From patchwork Mon Apr 13 12:20:23 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: zhukeqian X-Patchwork-Id: 11485491 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 F2B091392 for ; Mon, 13 Apr 2020 12:23:18 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D09522073E for ; Mon, 13 Apr 2020 12:23:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="sZc5B5Aj" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D09522073E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:Subject:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=o9p3O1HCBTea8xnzX2NS/fZLaQ0MK7X3Xn2rwtZiscs=; b=sZc5B5AjJNz5s7 UVmgbzJJT6MRGj3UWhzbpYXMlAmo2mONbB4mrefZZsYjlVMuYVUcQUvzEEmUnfwzI6D2Ej7elk/8X YvXADZJ9xW4A3kfOHTC0kqDFSaK1zOSVBRCzetZ2B2QNNFAYwHLLiuHsdJNKAq7R55htlG3d8r91C dIK0FQbMjZcvrwZc9LuGuV38l8AFz/ygj3HmoJlRN74NHrkUH55NTg8Pbp0/ZU2RU0kjn0Lp9lHr8 ywfPc60GLoK1lvp8kb96JI+ezvmdL1sMUR/g54nSOp8cpLaRxispbiW2Rk1M8GcW1aMvy+IxWa0rI OTU/vkDOcBFcYL+X5A/g==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jNy7P-0003dO-Ji; Mon, 13 Apr 2020 12:23:15 +0000 Received: from szxga07-in.huawei.com ([45.249.212.35] helo=huawei.com) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jNy7M-0003LO-LQ for linux-arm-kernel@lists.infradead.org; Mon, 13 Apr 2020 12:23:14 +0000 Received: from DGGEMS409-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 6B73DF5F703402750F59; Mon, 13 Apr 2020 20:22:52 +0800 (CST) Received: from linux-kDCJWP.huawei.com (10.175.104.212) by DGGEMS409-HUB.china.huawei.com (10.3.19.209) with Microsoft SMTP Server id 14.3.487.0; Mon, 13 Apr 2020 20:22:45 +0800 From: Keqian Zhu To: , , , Subject: [PATCH v2] KVM/arm64: Support enabling dirty log gradually in small chunks Date: Mon, 13 Apr 2020 20:20:23 +0800 Message-ID: <20200413122023.52583-1-zhukeqian1@huawei.com> X-Mailer: git-send-email 2.19.1 MIME-Version: 1.0 X-Originating-IP: [10.175.104.212] X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200413_052312_884056_F152F8B0 X-CRM114-Status: GOOD ( 13.48 ) X-Spam-Score: -2.3 (--) X-Spam-Report: SpamAssassin version 3.4.4 on bombadil.infradead.org summary: Content analysis details: (-2.3 points) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at https://www.dnswl.org/, medium trust [45.249.212.35 listed in list.dnswl.org] -0.0 SPF_HELO_PASS SPF: HELO matches SPF record -0.0 SPF_PASS SPF: sender matches SPF record X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Suzuki K Poulose , Marc Zyngier , Keqian Zhu , Sean Christopherson , James Morse , wanghaibin.wang@huawei.com, Jay Zhou , Paolo Bonzini , Will Deacon , Julien Thierry Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org There is already support of enabling dirty log graually in small chunks for x86 in commit 3c9bd4006bfc ("KVM: x86: enable dirty log gradually in small chunks"). This adds support for arm64. x86 still writes protect all huge pages when DIRTY_LOG_INITIALLY_ALL_SET is eanbled. However, for arm64, both huge pages and normal pages can be write protected gradually by userspace. Under the Huawei Kunpeng 920 2.6GHz platform, I did some tests on 128G Linux VMs with different page size. The memory pressure is 127G in each case. The time taken of memory_global_dirty_log_start in QEMU is listed below: Page Size Before After Optimization 4K 650ms 1.8ms 2M 4ms 1.8ms 1G 2ms 1.8ms Besides the time reduction, the biggest income is that we will minimize the performance side effect (because of dissloving huge pages and marking memslots dirty) on guest after enabling dirty log. Signed-off-by: Keqian Zhu --- Documentation/virt/kvm/api.rst | 2 +- arch/arm64/include/asm/kvm_host.h | 3 +++ virt/kvm/arm/mmu.c | 12 ++++++++++-- 3 files changed, 14 insertions(+), 3 deletions(-) diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index efbbe570aa9b..0017f63fa44f 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -5777,7 +5777,7 @@ will be initialized to 1 when created. This also improves performance because dirty logging can be enabled gradually in small chunks on the first call to KVM_CLEAR_DIRTY_LOG. KVM_DIRTY_LOG_INITIALLY_SET depends on KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE (it is also only available on -x86 for now). +x86 and arm64 for now). KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 was previously available under the name KVM_CAP_MANUAL_DIRTY_LOG_PROTECT, but the implementation had bugs that make diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 32c8a675e5a4..a723f84fab83 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -46,6 +46,9 @@ #define KVM_REQ_RECORD_STEAL KVM_ARCH_REQ(3) #define KVM_REQ_RELOAD_GICv4 KVM_ARCH_REQ(4) +#define KVM_DIRTY_LOG_MANUAL_CAPS (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE | \ + KVM_DIRTY_LOG_INITIALLY_SET) + DECLARE_STATIC_KEY_FALSE(userspace_irqchip_in_use); extern unsigned int kvm_sve_max_vl; diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c index e3b9ee268823..1077f653a611 100644 --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -2265,8 +2265,16 @@ void kvm_arch_commit_memory_region(struct kvm *kvm, * allocated dirty_bitmap[], dirty pages will be be tracked while the * memory slot is write protected. */ - if (change != KVM_MR_DELETE && mem->flags & KVM_MEM_LOG_DIRTY_PAGES) - kvm_mmu_wp_memory_region(kvm, mem->slot); + if (change != KVM_MR_DELETE && mem->flags & KVM_MEM_LOG_DIRTY_PAGES) { + /* + * If we're with initial-all-set, we don't need to write + * protect any pages because they're all reported as dirty. + * Huge pages and normal pages will be write protect gradually. + */ + if (!kvm_dirty_log_manual_protect_and_init_set(kvm)) { + kvm_mmu_wp_memory_region(kvm, mem->slot); + } + } } int kvm_arch_prepare_memory_region(struct kvm *kvm,