From: Borislav Petkov <bp@alien8.de>
To: Alex Deucher <alexdeucher@gmail.com>
Cc: Paul Menzel <pmenzel@molgen.mpg.de>,
Tom Lendacky <thomas.lendacky@amd.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, X86 ML <x86@kernel.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
LKML <linux-kernel@vger.kernel.org>,
amd-gfx list <amd-gfx@lists.freedesktop.org>
Subject: Re: `AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT=y` causes AMDGPU to fail on Ryzen: amdgpu: SME is not compatible with RAVEN
Date: Wed, 6 Oct 2021 15:46:44 +0200 [thread overview]
Message-ID: <YV2oxBw4I4kizvhF@zn.tnic> (raw)
In-Reply-To: <CADnq5_N5+SEW4JyXLc=FdSHnSbXrGKWjEw4vW1Jxv9-KdWf+Jg@mail.gmail.com>
On Wed, Oct 06, 2021 at 09:23:22AM -0400, Alex Deucher wrote:
> There could be some OEM systems that disable the IOMMU on the platform
> and don't provide a switch in the bios to enable it. The GPU driver
> will still work in that case, it will just not be able to enable KFD
> support for ROCm compute. SME won't work for most devices in that
> case however since most devices have a DMA mask too small to handle
> the C bit for encryption. SME should be dependent on IOMMU being
> enabled.
Yeah, I'd let you hash this out with Tom.
> I'm not an SME expert, but I thought that that was already the case.
Yeah, I think Paul wants this:
---
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index b79e88ee6627..e94c2df7a043 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1518,7 +1518,6 @@ config AMD_MEM_ENCRYPT
config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
bool "Activate AMD Secure Memory Encryption (SME) by default"
- default y
depends on AMD_MEM_ENCRYPT
help
Say yes to have system memory encrypted by default if running on
---
The reason we did this is so that you don't want to supply
mem_encrypt=on on the cmdline but didn't anticipate any such fun with
some devices.
> We just added the error condition in the GPU driver to prevent the
> driver from loading when the user forced SME on. IIRC, there were
> users that cared more about SME than graphics support.
Well, it's a distro kernel so we should at least try to make everyone
happy. :)
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2021-10-06 13:46 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-05 14:29 `AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT=y` causes AMDGPU to fail on Ryzen: amdgpu: SME is not compatible with RAVEN Paul Menzel
2021-10-05 14:38 ` Borislav Petkov
2021-10-06 6:27 ` Paul Menzel
2021-10-05 14:48 ` Alex Deucher
2021-10-06 9:42 ` Borislav Petkov
2021-10-06 13:23 ` Alex Deucher
2021-10-06 13:46 ` Borislav Petkov [this message]
2021-10-06 14:01 ` Tom Lendacky
2021-10-06 17:48 ` Borislav Petkov
2021-10-06 18:10 ` Alex Deucher
2021-10-06 18:21 ` Alex Deucher
2021-10-06 19:32 ` Borislav Petkov
2021-10-07 6:14 ` Christian König
2021-10-06 18:21 ` Borislav Petkov
2021-10-06 18:36 ` Alex Deucher
2021-10-06 19:34 ` Borislav Petkov
2021-10-06 21:39 ` Tom Lendacky
2021-10-11 13:05 ` Paul Menzel
2021-10-11 13:11 ` Borislav Petkov
2021-10-11 13:27 ` Tom Lendacky
2021-10-11 13:52 ` Paul Menzel
2021-10-11 13:58 ` Tom Lendacky
2021-10-11 14:21 ` Paul Menzel
2021-10-11 14:28 ` Tom Lendacky
2021-10-11 14:32 ` Alex Deucher
2021-10-11 16:03 ` [PATCH -v2] x86/Kconfig: Do not enable AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT automatically Borislav Petkov
2021-10-11 16:05 ` Alex Deucher
2021-10-11 16:29 ` Tom Lendacky
2021-10-11 17:18 ` [tip: x86/urgent] " tip-bot2 for Borislav Petkov
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