From patchwork Wed May 29 06:50:02 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: David Gibson X-Patchwork-Id: 1106856 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=gibson.dropbear.id.au Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=gibson.dropbear.id.au header.i=@gibson.dropbear.id.au header.b="CBkynX3b"; dkim-atps=neutral Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 45DMHz14ygz9s7h for ; Wed, 29 May 2019 17:08:31 +1000 (AEST) Received: from localhost ([127.0.0.1]:48618 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hVshJ-000685-2u for incoming@patchwork.ozlabs.org; Wed, 29 May 2019 03:08:29 -0400 Received: from eggs.gnu.org ([209.51.188.92]:48179) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hVsQT-0000Ns-VK for qemu-devel@nongnu.org; Wed, 29 May 2019 02:51:07 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hVsQS-0002tD-Hd for qemu-devel@nongnu.org; Wed, 29 May 2019 02:51:05 -0400 Received: from ozlabs.org ([203.11.71.1]:35659) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hVsQS-0002ew-08; Wed, 29 May 2019 02:51:04 -0400 Received: by ozlabs.org (Postfix, from userid 1007) id 45DLv62y36z9sPR; Wed, 29 May 2019 16:50:24 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1559112626; bh=LzYwwIlGfEvhgV7PTNG3ZY/kRSi2/VUEFH8zizDsTrY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CBkynX3bLmc3/tbQIvYailcVNHSM6blqSdAi/hHk76rlkbkOrDX8SzzREkVQgwH47 15ImpET85NqPP3QQtUToXjt9cMekq3WqT2DXxCwowajWiLDZaVFx2g3HqcN5eeUm6m sC8P8qyXrzIX4VWG2v/Pl0wCzX8V4m+kwtcRfGUY= From: David Gibson To: peter.maydell@linaro.org Date: Wed, 29 May 2019 16:50:02 +1000 Message-Id: <20190529065017.15149-30-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190529065017.15149-1-david@gibson.dropbear.id.au> References: <20190529065017.15149-1-david@gibson.dropbear.id.au> MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 203.11.71.1 Subject: [Qemu-devel] [PULL 29/44] spapr/xive: introduce a VM state change handler X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: lvivier@redhat.com, qemu-devel@nongnu.org, groug@kaod.org, qemu-ppc@nongnu.org, clg@kaod.org, David Gibson , rth@twiddle.net Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Cédric Le Goater This handler is in charge of stabilizing the flow of event notifications in the XIVE controller before migrating a guest. This is a requirement before transferring the guest EQ pages to a destination. When the VM is stopped, the handler sets the source PQs to PENDING to stop the flow of events and to possibly catch a triggered interrupt occuring while the VM is stopped. Their previous state is saved. The XIVE controller is then synced through KVM to flush any in-flight event notification and to stabilize the EQs. At this stage, the EQ pages are marked dirty to make sure the EQ pages are transferred if a migration sequence is in progress. The previous configuration of the sources is restored when the VM resumes, after a migration or a stop. If an interrupt was queued while the VM was stopped, the handler simply generates the missing trigger. Signed-off-by: Cédric Le Goater Reviewed-by: David Gibson Message-Id: <20190513084245.25755-6-clg@kaod.org> Signed-off-by: David Gibson --- hw/intc/spapr_xive_kvm.c | 96 ++++++++++++++++++++++++++++++++++++- include/hw/ppc/spapr_xive.h | 1 + 2 files changed, 96 insertions(+), 1 deletion(-) diff --git a/hw/intc/spapr_xive_kvm.c b/hw/intc/spapr_xive_kvm.c index 8dd4f96e0b..735577a6f8 100644 --- a/hw/intc/spapr_xive_kvm.c +++ b/hw/intc/spapr_xive_kvm.c @@ -433,9 +433,100 @@ static void kvmppc_xive_get_queues(SpaprXive *xive, Error **errp) } } +/* + * The primary goal of the XIVE VM change handler is to mark the EQ + * pages dirty when all XIVE event notifications have stopped. + * + * Whenever the VM is stopped, the VM change handler sets the source + * PQs to PENDING to stop the flow of events and to possibly catch a + * triggered interrupt occuring while the VM is stopped. The previous + * state is saved in anticipation of a migration. The XIVE controller + * is then synced through KVM to flush any in-flight event + * notification and stabilize the EQs. + * + * At this stage, we can mark the EQ page dirty and let a migration + * sequence transfer the EQ pages to the destination, which is done + * just after the stop state. + * + * The previous configuration of the sources is restored when the VM + * runs again. If an interrupt was queued while the VM was stopped, + * simply generate a trigger. + */ +static void kvmppc_xive_change_state_handler(void *opaque, int running, + RunState state) +{ + SpaprXive *xive = opaque; + XiveSource *xsrc = &xive->source; + Error *local_err = NULL; + int i; + + /* + * Restore the sources to their initial state. This is called when + * the VM resumes after a stop or a migration. + */ + if (running) { + for (i = 0; i < xsrc->nr_irqs; i++) { + uint8_t pq = xive_source_esb_get(xsrc, i); + uint8_t old_pq; + + old_pq = xive_esb_read(xsrc, i, XIVE_ESB_SET_PQ_00 + (pq << 8)); + + /* + * An interrupt was queued while the VM was stopped, + * generate a trigger. + */ + if (pq == XIVE_ESB_RESET && old_pq == XIVE_ESB_QUEUED) { + xive_esb_trigger(xsrc, i); + } + } + + return; + } + + /* + * Mask the sources, to stop the flow of event notifications, and + * save the PQs locally in the XiveSource object. The XiveSource + * state will be collected later on by its vmstate handler if a + * migration is in progress. + */ + for (i = 0; i < xsrc->nr_irqs; i++) { + uint8_t pq = xive_esb_read(xsrc, i, XIVE_ESB_GET); + + /* + * PQ is set to PENDING to possibly catch a triggered + * interrupt occuring while the VM is stopped (hotplug event + * for instance) . + */ + if (pq != XIVE_ESB_OFF) { + pq = xive_esb_read(xsrc, i, XIVE_ESB_SET_PQ_10); + } + xive_source_esb_set(xsrc, i, pq); + } + + /* + * Sync the XIVE controller in KVM, to flush in-flight event + * notification that should be enqueued in the EQs and mark the + * XIVE EQ pages dirty to collect all updates. + */ + kvm_device_access(xive->fd, KVM_DEV_XIVE_GRP_CTRL, + KVM_DEV_XIVE_EQ_SYNC, NULL, true, &local_err); + if (local_err) { + error_report_err(local_err); + return; + } +} + void kvmppc_xive_synchronize_state(SpaprXive *xive, Error **errp) { - kvmppc_xive_source_get_state(&xive->source); + /* + * When the VM is stopped, the sources are masked and the previous + * state is saved in anticipation of a migration. We should not + * synchronize the source state in that case else we will override + * the saved state. + */ + if (runstate_is_running()) { + kvmppc_xive_source_get_state(&xive->source); + } /* EAT: there is no extra state to query from KVM */ @@ -515,6 +606,9 @@ void kvmppc_xive_connect(SpaprXive *xive, Error **errp) "xive.tima", tima_len, xive->tm_mmap); sysbus_init_mmio(SYS_BUS_DEVICE(xive), &xive->tm_mmio); + xive->change = qemu_add_vm_change_state_handler( + kvmppc_xive_change_state_handler, xive); + kvm_kernel_irqchip = true; kvm_msi_via_irqfd_allowed = true; kvm_gsi_direct_mapping = true; diff --git a/include/hw/ppc/spapr_xive.h b/include/hw/ppc/spapr_xive.h index 7e49badd8c..734662c12a 100644 --- a/include/hw/ppc/spapr_xive.h +++ b/include/hw/ppc/spapr_xive.h @@ -42,6 +42,7 @@ typedef struct SpaprXive { /* KVM support */ int fd; void *tm_mmap; + VMChangeStateEntry *change; } SpaprXive; /*