From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f73.google.com (mail-wr1-f73.google.com [209.85.221.73]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 15FC3279DBE for ; Tue, 24 Jun 2025 09:23:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.73 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750756987; cv=none; b=h/RpZBKr/ZPKQ8jE0lZGTo4uQlRGej1/Dm/thSSgTG6yZYQemQRa8ZEAD8webuWWwmPXlM3DE2z4MxwfaiVnBL1iwUUnCTU44q0j6DCaFgWVWRjSIVae0Ccl7WSyyWFh4ET3uci6ZL1M92RE8tr1JXwvMRn27U/wMx5r+YU6FV0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750756987; c=relaxed/simple; bh=NLpwGNqu1U+2tmsJ+aXz+PezJD5PodPVGzOyX33N4OA=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=qNKr0K7RySBm90T1ba6ySZwgvaOqsHKHsMzP2q49pmY/3Qy3427Qr9rH82q7lG0qH//gDqy3Yqwa2gwvOt2DUZVwW1NEyc63EkqXbrN7pu90eeXqijSQtqfDSl42gFKQP5HYT3Q9odGIBJOVE4zouR8Zgq+aj6hoexEQmsHb1zo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--keirf.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=i5ojOb+d; arc=none smtp.client-ip=209.85.221.73 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--keirf.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="i5ojOb+d" Received: by mail-wr1-f73.google.com with SMTP id ffacd0b85a97d-3a4e9252ba0so2764383f8f.0 for ; Tue, 24 Jun 2025 02:23:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1750756984; x=1751361784; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=AVN7ijrerqrKRgMyDOXBQhh0QAZU9NZB9WAJvr5lBS8=; b=i5ojOb+dr85TwLkziSC7Yye9WZaJ4eweQu5cjgU5MrNQwhnwn1gyLyAz0fCjl5Nbnk eCvD1Q8Me+ECZ+eS/1GbwRWZXa8C1AMYaHYrWpFs8DfQx/eVcpr++CAKJ492Bwu2Kolg SbCi4J0Q+7nWTskjuwEnxS/NgaA6C/aNJuK1jzCDCLdY7p4Ckej7n3wrpsvd2yPNXHzJ lgWQeD9x7mceSzBKswvJ0hgi7ezK2mhkHfvEACoyk5iiKOgE7Yux3h00cIfKr1S4aKt7 BGo246v1S2TCD7eb6gf4Nrkjy1OtNsNGNWvuKTC5Y+FyLJ53IMcXpao2jC/LRG35LJls FD7A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1750756984; x=1751361784; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=AVN7ijrerqrKRgMyDOXBQhh0QAZU9NZB9WAJvr5lBS8=; b=F6iO5S/5L4Op2YO+sNwRkLIz/nbJYZH81R9NyEtDmO1XZa37JUIFG//K9Ea1pSQeOJ WwRmu4HEtoxOCSWPG7JfzMNREBn4chYsfO9fuRKw90rmppgZM0559s2XqQ3oGkeDFk/X hhU75HQIymORFvKz3F8pDJsBM3UfkNnRFqwgrUSlLvwsSvgmZ43ajY6LV2u1/yC36hde vtT+tH45VQvkvkmahPG8hELLvTxYWnIl47AXoaDUo+FsOioyzCgSTB3MViJdwDc04tkr zyTDbx9CFsOITIXTFA9XwW/u94IDcahep7OZVUyWwHvwF8Sdm0Xn7bgE3Rxt0Z9MSqOi lxyA== X-Forwarded-Encrypted: i=1; AJvYcCV3afzKV/sBqGk3FUD+GW84np4jAfs7rswiyEKAPCQIhGqR6SfvI9/vk7WQbjY4IVRz/NoJiCcZPYaSDzU=@vger.kernel.org X-Gm-Message-State: AOJu0YxR1otvzo4aMoLXwiLnddZ2EmkZXugCaXyV7XZ51g6paBWD8D/9 wJtbQgisxKHDFR2/u2P3UhfMRAoYIhfkiT/h/b/rMeNpFvcHT+JTbzHfdsan7zwkkfme8kkdWFk zYg== X-Google-Smtp-Source: AGHT+IGqR5KN60A+DlDRinsD9PxEgoB+9GsV+BbWlwoRfvGJZm269VIx0emnCkjD7fUm89pZbzqZPn7R9Q== X-Received: from wmsz14.prod.google.com ([2002:a05:600c:c16e:b0:44a:b793:9e40]) (user=keirf job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6000:25f2:b0:3a4:f8fa:8a3a with SMTP id ffacd0b85a97d-3a6d12de19dmr11877837f8f.18.1750756984556; Tue, 24 Jun 2025 02:23:04 -0700 (PDT) Date: Tue, 24 Jun 2025 09:22:52 +0000 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.50.0.rc2.761.g2dc52ea45b-goog Message-ID: <20250624092256.1105524-1-keirf@google.com> Subject: [PATCH 0/3] KVM: Speed up MMIO registrations From: Keir Fraser To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Eric Auger , Oliver Upton , Marc Zyngier , Will Deacon , Paolo Bonzini , Keir Fraser Content-Type: text/plain; charset="UTF-8" This series improves performance of MMIO registrations, which occur multiple times when booting a typical VM. The existing call to synchronize_srcu() may block for a considerable time: In our tests it was found to account for approximately 25% of a VM's startup time. arm64 vgic code is cleaned up and made responsible for its own setup synchronization, and the MMIO registration logic replaces synchronize_srcu() with a deferred callback to free the old io_bus struct. Keir Fraser (3): KVM: arm64: vgic-init: Remove vgic_ready() macro KVM: arm64: vgic: Explicitly implement vgic_dist::ready ordering KVM: Avoid synchronize_srcu() in kvm_io_bus_register_dev() arch/arm64/kvm/vgic/vgic-init.c | 14 +++----------- include/kvm/arm_vgic.h | 1 - include/linux/kvm_host.h | 1 + virt/kvm/kvm_main.c | 10 ++++++++-- 4 files changed, 12 insertions(+), 14 deletions(-) -- 2.50.0.rc2.761.g2dc52ea45b-goog