From nobody Thu Nov 28 14:54:14 2024 Received: from mail.zytor.com (terminus.zytor.com [198.137.202.136]) (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 865551BBBFC; Tue, 1 Oct 2024 05:02:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.136 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727758940; cv=none; b=j1ZHHRt0xgFHb7wFsBwTVYt7w+5H1oGi5ALKPCEUWizR8HHjl7sFH3R6aU9OsbbKGJXCyk3eNuQY/MPwa1RZcdFzyeASGyF+/hECmI/xwPjI2Lb/bePIb5ckhFwdMyVND9FwJAyhThLGCgesEgEF88Cajso52qUXIzpoVpkbA28= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727758940; c=relaxed/simple; bh=8NwOtEgXFXbccpyKBCaKNF/+A8akEbIhiKyud8HIOrY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=TRxebXvP6cnVihgALfsdSGJeRtszfTQsJhYS5rioY6JL7xqLC6/JTnGhae7KboQ1cXDanktYqL2jWfTHwEBw1hQWw98p03QFMiyKutfGSpY7uoLMpGtm3k8djiMP23hdGJQK7lBvgkJ/9fJcmfv9B98xTkEHKdlCYQQtn47L6bk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com; spf=pass smtp.mailfrom=zytor.com; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b=HKYM0QUV; arc=none smtp.client-ip=198.137.202.136 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zytor.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b="HKYM0QUV" Received: from terminus.zytor.com (terminus.zytor.com [IPv6:2607:7c80:54:3:0:0:0:136]) (authenticated bits=0) by mail.zytor.com (8.18.1/8.17.1) with ESMTPSA id 49151A7j3643828 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Mon, 30 Sep 2024 22:01:35 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 49151A7j3643828 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2024091601; t=1727758896; bh=sULUFEzl3r3MZGUBZyiAQe7f5ktOY3K1CWLQ4Ja4sN8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HKYM0QUV2DyCIgCdDwErfc+MbiGCsL4o0o0sFKYSfZr+Nt/8pIYVdw2OZMm81W4/d AR/vRseg3sBf9FtrTlGviT9AUnjr1IycMu8mWTNFfteP6ue6Csrpd9RWFiQpxyhTh6 +PzUlaZv37Jly9EJWgwXwkqbn1fi6j11nbcTj88zG9QLo4zuntXQxoT5lBK9RdksU4 TlyukvBkamMdzZNS03P0kLoj6mI7lIhaeMbpmFhlXdDv/5t94IKRNBln8thDS4vNmr mQOTnImZT60ooIGnxwyuIMQ2RAQPBnirBpaUBk7C+ue2N/AkgzY97k1YfMhAmihcRS o+Zjifa1IpVDw== From: "Xin Li (Intel)" To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org Cc: seanjc@google.com, pbonzini@redhat.com, corbet@lwn.net, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, luto@kernel.org, peterz@infradead.org, andrew.cooper3@citrix.com, xin@zytor.com Subject: [PATCH v3 20/27] KVM: x86: Allow WRMSRNS to be advertised to guests Date: Mon, 30 Sep 2024 22:01:03 -0700 Message-ID: <20241001050110.3643764-21-xin@zytor.com> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241001050110.3643764-1-xin@zytor.com> References: <20241001050110.3643764-1-xin@zytor.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: Xin Li Allow WRMSRNS to be advertised to guests. WRMSRNS behaves exactly like WRMSR with the only difference being that it is not a serializing instruction by default. It improves performance when being used in a hot path, e.g., setting FRED RSP0. Signed-off-by: Xin Li Signed-off-by: Xin Li (Intel) Tested-by: Shan Kang --- arch/x86/kvm/cpuid.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index c55d150ece8d..63a78ebf9482 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -700,7 +700,7 @@ void kvm_set_cpu_caps(void) kvm_cpu_cap_mask(CPUID_7_1_EAX, F(AVX_VNNI) | F(AVX512_BF16) | F(CMPCCXADD) | F(FZRM) | F(FSRS) | F(FSRC) | F(FRED) | F(LKGS) | - F(AMX_FP16) | F(AVX_IFMA) | F(LAM) + F(WRMSRNS) | F(AMX_FP16) | F(AVX_IFMA) | F(LAM) ); =20 kvm_cpu_cap_init_kvm_defined(CPUID_7_1_EDX, --=20 2.46.2