From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933389AbcIEN34 (ORCPT ); Mon, 5 Sep 2016 09:29:56 -0400 Received: from terminus.zytor.com ([198.137.202.10]:39132 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932254AbcIEN3x (ORCPT ); Mon, 5 Sep 2016 09:29:53 -0400 Date: Mon, 5 Sep 2016 06:29:14 -0700 From: tip-bot for Juergen Gross Message-ID: Cc: hpa@zytor.com, linux-kernel@vger.kernel.org, mingo@kernel.org, tglx@linutronix.de, jgross@suse.com, peterz@infradead.org, david.vrabel@citrix.com, torvalds@linux-foundation.org Reply-To: torvalds@linux-foundation.org, david.vrabel@citrix.com, peterz@infradead.org, jgross@suse.com, hpa@zytor.com, linux-kernel@vger.kernel.org, mingo@kernel.org, tglx@linutronix.de In-Reply-To: <1472453327-19050-5-git-send-email-jgross@suse.com> References: <1472453327-19050-5-git-send-email-jgross@suse.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:core/smp] xen: Add xen_pin_vcpu() to support calling functions on a dedicated pCPU Git-Commit-ID: 99bc67536d04bcb9133546284acfb15d033b8bfe X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 99bc67536d04bcb9133546284acfb15d033b8bfe Gitweb: http://git.kernel.org/tip/99bc67536d04bcb9133546284acfb15d033b8bfe Author: Juergen Gross AuthorDate: Mon, 29 Aug 2016 08:48:45 +0200 Committer: Ingo Molnar CommitDate: Mon, 5 Sep 2016 13:52:40 +0200 xen: Add xen_pin_vcpu() to support calling functions on a dedicated pCPU Some hardware models (e.g. Dell Studio 1555 laptops) require calls to the firmware to be issued on CPU 0 only. As Dom0 might have to use these calls, add xen_pin_vcpu() to achieve this functionality. In case either the domain doesn't have the privilege to make the related hypercall or the hypervisor isn't supporting it, issue a warning once and disable further pinning attempts. Signed-off-by: Juergen Gross Signed-off-by: Peter Zijlstra (Intel) Acked-by: David Vrabel Cc: Douglas_Warzecha@dell.com Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: akataria@vmware.com Cc: boris.ostrovsky@oracle.com Cc: chrisw@sous-sol.org Cc: hpa@zytor.com Cc: jdelvare@suse.com Cc: jeremy@goop.org Cc: linux@roeck-us.net Cc: pali.rohar@gmail.com Cc: rusty@rustcorp.com.au Cc: virtualization@lists.linux-foundation.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1472453327-19050-5-git-send-email-jgross@suse.com Signed-off-by: Ingo Molnar --- arch/x86/xen/enlighten.c | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index b86ebb1..bc9aaba 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -1925,6 +1925,45 @@ static void xen_set_cpu_features(struct cpuinfo_x86 *c) } } +static void xen_pin_vcpu(int cpu) +{ + static bool disable_pinning; + struct sched_pin_override pin_override; + int ret; + + if (disable_pinning) + return; + + pin_override.pcpu = cpu; + ret = HYPERVISOR_sched_op(SCHEDOP_pin_override, &pin_override); + + /* Ignore errors when removing override. */ + if (cpu < 0) + return; + + switch (ret) { + case -ENOSYS: + pr_warn("Unable to pin on physical cpu %d. In case of problems consider vcpu pinning.\n", + cpu); + disable_pinning = true; + break; + case -EPERM: + WARN(1, "Trying to pin vcpu without having privilege to do so\n"); + disable_pinning = true; + break; + case -EINVAL: + case -EBUSY: + pr_warn("Physical cpu %d not available for pinning. Check Xen cpu configuration.\n", + cpu); + break; + case 0: + break; + default: + WARN(1, "rc %d while trying to pin vcpu\n", ret); + disable_pinning = true; + } +} + const struct hypervisor_x86 x86_hyper_xen = { .name = "Xen", .detect = xen_platform, @@ -1933,6 +1972,7 @@ const struct hypervisor_x86 x86_hyper_xen = { #endif .x2apic_available = xen_x2apic_para_available, .set_cpu_features = xen_set_cpu_features, + .pin_vcpu = xen_pin_vcpu, }; EXPORT_SYMBOL(x86_hyper_xen);