Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752562Ab0HTIJp (ORCPT ); Fri, 20 Aug 2010 04:09:45 -0400 Received: from mx1.redhat.com ([209.132.183.28]:62613 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751728Ab0HTIJa (ORCPT ); Fri, 20 Aug 2010 04:09:30 -0400 From: Zachary Amsden To: kvm@vger.kernel.org Cc: Zachary Amsden , Avi Kivity , Marcelo Tosatti , Glauber Costa , Thomas Gleixner , John Stultz , linux-kernel@vger.kernel.org Subject: [KVM timekeeping 35/35] Add some debug stuff Date: Thu, 19 Aug 2010 22:07:49 -1000 Message-Id: <1282291669-25709-36-git-send-email-zamsden@redhat.com> In-Reply-To: <1282291669-25709-1-git-send-email-zamsden@redhat.com> References: <1282291669-25709-1-git-send-email-zamsden@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3527 Lines: 105 Very useful, debug-only output Signed-off-by: Zachary Amsden --- arch/x86/kvm/x86.c | 33 +++++++++++++++++++++++++++++++-- 1 files changed, 31 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 23d5138..c74a087 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -967,6 +967,9 @@ static void bump_guest_tsc(struct kvm_vcpu *vcpu, s64 bump, s64 kernel_ns) pr_debug("kvm: vcpu%d bumped TSC by %lld\n", vcpu->vcpu_id, bump); } +static int tsc_read_log; +static int tsc_read_cpu = -1; + void kvm_write_tsc(struct kvm_vcpu *vcpu, u64 data) { struct kvm *kvm = vcpu->kvm; @@ -983,6 +986,12 @@ void kvm_write_tsc(struct kvm_vcpu *vcpu, u64 data) if (sdiff < 0) sdiff = -sdiff; +#ifdef DEBUG + pr_debug("kvm: tsc%d write %llu (ofs %llu)\n", vcpu->vcpu_id, data, + offset); + tsc_read_log += 2; +#endif + /* * Special case: TSC write with a small delta of virtual * cycle time against real time is interpreted as an attempt @@ -999,7 +1008,8 @@ void kvm_write_tsc(struct kvm_vcpu *vcpu, u64 data) if (sdiff < nsec_to_cycles(kvm, NSEC_PER_SEC) ) { if (!check_tsc_unstable()) { offset = kvm->arch.last_tsc_offset; - pr_debug("kvm: matched tsc offset for %llu\n", data); + pr_debug("kvm: matched tsc%d offset for %llu\n", + vcpu->vcpu_id, data); } else { /* Unstable write; allow offset, preserve last write */ pr_debug("kvm: matched write on unstable tsc\n"); @@ -1029,6 +1039,16 @@ void kvm_read_tsc(struct kvm_vcpu *vcpu) kvm_register_write(vcpu, VCPU_REGS_RDX, tsc >> 32); vcpu->arch.last_guest_tsc = tsc; kvm_x86_ops->skip_emulated_instruction(vcpu); + +#ifdef DEBUG + if (tsc_read_log > 0 && vcpu->vcpu_id != tsc_read_cpu) { + --tsc_read_log; + tsc_read_cpu = vcpu->vcpu_id; + pr_debug("kvm_read_tsc: cpu%d [TRAP] %llu\n",vcpu->vcpu_id,tsc); + kvm_get_msr(vcpu, MSR_IA32_TSC, &tsc); + pr_debug("kvm_read_tsc: cpu%d [PASS] %llu\n",vcpu->vcpu_id,tsc); + } +#endif } EXPORT_SYMBOL_GPL(kvm_read_tsc); @@ -1070,11 +1090,16 @@ static int kvm_guest_time_update(struct kvm_vcpu *v) */ if (unlikely(vcpu->tsc_overrun)) { vcpu->tsc_overrun = 0; - if (vcpu->last_guest_tsc) + if (vcpu->last_guest_tsc) { + pr_debug("kvm: corrected TSC overrun of %llu\n", + vcpu->last_guest_tsc - tsc_timestamp); kvm_x86_ops->adjust_tsc_offset(v, vcpu->last_guest_tsc - tsc_timestamp); + } } kvm_x86_ops->set_tsc_trap(v, 0); + pr_debug("kvm: passing TSC vcpu%d tsc_mode: %d time_page %p\n", + v->vcpu_id, vcpu->tsc_mode, vcpu->time_page); } if (catchup) { @@ -1105,6 +1130,7 @@ static int kvm_guest_time_update(struct kvm_vcpu *v) bump_guest_tsc(v, vcpu->last_guest_tsc - tsc, kernel_ns); kvm_x86_ops->set_tsc_trap(v, 1); + pr_debug("kvm: trapping TSC on vcpu%d\n", v->vcpu_id); } /* If we're falling behind and not trapping, re-trigger */ @@ -1214,6 +1240,9 @@ static void kvm_update_tsc_trapping(struct kvm *kvm) kvm_for_each_vcpu(i, vcpu, kvm) { vcpu->arch.tsc_mode = best_tsc_mode(vcpu); kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu); + pr_debug("kvm: vcpu%d tsc_mode: %d time_page %p\n", + vcpu->vcpu_id, vcpu->arch.tsc_mode, + vcpu->arch.time_page); } } -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/