if (vcpu->arch.timing_min_duration[i] == 0xFFFFFFFF)
+ min = 0;
+ else
+ min = vcpu->arch.timing_min_duration[i];
+ if (vcpu->arch.timing_max_duration[i] == 0)
+ max = 0;
+ else
+ max = vcpu->arch.timing_max_duration[i];
+
+ seq_printf(m, "%12s: count %10d min %10lld "
+ "max %10lld sum %20lld sum_quad %20lld\n",
+ kvm_exit_names[i], vcpu->arch.timing_count_type[i],
+ vcpu->arch.timing_min_duration[i],
+ vcpu->arch.timing_max_duration[i],
+ vcpu->arch.timing_sum_duration[i],
+ vcpu->arch.timing_sum_quad_duration[i]);
+ }
+ return 0;
+}
+
+static ssize_t kvmppc_exit_timing_write(struct file *file,
+ const char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ size_t len;
+ int err;
+ const char __user *p;
+ char c;
+
+ len = 0;
+ p = user_buf;
+ while (len < count) {
+ if (get_user(c, p++))
+ err = -EFAULT;
+ if (c == 0 || c == '\n')
+ break;
+ len++;
+ }
+
+ if (len > 1) {
+ err = -EINVAL;
+ goto done;
+ }
+
+ if (copy_from_user(&c, user_buf, sizeof(c))) {
+ err = -EFAULT;
+ goto done;
+ }
+
+ if (c == 'c') {
+ struct seq_file *seqf = (struct seq_file *)file->private_data;
+ struct kvm_vcpu *vcpu = seqf->private;
+ /* write does not affect out buffers previsously generated with
+ * show. Seq file is locked here to prevent races of init with
+ * a show call */
+ mutex_lock(&seqf->lock);
+ kvmppc_init_timing_stats(vcpu);
+ mutex_unlock(&seqf->lock);
+ err = count;
+ } else {
+ err = -EINVAL;
+ goto done;
+ }
+
+done:
+ return err;
+}
+
+static int kvmppc_exit_timing_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, kvmppc_exit_timing_show, inode->i_private);
+}
+
+static struct file_operations kvmppc_exit_timing_fops = {
+ .owner = THIS_MODULE,
+ .open = kvmppc_exit_timing_open,
+ .read = seq_read,
+ .write = kvmppc_exit_timing_write,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+void kvmppc_create_vcpu_debugfs(struct kvm_vcpu *vcpu, unsigned int id)
+{
+ static char dbg_fname[50];
+ struct dentry *debugfs_file;
+
+ snprintf(dbg_fname, sizeof(dbg_fname), "vm%u_vcpu%03u_timing",
+ current->pid, id);
+ debugfs_file = debugfs_create_file(dbg_fname, 0666,
+ kvm_debugfs_dir, vcpu,
+ &kvmppc_exit_timing_fops);
+
+ if (!debugfs_file) {
+ printk(KERN_ERR"%s: error creating debugfs file %s\n",
+ __func__, dbg_fname);
+ return;
+ }
+
+ vcpu->arch.debugfs_exit_timing = debugfs_file;
+}
+
+void kvmppc_remove_vcpu_debugfs(struct kvm_vcpu *vcpu)
+{
+ if (vcpu->arch.debugfs_exit_timing) {
+ debugfs_remove(vcpu->arch.debugfs_exit_timing);
+ vcpu->arch.debugfs_exit_timing = NULL;
+ }
+}
diff --git a/arch/powerpc/kvm/timing.h b/arch/powerpc/kvm/timing.h
new file mode 100644
index 0000000..1af7181
--- /dev/null
+++ b/arch/powerpc/kvm/timing.h
@@ -0,0 +1,102 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * Copyright IBM Corp. 2008
+ *
+ * Authors: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
+ */
+
+#ifndef __POWERPC_KVM_EXITTIMING_H__
+#define __POWERPC_KVM_EXITTIMING_H__
+
+#include <linux/kvm_host.h>
+#include <asm/kvm_host.h>
+
+#ifdef CONFIG_KVM_EXIT_TIMING
+void kvmppc_init_timing_stats(struct kvm_vcpu *vcpu);
+void kvmppc_update_timing_stats(struct kvm_vcpu *vcpu);
+void kvmppc_create_vcpu_debugfs(struct kvm_vcpu *vcpu, unsigned int id);
+void kvmppc_remove_vcpu_debugfs(struct kvm_vcpu *vcpu);
+
+static inline void kvmppc_set_exit_type(struct kvm_vcpu *vcpu, int type)
+{
+ vcpu->arch.last_exit_type = type;
+}
+
+#else
+/* if exit timing is not configured there is no need to build the c file */
+static inline void kvmppc_init_timing_stats(struct kvm_vcpu *vcpu) {}
+static inline void kvmppc_update_timing_stats(struct kvm_vcpu *vcpu) {}
+static inline void kvmppc_create_vcpu_debugfs(struct kvm_vcpu *vcpu,
+ unsigned int id) {}
+static inline void kvmppc_remove_vcpu_debugfs(struct kvm_vcpu *vcpu) {}
+static inline void kvmppc_set_exit_type(struct kvm_vcpu *vcpu, int type) {}
+#endif /* CONFIG_KVM_EXIT_TIMING */
+
+/* account the exit in kvm_stats */
+static inline void account_exit_stat(struct kvm_vcpu *vcpu, int type)
+{
+ /* type has to be known at build time for optimization */
+ BUILD_BUG_ON(__builtin_constant_p(type));
+ switch (type) {
+ case EXT_INTR_EXITS:
+ vcpu->stat.ext_intr_exits++;
+ break;
+ case DEC_EXITS:
+ vcpu->stat.dec_exits++;
+ break;
+ case EMULATED_INST_EXITS:
+ vcpu->stat.emulated_inst_exits++;
+ break;
+ case DCR_EXITS:
+ vcpu->stat.dcr_exits++;
+ break;
+ case DSI_EXITS:
+ vcpu->stat.dsi_exits++;
+ break;
+ case ISI_EXITS:
+ vcpu->stat.isi_exits++;
+ break;
+ case SYSCALL_EXITS:
+ vcpu->stat.syscall_exits++;
+ break;
+ case DTLB_REAL_MISS_EXITS:
+ vcpu->stat.dtlb_real_miss_exits++;
+ break;
+ case DTLB_VIRT_MISS_EXITS:
+ vcpu->stat.dtlb_virt_miss_exits++;
+ break;
+ case MMIO_EXITS:
+ vcpu->stat.mmio_exits++;
+ break;
+ case ITLB_REAL_MISS_EXITS:
+ vcpu->stat.itlb_real_miss_exits++;
+ break;
+ case ITLB_VIRT_MISS_EXITS:
+ vcpu->stat.itlb_virt_miss_exits++;
+ break;
+ case SIGNAL_EXITS:
+ vcpu->stat.signal_exits++;
+ break;
+ }
+}
+
+/* wrapper to set exit time and account for it in kvm_stats */
+static inline void account_exit(struct kvm_vcpu *vcpu, int type)
+{
+ kvmppc_set_exit_type(vcpu, type);
+ account_exit_stat(vcpu, type);
+}
+
+#endif /* __POWERPC_KVM_EXITTIMING_H__ */