From patchwork Fri Jun 7 19:12:56 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Tokarev X-Patchwork-Id: 13690688 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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 91AF0C27C55 for ; Fri, 7 Jun 2024 22:32:55 +0000 (UTC) Received: from [::1] (helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sFf39-0004X3-Jn; Fri, 07 Jun 2024 15:14:55 -0400 Received: from [2001:470:142:3::10] (helo=eggs.gnu.org) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sFf37-0004O7-Pb; Fri, 07 Jun 2024 15:14:53 -0400 Received: from isrv.corpit.ru ([86.62.121.231]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sFf35-0002BR-SI; Fri, 07 Jun 2024 15:14:53 -0400 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id 769956E54E; Fri, 7 Jun 2024 22:14:05 +0300 (MSK) Received: from tls.msk.ru (mjt.wg.tls.msk.ru [192.168.177.130]) by tsrv.corpit.ru (Postfix) with SMTP id 902B5E274A; Fri, 7 Jun 2024 22:13:10 +0300 (MSK) Received: (nullmailer pid 528740 invoked by uid 1000); Fri, 07 Jun 2024 19:13:08 -0000 From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Daniel Henrique Barboza , Joseph Chan , Alistair Francis , Michael Tokarev Subject: [Stable-8.2.5 37/45] target/riscv: prioritize pmp errors in raise_mmu_exception() Date: Fri, 7 Jun 2024 22:12:56 +0300 Message-Id: <20240607191307.528622-17-mjt@tls.msk.ru> X-Mailer: git-send-email 2.39.2 In-Reply-To: References: MIME-Version: 1.0 Received-SPF: pass client-ip=86.62.121.231; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -68 X-Spam_score: -6.9 X-Spam_bar: ------ X-Spam_report: (-6.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Daniel Henrique Barboza raise_mmu_exception(), as is today, is prioritizing guest page faults by checking first if virt_enabled && !first_stage, and then considering the regular inst/load/store faults. There's no mention in the spec about guest page fault being a higher priority that PMP faults. In fact, privileged spec section 3.7.1 says: "Attempting to fetch an instruction from a PMP region that does not have execute permissions raises an instruction access-fault exception. Attempting to execute a load or load-reserved instruction which accesses a physical address within a PMP region without read permissions raises a load access-fault exception. Attempting to execute a store, store-conditional, or AMO instruction which accesses a physical address within a PMP region without write permissions raises a store access-fault exception." So, in fact, we're doing it wrong - PMP faults should always be thrown, regardless of also being a first or second stage fault. The way riscv_cpu_tlb_fill() and get_physical_address() work is adequate: a TRANSLATE_PMP_FAIL error is immediately reported and reflected in the 'pmp_violation' flag. What we need is to change raise_mmu_exception() to prioritize it. Reported-by: Joseph Chan Fixes: 82d53adfbb ("target/riscv/cpu_helper.c: Invalid exception on MMU translation stage") Signed-off-by: Daniel Henrique Barboza Reviewed-by: Alistair Francis Message-ID: <20240413105929.7030-1-alexei.filippov@syntacore.com> Cc: qemu-stable Signed-off-by: Alistair Francis (cherry picked from commit 68e7c86927afa240fa450578cb3a4f18926153e4) Signed-off-by: Michael Tokarev diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c index da1a153abf..cf97c782dd 100644 --- a/target/riscv/cpu_helper.c +++ b/target/riscv/cpu_helper.c @@ -1162,28 +1162,30 @@ static void raise_mmu_exception(CPURISCVState *env, target_ulong address, switch (access_type) { case MMU_INST_FETCH: - if (env->virt_enabled && !first_stage) { + if (pmp_violation) { + cs->exception_index = RISCV_EXCP_INST_ACCESS_FAULT; + } else if (env->virt_enabled && !first_stage) { cs->exception_index = RISCV_EXCP_INST_GUEST_PAGE_FAULT; } else { - cs->exception_index = pmp_violation ? - RISCV_EXCP_INST_ACCESS_FAULT : RISCV_EXCP_INST_PAGE_FAULT; + cs->exception_index = RISCV_EXCP_INST_PAGE_FAULT; } break; case MMU_DATA_LOAD: - if (two_stage && !first_stage) { + if (pmp_violation) { + cs->exception_index = RISCV_EXCP_LOAD_ACCESS_FAULT; + } else if (two_stage && !first_stage) { cs->exception_index = RISCV_EXCP_LOAD_GUEST_ACCESS_FAULT; } else { - cs->exception_index = pmp_violation ? - RISCV_EXCP_LOAD_ACCESS_FAULT : RISCV_EXCP_LOAD_PAGE_FAULT; + cs->exception_index = RISCV_EXCP_LOAD_PAGE_FAULT; } break; case MMU_DATA_STORE: - if (two_stage && !first_stage) { + if (pmp_violation) { + cs->exception_index = RISCV_EXCP_STORE_AMO_ACCESS_FAULT; + } else if (two_stage && !first_stage) { cs->exception_index = RISCV_EXCP_STORE_GUEST_AMO_ACCESS_FAULT; } else { - cs->exception_index = pmp_violation ? - RISCV_EXCP_STORE_AMO_ACCESS_FAULT : - RISCV_EXCP_STORE_PAGE_FAULT; + cs->exception_index = RISCV_EXCP_STORE_PAGE_FAULT; } break; default: