From patchwork Thu Sep 12 06:18:38 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ani Sinha X-Patchwork-Id: 1984405 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=OcY9LYFr; dkim-atps=neutral Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) 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=patchwork.ozlabs.org) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4X46j95LHpz1y1y for ; Thu, 12 Sep 2024 16:19:25 +1000 (AEST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sodAR-0003hA-Oy; Thu, 12 Sep 2024 02:18:59 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sodAQ-0003bg-Ci for qemu-devel@nongnu.org; Thu, 12 Sep 2024 02:18:58 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sodAO-0007lw-N5 for qemu-devel@nongnu.org; Thu, 12 Sep 2024 02:18:58 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1726121935; 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=qdljBIE1wnO1o1WeSrRcjuRU9723daTDWmWRls2lHV8=; b=OcY9LYFrvHI+igAE65afB9L+YpdAM1Pz4qmdSHNYRlzkYlttAOjcRQvW9FxHAkX61fTfdO fVFTWdW5LLTjEQ2dXdY9A9P83DY0gYmXtx8vG2ZpdiNBuqS9wygbjeiaO6m/RRQ/A5tMAf p7zhGmq/gvZm5r12oMeoyAjrIMPARfc= Received: from mail-pl1-f199.google.com (mail-pl1-f199.google.com [209.85.214.199]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-67-2FuRfqLfPi6ogTkoOqDXlw-1; Thu, 12 Sep 2024 02:18:53 -0400 X-MC-Unique: 2FuRfqLfPi6ogTkoOqDXlw-1 Received: by mail-pl1-f199.google.com with SMTP id d9443c01a7336-205516d992eso8377475ad.3 for ; Wed, 11 Sep 2024 23:18:53 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1726121933; x=1726726733; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=qdljBIE1wnO1o1WeSrRcjuRU9723daTDWmWRls2lHV8=; b=Ia/daGOiIUOSO+H2vQ7IJIuzIOQVpBUGogSMxqn4FuTPF4rlna9J9/tjOYGs6a7gCE CD3nHnI9fbsrozSiulQQEYb3WWJSLGkwCqTxip8KZSxgc25KvyKOL9oca+x6rsuf8XJm oZn5TqgnaajepKVY9ys6fnjFoTef55cnYCRsZx8KQb0ZUzohi6s6FZodP0ioax5zhUuj veckMGPSrNRtNPNWUxtPFpY1krawRQuR1kAdHrds/SaNAePfvccpyY44QrVGpUhKNtBS Vn1Y4XoosMU9EeebFizy9Lss67GoGMNHetff6Yt+yGccjRxqaJkI7+tEcvnIhWM2FPNL b6Ew== X-Forwarded-Encrypted: i=1; AJvYcCUcPW//yyuQWPIge+4rEfRnRvFuJhA+ewnNa+wgUs0fSsOSynlBc9y9dRdnW7S9Pytf7idorYdU/JRr@nongnu.org X-Gm-Message-State: AOJu0YyufmHi0F0wiyYQ1dzJEzaVyB0xf3YtPBpHWmmCQdOgp3r9xxGb xX/liwQ+LtUm16wTGfeIVrEn6fUTtewm4XKafKXIO08tQ0NrBaBynddApQH6aLrzaDTC9IGr/DC EW3ijDSHfQhyL0VJb1rkpofC2NAVJeM0I+6l/jvZKz3OHep3zAKrM X-Received: by 2002:a17:902:e852:b0:202:49e:6a35 with SMTP id d9443c01a7336-2076e33e935mr28065025ad.19.1726121932617; Wed, 11 Sep 2024 23:18:52 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHKzhzW+CekLd+GsI4x5ghgEvoYSLHVyPmx+X/rUn7ap1rlRZgslul0eln4r/hrDoSF6i6SjA== X-Received: by 2002:a17:902:e852:b0:202:49e:6a35 with SMTP id d9443c01a7336-2076e33e935mr28064685ad.19.1726121932116; Wed, 11 Sep 2024 23:18:52 -0700 (PDT) Received: from localhost.localdomain ([115.96.132.12]) by smtp.googlemail.com with ESMTPSA id d9443c01a7336-2076af49af0sm8420995ad.107.2024.09.11.23.18.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 11 Sep 2024 23:18:51 -0700 (PDT) From: Ani Sinha To: Paolo Bonzini Cc: Ani Sinha , kvm@vger.kernel.org, qemu-devel@nongnu.org Subject: [PATCH] accel/kvm: refactor dirty ring setup Date: Thu, 12 Sep 2024 11:48:38 +0530 Message-ID: <20240912061838.4501-1-anisinha@redhat.com> X-Mailer: git-send-email 2.42.0 MIME-Version: 1.0 Received-SPF: pass client-ip=170.10.129.124; envelope-from=anisinha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.144, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Refactor setting up of dirty ring code in kvm_init() so that is can be reused in the future patchsets. Signed-off-by: Ani Sinha --- accel/kvm/kvm-all.c | 88 +++++++++++++++++++++++++-------------------- 1 file changed, 50 insertions(+), 38 deletions(-) diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index 75d11a07b2..92f954ecfb 100644 --- a/accel/kvm/kvm-all.c +++ b/accel/kvm/kvm-all.c @@ -2385,6 +2385,55 @@ uint32_t kvm_dirty_ring_size(void) return kvm_state->kvm_dirty_ring_size; } +static int kvm_setup_dirty_ring(KVMState *s) +{ + uint64_t dirty_log_manual_caps; + int ret; + + /* + * Enable KVM dirty ring if supported, otherwise fall back to + * dirty logging mode + */ + ret = kvm_dirty_ring_init(s); + if (ret < 0) { + return ret; + } + + /* + * KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 is not needed when dirty ring is + * enabled. More importantly, KVM_DIRTY_LOG_INITIALLY_SET will assume no + * page is wr-protected initially, which is against how kvm dirty ring is + * usage - kvm dirty ring requires all pages are wr-protected at the very + * beginning. Enabling this feature for dirty ring causes data corruption. + * + * TODO: Without KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 and kvm clear dirty log, + * we may expect a higher stall time when starting the migration. In the + * future we can enable KVM_CLEAR_DIRTY_LOG to work with dirty ring too: + * instead of clearing dirty bit, it can be a way to explicitly wr-protect + * guest pages. + */ + if (!s->kvm_dirty_ring_size) { + dirty_log_manual_caps = + kvm_check_extension(s, KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2); + dirty_log_manual_caps &= (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE | + KVM_DIRTY_LOG_INITIALLY_SET); + s->manual_dirty_log_protect = dirty_log_manual_caps; + if (dirty_log_manual_caps) { + ret = kvm_vm_enable_cap(s, KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2, 0, + dirty_log_manual_caps); + if (ret) { + warn_report("Trying to enable capability %"PRIu64" of " + "KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 but failed. " + "Falling back to the legacy mode. ", + dirty_log_manual_caps); + s->manual_dirty_log_protect = 0; + } + } + } + + return 0; +} + static int kvm_init(MachineState *ms) { MachineClass *mc = MACHINE_GET_CLASS(ms); @@ -2404,7 +2453,6 @@ static int kvm_init(MachineState *ms) const KVMCapabilityInfo *missing_cap; int ret; int type; - uint64_t dirty_log_manual_caps; qemu_mutex_init(&kml_slots_lock); @@ -2551,47 +2599,11 @@ static int kvm_init(MachineState *ms) s->coalesced_pio = s->coalesced_mmio && kvm_check_extension(s, KVM_CAP_COALESCED_PIO); - /* - * Enable KVM dirty ring if supported, otherwise fall back to - * dirty logging mode - */ - ret = kvm_dirty_ring_init(s); + ret = kvm_setup_dirty_ring(s); if (ret < 0) { goto err; } - /* - * KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 is not needed when dirty ring is - * enabled. More importantly, KVM_DIRTY_LOG_INITIALLY_SET will assume no - * page is wr-protected initially, which is against how kvm dirty ring is - * usage - kvm dirty ring requires all pages are wr-protected at the very - * beginning. Enabling this feature for dirty ring causes data corruption. - * - * TODO: Without KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 and kvm clear dirty log, - * we may expect a higher stall time when starting the migration. In the - * future we can enable KVM_CLEAR_DIRTY_LOG to work with dirty ring too: - * instead of clearing dirty bit, it can be a way to explicitly wr-protect - * guest pages. - */ - if (!s->kvm_dirty_ring_size) { - dirty_log_manual_caps = - kvm_check_extension(s, KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2); - dirty_log_manual_caps &= (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE | - KVM_DIRTY_LOG_INITIALLY_SET); - s->manual_dirty_log_protect = dirty_log_manual_caps; - if (dirty_log_manual_caps) { - ret = kvm_vm_enable_cap(s, KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2, 0, - dirty_log_manual_caps); - if (ret) { - warn_report("Trying to enable capability %"PRIu64" of " - "KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 but failed. " - "Falling back to the legacy mode. ", - dirty_log_manual_caps); - s->manual_dirty_log_protect = 0; - } - } - } - #ifdef KVM_CAP_VCPU_EVENTS s->vcpu_events = kvm_check_extension(s, KVM_CAP_VCPU_EVENTS); #endif