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AJvYcCXGEZx+CJzm05j/DGOKr9yBzL0afCuB0BApZSPbMkhiI2rL7+4qUGfbVaoBt16Lvrh6SNClvC29xf279m3JJvKep5In8EIxnexp96eR X-Gm-Message-State: AOJu0Yz8v/4c7HrcPcCSvJD8m4kSGXhMm56Tu3j/rgMRM7WPuHI6y1Sz LTwInXdAVRtViDdDzDnuygxVdX8n/sc87HBwXMgs/+ZiROGHPPXy7weLWf0d+z7DW7KJvzDhAjn cdA== X-Google-Smtp-Source: AGHT+IFDl7XFIOm8A1NmS3vcwpT/MgK3tN/OkPbki64TqjyNIDNoD+ptTocUGrk3ulp5wCxMH2rUOUx0gmM= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a25:4e41:0:b0:de5:53a9:384a with SMTP id c62-20020a254e41000000b00de553a9384amr504841ybb.13.1713881425302; Tue, 23 Apr 2024 07:10:25 -0700 (PDT) Date: Tue, 23 Apr 2024 07:10:23 -0700 In-Reply-To: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <9d3c997264829d0e2b28718222724ae8f9e7d8b4.1713559768.git.jpoimboe@kernel.org> Message-ID: Subject: Re: [PATCH v4 2/5] cpu/speculation: Fix CPU mitigation defaults for !x86 From: Sean Christopherson To: Josh Poimboeuf Cc: x86@kernel.org, linux-kernel@vger.kernel.org, Linus Torvalds , Daniel Sneddon , Pawan Gupta , Thomas Gleixner , Alexandre Chartre , Konrad Rzeszutek Wilk , Peter Zijlstra , Greg Kroah-Hartman , Andrew Cooper , Dave Hansen , Nikolay Borisov , KP Singh , Waiman Long , Borislav Petkov , Ingo Molnar , Stephen Rothwell , Michael Ellerman , Geert Uytterhoeven Content-Type: text/plain; charset="us-ascii" On Fri, Apr 19, 2024, Sean Christopherson wrote: > On Fri, Apr 19, 2024, Josh Poimboeuf wrote: > > CPU speculative execution mitigations were inadvertently disabled on > > non-x86 arches by the following commit: > > > > f337a6a21e2f ("x86/cpu: Actually turn off mitigations by default for SPECULATION_MITIGATIONS=n") > > > > Fix it by replacing CONFIG_SPECULATION_MITIGATIONS with a new generic > > CONFIG_CPU_MITIGATIONS option and moving the x86-specific mitigations to > > a separate menu which depends on CONFIG_CPU_MITIGATIONS. > > Ah drat, I didn't check my mailbox until after Cc'ing Linus my own version[*]. > > I don't have a strong preference between the two, though I do think it's worth > nothing that this will (obvioulsy) allow disabling mitigations at compile time > on all architectures, which may or may not be desirable. > > [*] https://lore.kernel.org/all/20240420000556.2645001-2-seanjc@google.com Josh, when you get a chance, can you weigh in on my menu-preserving approach? I want to get this resolved asap so that we're not scrambing on Friday again :-)