From patchwork Mon Oct 1 15:54:37 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Punit Agrawal X-Patchwork-Id: 10622383 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2728C15A6 for ; Mon, 1 Oct 2018 15:56:48 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0EADE28DBC for ; Mon, 1 Oct 2018 15:56:48 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 025E629072; Mon, 1 Oct 2018 15:56:47 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id D47C328DBC for ; Mon, 1 Oct 2018 15:56:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: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=hh2S1WC+uLlesKdrO8xOXxGG7tJe3BJzQI1uehoTknk=; b=a8vArtNZeb6hOm0tfSNvL0aPRz EP0/EULzcE1/7SSlZrp/gEIt108KCq3QSgHDEV9nQgeA2pKdqSyHEUqFOH4H0IvBwgtS6gPC4Ecb2 c1XpZWTLUPpP+KpLHZ7RvFvC/ZzJHUzT6hZes4cl4pVvcafNwQwLNB7uAA7ZgeuvOEHfLgphBcX9z UGC8nfKl5l3hkDA9IiEB0Wrvlvf4H7DeW6QXQjBs1zObwWx7kA5khzZDuVVZuKu9yoEWljABD6Rnm C+lRaIjHvz3Wu0EOkiChOIcGgRhN8DT0tNUC4DfR1NnjD/fl/1IBQU/vXDLxUzYjYvv1SmTiFn0y8 pbqHh1DA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1g70Yq-0003ss-Kz; Mon, 01 Oct 2018 15:56:40 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1g70Xd-0002tv-K0 for linux-arm-kernel@lists.infradead.org; Mon, 01 Oct 2018 15:55:34 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 2DEBD15BF; Mon, 1 Oct 2018 08:55:23 -0700 (PDT) Received: from localhost (e105922-lin.emea.arm.com [10.4.13.28]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C370E3F5D3; Mon, 1 Oct 2018 08:55:22 -0700 (PDT) From: Punit Agrawal To: kvmarm@lists.cs.columbia.edu Subject: [PATCH v8 3/9] KVM: arm/arm64: Re-factor setting the Stage 2 entry to exec on fault Date: Mon, 1 Oct 2018 16:54:37 +0100 Message-Id: <20181001155443.23032-4-punit.agrawal@arm.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20181001155443.23032-1-punit.agrawal@arm.com> References: <20181001155443.23032-1-punit.agrawal@arm.com> X-ARM-No-Footer: FoSSMail X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20181001_085525_730816_49BD5F5D X-CRM114-Status: GOOD ( 15.92 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: suzuki.poulose@arm.com, marc.zyngier@arm.com, Punit Agrawal , will.deacon@arm.com, linux-kernel@vger.kernel.org, Christoffer Dall , linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Stage 2 fault handler marks a page as executable if it is handling an execution fault or if it was a permission fault in which case the executable bit needs to be preserved. The logic to decide if the page should be marked executable is duplicated for PMD and PTE entries. To avoid creating another copy when support for PUD hugepages is introduced refactor the code to share the checks needed to mark a page table entry as executable. Signed-off-by: Punit Agrawal Reviewed-by: Suzuki K Poulose Cc: Christoffer Dall Cc: Marc Zyngier --- virt/kvm/arm/mmu.c | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-) diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c index 5b76ee204000..ec64d21c6571 100644 --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -1481,7 +1481,8 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, unsigned long fault_status) { int ret; - bool write_fault, exec_fault, writable, hugetlb = false, force_pte = false; + bool write_fault, writable, hugetlb = false, force_pte = false; + bool exec_fault, needs_exec; unsigned long mmu_seq; gfn_t gfn = fault_ipa >> PAGE_SHIFT; struct kvm *kvm = vcpu->kvm; @@ -1606,19 +1607,25 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, if (exec_fault) invalidate_icache_guest_page(pfn, vma_pagesize); + /* + * If we took an execution fault we have made the + * icache/dcache coherent above and should now let the s2 + * mapping be executable. + * + * Write faults (!exec_fault && FSC_PERM) are orthogonal to + * execute permissions, and we preserve whatever we have. + */ + needs_exec = exec_fault || + (fault_status == FSC_PERM && stage2_is_exec(kvm, fault_ipa)); + if (hugetlb && vma_pagesize == PMD_SIZE) { pmd_t new_pmd = pfn_pmd(pfn, mem_type); new_pmd = pmd_mkhuge(new_pmd); if (writable) new_pmd = kvm_s2pmd_mkwrite(new_pmd); - if (exec_fault) { + if (needs_exec) new_pmd = kvm_s2pmd_mkexec(new_pmd); - } else if (fault_status == FSC_PERM) { - /* Preserve execute if XN was already cleared */ - if (stage2_is_exec(kvm, fault_ipa)) - new_pmd = kvm_s2pmd_mkexec(new_pmd); - } ret = stage2_set_pmd_huge(kvm, memcache, fault_ipa, &new_pmd); } else { @@ -1629,13 +1636,8 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, mark_page_dirty(kvm, gfn); } - if (exec_fault) { + if (needs_exec) new_pte = kvm_s2pte_mkexec(new_pte); - } else if (fault_status == FSC_PERM) { - /* Preserve execute if XN was already cleared */ - if (stage2_is_exec(kvm, fault_ipa)) - new_pte = kvm_s2pte_mkexec(new_pte); - } ret = stage2_set_pte(kvm, memcache, fault_ipa, &new_pte, flags); }