From nobody Sat May 18 04:13:19 2024 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1666982247532598.107643352358; Fri, 28 Oct 2022 11:37:27 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ooUDf-0003Gh-Ma; Fri, 28 Oct 2022 14:36:39 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ooUDe-0003GI-OF; Fri, 28 Oct 2022 14:36:38 -0400 Received: from [200.168.210.66] (helo=outlook.eldorado.org.br) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ooUDb-0004sB-Qh; Fri, 28 Oct 2022 14:36:38 -0400 Received: from p9ibm ([10.10.71.235]) by outlook.eldorado.org.br over TLS secured channel with Microsoft SMTPSVC(8.5.9600.16384); Fri, 28 Oct 2022 15:36:29 -0300 Received: from eldorado.org.br (unknown [10.10.70.45]) by p9ibm (Postfix) with ESMTP id C8A65800094; Fri, 28 Oct 2022 15:36:28 -0300 (-03) From: Leandro Lupori To: qemu-ppc@nongnu.org, qemu-devel@nongnu.org Cc: danielhb413@gmail.com, clg@kaod.org, david@gibson.dropbear.id.au, groug@kaod.org, Leandro Lupori , Victor Colombo Subject: [PATCH] target/ppc: Fix regression in Radix MMU Date: Fri, 28 Oct 2022 15:36:17 -0300 Message-Id: <20221028183617.121786-1-leandro.lupori@eldorado.org.br> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-OriginalArrivalTime: 28 Oct 2022 18:36:29.0356 (UTC) FILETIME=[31ADC6C0:01D8EAFC] X-Host-Lookup-Failed: Reverse DNS lookup failed for 200.168.210.66 (failed) Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=200.168.210.66; envelope-from=leandro.lupori@eldorado.org.br; helo=outlook.eldorado.org.br X-Spam_score_int: -10 X-Spam_score: -1.1 X-Spam_bar: - X-Spam_report: (-1.1 / 5.0 requ) BAYES_00=-1.9, RDNS_NONE=0.793, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no 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: , Sender: "Qemu-devel" Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1666982250305100001 Content-Type: text/plain; charset="utf-8" Commit 47e83d9107 ended up unintentionally changing the control flow of ppc_radix64_process_scoped_xlate(). When guest_visible is false, it must not raise an exception, even if the radix configuration is not valid. This regression prevented Linux boot in a nested environment with L1 using TCG and emulating KVM (cap-nested-hv=3Don) and L2 using KVM. L2 would hang on Linux's futex_init(), when it tested how a futex_atomic_cmpxchg_inatomic() handled a fault, because L1 would start a loop of trying to perform partition scoped translations and raising exceptions. Fixes: 47e83d9107 ("target/ppc: Improve Radix xlate level validation") Reported-by: Victor Colombo Signed-off-by: Leandro Lupori Reviewed-by: Daniel Henrique Barboza Tested-by: V=C3=ADctor Colombo --- target/ppc/mmu-radix64.c | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-) diff --git a/target/ppc/mmu-radix64.c b/target/ppc/mmu-radix64.c index 00f2e9fa2e..171379db69 100644 --- a/target/ppc/mmu-radix64.c +++ b/target/ppc/mmu-radix64.c @@ -238,6 +238,8 @@ static void ppc_radix64_set_rc(PowerPCCPU *cpu, MMUAcce= ssType access_type, =20 static bool ppc_radix64_is_valid_level(int level, int psize, uint64_t nls) { + bool ret; + /* * Check if this is a valid level, according to POWER9 and POWER10 * Processor User's Manuals, sections 4.10.4.1 and 5.10.6.1, respectiv= ely: @@ -249,16 +251,24 @@ static bool ppc_radix64_is_valid_level(int level, int= psize, uint64_t nls) */ switch (level) { case 0: /* Root Page Dir */ - return psize =3D=3D 52 && nls =3D=3D 13; + ret =3D psize =3D=3D 52 && nls =3D=3D 13; + break; case 1: case 2: - return nls =3D=3D 9; + ret =3D nls =3D=3D 9; + break; case 3: - return nls =3D=3D 9 || nls =3D=3D 5; + ret =3D nls =3D=3D 9 || nls =3D=3D 5; + break; default: - qemu_log_mask(LOG_GUEST_ERROR, "invalid radix level: %d\n", level); - return false; + ret =3D false; + } + + if (unlikely(!ret)) { + qemu_log_mask(LOG_GUEST_ERROR, "invalid radix configuration: " + "level %d size %d nls %ld\n", level, psize, nls); } + return ret; } =20 static int ppc_radix64_next_level(AddressSpace *as, vaddr eaddr, @@ -519,11 +529,13 @@ static int ppc_radix64_process_scoped_xlate(PowerPCCP= U *cpu, =20 if (!ppc_radix64_is_valid_level(level++, *g_page_size, nls)) { fault_cause |=3D DSISR_R_BADCONFIG; - return 1; + ret =3D 1; + } else { + ret =3D ppc_radix64_next_level(cs->as, eaddr & R_EADDR_MAS= K, + &h_raddr, &nls, g_page_size, + &pte, &fault_cause); } =20 - ret =3D ppc_radix64_next_level(cs->as, eaddr & R_EADDR_MASK, &= h_raddr, - &nls, g_page_size, &pte, &fault_c= ause); if (ret) { /* No valid pte */ if (guest_visible) { --=20 2.25.1