From patchwork Mon Nov 30 12:18:47 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yanan Wang X-Patchwork-Id: 11940325 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=-18.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 E135DC64E7B for ; Mon, 30 Nov 2020 12:20:57 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 6DBC9206D8 for ; Mon, 30 Nov 2020 12:20:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="aw3vMGaL" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6DBC9206D8 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+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: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:List-Owner; bh=r2wiL3+3dqoLTNY01iN517Jq/T2nnSJVnzRk+SwsKIQ=; b=aw3vMGaLOZBfTsm/PAmNWwh1I irOVNcFjYRcUtDA7uFZBahXajU7MxHK6qdn50dEBSqtrx6OddN2vGQr8MyDD5w2calsdCNOpSYP7a rfcZoS2pNxfRT3PEk6lNbjaauuhX1RhD5OkvARdwqiSEzJrsBSji8APScxxuipyFMyC7ZTCVkI9e2 mzC+C+GkhIJMO5rPvAO3MPhVIT3G0BCqX8IUClGOcRG8KIoCjaNtVf0NzVoMzLQVEeZscPFAxUsrj abx3GbB+UzwJ31ArYekzwtK9b7VrRHmY+iBYEnBbTmhRcf1iJPYISeiNmEouSF4rikyb69cGcr8M6 6G1/U0cFQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kji9W-0005j8-NP; Mon, 30 Nov 2020 12:19:34 +0000 Received: from szxga07-in.huawei.com ([45.249.212.35]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kji9O-0005gX-4s for linux-arm-kernel@lists.infradead.org; Mon, 30 Nov 2020 12:19:27 +0000 Received: from DGGEMS402-HUB.china.huawei.com (unknown [172.30.72.59]) by szxga07-in.huawei.com (SkyGuard) with ESMTP id 4Cl45q2cDnz711V; Mon, 30 Nov 2020 20:18:55 +0800 (CST) Received: from DESKTOP-TMVL5KK.china.huawei.com (10.174.186.123) by DGGEMS402-HUB.china.huawei.com (10.3.19.202) with Microsoft SMTP Server id 14.3.487.0; Mon, 30 Nov 2020 20:19:10 +0800 From: Yanan Wang To: , , Marc Zyngier , Catalin Marinas , Will Deacon , James Morse , "Julien Thierry" , Suzuki K Poulose , Gavin Shan , Quentin Perret Subject: [RFC PATCH 3/3] KVM: arm64: Add usage of stage 2 fault lookup level in user_mem_abort() Date: Mon, 30 Nov 2020 20:18:47 +0800 Message-ID: <20201130121847.91808-4-wangyanan55@huawei.com> X-Mailer: git-send-email 2.8.4.windows.1 In-Reply-To: <20201130121847.91808-1-wangyanan55@huawei.com> References: <20201130121847.91808-1-wangyanan55@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.174.186.123] X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201130_071926_722039_D7FDF5E1 X-CRM114-Status: GOOD ( 18.01 ) 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: lushenming@huawei.com, jiangkunkun@huawei.com, Yanan Wang , yezengruan@huawei.com, wangjingyi11@huawei.com, yuzenghui@huawei.com, wanghaibin.wang@huawei.com, zhukeqian1@huawei.com Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org If we get a FSC_PERM fault, just using (logging_active && writable) to determine calling kvm_pgtable_stage2_map(). There will be two more cases we should consider. (1) After logging_active is configged back to false from true. When we get a FSC_PERM fault with write_fault and adjustment of hugepage is needed, we should merge tables back to a block entry. This case is ignored by still calling kvm_pgtable_stage2_relax_perms(), which will lead to an endless loop and guest panic due to soft lockup. (2) We use (FSC_PERM && logging_active && writable) to determine collapsing a block entry into a table by calling kvm_pgtable_stage2_map(). But sometimes we may only need to relax permissions when trying to write to a page other than a block. In this condition, using kvm_pgtable_stage2_relax_perms() will be fine. The ISS filed bit[1:0] in ESR_EL2 regesiter indicates the stage2 lookup level at which a D-abort or I-abort occured. By comparing granule of the fault lookup level with vma_pagesize, we can strictly distinguish conditions of calling kvm_pgtable_stage2_relax_perms() or kvm_pgtable_stage2_map(), and the above two cases will be well considered. Suggested-by: Keqian Zhu Signed-off-by: Yanan Wang --- arch/arm64/include/asm/esr.h | 1 + arch/arm64/include/asm/kvm_emulate.h | 5 +++++ arch/arm64/kvm/mmu.c | 11 +++++++++-- 3 files changed, 15 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/esr.h b/arch/arm64/include/asm/esr.h index 22c81f1edda2..85a3e49f92f4 100644 --- a/arch/arm64/include/asm/esr.h +++ b/arch/arm64/include/asm/esr.h @@ -104,6 +104,7 @@ /* Shared ISS fault status code(IFSC/DFSC) for Data/Instruction aborts */ #define ESR_ELx_FSC (0x3F) #define ESR_ELx_FSC_TYPE (0x3C) +#define ESR_ELx_FSC_LEVEL (0x03) #define ESR_ELx_FSC_EXTABT (0x10) #define ESR_ELx_FSC_SERROR (0x11) #define ESR_ELx_FSC_ACCESS (0x08) diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h index 5ef2669ccd6c..2e0e8edf6306 100644 --- a/arch/arm64/include/asm/kvm_emulate.h +++ b/arch/arm64/include/asm/kvm_emulate.h @@ -350,6 +350,11 @@ static __always_inline u8 kvm_vcpu_trap_get_fault_type(const struct kvm_vcpu *vc return kvm_vcpu_get_esr(vcpu) & ESR_ELx_FSC_TYPE; } +static __always_inline u8 kvm_vcpu_trap_get_fault_level(const struct kvm_vcpu *vcpu) +{ + return kvm_vcpu_get_esr(vcpu) & ESR_ELx_FSC_LEVEL; +{ + static __always_inline bool kvm_vcpu_abt_issea(const struct kvm_vcpu *vcpu) { switch (kvm_vcpu_trap_get_fault(vcpu)) { diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 1a01da9fdc99..75814a02d189 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -754,10 +754,12 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, gfn_t gfn; kvm_pfn_t pfn; bool logging_active = memslot_is_logging(memslot); - unsigned long vma_pagesize; + unsigned long fault_level = kvm_vcpu_trap_get_fault_level(vcpu); + unsigned long vma_pagesize, fault_granule; enum kvm_pgtable_prot prot = KVM_PGTABLE_PROT_R; struct kvm_pgtable *pgt; + fault_granule = 1UL << ARM64_HW_PGTABLE_LEVEL_SHIFT(fault_level); write_fault = kvm_is_write_fault(vcpu); exec_fault = kvm_vcpu_trap_is_exec_fault(vcpu); VM_BUG_ON(write_fault && exec_fault); @@ -896,7 +898,12 @@ 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; - if (fault_status == FSC_PERM && !(logging_active && writable)) { + /* + * Under the premise of getting a FSC_PERM fault, we just need to relax + * permissions only if vma_pagesize equals fault_granule. Otherwise, + * kvm_pgtable_stage2_map() should be called to change block size. + */ + if (fault_status == FSC_PERM && vma_pagesize == fault_granule) { ret = kvm_pgtable_stage2_relax_perms(pgt, fault_ipa, prot); } else { ret = kvm_pgtable_stage2_map(pgt, fault_ipa, vma_pagesize,