From patchwork Tue Nov 29 19:19:45 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oliver Upton X-Patchwork-Id: 13059065 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 8F848C4332F for ; Tue, 29 Nov 2022 19:24:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=l8Qui4Nt8DqQ4y455IJFJswHtY0s+WL2DcO1di8a+84=; b=Zul63sRU/5wC26 yotmVgvd31Dk1v4jODkhtDsuztz7yk4scdZRdhLFX8QfP4Uu3ZN/qWL5rrTWELJgRSJ4Rm1E5o3Fq GBJry7ByrGHc2jsxCutviIKrgLfrDsvzt8TTFiuerQrkhJPpzn+510+9nABHcpA5Hu8GQ09dNJRPJ zXhjSPvm0Vm+3b1fnWqdt1JTfK+IReOUcs9zwiOAd9/Z04NrupXV5tkZuI6iCFvjdyCZFP5RE4x5V RZSrUfIX0H8GQ4Cz9HFZepYllmNmc2g8YAV2Xxk4PYzOW+6+OileWYGTQOJRj+Xcyd9a3jhBhg9tv SbvReVen8aYjrrSJivnQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1p06Co-00B2MX-8D; Tue, 29 Nov 2022 19:23:46 +0000 Received: from out2.migadu.com ([188.165.223.204]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1p069O-00AzyI-Sz for linux-arm-kernel@lists.infradead.org; Tue, 29 Nov 2022 19:20:17 +0000 X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1669749602; 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: in-reply-to:in-reply-to:references:references; bh=kcCcdEvvwNGIdQ75NLzM3W5ItGtWtDkpHRzsetWKNGE=; b=hxIfAAInTnpV80RJl1MOplU9B+F7wko1aZ0kXwoNfPeIZ7mLgQMPu/2k0UoJcp40WP/Rbd 2bDrV8+x6MOHHN9BWWHQ5tkBOIM2kbW4M6a6SKLfqI8MCQ80kj47HEfkIrGFCirYKQP9u7 OmDozB0QEQ52eFKqV6Kq+CasS6AhCOg= From: Oliver Upton To: Marc Zyngier , James Morse , Alexandru Elisei , Suzuki K Poulose , Oliver Upton , Catalin Marinas , Will Deacon Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH 3/4] KVM: arm64: Handle access faults behind the read lock Date: Tue, 29 Nov 2022 19:19:45 +0000 Message-Id: <20221129191946.1735662-4-oliver.upton@linux.dev> In-Reply-To: <20221129191946.1735662-1-oliver.upton@linux.dev> References: <20221129191946.1735662-1-oliver.upton@linux.dev> MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221129_112015_178493_C7E37343 X-CRM114-Status: UNSURE ( 9.91 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org As the underlying software walkers are able to traverse and update stage-2 in parallel there is no need to serialize access faults. Only take the read lock when handling an access fault. Signed-off-by: Oliver Upton Reviewed-by: Ricardo Koller --- arch/arm64/kvm/hyp/pgtable.c | 2 +- arch/arm64/kvm/mmu.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c index 9626f615d9b8..1a3dd9774707 100644 --- a/arch/arm64/kvm/hyp/pgtable.c +++ b/arch/arm64/kvm/hyp/pgtable.c @@ -1097,7 +1097,7 @@ kvm_pte_t kvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr) int ret; ret = stage2_update_leaf_attrs(pgt, addr, 1, KVM_PTE_LEAF_ATTR_LO_S2_AF, 0, - &pte, NULL, 0); + &pte, NULL, KVM_PGTABLE_WALK_SHARED); if (!ret) dsb(ishst); diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 886ad5ee767a..347985a56414 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -1404,10 +1404,10 @@ static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa) trace_kvm_access_fault(fault_ipa); - write_lock(&vcpu->kvm->mmu_lock); + read_lock(&vcpu->kvm->mmu_lock); mmu = vcpu->arch.hw_mmu; pte = kvm_pgtable_stage2_mkyoung(mmu->pgt, fault_ipa); - write_unlock(&vcpu->kvm->mmu_lock); + read_unlock(&vcpu->kvm->mmu_lock); if (kvm_pte_valid(pte)) kvm_set_pfn_accessed(kvm_pte_to_pfn(pte));