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[127.0.0.1]) by director2.derp.mail-out.ovh.net (inspect_sender_mail_agent) with SMTP for ; Wed, 20 Aug 2025 10:21:43 +0000 (UTC) Received: from mta3.priv.ovhmail-u1.ea.mail.ovh.net (unknown [10.110.37.181]) by director2.derp.mail-out.ovh.net (Postfix) with ESMTPS id 4c6Mtt72Wvz1xpf; Wed, 20 Aug 2025 10:21:42 +0000 (UTC) Received: from orca.pet (unknown [10.1.6.10]) by mta3.priv.ovhmail-u1.ea.mail.ovh.net (Postfix) with ESMTPSA id 945D494329C; Wed, 20 Aug 2025 10:21:40 +0000 (UTC) Authentication-Results:garm.ovh; auth=pass (GARM-106R006643a39dd-4f29-4819-869f-07233b346813, 616188B862BD6F9D24C783D7A018D61FF224AB69) smtp.auth=marcos@orca.pet X-OVh-ClientIp:79.117.22.109 Message-ID: Date: Wed, 20 Aug 2025 12:21:40 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] x86: add hintable NOPs emulation To: Borislav Petkov Cc: "Ahmed S. Darwish" , linux-kernel@vger.kernel.org, Thomas Gleixner , Ingo Molnar , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Brian Gerst , Uros Bizjak , Ard Biesheuvel , David Kaplan , Kees Cook , "Peter Zijlstra (Intel)" , Andrew Cooper , Oleg Nesterov , "Xin Li (Intel)" , Sabyrzhan Tasbolatov References: <20250820013452.495481-1-marcos@orca.pet> <2cd7b099-095d-405c-a7d9-b0f1f72184c2@orca.pet> <20250820094347.GDaKWY02hR3AAoT7la@fat_crate.local> <20250820095556.GEaKWbrMh24T7jTfBg@fat_crate.local> <3db7d599-c2a7-4bec-94b1-4872649dde8d@orca.pet> <20250820100812.GFaKWejCFMSAS6QIfS@fat_crate.local> Content-Language: es-ES From: Marcos Del Sol Vives In-Reply-To: <20250820100812.GFaKWejCFMSAS6QIfS@fat_crate.local> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Ovh-Tracer-Id: 11652782562187433652 X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: -100 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgeeffedrtdefgdduheekudduucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecuqfggjfdpvefjgfevmfevgfenuceurghilhhouhhtmecuhedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhepkfffgggfuffvvehfhfgjtgfgsehtkeertddtvdejnecuhfhrohhmpeforghrtghoshcuffgvlhcuufholhcugghivhgvshcuoehmrghrtghoshesohhrtggrrdhpvghtqeenucggtffrrghtthgvrhhnpedtgedugfeiudfgkeduhfelgfejgfeuvdejffeiveegteejvddviefhiedujedvheenucfkphepuddvjedrtddrtddruddpjeelrdduudejrddvvddruddtleenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepihhnvghtpeduvdejrddtrddtrddupdhmrghilhhfrhhomhepmhgrrhgtohhssehorhgtrgdrphgvthdpnhgspghrtghpthhtohepudekpdhrtghpthhtohepsghpsegrlhhivghnkedruggvpdhrtghpthhtohepuggrvhhiugdrkhgrphhlrghnsegrmhgurdgtohhmpdhrtghpthhtoheprghnughrvgifrdgtohhophgvrhefsegtihhtrhhigidrtghomhdprhgtphhtthhopegsrhhgvghrshhtsehgmhgrihhlrdgtohhmpdhrtghpthhtohepshhnohhvihhtohhllhesghhmrghilhdrtghomhdprhgtphhtthhopehusghiiihjrghksehgmhgrihhlrdgtohhmpdhrtghpthhtohepphgvthgvrhiisehinhhfrhgrug gvrggurdhorhhgpdhrtghpthhtoheprghruggssehkvghrnhgvlhdrohhrghdprhgtphhtthhopehkvggvsheskhgvrhhnvghlrdhorhhg DKIM-Signature: a=rsa-sha256; bh=0WgxTiwE9lCVl6akB+HLPooec9IpmzRQo97+ST4njzk=; c=relaxed/relaxed; d=orca.pet; h=From; s=ovhmo-selector-1; t=1755685303; v=1; b=B2jm7XyDbBMZ7gAWvtUyhkh4VmzcW4JnDhumIuKsvqplgZsXNNBJzKafdkPcETBuCALLR6AW Q1xDWRm5aYugFC1Hk/FQZJppc/WUQD1EoheJ/awJfWhJ/yuBbE/qncAnzkLIi6ML/15Ma7wKcKZ CavsBop0PAsN+HYxrMzFKqcalNoYAOKWgOMUUFHaL0yGrrNno9WctFErNAz4+g8uWXy4GSNMB1Y kMy4OfonruQo3fDzBRoUJ/OgbJn8kJ3Um6T+mFCgceEVRB/pvN8y9Mah8Cuu5D4ML0UV8kDLqYT wk5x/J9pK1ctJiy3/0CWce/abw/o/ESXxLqXc59oZ51ZA== El 20/08/2025 a las 12:08, Borislav Petkov escribió: > On Wed, Aug 20, 2025 at 12:01:30PM +0200, Marcos Del Sol Vives wrote: >> Please define "once". Once per what? Per boot? Per executable? Per process? > > pr_err_once(). Per boot. Would a simple: > pr_warn_once("Your processor does not correctly handle hintable NOPs.\n"); > pr_warn_once("The kernel will emulate them, but the performance will be impacted!\n"); work for you, then? With no thread information, as that might make the user think there is only once binary impacted.