From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E01D0C43461 for ; Thu, 15 Apr 2021 11:51:01 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id 64763613B0 for ; Thu, 15 Apr 2021 11:51:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 64763613B0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 085EC4B5B1; Thu, 15 Apr 2021 07:51:01 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 557FxAWOHocc; Thu, 15 Apr 2021 07:50:59 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id D68BC4B728; Thu, 15 Apr 2021 07:50:59 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 7726C4B673 for ; Thu, 15 Apr 2021 07:50:58 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id dHFIMH-jpepg for ; Thu, 15 Apr 2021 07:50:57 -0400 (EDT) Received: from szxga06-in.huawei.com (szxga06-in.huawei.com [45.249.212.32]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id 459794B761 for ; Thu, 15 Apr 2021 07:50:57 -0400 (EDT) Received: from DGGEMS407-HUB.china.huawei.com (unknown [172.30.72.60]) by szxga06-in.huawei.com (SkyGuard) with ESMTP id 4FLd0W4RGXzlXKt; Thu, 15 Apr 2021 19:48:59 +0800 (CST) Received: from DESKTOP-TMVL5KK.china.huawei.com (10.174.187.128) by DGGEMS407-HUB.china.huawei.com (10.3.19.207) with Microsoft SMTP Server id 14.3.498.0; Thu, 15 Apr 2021 19:50:41 +0800 From: Yanan Wang To: Marc Zyngier , Will Deacon , "Quentin Perret" , Alexandru Elisei , , , , Subject: [PATCH v5 6/6] KVM: arm64: Distinguish cases of memcache allocations completely Date: Thu, 15 Apr 2021 19:50:32 +0800 Message-ID: <20210415115032.35760-7-wangyanan55@huawei.com> X-Mailer: git-send-email 2.8.4.windows.1 In-Reply-To: <20210415115032.35760-1-wangyanan55@huawei.com> References: <20210415115032.35760-1-wangyanan55@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.174.187.128] X-CFilter-Loop: Reflected Cc: Catalin Marinas X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu With a guest translation fault, the memcache pages are not needed if KVM is only about to install a new leaf entry into the existing page table. And with a guest permission fault, the memcache pages are also not needed for a write_fault in dirty-logging time if KVM is only about to update the existing leaf entry instead of collapsing a block entry into a table. By comparing fault_granule and vma_pagesize, cases that require allocations from memcache and cases that don't can be distinguished completely. Signed-off-by: Yanan Wang --- arch/arm64/kvm/mmu.c | 25 ++++++++++++------------- 1 file changed, 12 insertions(+), 13 deletions(-) diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index aa536392b308..9e35aa5d29f2 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -895,19 +895,6 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, gfn = fault_ipa >> PAGE_SHIFT; mmap_read_unlock(current->mm); - /* - * Permission faults just need to update the existing leaf entry, - * and so normally don't require allocations from the memcache. The - * only exception to this is when dirty logging is enabled at runtime - * and a write fault needs to collapse a block entry into a table. - */ - if (fault_status != FSC_PERM || (logging_active && write_fault)) { - ret = kvm_mmu_topup_memory_cache(memcache, - kvm_mmu_cache_min_pages(kvm)); - if (ret) - return ret; - } - mmu_seq = vcpu->kvm->mmu_notifier_seq; /* * Ensure the read of mmu_notifier_seq happens before we call @@ -970,6 +957,18 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, else if (cpus_have_const_cap(ARM64_HAS_CACHE_DIC)) prot |= KVM_PGTABLE_PROT_X; + /* + * Allocations from the memcache are required only when granule of the + * lookup level where the guest fault happened exceeds vma_pagesize, + * which means new page tables will be created in the fault handlers. + */ + if (fault_granule > vma_pagesize) { + ret = kvm_mmu_topup_memory_cache(memcache, + kvm_mmu_cache_min_pages(kvm)); + if (ret) + return ret; + } + /* * Under the premise of getting a FSC_PERM fault, we just need to relax * permissions only if vma_pagesize equals fault_granule. Otherwise, -- 2.23.0 _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm