From: "Graf (AWS), Alexander" <graf@amazon.de> To: "Suthikulpanit, Suravee" <Suravee.Suthikulpanit@amd.com> Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, "kvm@vger.kernel.org" <kvm@vger.kernel.org>, "pbonzini@redhat.com" <pbonzini@redhat.com>, "rkrcmar@redhat.com" <rkrcmar@redhat.com>, "joro@8bytes.org" <joro@8bytes.org>, "Schoenherr, Jan H." <jschoenh@amazon.de>, "Raslan, KarimAllah" <karahmed@amazon.de>, "Lukaszewicz, Rimas" <rimasluk@amazon.com>, "Grimm, Jon" <Jon.Grimm@amd.com> Subject: Re: [PATCH v2 04/15] kvm: x86: Add per-VM APICv state debugfs Date: Wed, 28 Aug 2019 19:36:03 +0000 Message-ID: <9A47CE02-18B0-40C3-962A-D317A32F2073@amazon.de> (raw) In-Reply-To: <1bfccb79-5ace-0dba-a201-e069f77f740a@amd.com> > Am 28.08.2019 um 20:41 schrieb Suthikulpanit, Suravee <Suravee.Suthikulpanit@amd.com>: > > Alex, > >> On 8/27/19 3:20 AM, Alexander Graf wrote: >> >> >>> On 26.08.19 21:41, Suthikulpanit, Suravee wrote: >>> Alex, >>> >>>> On 8/19/2019 4:57 AM, Alexander Graf wrote: >>>> >>>> >>>>> On 15.08.19 18:25, Suthikulpanit, Suravee wrote: >>>>> Currently, there is no way to tell whether APICv is active >>>>> on a particular VM. This often cause confusion since APICv >>>>> can be deactivated at runtime. >>>>> >>>>> Introduce a debugfs entry to report APICv state of a VM. >>>>> This creates a read-only file: >>>>> >>>>> /sys/kernel/debug/kvm/70860-14/apicv-state >>>>> >>>>> Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> >>>> >>>> Shouldn't this first and foremost be a VM ioctl so that user space >>>> can inquire its own state? >>>> >>>> >>>> Alex >>> >>> I introduce this mainly for debugging similar to how KVM is currently >>> provides >>> some per-VCPU information: >>> >>> /sys/kernel/debug/kvm/15957-14/vcpu0/ >>> lapic_timer_advance_ns >>> tsc-offset >>> tsc-scaling-ratio >>> tsc-scaling-ratio-frac-bits >>> >>> I'm not sure if this needs to be VM ioctl at this point. If this >>> information is >>> useful for user-space tool to inquire via ioctl, we can also provide it. >> >> I'm mostly thinking of something like "info apic" in QEMU which to me >> seems like the natural place for APIC information exposure to a user. > > I could not find QEMU "info apic". I assume you meant "info lapic", > which provides information specific to each local APIC (i.e. per-vcpu). Or maybe even "info kvm" :). I think you get the point. > >> The problem with debugfs is that it's not accessible to the user that >> created the VM, but only root, right? > > Hm, you are right. I'll also look into also adding ioctl interface then. Thanks! Alex Amazon Development Center Germany GmbH Krausenstr. 38 10117 Berlin Geschaeftsfuehrung: Christian Schlaeger, Ralf Herbrich Eingetragen am Amtsgericht Charlottenburg unter HRB 149173 B Sitz: Berlin Ust-ID: DE 289 237 879
next prev parent reply index Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-08-15 16:25 [PATCH v2 00/15] kvm: x86: Support AMD SVM AVIC w/ in-kernel irqchip mode Suthikulpanit, Suravee 2019-08-15 16:25 ` [PATCH v2 01/15] kvm: x86: Modify kvm_x86_ops.get_enable_apicv() to use struct kvm parameter Suthikulpanit, Suravee 2019-08-27 7:15 ` Vitaly Kuznetsov 2019-08-15 16:25 ` [PATCH v2 02/15] kvm: x86: Introduce KVM APICv state Suthikulpanit, Suravee 2019-08-19 9:49 ` Alexander Graf 2019-08-26 19:06 ` Suthikulpanit, Suravee 2019-08-15 16:25 ` [PATCH v2 03/15] kvm: Add arch-specific per-VM debugfs support Suthikulpanit, Suravee 2019-08-15 16:25 ` [PATCH v2 04/15] kvm: x86: Add per-VM APICv state debugfs Suthikulpanit, Suravee 2019-08-19 9:57 ` Alexander Graf 2019-08-26 19:41 ` Suthikulpanit, Suravee 2019-08-27 8:20 ` Alexander Graf 2019-08-28 18:39 ` Suthikulpanit, Suravee 2019-08-28 19:36 ` Graf (AWS), Alexander [this message] 2019-08-15 16:25 ` [PATCH v2 05/15] kvm: lapic: Introduce APICv update helper function Suthikulpanit, Suravee 2019-08-27 7:22 ` Vitaly Kuznetsov 2019-08-15 16:25 ` [PATCH v2 06/15] kvm: x86: Add support for activate/de-activate APICv at runtime Suthikulpanit, Suravee 2019-08-27 7:29 ` Vitaly Kuznetsov 2019-08-27 8:05 ` Alexander Graf 2019-08-15 16:25 ` [PATCH v2 07/15] kvm: x86: svm: Add support to activate/deactivate posted interrupts Suthikulpanit, Suravee 2019-08-15 16:25 ` [PATCH v2 08/15] svm: Add support for setup/destroy virutal APIC backing page for AVIC Suthikulpanit, Suravee 2019-08-15 16:25 ` [PATCH v2 09/15] svm: Add support for activate/deactivate AVIC at runtime Suthikulpanit, Suravee 2019-08-19 10:28 ` Alexander Graf 2019-08-15 16:25 ` [PATCH v2 10/15] kvm: x86: hyperv: Use APICv deactivate request interface Suthikulpanit, Suravee 2019-08-19 10:31 ` Alexander Graf 2019-08-15 16:25 ` [PATCH v2 11/15] svm: Temporary deactivate AVIC during ExtINT handling Suthikulpanit, Suravee 2019-08-19 10:35 ` Alexander Graf 2019-08-28 15:17 ` Suthikulpanit, Suravee 2019-08-28 19:37 ` Graf (AWS), Alexander 2019-09-10 15:46 ` Suthikulpanit, Suravee 2019-08-15 16:25 ` [PATCH v2 12/15] kvm: i8254: Check LAPIC EOI pending when injecting irq on SVM AVIC Suthikulpanit, Suravee 2019-08-19 10:42 ` Alexander Graf 2019-08-26 20:46 ` Suthikulpanit, Suravee 2019-08-27 9:10 ` Alexander Graf 2019-09-13 14:50 ` Suthikulpanit, Suravee 2019-08-15 16:25 ` [PATCH v2 13/15] kvm: lapic: Clean up APIC predefined macros Suthikulpanit, Suravee 2019-08-15 16:25 ` [PATCH v2 14/15] kvm: ioapic: Delay update IOAPIC EOI for RTC Suthikulpanit, Suravee 2019-08-19 11:00 ` Alexander Graf 2019-09-04 2:06 ` Suthikulpanit, Suravee 2019-08-15 16:25 ` [PATCH v2 15/15] svm: Allow AVIC with in-kernel irqchip mode Suthikulpanit, Suravee
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=9A47CE02-18B0-40C3-962A-D317A32F2073@amazon.de \ --to=graf@amazon.de \ --cc=Jon.Grimm@amd.com \ --cc=Suravee.Suthikulpanit@amd.com \ --cc=joro@8bytes.org \ --cc=jschoenh@amazon.de \ --cc=karahmed@amazon.de \ --cc=kvm@vger.kernel.org \ --cc=linux-kernel@vger.kernel.org \ --cc=pbonzini@redhat.com \ --cc=rimasluk@amazon.com \ --cc=rkrcmar@redhat.com \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: link
KVM Archive on lore.kernel.org Archives are clonable: git clone --mirror https://lore.kernel.org/kvm/0 kvm/git/0.git # If you have public-inbox 1.1+ installed, you may # initialize and index your mirror using the following commands: public-inbox-init -V2 kvm kvm/ https://lore.kernel.org/kvm \ kvm@vger.kernel.org public-inbox-index kvm Example config snippet for mirrors Newsgroup available over NNTP: nntp://nntp.lore.kernel.org/org.kernel.vger.kvm AGPL code for this site: git clone https://public-inbox.org/public-inbox.git