From nobody Sun Dec 14 19:23:49 2025 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.15]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2B9624086A for ; Thu, 22 May 2025 02:45:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.15 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747881916; cv=none; b=u+fxKQK3vV501rAmlKxpC9Zz+clLi09xN9zMUCe2EtCqjD78b0xPeHbPANrTf2z0TyPO3ORjqq6zCvGNtnEL+7eMWWZBuSiCijdJAbBZczeJ8MTEZgmjZTIm5TB6mh2kpAnOAClgc0CJPFqZmVb9K5dpJ0B3EXJQH1fXrmU+HJ0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747881916; c=relaxed/simple; bh=nquVPncXX39k9Guyv3btazppR+HflSexO+EgPb58o/8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=N4iROl0DxWUeEExcl78ze9lE/BLgjMVLQI7LhNgj6o3v/1Od1yquJq1sfvXm/TGeAkJYZumRYTOsOxEFzrD6nFpFILOo4fYmWz0AB+wbbsAuc3rCb7mOGkqL+4z7oLVpYpWNXaIMmJEcWhNUoWOYD3m0p+8j9CwrIbiyhKYgVmU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=WGz8X0O6; arc=none smtp.client-ip=192.198.163.15 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="WGz8X0O6" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1747881915; x=1779417915; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=nquVPncXX39k9Guyv3btazppR+HflSexO+EgPb58o/8=; b=WGz8X0O6b3wzTKnV0jFcRd8jwUKl39RyIXx1sEUL9NddXtk1IGXGNEPw GXhHVYzh6VIBGRzW893eMvB6IWchM8duXcrvT4nIsnBGwxuqFRxf6UmR1 KBaD/nX9wFP9Hp7eliyO9xEt39Nti0qQ0aLtbkMtu9ygBoiugUDw0l8/o 7L4YW30EgAzdmYI072pAWVDCtxtsxV/AuAneG0XvtCMYHZ8afLFr7D4WF IQZvA+ohfFnn6PYHaa1CrogSWTrxZ2Gv7N6VMeZDaxp8V9N7KtuN2c3g0 tyQuHS1nyhcyH11F+ID5MxO9Qp2y+VWu+em+zFF+BvgA+Pwscrav/GZ8z g==; X-CSE-ConnectionGUID: uZYRHm6WSuyJe+iRjrkCEg== X-CSE-MsgGUID: FhC5iwJ2SGOPy04W9cd2Cw== X-IronPort-AV: E=McAfee;i="6700,10204,11440"; a="50027072" X-IronPort-AV: E=Sophos;i="6.15,305,1739865600"; d="scan'208";a="50027072" Received: from fmviesa010.fm.intel.com ([10.60.135.150]) by fmvoesa109.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 May 2025 19:45:14 -0700 X-CSE-ConnectionGUID: +kq5HQXvR1GEl6YwmwxKUw== X-CSE-MsgGUID: XVSeH6KGQI+p3W30HFiU/A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.15,305,1739865600"; d="scan'208";a="140889366" Received: from ssuvarig-mobl.amr.corp.intel.com (HELO desk) ([10.125.146.23]) by fmviesa010-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 May 2025 19:45:09 -0700 Date: Wed, 21 May 2025 19:45:08 -0700 From: Pawan Gupta To: x86@kernel.org Cc: David Kaplan , linux-kernel@vger.kernel.org, "H. Peter Anvin" , Josh Poimboeuf Subject: [PATCH v2 4/7] x86/its: Use switch/case to apply mitigation Message-ID: <20250521-eibrs-fix-v2-4-70e2598e932c@linux.intel.com> X-Mailer: b4 0.14.2 References: <20250521-eibrs-fix-v2-0-70e2598e932c@linux.intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20250521-eibrs-fix-v2-0-70e2598e932c@linux.intel.com> Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Prepare to apply stuffing mitigation in its_apply_mitigation(). This is currently only done via retbleed mitigation. Also using switch/case makes it evident that mitigation mode like VMEXIT_ONLY doesn't need any special handling. Signed-off-by: Pawan Gupta Reviewed-by: Nikolay Borisov --- arch/x86/kernel/cpu/bugs.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index a088302b320cf68344e28be7710b5a3582bba9ea..fbfc08f5f9f652beb677a1b5310= e4322600082ac 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -1471,15 +1471,21 @@ static void __init its_update_mitigation(void) =20 static void __init its_apply_mitigation(void) { + switch (its_mitigation) { + case ITS_MITIGATION_OFF: + case ITS_MITIGATION_AUTO: + case ITS_MITIGATION_VMEXIT_ONLY: /* its=3Dstuff forces retbleed stuffing and is enabled there. */ - if (its_mitigation !=3D ITS_MITIGATION_ALIGNED_THUNKS) - return; - - if (!boot_cpu_has(X86_FEATURE_RETPOLINE)) - setup_force_cpu_cap(X86_FEATURE_INDIRECT_THUNK_ITS); + case ITS_MITIGATION_RETPOLINE_STUFF: + break; + case ITS_MITIGATION_ALIGNED_THUNKS: + if (!boot_cpu_has(X86_FEATURE_RETPOLINE)) + setup_force_cpu_cap(X86_FEATURE_INDIRECT_THUNK_ITS); =20 - setup_force_cpu_cap(X86_FEATURE_RETHUNK); - set_return_thunk(its_return_thunk); + setup_force_cpu_cap(X86_FEATURE_RETHUNK); + set_return_thunk(its_return_thunk); + break; + } } =20 #undef pr_fmt --=20 2.34.1