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 Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by smtp.lore.kernel.org (Postfix) with ESMTP id AD271C4332F for ; Tue, 29 Nov 2022 19:20:07 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 521D04B3E8; Tue, 29 Nov 2022 14:20:07 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Authentication-Results: mm01.cs.columbia.edu (amavisd-new); dkim=softfail (fail, message has been altered) header.i=@linux.dev 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 OSLia-YbibZx; Tue, 29 Nov 2022 14:20:06 -0500 (EST) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 4666D43479; Tue, 29 Nov 2022 14:20:06 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 720BA40399 for ; Tue, 29 Nov 2022 14:20:04 -0500 (EST) 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 E10mB-BnlXhg for ; Tue, 29 Nov 2022 14:20:03 -0500 (EST) Received: from out2.migadu.com (out2.migadu.com [188.165.223.204]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id 7167840F30 for ; Tue, 29 Nov 2022 14:20:03 -0500 (EST) 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 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 Cc: kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org 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 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 --- 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)); -- 2.38.1.584.g0f3c55d4c2-goog _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out2.migadu.com (out2.migadu.com [188.165.223.204]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 279A9BA27 for ; Tue, 29 Nov 2022 19:20:04 +0000 (UTC) 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> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT Message-ID: <20221129191945.dlV-7IULFgfsQlHYvd8aKBiPe8z4RDG6ifiSqbXBCzU@z> 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 --- 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)); -- 2.38.1.584.g0f3c55d4c2-goog