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authorHollis Blanchard <hollisb@us.ibm.com>2008-12-02 15:51:57 -0600
committerAvi Kivity <avi@redhat.com>2008-12-31 16:55:41 +0200
commit73e75b416ffcfa3a84952d8e389a0eca080f00e1 (patch)
tree6195be5b0fa56235550679f35ca990093dd081ca /arch/powerpc/kvm/timing.h
parentc5fbdffbda79254047ec83b09c1a61a3655d052a (diff)
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>
Diffstat (limited to 'arch/powerpc/kvm/timing.h')
-rw-r--r--arch/powerpc/kvm/timing.h102
1 files changed, 102 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/timing.h b/arch/powerpc/kvm/timing.h
new file mode 100644
index 00000000000..1af7181fa2b
--- /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__ */