From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964903AbcIPPAj (ORCPT ); Fri, 16 Sep 2016 11:00:39 -0400 Received: from mx1.redhat.com ([209.132.183.28]:46502 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935678AbcIPPAC (ORCPT ); Fri, 16 Sep 2016 11:00:02 -0400 Subject: Re: [PATCH v2 0/6] kvm: x86: export TSC information to user-space To: Luiz Capitulino References: <1474036056-21270-1-git-send-email-lcapitulino@redhat.com> <20160916105905.2fb512b9@redhat.com> Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, rkrcmar@redhat.com, rostedt@goodmis.org, mhiramat@kernel.org, mtosatti@redhat.com From: Paolo Bonzini Message-ID: <888c2786-3dd5-d205-a433-b8d250702625@redhat.com> Date: Fri, 16 Sep 2016 16:59:55 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0 MIME-Version: 1.0 In-Reply-To: <20160916105905.2fb512b9@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Fri, 16 Sep 2016 15:00:01 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 16/09/2016 16:59, Luiz Capitulino wrote: > On Fri, 16 Sep 2016 16:56:34 +0200 > Paolo Bonzini wrote: > >> On 16/09/2016 16:27, Luiz Capitulino wrote: >>> [Introduction will follow] >>> >>> Changelog >>> --------- >>> >>> v2 >>> >>> - add tsc_offset field to struct kvm_vcpu_arch >>> - drop read_tsc_offset() >>> - add per-vcpu dir entries in debugfs >>> - export TSC scaling info (besides TSC offset) >>> - export the TSC offset as a signed number >>> - drop patch that wrongly tried to improve error >>> handling in kvm_create_vm_debugfs() >> >> I've tested this patch on an AMD machine with TSC scaling, so I'm >> pushing it shortly to kvm/queue. > > Thanks for the testing! Btw, I don't mind letting it sit on the > list for a few days for review (well, no submitter should mind > this). That's what kvm/queue is for. :) Paolo >> >> Paolo >> >>> Intro >>> ----- >>> >>> This series exports a VM's TSC offset and TSC scaling >>> information to user-space via a new per-vcpu directory >>> in debugfs. For example: >>> >>> /sys/kernel/debug/kvm/66828-10/vcpu0/tsc-offset >>> /sys/kernel/debug/kvm/66828-10/vcpu0/tsc-scaling-ratio >>> /sys/kernel/debug/kvm/66828-10/vcpu0/tsc-scaling-ratio-frac-bits >>> >>> The TSC offset in particular is needed in user-space >>> in order for tracing tools, such as trace-cmd, to be >>> able to merge the host and guest traces using the >>> host TSC. This is explained in detail in this thread: >>> >>> [Qemu-devel] [RFC] host and guest kernel trace merging >>> https://lists.nongnu.org/archive/html/qemu-devel/2016-03/msg00887.html >>> >>> Luiz Capitulino (6): >>> kvm: x86: add tsc_offset field to struct kvm_vcpu_arch >>> kvm: x86: drop read_tsc_offset() >>> kvm: kvm_destroy_vm_debugfs(): check debugfs_stat_data pointer >>> kvm: add stubs for arch specific debugfs support >>> kvm: create per-vcpu dirs in debugfs >>> kvm: x86: export TSC information to user-space >>> >>> arch/arm/kvm/arm.c | 10 ++++++ >>> arch/mips/kvm/mips.c | 10 ++++++ >>> arch/powerpc/kvm/powerpc.c | 10 ++++++ >>> arch/s390/kvm/kvm-s390.c | 10 ++++++ >>> arch/x86/include/asm/kvm_host.h | 2 +- >>> arch/x86/kvm/Makefile | 2 +- >>> arch/x86/kvm/debugfs.c | 69 +++++++++++++++++++++++++++++++++++++++++ >>> arch/x86/kvm/svm.c | 8 ----- >>> arch/x86/kvm/vmx.c | 6 ---- >>> arch/x86/kvm/x86.c | 12 +++++-- >>> include/linux/kvm_host.h | 4 +++ >>> virt/kvm/kvm_main.c | 40 ++++++++++++++++++++++-- >>> 12 files changed, 161 insertions(+), 22 deletions(-) >>> create mode 100644 arch/x86/kvm/debugfs.c >>> >> >