From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 062EB1E3766; Thu, 24 Oct 2024 14:17:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729779472; cv=none; b=qPw6U5I3L+L1kf92qTwO+t+xm9lDXqAKifbBmbUlGw4cOEwt7+Rsut8GVEHERG8CVq8CswJNeBJq1t1/U9llSuWQcY4ebpTwCZkuUB7lgxo/xuSt29g+cylb32y+O+mB450qrUcfwpnceEnqdd90kb3eq3ox7+rjfrNkFsb65qA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729779472; c=relaxed/simple; bh=4uD2k8h2vy1UgxcQ+HHmd+XNAwZMm6TvGvEVPby1hNs=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=YSnwCd36FHGH7CMW3xrnDW0g2mkUEFktBocht6Jh21g/IXTJNrBeV8qm4P5e6HxIOlWtwtkJEr20fFXqPYbqObmemauwSHRW1IAAPsHqGXyiKkbfAW4DUCloTzNgNg3PoE4/SPRVxmF+MJdhqee3DZCruVznK7/+/TkmCPQ9zg4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Z+PJztDa; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Z+PJztDa" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D18BAC4CEC7; Thu, 24 Oct 2024 14:17:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729779471; bh=4uD2k8h2vy1UgxcQ+HHmd+XNAwZMm6TvGvEVPby1hNs=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=Z+PJztDa3DLJi8zczBtunJjYtTgbSB/pWYuOXBfkLIyw6TJiCAQ0WRq/AQHNYvMIO ypPUss6EbEuI+coFbJNqOQ7DB+SW8zeDyvxK1TRcGHKz3TKoE8rdW6wGUWGYFTZfzL pqbUZrnT461zBGjqAr82cZ5oVy50OPec5abANxSAzPIpWWUz5lKPIPkuWR2RcW+Ak/ Lc6LA81PZMJ5+ZtTF2j46hgvE/ZCfmDp2TRENpjxGGbiUvUVIlIorJpIWJWxPb7jXl 4P5XKju/mwmLSgkExTYhQYAm8xCA2feq6F05VCgttXD1PUf43IL0rqbydLFMxZfMKo QUgNloX/6Rwnw== X-Mailer: emacs 31.0.50 (via feedmail 11-beta-1 I) From: Aneesh Kumar K.V To: Steven Price , kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: Steven Price , Catalin Marinas , Marc Zyngier , Will Deacon , James Morse , Oliver Upton , Suzuki K Poulose , Zenghui Yu , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Joey Gouly , Alexandru Elisei , Christoffer Dall , Fuad Tabba , linux-coco@lists.linux.dev, Ganapatrao Kulkarni , Gavin Shan , Shanker Donthineni , Alper Gun Subject: Re: [PATCH v5 04/43] arm64: RME: Handle Granule Protection Faults (GPFs) In-Reply-To: <20241004152804.72508-5-steven.price@arm.com> References: <20241004152804.72508-1-steven.price@arm.com> <20241004152804.72508-5-steven.price@arm.com> Date: Thu, 24 Oct 2024 19:47:41 +0530 Message-ID: Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain Steven Price writes: > If the host attempts to access granules that have been delegated for use > in a realm these accesses will be caught and will trigger a Granule > Protection Fault (GPF). > > A fault during a page walk signals a bug in the kernel and is handled by > oopsing the kernel. A non-page walk fault could be caused by user space > having access to a page which has been delegated to the kernel and will > trigger a SIGBUS to allow debugging why user space is trying to access a > delegated page. > A non-page walk fault can also be caused by host kernel trying to access a page which it had delegated before. It would be nice to dump details like FAR in that case. Right now it shows only the below. [ 285.122310] Internal error: Granule Protection Fault not on table walk: 0000000096000068 [#1] PREEMPT SMP [ 285.122427] Modules linked in: [ 285.122512] CPU: 1 UID: 0 PID: 217 Comm: kvm-vcpu-0 Not tainted 6.12.0-rc1-00082-g8461d8333829 #42 [ 285.122656] Hardware name: FVP Base RevC (DT) [ 285.122733] pstate: 81400009 (Nzcv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--) [ 285.122871] pc : clear_page+0x18/0x50 [ 285.122975] lr : kvm_gmem_get_pfn+0xbc/0x190 [ 285.123110] sp : ffff800082cef900 [ 285.123182] x29: ffff800082cef910 x28: 0000000090000000 x27: 0000000090000006 ..... -aneesh > > Signed-off-by: Steven Price > --- > Changes since v2: > * Include missing "Granule Protection Fault at level -1" > --- > arch/arm64/mm/fault.c | 31 +++++++++++++++++++++++++------ > 1 file changed, 25 insertions(+), 6 deletions(-) > > diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c > index 8b281cf308b3..f9d72a936d48 100644 > --- a/arch/arm64/mm/fault.c > +++ b/arch/arm64/mm/fault.c > @@ -804,6 +804,25 @@ static int do_tag_check_fault(unsigned long far, unsigned long esr, > return 0; > } > > +static int do_gpf_ptw(unsigned long far, unsigned long esr, struct pt_regs *regs) > +{ > + const struct fault_info *inf = esr_to_fault_info(esr); > + > + die_kernel_fault(inf->name, far, esr, regs); > + return 0; > +} > + > +static int do_gpf(unsigned long far, unsigned long esr, struct pt_regs *regs) > +{ > + const struct fault_info *inf = esr_to_fault_info(esr); > + > + if (!is_el1_instruction_abort(esr) && fixup_exception(regs)) > + return 0; > + > + arm64_notify_die(inf->name, regs, inf->sig, inf->code, far, esr); > + return 0; > +} > + > static const struct fault_info fault_info[] = { > { do_bad, SIGKILL, SI_KERNEL, "ttbr address size fault" }, > { do_bad, SIGKILL, SI_KERNEL, "level 1 address size fault" }, > @@ -840,12 +859,12 @@ static const struct fault_info fault_info[] = { > { do_bad, SIGKILL, SI_KERNEL, "unknown 32" }, > { do_alignment_fault, SIGBUS, BUS_ADRALN, "alignment fault" }, > { do_bad, SIGKILL, SI_KERNEL, "unknown 34" }, > - { do_bad, SIGKILL, SI_KERNEL, "unknown 35" }, > - { do_bad, SIGKILL, SI_KERNEL, "unknown 36" }, > - { do_bad, SIGKILL, SI_KERNEL, "unknown 37" }, > - { do_bad, SIGKILL, SI_KERNEL, "unknown 38" }, > - { do_bad, SIGKILL, SI_KERNEL, "unknown 39" }, > - { do_bad, SIGKILL, SI_KERNEL, "unknown 40" }, > + { do_gpf_ptw, SIGKILL, SI_KERNEL, "Granule Protection Fault at level -1" }, > + { do_gpf_ptw, SIGKILL, SI_KERNEL, "Granule Protection Fault at level 0" }, > + { do_gpf_ptw, SIGKILL, SI_KERNEL, "Granule Protection Fault at level 1" }, > + { do_gpf_ptw, SIGKILL, SI_KERNEL, "Granule Protection Fault at level 2" }, > + { do_gpf_ptw, SIGKILL, SI_KERNEL, "Granule Protection Fault at level 3" }, > + { do_gpf, SIGBUS, SI_KERNEL, "Granule Protection Fault not on table walk" }, > { do_bad, SIGKILL, SI_KERNEL, "level -1 address size fault" }, > { do_bad, SIGKILL, SI_KERNEL, "unknown 42" }, > { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level -1 translation fault" }, > -- > 2.34.1