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Peter Anvin" , Andy Lutomirski , Peter Zijlstra , Richard Henderson , Matt Turner , Vineet Gupta , Russell King , Catalin Marinas , Will Deacon , Guo Ren , Brian Cain , Huacai Chen , WANG Xuerui , Geert Uytterhoeven , Michal Simek , Thomas Bogendoerfer , Dinh Nguyen , Jonas Bonn , Stefan Kristiansson , Stafford Horne , "James E.J. Bottomley" , Helge Deller , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Naveen N Rao , Madhavan Srinivasan , Paul Walmsley , Palmer Dabbelt , Albert Ou , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Yoshinori Sato , Rich Felker , John Paul Adrian Glaubitz , "David S. Miller" , Andreas Larsson , Richard Weinberger , Anton Ivanov , Johannes Berg , Chris Zankel , Max Filippov , Arnd Bergmann , Andrew Morton , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , Uladzislau Rezki , Christoph Hellwig , Masami Hiramatsu , Mathieu Desnoyers , Mike Rapoport , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , Dennis Zhou , Tejun Heo , Christoph Lameter , Sean Christopherson , Paolo Bonzini , Ard Biesheuvel , Josh Poimboeuf , Pawan Gupta , x86@kernel.org, linux-kernel@vger.kernel.org, linux-alpha@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, loongarch@lists.linux.dev, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-openrisc@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, kvm@vger.kernel.org, linux-efi@vger.kernel.org, Junaid Shahid Subject: Re: [PATCH RFC v2 02/29] x86: Create CONFIG_MITIGATION_ADDRESS_SPACE_ISOLATION Message-ID: <20250116164305.GEZ4k3Gd2IoJpJzEIl@fat_crate.local> References: <20250110-asi-rfc-v2-v2-0-8419288bc805@google.com> <20250110-asi-rfc-v2-v2-2-8419288bc805@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20250110-asi-rfc-v2-v2-2-8419288bc805@google.com> X-Stat-Signature: wwwkqmid7ae78tkowit4kyxbdfx6p5ps X-Rspamd-Queue-Id: DBAA9100012 X-Rspam-User: X-Rspamd-Server: rspam06 X-HE-Tag: 1737045906-7297 X-HE-Meta: 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 C9rpDQeC MrlJq9Z9L21whtNwFCmxdgfSLR6OGQM2NJ3tAUwgayiO8Zw7Yaa26Tp985xA97JDdaQGBY6iIw7FENuJtD7SQioR6u1olxo4jSCgZ4z9C9FxvEgx1+7/miSEtzRufMr8eTDD+0kr2zBuFSQUi8XKH71+wlmvU7/AJafnAhQUWR5D+xUjoYK4SMegoJfO9+77g709OdibOqVADkl4wYkScBQn41fIDXaIklzyXyp+XoUkeVBVVRcAbhBJ0k6qJzZFDvdjTEetyl5BnWpY0c3bjM3HOYBw4Z9/goXa+SUsBajOmcfLCow7powHGmALPQtB9/KKvZZt6yGM2tSfeDf4Zm3464w== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Fri, Jan 10, 2025 at 06:40:28PM +0000, Brendan Jackman wrote: > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > index 7b9a7e8f39acc8e9aeb7d4213e87d71047865f5c..5a50582eb210e9d1309856a737d32b76fa1bfc85 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -2519,6 +2519,20 @@ config MITIGATION_PAGE_TABLE_ISOLATION > > See Documentation/arch/x86/pti.rst for more details. > > +config MITIGATION_ADDRESS_SPACE_ISOLATION > + bool "Allow code to run with a reduced kernel address space" > + default n > + depends on X86_64 && !PARAVIRT && !UML > + help > + This feature provides the ability to run some kernel code s/This feature provide/Provide/ > + with a reduced kernel address space. This can be used to > + mitigate some speculative execution attacks. > + > + The !PARAVIRT dependency is only because of lack of testing; in theory > + the code is written to work under paravirtualization. In practice > + there are likely to be unhandled cases, in particular concerning TLB > + flushes. Right, this paragraph should be under the "---" line too until PARAVIRT gets tested, ofc. Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette