From patchwork Fri Jun 26 07:22:33 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 11626647 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 169EE92A for ; Fri, 26 Jun 2020 07:24:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F113C2076E for ; Fri, 26 Jun 2020 07:24:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="V3RBsSGO" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728667AbgFZHYF (ORCPT ); Fri, 26 Jun 2020 03:24:05 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:31757 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727872AbgFZHYE (ORCPT ); Fri, 26 Jun 2020 03:24:04 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1593156242; 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: in-reply-to:in-reply-to:references:references; bh=wozGLqz2fRF3pRwdur0UZYB+DAvo0sfFJAq6Na+K1ik=; b=V3RBsSGODvhEu3TBQXL3lQuOJ456Akw7+VtafpJlFCOR6NtT1qcLVUx56QEruersyl9Eqc 1ad3uAlcxMX3sywlAf3lmX0QG2KaKcer9UZbEM0TiDSjOiXUltvDBVTq8vndkb8qLolCUI cZ09xlx10Xs32iOG7CHmWzhWqZ+utOs= 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-213-FYdwfN2aMym4V8JG1a2-lg-1; Fri, 26 Jun 2020 03:23:59 -0400 X-MC-Unique: FYdwfN2aMym4V8JG1a2-lg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D7582100960F; Fri, 26 Jun 2020 07:23:57 +0000 (UTC) Received: from t480s.redhat.com (ovpn-113-35.ams2.redhat.com [10.36.113.35]) by smtp.corp.redhat.com (Postfix) with ESMTP id C216B1C8; Fri, 26 Jun 2020 07:23:52 +0000 (UTC) From: David Hildenbrand To: qemu-devel@nongnu.org Cc: kvm@vger.kernel.org, qemu-s390x@nongnu.org, Richard Henderson , Paolo Bonzini , "Dr . David Alan Gilbert" , Eduardo Habkost , "Michael S . Tsirkin" , David Hildenbrand , Juan Quintela Subject: [PATCH v5 06/21] virtio-balloon: Rip out qemu_balloon_inhibit() Date: Fri, 26 Jun 2020 09:22:33 +0200 Message-Id: <20200626072248.78761-7-david@redhat.com> In-Reply-To: <20200626072248.78761-1-david@redhat.com> References: <20200626072248.78761-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org The only remaining special case is postcopy. It cannot handle concurrent discards yet, which would result in requesting already sent pages from the source. Special-case it in virtio-balloon instead. Introduce migration_in_incoming_postcopy(), to find out if incoming postcopy is active. Reviewed-by: Dr. David Alan Gilbert Reviewed-by: Michael S. Tsirkin Cc: "Michael S. Tsirkin" Cc: Juan Quintela Cc: "Dr. David Alan Gilbert" Signed-off-by: David Hildenbrand --- balloon.c | 18 ------------------ hw/virtio/virtio-balloon.c | 10 ++++++++-- include/migration/misc.h | 2 ++ include/sysemu/balloon.h | 2 -- migration/migration.c | 7 +++++++ migration/postcopy-ram.c | 23 ----------------------- 6 files changed, 17 insertions(+), 45 deletions(-) diff --git a/balloon.c b/balloon.c index 5fff79523a..354408c6ea 100644 --- a/balloon.c +++ b/balloon.c @@ -36,24 +36,6 @@ static QEMUBalloonEvent *balloon_event_fn; static QEMUBalloonStatus *balloon_stat_fn; static void *balloon_opaque; -static int balloon_inhibit_count; - -bool qemu_balloon_is_inhibited(void) -{ - return atomic_read(&balloon_inhibit_count) > 0 || - ram_block_discard_is_disabled(); -} - -void qemu_balloon_inhibit(bool state) -{ - if (state) { - atomic_inc(&balloon_inhibit_count); - } else { - atomic_dec(&balloon_inhibit_count); - } - - assert(atomic_read(&balloon_inhibit_count) >= 0); -} static bool have_balloon(Error **errp) { diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c index 10507b2a43..5faa9de558 100644 --- a/hw/virtio/virtio-balloon.c +++ b/hw/virtio/virtio-balloon.c @@ -63,6 +63,12 @@ static bool virtio_balloon_pbp_matches(PartiallyBalloonedPage *pbp, return pbp->base_gpa == base_gpa; } +static bool virtio_balloon_inhibited(void) +{ + /* Postcopy cannot deal with concurrent discards, so it's special. */ + return ram_block_discard_is_disabled() || migration_in_incoming_postcopy(); +} + static void balloon_inflate_page(VirtIOBalloon *balloon, MemoryRegion *mr, hwaddr mr_offset, PartiallyBalloonedPage *pbp) @@ -336,7 +342,7 @@ static void virtio_balloon_handle_report(VirtIODevice *vdev, VirtQueue *vq) * accessible by another device or process, or if the guest is * expecting it to retain a non-zero value. */ - if (qemu_balloon_is_inhibited() || dev->poison_val) { + if (virtio_balloon_inhibited() || dev->poison_val) { goto skip_element; } @@ -421,7 +427,7 @@ static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq) trace_virtio_balloon_handle_output(memory_region_name(section.mr), pa); - if (!qemu_balloon_is_inhibited()) { + if (!virtio_balloon_inhibited()) { if (vq == s->ivq) { balloon_inflate_page(s, section.mr, section.offset_within_region, &pbp); diff --git a/include/migration/misc.h b/include/migration/misc.h index d2762257aa..34e7d75713 100644 --- a/include/migration/misc.h +++ b/include/migration/misc.h @@ -69,6 +69,8 @@ bool migration_has_failed(MigrationState *); /* ...and after the device transmission */ bool migration_in_postcopy_after_devices(MigrationState *); void migration_global_dump(Monitor *mon); +/* True if incomming migration entered POSTCOPY_INCOMING_DISCARD */ +bool migration_in_incoming_postcopy(void); /* migration/block-dirty-bitmap.c */ void dirty_bitmap_mig_init(void); diff --git a/include/sysemu/balloon.h b/include/sysemu/balloon.h index aea0c44985..20a2defe3a 100644 --- a/include/sysemu/balloon.h +++ b/include/sysemu/balloon.h @@ -23,7 +23,5 @@ typedef void (QEMUBalloonStatus)(void *opaque, BalloonInfo *info); int qemu_add_balloon_handler(QEMUBalloonEvent *event_func, QEMUBalloonStatus *stat_func, void *opaque); void qemu_remove_balloon_handler(void *opaque); -bool qemu_balloon_is_inhibited(void); -void qemu_balloon_inhibit(bool state); #endif diff --git a/migration/migration.c b/migration/migration.c index 481a590f72..d365d82209 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -1772,6 +1772,13 @@ bool migration_in_postcopy_after_devices(MigrationState *s) return migration_in_postcopy() && s->postcopy_after_devices; } +bool migration_in_incoming_postcopy(void) +{ + PostcopyState ps = postcopy_state_get(); + + return ps >= POSTCOPY_INCOMING_DISCARD && ps < POSTCOPY_INCOMING_END; +} + bool migration_is_idle(void) { MigrationState *s = current_migration; diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c index a36402722b..b41a9fe2fd 100644 --- a/migration/postcopy-ram.c +++ b/migration/postcopy-ram.c @@ -27,7 +27,6 @@ #include "qemu/notify.h" #include "qemu/rcu.h" #include "sysemu/sysemu.h" -#include "sysemu/balloon.h" #include "qemu/error-report.h" #include "trace.h" #include "hw/boards.h" @@ -520,20 +519,6 @@ int postcopy_ram_incoming_init(MigrationIncomingState *mis) return 0; } -/* - * Manage a single vote to the QEMU balloon inhibitor for all postcopy usage, - * last caller wins. - */ -static void postcopy_balloon_inhibit(bool state) -{ - static bool cur_state = false; - - if (state != cur_state) { - qemu_balloon_inhibit(state); - cur_state = state; - } -} - /* * At the end of a migration where postcopy_ram_incoming_init was called. */ @@ -565,8 +550,6 @@ int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis) mis->have_fault_thread = false; } - postcopy_balloon_inhibit(false); - if (enable_mlock) { if (os_mlock() < 0) { error_report("mlock: %s", strerror(errno)); @@ -1160,12 +1143,6 @@ int postcopy_ram_incoming_setup(MigrationIncomingState *mis) } memset(mis->postcopy_tmp_zero_page, '\0', mis->largest_page_size); - /* - * Ballooning can mark pages as absent while we're postcopying - * that would cause false userfaults. - */ - postcopy_balloon_inhibit(true); - trace_postcopy_ram_enable_notify(); return 0;