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Date:   Thu, 25 Aug 2022 07:57:27 +0300
From:   Jarkko Sakkinen <jarkko@kernel.org>
To:     Dave Hansen <dave.hansen@intel.com>
Cc:     Paul Menzel <pmenzel@molgen.mpg.de>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        x86@kernel.org, "Chatre, Reinette" <reinette.chatre@intel.com>,
        linux-sgx@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>
Subject: Re: WARNING: CPU: 1 PID: 83 at arch/x86/kernel/cpu/sgx/main.c:446
 ksgxd+0x1b7/0x1d0
Message-ID: <YwcBN+1Q7JiYC7cb@kernel.org>
References: <ce0b4d26-3a6e-7c5a-5f66-44cba05f9f35@molgen.mpg.de>
 <4253695b-85aa-a2fb-fbf6-718db8b6c20c@molgen.mpg.de>
 <46e3483b-a5ab-2a05-8a28-f9ea87e881c3@intel.com>
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On Fri, Aug 19, 2022 at 11:28:24AM -0700, Dave Hansen wrote:
> On 8/19/22 09:02, Paul Menzel wrote:
> > On the Dell XPS 13 9370, Linux 5.18.16 prints the warning below:
> > 
> > ```
> > [    0.000000] Linux version 5.18.0-4-amd64
> > (debian-kernel@lists.debian.org) (gcc-11 (Debian 11.3.0-5) 11.3.0, GNU
> > ld (GNU Binutils for Debian) 2.38.90.20220713) #1 SMP PREEMPT_DYNAMIC
> > Debian 5.18.16-1 (2022-08-10)
> > [    0.000000] Command line: BOOT_IMAGE=/vmlinuz-5.18.0-4-amd64
> > root=UUID=56f398e0-1e25-4fda-aa9f-611dece4b333 ro quiet
> > […]
> > [    0.000000] DMI: Dell Inc. XPS 13 9370/0RMYH9, BIOS 1.21.0 07/06/2022
> > […]
> > [    0.235418] sgx: EPC section 0x40200000-0x45f7ffff
> 
> Hi Paul,
> 
> Would you be able to send the entire dmesg, along with:
> 
> 	cat /proc/iomem # (as root)
> and
> 	cpuid -1 --raw
> 
> I'm suspecting either a BIOS problem.  Reinette (cc'd) also thought this
> might be a case of the SGX initialization getting a bit too far along
> when it should have been disabled.
> 
> We had some bugs where we didn't stop fast enough after spitting out the
> "SGX Launch Control is locked..." errors.

For some reason the pages do not get properly sanitized:

	/* sanity check: */
	WARN_ON(!list_empty(&sgx_dirty_page_list));

EPC should be good, given that EREMOVE does not fail.
If SGX would be disabled, also EREMOVE should fail.

BR, Jarkko