From nobody Thu Oct 2 02:12:36 2025 Received: from mail-wr1-f74.google.com (mail-wr1-f74.google.com [209.85.221.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 29C403128B1 for ; Wed, 24 Sep 2025 15:00:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.74 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758726032; cv=none; b=D0EeoCF67bxoKRka3eOroKq/6TpyP+09KKj+9/uxZTmV4nYSLrgOAmBAc5pW4kAmaaLgzWv4nRMEiloUKchzr0UW6IP8oyKiDUK77r523VNZwk+5qW07Uy2SkOZ8sd+AwzcIKTyNQc42/HNACWoROe+CnYxv7/js1IGy43mtoJA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758726032; c=relaxed/simple; bh=qDMukE+vGFaZgPAnzYH5a2YY1R/PccU0PwTyvnM0oxg=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=I/Ewj4Fmx6tRDJqWy4e2X8VdN4CAAUSyUfnibgKrsa/fBFdKmVoRoMsA98+8dZkTY+TLxYzkba9+Z44SqOHlzbHTU7rXh5Rdo1tsjVqqRhusJ2jz4J5WI56nnNSxbMg9NPGVltOl/zXn46wwoRHphzQO8mPwQWWbbOxQ5fr0c3s= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--jackmanb.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=GDcp2xYN; arc=none smtp.client-ip=209.85.221.74 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--jackmanb.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="GDcp2xYN" Received: by mail-wr1-f74.google.com with SMTP id ffacd0b85a97d-40657e09e85so826715f8f.1 for ; Wed, 24 Sep 2025 08:00:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1758726029; x=1759330829; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=oP8jWp4MkINOH7Jswzd6ZODnFl0qB6e1xzS3CEKeQl0=; b=GDcp2xYNYT0h1c/L6kwFXyvgWnk/38WWVtqaheANUHHs6d7S8leklwmrq6nAUpdAFb BVuP1ynePhqlCyCeaxElyoiiIGJFzCULiqIlxZ2hd2kdPoitelijiAE6G3O0UFyVB2o0 HnJNMHxInqVKPecnBxYz3jLQDtZoq6fRbfL0g/Arcxetj6hFcnsEBuvwn0CRj/na7Crd T/VcizgT+btSrUNmKPCskfwMGR6zEFS6j5M7T1nmrLOnn6r2kLBkG7qOgKbFz0g709kN tHNR/KKZiuhD2UmOs/uk5CnawkDsFJ8GsMZE1kLEiYt5JckqNARMCsy9Y8gRc0ldGG5X qBjA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1758726029; x=1759330829; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=oP8jWp4MkINOH7Jswzd6ZODnFl0qB6e1xzS3CEKeQl0=; b=o+AGTN7ghHDq64COic2MNca21JQm2QcGQVTWzkgTExY1d8JICvw8QOoa2/Rz45PalB WE4y8R44E3BakIzQ+t1MmM+lHqeB2i0yv9eaFWvXPbCxZdFevurNJ0zWV6CoHORvQqTy C6y4gsKrFq2BP05MkSkBmYB1f1h2ntsN87hytb2dI4aj6wgKXi2P4MDaeDvxvxkHSjpA oJwab5NexS7rDPuKGPGLclaocIffJb1HuytyJTVwhZj46FpJ39sQV6Mrx9y8AvZhkdU2 scpsoA7ABt5VqslwMkVH0S4hSeK0OyvIpXjxHWeEtTIfkZDp84y/gZFw9vTzO8dgjaAD cZMA== X-Forwarded-Encrypted: i=1; AJvYcCVXk4/erDpR0L6J4JUsmcfhT4RlVAugApasxPfRohVofEnIsc8XrWyKMQDzKGkHEJW5TjpR0+vmC7cyttw=@vger.kernel.org X-Gm-Message-State: AOJu0Yz18RceoowOTRNrthLbG7wGoowgHrDHPrw5/AXzAtrdcXA9GQxN jeILeUTHjT/n0MxQ1j+kJWKvK1NQeIwUsb6ORBs+mJ3xQ56kuInV9MjAcMDHf/fMibCmSfAtu/w n10OirrGWkiCqaw== X-Google-Smtp-Source: AGHT+IHodywAlVICR2SlEwjI/nDMWsb7c+Q0rCIs295IEGPrhzAjMAXo4iCffE/QGARjzAt8FOBx8w/TD0aqww== X-Received: from wrvh13.prod.google.com ([2002:a5d:548d:0:b0:3ec:e12a:e26]) (user=jackmanb job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6000:240a:b0:3e2:ac0:8c55 with SMTP id ffacd0b85a97d-40e50f5651fmr215557f8f.55.1758726028587; Wed, 24 Sep 2025 08:00:28 -0700 (PDT) Date: Wed, 24 Sep 2025 14:59:55 +0000 In-Reply-To: <20250924-b4-asi-page-alloc-v1-0-2d861768041f@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250924-b4-asi-page-alloc-v1-0-2d861768041f@google.com> X-Mailer: b4 0.14.2 Message-ID: <20250924-b4-asi-page-alloc-v1-20-2d861768041f@google.com> Subject: [PATCH 20/21] x86/mm/asi: don't use global pages when ASI enabled From: Brendan Jackman To: jackmanb@google.com, Andy Lutomirski , Lorenzo Stoakes , "Liam R. Howlett" , Suren Baghdasaryan , Michal Hocko , Johannes Weiner , Zi Yan , Axel Rasmussen , Yuanchu Xie , Roman Gushchin Cc: peterz@infradead.org, bp@alien8.de, dave.hansen@linux.intel.com, mingo@redhat.com, tglx@linutronix.de, akpm@linux-foundation.org, david@redhat.com, derkling@google.com, junaids@google.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, reijiw@google.com, rientjes@google.com, rppt@kernel.org, vbabka@suse.cz, x86@kernel.org, yosry.ahmed@linux.dev Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable For the same reason as with PTI, ASI means kernel pages can't be global: TLB entries from the unrestricted address space must not carry over into the restricted address space. Signed-off-by: Brendan Jackman --- arch/x86/mm/init.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index 8fd34475af7ccd49d0124e13a87342d3bfef3e05..45bbe764ca4e0abc13d41590dc4= ff466180cca31 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -249,8 +249,9 @@ static void __init probe_page_size_mask(void) =20 /* By the default is everything supported: */ __default_kernel_pte_mask =3D __supported_pte_mask; - /* Except when with PTI where the kernel is mostly non-Global: */ - if (cpu_feature_enabled(X86_FEATURE_PTI)) + /* Except when with PTI/ASI where the kernel is mostly non-Global: */ + if (cpu_feature_enabled(X86_FEATURE_PTI) || + cpu_feature_enabled(X86_FEATURE_ASI)) __default_kernel_pte_mask &=3D ~_PAGE_GLOBAL; =20 /* Enable 1 GB linear kernel mappings if available: */ --=20 2.50.1