From patchwork Sat May 9 11:05:39 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xiaoyao Li X-Patchwork-Id: 11537911 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7661015E6 for ; Sat, 9 May 2020 03:04:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6949724969 for ; Sat, 9 May 2020 03:04:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728787AbgEIDD7 (ORCPT ); Fri, 8 May 2020 23:03:59 -0400 Received: from mga12.intel.com ([192.55.52.136]:55127 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728718AbgEIDD5 (ORCPT ); Fri, 8 May 2020 23:03:57 -0400 IronPort-SDR: 6vXjjzZfwAWo6AH0Zqhyntqwqy38ZTfpXgpPOh61vsZj708UkI2iyIAT4nAgqo6rBDxL+P+SIc dMwYBstv8ScQ== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 May 2020 20:03:57 -0700 IronPort-SDR: IH3LtByqkiLmCjjX1nZJz2E2JCjchxKQZ7+/3LW8VOr8UgyRDKzILsAY+XQbuB5s3F1wZa3rVS bjGjBUsEVnWw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,370,1583222400"; d="scan'208";a="408311074" Received: from lxy-dell.sh.intel.com ([10.239.159.21]) by orsmga004.jf.intel.com with ESMTP; 08 May 2020 20:03:52 -0700 From: Xiaoyao Li To: Paolo Bonzini , Thomas Gleixner , Sean Christopherson , kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org, x86@kernel.org, Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , Andy Lutomirski , peterz@infradead.org, Arvind Sankar , Tony Luck , Fenghua Yu , Xiaoyao Li Subject: [PATCH v9 5/8] x86/kvm: Introduce paravirt split lock detection enumeration Date: Sat, 9 May 2020 19:05:39 +0800 Message-Id: <20200509110542.8159-6-xiaoyao.li@intel.com> X-Mailer: git-send-email 2.18.2 In-Reply-To: <20200509110542.8159-1-xiaoyao.li@intel.com> References: <20200509110542.8159-1-xiaoyao.li@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Introduce KVM_FEATURE_SPLIT_LOCK_DETECT, for which linux guest running on KVM can enumerate the avaliablility of feature split lock detection. Introduce KVM_HINTS_SLD_FATAL, which tells whether host is sld_fatal mode, i.e., whether split lock detection is forced on for guest vcpu. Signed-off-by: Xiaoyao Li --- Documentation/virt/kvm/cpuid.rst | 29 ++++++++++++++++++++-------- arch/x86/include/uapi/asm/kvm_para.h | 8 +++++--- 2 files changed, 26 insertions(+), 11 deletions(-) diff --git a/Documentation/virt/kvm/cpuid.rst b/Documentation/virt/kvm/cpuid.rst index 01b081f6e7ea..a7e85ac090a8 100644 --- a/Documentation/virt/kvm/cpuid.rst +++ b/Documentation/virt/kvm/cpuid.rst @@ -86,6 +86,12 @@ KVM_FEATURE_PV_SCHED_YIELD 13 guest checks this feature bit before using paravirtualized sched yield. +KVM_FEATURE_SPLIT_LOCK_DETECT 14 guest checks this feature bit for + available of split lock detection. + + KVM doesn't support enumerating + split lock detection via CPU model + KVM_FEATURE_CLOCSOURCE_STABLE_BIT 24 host will warn if no guest-side per-cpu warps are expeced in kvmclock @@ -97,11 +103,18 @@ KVM_FEATURE_CLOCSOURCE_STABLE_BIT 24 host will warn if no guest-side Where ``flag`` here is defined as below: -================== ============ ================================= -flag value meaning -================== ============ ================================= -KVM_HINTS_REALTIME 0 guest checks this feature bit to - determine that vCPUs are never - preempted for an unlimited time - allowing optimizations -================== ============ ================================= +================================ ============ ================================= +flag value meaning +================================ ============ ================================= +KVM_HINTS_REALTIME 0 guest checks this feature bit to + determine that vCPUs are never + preempted for an unlimited time + allowing optimizations + +KVM_HINTS_SLD_FATAL 1 set if split lock detection is + forced on in the host, in which + case KVM will kill the guest if it + generates a split lock #AC with + SLD disabled from guest's + perspective +================================ ============ ================================= diff --git a/arch/x86/include/uapi/asm/kvm_para.h b/arch/x86/include/uapi/asm/kvm_para.h index 2a8e0b6b9805..a8fe0221403a 100644 --- a/arch/x86/include/uapi/asm/kvm_para.h +++ b/arch/x86/include/uapi/asm/kvm_para.h @@ -31,14 +31,16 @@ #define KVM_FEATURE_PV_SEND_IPI 11 #define KVM_FEATURE_POLL_CONTROL 12 #define KVM_FEATURE_PV_SCHED_YIELD 13 - -#define KVM_HINTS_REALTIME 0 - +#define KVM_FEATURE_SPLIT_LOCK_DETECT 14 /* The last 8 bits are used to indicate how to interpret the flags field * in pvclock structure. If no bits are set, all flags are ignored. */ #define KVM_FEATURE_CLOCKSOURCE_STABLE_BIT 24 +/* KVM feature hints in CPUID.0x40000001.EDX */ +#define KVM_HINTS_REALTIME 0 +#define KVM_HINTS_SLD_FATAL 1 + #define MSR_KVM_WALL_CLOCK 0x11 #define MSR_KVM_SYSTEM_TIME 0x12