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=-11.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 1AEA4C4727C for ; Thu, 1 Oct 2020 10:12:52 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id 7E73720838 for ; Thu, 1 Oct 2020 10:12:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7E73720838 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.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 D25F14B2DB; Thu, 1 Oct 2020 06:12:50 -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 F9m4hhq65Qbi; Thu, 1 Oct 2020 06:12:49 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 90B324B307; Thu, 1 Oct 2020 06:12:49 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 6B5F94B2BD for ; Thu, 1 Oct 2020 06:12:48 -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 M5YknJLz0k+N for ; Thu, 1 Oct 2020 06:12:47 -0400 (EDT) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 0F0864B275 for ; Thu, 1 Oct 2020 06:12:47 -0400 (EDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 8F2FBD6E; Thu, 1 Oct 2020 03:12:46 -0700 (PDT) Received: from [192.168.0.110] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id F364A3F70D; Thu, 1 Oct 2020 03:12:45 -0700 (PDT) Subject: Re: [PATCH] KVM: arm64: Pass level hint to TLBI during stage-2 permission fault To: Will Deacon , kvmarm@lists.cs.columbia.edu References: <20200930131801.16889-1-will@kernel.org> From: Alexandru Elisei Message-ID: <59870762-a477-215a-6266-a94940dbd961@arm.com> Date: Thu, 1 Oct 2020 11:13:49 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <20200930131801.16889-1-will@kernel.org> Content-Language: en-US Cc: Marc Zyngier , kernel-team@android.com 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 Hi, On 9/30/20 2:18 PM, Will Deacon wrote: > Alex pointed out that we don't pass a level hint to the TLBI instruction > when handling a stage-2 permission fault, even though the walker does > at some point have the level information in its hands. > > Rework stage2_update_leaf_attrs() so that it can optionally return the > level of the updated pte to its caller, which can in turn be used to > provide the correct TLBI level hint. Looks correct to me. I checked and all the functions that don't do a tlbi pass NULL as the level pointer, and the level parameter is always set by the walker algorithm (if level had an invalid value, no invalidation would have been performed): Reviewed-by: Alexandru Elisei Thanks, Alex > > Cc: Marc Zyngier > Link: https://lore.kernel.org/r/595cc73e-636e-8b3a-f93a-b4e9fb218db8@arm.com > Reported-by: Alexandru Elisei > Signed-off-by: Will Deacon > --- > arch/arm64/kvm/hyp/pgtable.c | 23 ++++++++++++++++------- > 1 file changed, 16 insertions(+), 7 deletions(-) > > diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c > index 603d6b415337..0cdf6e461cbd 100644 > --- a/arch/arm64/kvm/hyp/pgtable.c > +++ b/arch/arm64/kvm/hyp/pgtable.c > @@ -694,6 +694,7 @@ struct stage2_attr_data { > kvm_pte_t attr_set; > kvm_pte_t attr_clr; > kvm_pte_t pte; > + u32 level; > }; > > static int stage2_attr_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, > @@ -706,6 +707,7 @@ static int stage2_attr_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, > if (!kvm_pte_valid(pte)) > return 0; > > + data->level = level; > data->pte = pte; > pte &= ~data->attr_clr; > pte |= data->attr_set; > @@ -723,7 +725,8 @@ static int stage2_attr_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, > > static int stage2_update_leaf_attrs(struct kvm_pgtable *pgt, u64 addr, > u64 size, kvm_pte_t attr_set, > - kvm_pte_t attr_clr, kvm_pte_t *orig_pte) > + kvm_pte_t attr_clr, kvm_pte_t *orig_pte, > + u32 *level) > { > int ret; > kvm_pte_t attr_mask = KVM_PTE_LEAF_ATTR_LO | KVM_PTE_LEAF_ATTR_HI; > @@ -743,20 +746,24 @@ static int stage2_update_leaf_attrs(struct kvm_pgtable *pgt, u64 addr, > > if (orig_pte) > *orig_pte = data.pte; > + > + if (level) > + *level = data.level; > return 0; > } > > int kvm_pgtable_stage2_wrprotect(struct kvm_pgtable *pgt, u64 addr, u64 size) > { > return stage2_update_leaf_attrs(pgt, addr, size, 0, > - KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W, NULL); > + KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W, > + NULL, NULL); > } > > kvm_pte_t kvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr) > { > kvm_pte_t pte = 0; > stage2_update_leaf_attrs(pgt, addr, 1, KVM_PTE_LEAF_ATTR_LO_S2_AF, 0, > - &pte); > + &pte, NULL); > dsb(ishst); > return pte; > } > @@ -765,7 +772,7 @@ kvm_pte_t kvm_pgtable_stage2_mkold(struct kvm_pgtable *pgt, u64 addr) > { > kvm_pte_t pte = 0; > stage2_update_leaf_attrs(pgt, addr, 1, 0, KVM_PTE_LEAF_ATTR_LO_S2_AF, > - &pte); > + &pte, NULL); > /* > * "But where's the TLBI?!", you scream. > * "Over in the core code", I sigh. > @@ -778,7 +785,7 @@ kvm_pte_t kvm_pgtable_stage2_mkold(struct kvm_pgtable *pgt, u64 addr) > bool kvm_pgtable_stage2_is_young(struct kvm_pgtable *pgt, u64 addr) > { > kvm_pte_t pte = 0; > - stage2_update_leaf_attrs(pgt, addr, 1, 0, 0, &pte); > + stage2_update_leaf_attrs(pgt, addr, 1, 0, 0, &pte, NULL); > return pte & KVM_PTE_LEAF_ATTR_LO_S2_AF; > } > > @@ -786,6 +793,7 @@ int kvm_pgtable_stage2_relax_perms(struct kvm_pgtable *pgt, u64 addr, > enum kvm_pgtable_prot prot) > { > int ret; > + u32 level; > kvm_pte_t set = 0, clr = 0; > > if (prot & KVM_PGTABLE_PROT_R) > @@ -797,8 +805,9 @@ int kvm_pgtable_stage2_relax_perms(struct kvm_pgtable *pgt, u64 addr, > if (prot & KVM_PGTABLE_PROT_X) > clr |= KVM_PTE_LEAF_ATTR_HI_S2_XN; > > - ret = stage2_update_leaf_attrs(pgt, addr, 1, set, clr, NULL); > - kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, pgt->mmu, addr, 0); > + ret = stage2_update_leaf_attrs(pgt, addr, 1, set, clr, NULL, &level); > + if (!ret) > + kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, pgt->mmu, addr, level); > return ret; > } > _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm