From patchwork Thu Dec 17 01:49:40 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Keqian Zhu X-Patchwork-Id: 1417441 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: 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=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=huawei.com Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4CxFQ20hwnz9sSf for ; Thu, 17 Dec 2020 12:53:14 +1100 (AEDT) Received: from localhost ([::1]:52218 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kpiTg-000365-4v for incoming@patchwork.ozlabs.org; Wed, 16 Dec 2020 20:53:12 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:51796) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kpiR8-0000yD-Hd; Wed, 16 Dec 2020 20:50:34 -0500 Received: from szxga07-in.huawei.com ([45.249.212.35]:2608) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kpiR5-0005tD-E3; Wed, 16 Dec 2020 20:50:34 -0500 Received: from DGGEMS402-HUB.china.huawei.com (unknown [172.30.72.58]) by szxga07-in.huawei.com (SkyGuard) with ESMTP id 4CxFKz3sWmz7FlN; Thu, 17 Dec 2020 09:49:43 +0800 (CST) Received: from DESKTOP-5IS4806.china.huawei.com (10.174.187.37) by DGGEMS402-HUB.china.huawei.com (10.3.19.202) with Microsoft SMTP Server id 14.3.498.0; Thu, 17 Dec 2020 09:50:14 +0800 From: Keqian Zhu To: Peter Maydell , Paolo Bonzini , "Dr . David Alan Gilbert" , Andrew Jones , Peter Xu Subject: [PATCH v2 1/2] accel: kvm: Fix memory waste under mismatch page size Date: Thu, 17 Dec 2020 09:49:40 +0800 Message-ID: <20201217014941.22872-2-zhukeqian1@huawei.com> X-Mailer: git-send-email 2.8.4.windows.1 In-Reply-To: <20201217014941.22872-1-zhukeqian1@huawei.com> References: <20201217014941.22872-1-zhukeqian1@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.174.187.37] X-CFilter-Loop: Reflected Received-SPF: pass client-ip=45.249.212.35; envelope-from=zhukeqian1@huawei.com; helo=szxga07-in.huawei.com X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: jiangkunkun@huawei.com, qemu-devel@nongnu.org, qemu-arm@nongnu.org, Zenghui Yu , wanghaibin.wang@huawei.com, Keqian Zhu Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" When handle dirty log, we face qemu_real_host_page_size and TARGET_PAGE_SIZE. The first one is the granule of KVM dirty bitmap, and the second one is the granule of QEMU dirty bitmap. As qemu_real_host_page_size >= TARGET_PAGE_SIZE (kvm_init() enforced it), misuse TARGET_PAGE_SIZE to init kvmslot dirty_bmap may waste memory. For example, when qemu_real_host_page_size is 64K and TARGET_PAGE_SIZE is 4K, it wastes 93.75% (15/16) memory. Signed-off-by: Keqian Zhu Reviewed-by: Andrew Jones Reviewed-by: Peter Xu --- accel/kvm/kvm-all.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- v2 - Address Andrew's comment (qemu_real_host_page_size >= TARGET_PAGE_SIZE is a rule). - Add Andrew and Peter's R-b. diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index 389eaace72..f6b16a8df8 100644 --- a/accel/kvm/kvm-all.c +++ b/accel/kvm/kvm-all.c @@ -620,8 +620,12 @@ static void kvm_memslot_init_dirty_bitmap(KVMSlot *mem) * too, in most cases). * So for now, let's align to 64 instead of HOST_LONG_BITS here, in * a hope that sizeof(long) won't become >8 any time soon. + * + * Note: the granule of kvm dirty log is qemu_real_host_page_size. + * And mem->memory_size is aligned to it (otherwise this mem can't + * be registered to KVM). */ - hwaddr bitmap_size = ALIGN(((mem->memory_size) >> TARGET_PAGE_BITS), + hwaddr bitmap_size = ALIGN(mem->memory_size / qemu_real_host_page_size, /*HOST_LONG_BITS*/ 64) / 8; mem->dirty_bmap = g_malloc0(bitmap_size); } From patchwork Thu Dec 17 01:49:41 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Keqian Zhu X-Patchwork-Id: 1417440 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: 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=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=huawei.com Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4CxFND00m9z9sTK for ; Thu, 17 Dec 2020 12:51:39 +1100 (AEDT) Received: from localhost ([::1]:47430 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kpiSA-0000z3-0g for incoming@patchwork.ozlabs.org; Wed, 16 Dec 2020 20:51:38 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:51798) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kpiR8-0000yN-Uj; Wed, 16 Dec 2020 20:50:35 -0500 Received: from szxga07-in.huawei.com ([45.249.212.35]:2609) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kpiR5-0005tC-Dr; Wed, 16 Dec 2020 20:50:34 -0500 Received: from DGGEMS402-HUB.china.huawei.com (unknown [172.30.72.58]) by szxga07-in.huawei.com (SkyGuard) with ESMTP id 4CxFKz3bs1z7Fhk; Thu, 17 Dec 2020 09:49:43 +0800 (CST) Received: from DESKTOP-5IS4806.china.huawei.com (10.174.187.37) by DGGEMS402-HUB.china.huawei.com (10.3.19.202) with Microsoft SMTP Server id 14.3.498.0; Thu, 17 Dec 2020 09:50:14 +0800 From: Keqian Zhu To: Peter Maydell , Paolo Bonzini , "Dr . David Alan Gilbert" , Andrew Jones , Peter Xu Subject: [PATCH v2 2/2] accel: kvm: Add aligment assert for kvm_log_clear_one_slot Date: Thu, 17 Dec 2020 09:49:41 +0800 Message-ID: <20201217014941.22872-3-zhukeqian1@huawei.com> X-Mailer: git-send-email 2.8.4.windows.1 In-Reply-To: <20201217014941.22872-1-zhukeqian1@huawei.com> References: <20201217014941.22872-1-zhukeqian1@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.174.187.37] X-CFilter-Loop: Reflected Received-SPF: pass client-ip=45.249.212.35; envelope-from=zhukeqian1@huawei.com; helo=szxga07-in.huawei.com X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: jiangkunkun@huawei.com, qemu-devel@nongnu.org, qemu-arm@nongnu.org, Zenghui Yu , wanghaibin.wang@huawei.com, Keqian Zhu Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" The parameters start and size are transfered from QEMU memory emulation layer. It can promise that they are TARGET_PAGE_SIZE aligned. However, KVM needs they are qemu_real_page_size aligned. Though no caller breaks this aligned requirement currently, we'd better add an explicit assert to avoid future breaking. Signed-off-by: Keqian Zhu Reviewed-by: Andrew Jones Acked-by: Peter Xu --- accel/kvm/kvm-all.c | 7 +++++++ 1 file changed, 7 insertions(+) --- v2 - Address Andrew's commment (Use assert instead of return err). diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index f6b16a8df8..73b195cc41 100644 --- a/accel/kvm/kvm-all.c +++ b/accel/kvm/kvm-all.c @@ -692,6 +692,10 @@ out: #define KVM_CLEAR_LOG_ALIGN (qemu_real_host_page_size << KVM_CLEAR_LOG_SHIFT) #define KVM_CLEAR_LOG_MASK (-KVM_CLEAR_LOG_ALIGN) +/* + * As the granule of kvm dirty log is qemu_real_host_page_size, + * @start and @size are expected and restricted to align to it. + */ static int kvm_log_clear_one_slot(KVMSlot *mem, int as_id, uint64_t start, uint64_t size) { @@ -701,6 +705,9 @@ static int kvm_log_clear_one_slot(KVMSlot *mem, int as_id, uint64_t start, unsigned long *bmap_clear = NULL, psize = qemu_real_host_page_size; int ret; + /* Make sure start and size are qemu_real_host_page_size aligned */ + assert(QEMU_IS_ALIGNED(start | size, psize)); + /* * We need to extend either the start or the size or both to * satisfy the KVM interface requirement. Firstly, do the start