From 73e75b416ffcfa3a84952d8e389a0eca080f00e1 Mon Sep 17 00:00:00 2001 From: Hollis Blanchard Date: Tue, 2 Dec 2008 15:51:57 -0600 Subject: 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 Signed-off-by: Hollis Blanchard Signed-off-by: Avi Kivity --- arch/powerpc/kvm/booke_interrupts.S | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) (limited to 'arch/powerpc/kvm/booke_interrupts.S') diff --git a/arch/powerpc/kvm/booke_interrupts.S b/arch/powerpc/kvm/booke_interrupts.S index eb2186823e4e..084ebcd7dd83 100644 --- a/arch/powerpc/kvm/booke_interrupts.S +++ b/arch/powerpc/kvm/booke_interrupts.S @@ -107,6 +107,18 @@ _GLOBAL(kvmppc_resume_host) 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 @@ lightweight_exit: 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 -- cgit v1.2.3