From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 455A112838A; Tue, 16 Apr 2024 11:17:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713266232; cv=none; b=UNy8mslyF5OJhIqKrgSWAiuJxhkT93vK//mRZ2yFjMdD7DhBMJyoHCPYb0PicS86iROdROKJ9ZwB8zAQ4BJchITJxVluyPIH5/hlBdH2fZyVS801oF0AEy96LaTktN5BSJ5IYAdGRkQutVuIeBvqhy/ojdS6l2p5Q5dQCPrr4ew= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713266232; c=relaxed/simple; bh=9FhYJpvHXnQmHxgxXicQhyk+mTtDwkQy/D0WwG1gg9s=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=UKZVOjg1idCHDY7Wy5mm/i4QacZyZzFCoImZ/eI4jkrUQxFwBTKBPAd1sJrfI27wHKcfJR+mcP6H7WrEmgHEYKNhbWhycqG3FYPIOSUwdF4/REKcLW9Y09abzmMqs8qdwrAbWLc8m8YLlFnSXXGh4VEf0jnl+PH/t5cFatmsVdQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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 A532F339; Tue, 16 Apr 2024 04:17:38 -0700 (PDT) Received: from [10.1.197.1] (ewhatever.cambridge.arm.com [10.1.197.1]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3473C3F738; Tue, 16 Apr 2024 04:17:08 -0700 (PDT) Message-ID: Date: Tue, 16 Apr 2024 12:17:06 +0100 Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 04/43] arm64: RME: Handle Granule Protection Faults (GPFs) To: Steven Price , kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: Catalin Marinas , Marc Zyngier , Will Deacon , James Morse , Oliver Upton , 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 References: <20240412084056.1733704-1-steven.price@arm.com> <20240412084309.1733783-1-steven.price@arm.com> <20240412084309.1733783-5-steven.price@arm.com> Content-Language: en-US From: Suzuki K Poulose In-Reply-To: <20240412084309.1733783-5-steven.price@arm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 12/04/2024 09:42, Steven Price wrote: > 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. > > Signed-off-by: Steven Price > --- > arch/arm64/mm/fault.c | 29 ++++++++++++++++++++++++----- > 1 file changed, 24 insertions(+), 5 deletions(-) > > diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c > index 8251e2fea9c7..91da0f446dd9 100644 > --- a/arch/arm64/mm/fault.c > +++ b/arch/arm64/mm/fault.c > @@ -765,6 +765,25 @@ 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" }, > @@ -802,11 +821,11 @@ static const struct fault_info fault_info[] = { > { do_alignment_fault, SIGBUS, BUS_ADRALN, "alignment fault" }, > { do_bad, SIGKILL, SI_KERNEL, "unknown 34" }, > { do_bad, SIGKILL, SI_KERNEL, "unknown 35" }, Should this also be converted to do_gpf_ptw, "GPF at level -1", given we support LPA2 ? > - { 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 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" }, Rest looks fine to me. Suzuki