From patchwork Wed May 6 09:49:36 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 11530901 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 510DE139F for ; Wed, 6 May 2020 09:50:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3ABB220714 for ; Wed, 6 May 2020 09:50:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Y1Ax3kqX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729173AbgEFJue (ORCPT ); Wed, 6 May 2020 05:50:34 -0400 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:33943 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729146AbgEFJud (ORCPT ); Wed, 6 May 2020 05:50:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1588758632; 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=VLvhweL9MM4fO8C2USx4CrswD98agNtloG3GZKunYNo=; b=Y1Ax3kqX0lWncYYOpYA1TFgwjgu3f7yjV+1Jaz0VblmjNX1XMERhcAM8IAkv43wMIkSEs6 1KczJ8R4LL7QcJClmOCTLtQDu/Wnx5t/9P9RVaIdJO4VFk1YiFpcItaoshlmioZXXl1WuX 5El3LEBMwLvSBRQHEW2CvowJS0txHHw= 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-193-xu27MMluPju_Nh_onFEfNA-1; Wed, 06 May 2020 05:50:27 -0400 X-MC-Unique: xu27MMluPju_Nh_onFEfNA-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E78CC461; Wed, 6 May 2020 09:50:25 +0000 (UTC) Received: from t480s.redhat.com (ovpn-113-17.ams2.redhat.com [10.36.113.17]) by smtp.corp.redhat.com (Postfix) with ESMTP id E4A305C1BD; Wed, 6 May 2020 09:50:23 +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 v1 05/17] virtio-balloon: Rip out qemu_balloon_inhibit() Date: Wed, 6 May 2020 11:49:36 +0200 Message-Id: <20200506094948.76388-6-david@redhat.com> In-Reply-To: <20200506094948.76388-1-david@redhat.com> References: <20200506094948.76388-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 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. 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 | 12 +++++++++++- include/sysemu/balloon.h | 2 -- migration/postcopy-ram.c | 23 ----------------------- 4 files changed, 11 insertions(+), 44 deletions(-) diff --git a/balloon.c b/balloon.c index c49f57c27b..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_broken(); -} - -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 a4729f7fc9..aa5b89fb47 100644 --- a/hw/virtio/virtio-balloon.c +++ b/hw/virtio/virtio-balloon.c @@ -29,6 +29,7 @@ #include "trace.h" #include "qemu/error-report.h" #include "migration/misc.h" +#include "migration/postcopy-ram.h" #include "hw/virtio/virtio-bus.h" #include "hw/virtio/virtio-access.h" @@ -63,6 +64,15 @@ static bool virtio_balloon_pbp_matches(PartiallyBalloonedPage *pbp, return pbp->base_gpa == base_gpa; } +static bool virtio_balloon_inhibited(void) +{ + PostcopyState ps = postcopy_state_get(); + + /* Postcopy cannot deal with concurrent discards (yet), so it's special. */ + return ram_block_discard_is_broken() || + (ps >= POSTCOPY_INCOMING_DISCARD && ps < POSTCOPY_INCOMING_END); +} + static void balloon_inflate_page(VirtIOBalloon *balloon, MemoryRegion *mr, hwaddr mr_offset, PartiallyBalloonedPage *pbp) @@ -360,7 +370,7 @@ 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/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/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;