From nobody Thu Oct 9 07:00:56 2025 Received: from shelob.surriel.com (shelob.surriel.com [96.67.55.147]) (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 3D42B2376E0 for ; Thu, 19 Jun 2025 20:13:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.67.55.147 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750363988; cv=none; b=HPxq6nyAndVXHxvPj2rFEzuSSufoBebvMx4It4EngZs1mp1sggwJX44F/aLJ4eFQcHd0hE1ewCKHcmHej/anWB3J5lc+ngo0VmETYr4s+q7DZrz1yeKyEtp1Qxj1+NNf4lwlvbCa2XXyfeJ7HqNm7d1sdp3824PZ6MjvjqzKi4k= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750363988; c=relaxed/simple; bh=OAMl2/2Up5MxIckrOMb5nox+KObSWQMglG+ax9q9st8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kFHAvHRyt41pw8YZ26SczcLu5uXvEhJ39XvcZZje8vx2Wgw9CKo6zuU0nW8FOE6fQhpv7SDnFBWA0RlpnjQHYyYZ8Dp/KLvJQNFNrY5izPcyHAr2qLH9f5UySJ/37u+y6uhmkScwU8B8r+azM06NZMiTXXnCTRgkVEko9wiMkm0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=surriel.com; spf=pass smtp.mailfrom=surriel.com; dkim=pass (2048-bit key) header.d=surriel.com header.i=@surriel.com header.b=QE3hRafb; arc=none smtp.client-ip=96.67.55.147 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=surriel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=surriel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=surriel.com header.i=@surriel.com header.b="QE3hRafb" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=surriel.com ; s=mail; h=Content-Transfer-Encoding:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=f4zP15oJQMI/cNiQtQETjNBzcgWHpdktSGMgq1QqQy0=; b=QE3hRafbl5/SUMnuyBSz5icpda l7aN1fbrive6B7/aPZ0Am/kziLy6uOL5Y0bsF9RscZRni0l9mCy8j9Jt63QebgfEecE29eEzrnJMQ q3Go2tcpvIFeMFCsLnoYpDrEcurf1kAWZWEXwe097NpqVtOIb0Hs0sNUPnSRuW7ItqOa98XqFS+ba S3LfzLVjTupovxtqaqw5CmEklefSy7Kv3WkUenJGf1pU3LSW0ipepwP+03yS81r8JroEUeyxgWS61 pbE6i7B+pTDvC2VTDYo4Nt9R3AumxvKDnPNZ6IIWxkVTT3sGL/4yKroo2UNTiv87h37fxRVfdLdtT I/6Qw4aQ==; Received: from fangorn.home.surriel.com ([10.0.13.7]) by shelob.surriel.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.97.1) (envelope-from ) id 1uSLV6-000000000CT-1OF1; Thu, 19 Jun 2025 16:04:44 -0400 From: Rik van Riel To: linux-kernel@vger.kernel.org Cc: kernel-team@meta.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, bp@alien8.de, x86@kernel.org, nadav.amit@gmail.com, seanjc@google.com, tglx@linutronix.de, mingo@kernel.org, Yu-cheng Yu , Rik van Riel Subject: [RFC PATCH v4 1/8] x86/mm: Introduce Remote Action Request MSRs Date: Thu, 19 Jun 2025 16:03:53 -0400 Message-ID: <20250619200442.1694583-2-riel@surriel.com> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250619200442.1694583-1-riel@surriel.com> References: <20250619200442.1694583-1-riel@surriel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Yu-cheng Yu Remote Action Request (RAR) is a model-specific feature to speed up inter-processor operations by moving parts of those operations from software to hardware. The current RAR implementation handles TLB flushes and MSR writes. This patch introduces RAR MSRs. RAR is introduced in later patches. There are five RAR MSRs: MSR_CORE_CAPABILITIES MSR_IA32_RAR_CTRL MSR_IA32_RAR_ACT_VEC MSR_IA32_RAR_PAYLOAD_BASE MSR_IA32_RAR_INFO Signed-off-by: Yu-cheng Yu Signed-off-by: Rik van Riel --- arch/x86/include/asm/msr-index.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-in= dex.h index b7dded3c8113..367a62c50aa2 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -110,6 +110,8 @@ =20 /* Abbreviated from Intel SDM name IA32_CORE_CAPABILITIES */ #define MSR_IA32_CORE_CAPS 0x000000cf +#define MSR_IA32_CORE_CAPS_RAR_BIT 1 +#define MSR_IA32_CORE_CAPS_RAR BIT(MSR_IA32_CORE_CAPS_RAR_BIT) #define MSR_IA32_CORE_CAPS_INTEGRITY_CAPS_BIT 2 #define MSR_IA32_CORE_CAPS_INTEGRITY_CAPS BIT(MSR_IA32_CORE_CAPS_INTEGRI= TY_CAPS_BIT) #define MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT_BIT 5 @@ -122,6 +124,17 @@ #define SNB_C3_AUTO_UNDEMOTE (1UL << 27) #define SNB_C1_AUTO_UNDEMOTE (1UL << 28) =20 +/* + * Remote Action Requests (RAR) MSRs + */ +#define MSR_IA32_RAR_CTRL 0x000000ed +#define MSR_IA32_RAR_ACT_VEC 0x000000ee +#define MSR_IA32_RAR_PAYLOAD_BASE 0x000000ef +#define MSR_IA32_RAR_INFO 0x000000f0 + +#define RAR_CTRL_ENABLE BIT(31) +#define RAR_CTRL_IGNORE_IF BIT(30) + #define MSR_MTRRcap 0x000000fe =20 #define MSR_IA32_ARCH_CAPABILITIES 0x0000010a --=20 2.49.0