From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9BAA1C433EF for ; Wed, 6 Oct 2021 07:37:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7C93661177 for ; Wed, 6 Oct 2021 07:37:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237406AbhJFHjr (ORCPT ); Wed, 6 Oct 2021 03:39:47 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:39735 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230013AbhJFHjq (ORCPT ); Wed, 6 Oct 2021 03:39:46 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1633505874; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=Gyw5R4SyvxKZs08K5h9MF/DzccP5WiPryhGpnJiBB6w=; b=X3xd1ic5okDhjU5MRCVBW/Y7Fx+FQv2HJIhbeVV4X0BOpUntl7t1DXvaaYmMjp2gsbq4pi 2EyKV6zexP52eQk2cQA80QbaIsnZbeM8ZqP2fUZlMfzy5R/dW1NGhJvQLtugxKYB0oqXMY lg6614tUdbZOB8HrFhnzLBJNJ4RMsRY= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-51-PRnThVInPqCZG6UN_wl6-g-1; Wed, 06 Oct 2021 03:37:51 -0400 X-MC-Unique: PRnThVInPqCZG6UN_wl6-g-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1E8C1801E72; Wed, 6 Oct 2021 07:37:50 +0000 (UTC) Received: from thinkpad.redhat.com (unknown [10.39.192.69]) by smtp.corp.redhat.com (Postfix) with ESMTP id DB2DF5D9CA; Wed, 6 Oct 2021 07:37:46 +0000 (UTC) From: Laurent Vivier To: kvm-ppc@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org, Benjamin Herrenschmidt , Michael Ellerman , linux-kernel@vger.kernel.org, Nicholas Piggin , Paul Mackerras , Laurent Vivier Subject: [PATCH] KVM: PPC: Defer vtime accounting 'til after IRQ handling Date: Wed, 6 Oct 2021 09:37:45 +0200 Message-Id: <20211006073745.82109-1-lvivier@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit 61bd0f66ff92 has moved guest_enter() out of the interrupt protected area to be able to have updated tick counters, but commit 112665286d08 moved back to this area to avoid wrong context warning (or worse). None of them are correct, to fix the problem port to POWER the x86 fix 160457140187 ("KVM: x86: Defer vtime accounting 'til after IRQ handling"): "Defer the call to account guest time until after servicing any IRQ(s) that happened in the guest or immediately after VM-Exit. Tick-based accounting of vCPU time relies on PF_VCPU being set when the tick IRQ handler runs, and IRQs are blocked throughout the main sequence of vcpu_enter_guest(), including the call into vendor code to actually enter and exit the guest." Link: https://bugzilla.redhat.com/show_bug.cgi?id=2009312 Fixes: 61bd0f66ff92 ("KVM: PPC: Book3S HV: Fix guest time accounting with VIRT_CPU_ACCOUNTING_GEN") Fixes: 112665286d08 ("KVM: PPC: Book3S HV: Context tracking exit guest context before enabling irqs") Cc: npiggin@gmail.com Signed-off-by: Laurent Vivier --- arch/powerpc/kvm/book3s_hv.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 2acb1c96cfaf..43e1ce853785 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -3695,6 +3695,8 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc) srcu_read_unlock(&vc->kvm->srcu, srcu_idx); + context_tracking_guest_exit(); + set_irq_happened(trap); spin_lock(&vc->lock); @@ -3726,9 +3728,8 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc) kvmppc_set_host_core(pcpu); - guest_exit_irqoff(); - local_irq_enable(); + vtime_account_guest_exit(); /* Let secondaries go back to the offline loop */ for (i = 0; i < controlled_threads; ++i) { @@ -4506,13 +4507,14 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit, srcu_read_unlock(&kvm->srcu, srcu_idx); + context_tracking_guest_exit(); + set_irq_happened(trap); kvmppc_set_host_core(pcpu); - guest_exit_irqoff(); - local_irq_enable(); + vtime_account_guest_exit(); cpumask_clear_cpu(pcpu, &kvm->arch.cpu_in_guest); -- 2.31.1