From patchwork Fri Apr 25 15:19:53 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Hogan X-Patchwork-Id: 4064021 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 30B7FBFF02 for ; Fri, 25 Apr 2014 15:22:03 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 3BFFB20295 for ; Fri, 25 Apr 2014 15:22:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 992D520395 for ; Fri, 25 Apr 2014 15:21:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752494AbaDYPVz (ORCPT ); Fri, 25 Apr 2014 11:21:55 -0400 Received: from mailapp01.imgtec.com ([195.89.28.114]:64198 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752099AbaDYPUk (ORCPT ); Fri, 25 Apr 2014 11:20:40 -0400 Received: from KLMAIL01.kl.imgtec.org (unknown [192.168.5.35]) by Websense Email Security Gateway with ESMTPS id A4F1265B13305; Fri, 25 Apr 2014 16:20:34 +0100 (IST) Received: from KLMAIL02.kl.imgtec.org (192.168.5.97) by KLMAIL01.kl.imgtec.org (192.168.5.35) with Microsoft SMTP Server (TLS) id 14.3.181.6; Fri, 25 Apr 2014 16:20:37 +0100 Received: from LEMAIL01.le.imgtec.org (192.168.152.62) by klmail02.kl.imgtec.org (192.168.5.97) with Microsoft SMTP Server (TLS) id 14.3.181.6; Fri, 25 Apr 2014 16:20:37 +0100 Received: from jhogan-linux.le.imgtec.org (192.168.154.65) by LEMAIL01.le.imgtec.org (192.168.152.62) with Microsoft SMTP Server (TLS) id 14.3.174.1; Fri, 25 Apr 2014 16:20:37 +0100 From: James Hogan To: Paolo Bonzini CC: James Hogan , Gleb Natapov , , Ralf Baechle , , Sanjay Lal Subject: [PATCH 10/21] MIPS: KVM: Migrate hrtimer to follow VCPU Date: Fri, 25 Apr 2014 16:19:53 +0100 Message-ID: <1398439204-26171-11-git-send-email-james.hogan@imgtec.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1398439204-26171-1-git-send-email-james.hogan@imgtec.com> References: <1398439204-26171-1-git-send-email-james.hogan@imgtec.com> MIME-Version: 1.0 X-Originating-IP: [192.168.154.65] Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Spam-Status: No, score=-7.5 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP When a VCPU is scheduled in on a different CPU, refresh the hrtimer used for emulating count/compare so that it gets migrated to the same CPU. This should prevent a timer interrupt occurring on a different CPU to where the guest it relates to is running, which would cause the guest timer interrupt not to be delivered until after the next guest exit. Signed-off-by: James Hogan Cc: Paolo Bonzini Cc: Gleb Natapov Cc: kvm@vger.kernel.org Cc: Ralf Baechle Cc: linux-mips@linux-mips.org Cc: Sanjay Lal --- arch/mips/include/asm/kvm_host.h | 1 + arch/mips/kvm/kvm_mips_emul.c | 17 +++++++++++++++++ arch/mips/kvm/kvm_tlb.c | 6 ++++++ 3 files changed, 24 insertions(+) diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h index 90e1c0005ff4..f56bb699506e 100644 --- a/arch/mips/include/asm/kvm_host.h +++ b/arch/mips/include/asm/kvm_host.h @@ -705,6 +705,7 @@ extern enum emulation_result kvm_mips_complete_mmio_load(struct kvm_vcpu *vcpu, struct kvm_run *run); enum emulation_result kvm_mips_emulate_count(struct kvm_vcpu *vcpu); +void kvm_mips_migrate_count(struct kvm_vcpu *vcpu); enum emulation_result kvm_mips_check_privilege(unsigned long cause, uint32_t *opc, diff --git a/arch/mips/kvm/kvm_mips_emul.c b/arch/mips/kvm/kvm_mips_emul.c index bad31c6235d4..7be7317be45d 100644 --- a/arch/mips/kvm/kvm_mips_emul.c +++ b/arch/mips/kvm/kvm_mips_emul.c @@ -249,6 +249,23 @@ enum emulation_result kvm_mips_emulate_count(struct kvm_vcpu *vcpu) return er; } +/** + * kvm_mips_migrate_count() - Migrate timer. + * @vcpu: Virtual CPU. + * + * Migrate CP0_Count hrtimer to the current CPU by cancelling and restarting it + * if it was running prior to being cancelled. + * + * Must be called when the VCPU is migrated to a different CPU to ensure that + * timer expiry during guest execution interrupts the guest and causes the + * interrupt to be delivered in a timely manner. + */ +void kvm_mips_migrate_count(struct kvm_vcpu *vcpu) +{ + if (hrtimer_cancel(&vcpu->arch.comparecount_timer)) + hrtimer_restart(&vcpu->arch.comparecount_timer); +} + enum emulation_result kvm_mips_emul_eret(struct kvm_vcpu *vcpu) { struct mips_coproc *cop0 = vcpu->arch.cop0; diff --git a/arch/mips/kvm/kvm_tlb.c b/arch/mips/kvm/kvm_tlb.c index 9d371ee0a755..1f61fe6739da 100644 --- a/arch/mips/kvm/kvm_tlb.c +++ b/arch/mips/kvm/kvm_tlb.c @@ -691,6 +691,12 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) if (vcpu->arch.last_sched_cpu != cpu) { kvm_info("[%d->%d]KVM VCPU[%d] switch\n", vcpu->arch.last_sched_cpu, cpu, vcpu->vcpu_id); + /* + * Migrate the timer interrupt to the current CPU so that it + * always interrupts the guest and synchronously triggers a + * guest timer interrupt. + */ + kvm_mips_migrate_count(vcpu); } if (!newasid) {