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KVM: ppc: Implement in-kernel exit timing statistics

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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>
This commit is contained in:
Hollis Blanchard
2008-12-02 15:51:57 -06:00
committed by Avi Kivity
parent c5fbdffbda
commit 73e75b416f
13 changed files with 516 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files

36
arch/powerpc/kvm/booke.c
View File

@@ -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 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
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 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
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 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
/* 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 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
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 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
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 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
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 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
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 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
* 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 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
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 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
mtspr(SPRN_DBSR, dbsr);
run->exit_reason = KVM_EXIT_DEBUG;
account_exit(vcpu, DEBUG_EXITS);
r = RESUME_HOST;
break;
}
@@ -398,7 +404,7 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
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 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
* before it's programmed its own IVPR. */
vcpu->arch.ivpr = 0x55550000;
kvmppc_init_timing_stats(vcpu);
return kvmppc_core_vcpu_setup(vcpu);
}