From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.17]) (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 D9C2642AFA7; Thu, 6 Aug 2026 11:24:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.17 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786015470; cv=none; b=A3V56TTrGBF9BtLUYR/Zan0gEDIU2sTTQ/bwXisANISIbk6+gFwp9C2w/hqVTPdU8HCqhdo5e4SEdR/0Ok2k06YQ0ZglLUYnuqSNSogJL3LyWR1hbQ09mmuJaoYHYjer/gzcgcvBLN61wxQ4zgKbpfv7TXm3NikB/HdKTYFQS14= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786015470; c=relaxed/simple; bh=OyIh6aMTzBARNySVPQ7G1lgNnAHsMqs1DMU0W7y+f5U=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=r9MLy9X12tj1oSCBwQv32ovxCrTwl7hO98uLIW09nnOPCA2XR3w4OvgkxpvpSRvJrGqs7Pm/Z0JdSbMRxAV7hdz3mzfISzGguVmcknqVEWlPcYXTrvhLzTpud63Cs3PlS7XUUxqrxHmWaPY/9K/X55GHsIuKuuPQDzjG5j9jE5A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=bbdeI7nL; arc=none smtp.client-ip=198.175.65.17 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="bbdeI7nL" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1786015469; x=1817551469; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=OyIh6aMTzBARNySVPQ7G1lgNnAHsMqs1DMU0W7y+f5U=; b=bbdeI7nLRCqn/rBcFHsntcm1/Bxqe/UpV9AK7XgPsT/+vWKV1Z+U99M5 /OvtpzZYNPSvcTVom8WykRY5E1ryKWExH7mj+7Zr9cCAbIghjl1JDWFjL 2H+up/XV7QdO3sCVRBr1RFC/x2E5dOl4DvQbjBVI+MNGg3KU34RX4ODZz ZEsCnggOaQ9OiMZYi4C8BT5LFcOBAfkjBCklgOCFpid4sTWF9/GkZfGLj 3jWKnPEOMPBcnzAYF1537z9lfgwuUcVlzNuiKML9/hg5Cc3yXyZOhY9nj QfbJzAPse6I3n31v+OXu3lt95EHI3veSMPbh2ZtByjC88oo+PSmbKVD7t g==; X-CSE-ConnectionGUID: TE03s/bfQx2wCv0MMKi8Og== X-CSE-MsgGUID: CeVWgc7hQdGMJU5tRTXa5w== X-IronPort-AV: E=McAfee;i="6800,10657,11866"; a="86617200" X-IronPort-AV: E=Sophos;i="6.25,208,1779174000"; d="scan'208";a="86617200" Received: from fmviesa005.fm.intel.com ([10.60.135.145]) by orvoesa109.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Aug 2026 04:24:28 -0700 X-CSE-ConnectionGUID: lWp+ZP4PTx+/lClfzlMaxQ== X-CSE-MsgGUID: L+5hv8UxTG2pvq2w+BTXbQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.25,208,1779174000"; d="scan'208";a="267225064" Received: from lxy-clx-4s.sh.intel.com ([10.239.48.33]) by fmviesa005.fm.intel.com with ESMTP; 06 Aug 2026 04:24:27 -0700 From: Xiaoyao Li To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, xiaoyao.li@intel.com Subject: [PATCH 2/3] KVM: x86: Reject enabling KVM_CAP_X86_BUS_LOCK_EXIT when !kvm_caps.has_bus_lock_exit Date: Thu, 6 Aug 2026 19:19:22 +0800 Message-ID: <20260806111923.1990562-3-xiaoyao.li@intel.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260806111923.1990562-1-xiaoyao.li@intel.com> References: <20260806111923.1990562-1-xiaoyao.li@intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Return -EINVAL to reject the enabling of KVM_CAP_X86_BUS_LOCK_EXIT from userspace when kvm_caps.has_bus_lock_exit is false. For KVM_BUS_LOCK_DETECTION_EXIT, if KVM doesn't support BUS LOCK EXIT, return error to userspace instead of success. For KVM_BUS_LOCK_DETECTION_OFF, it seems OK to allow it when KVM doesn't support bus_lock_exit. But from an API perspective, it implies inconsistency that KVM_CAP_X86_BUS_LOCK_EXIT reports 0 but setting KVM_BUS_LOCK_DETECTION_OFF is allowed. To keep it consistent, also return error for KVM_BUS_LOCK_DETECTION_OFF when KVM doesn't support BUS LOCK EXIT. Fixes: fe6b6bc802b4 ("KVM: VMX: Enable bus lock VM exit") Signed-off-by: Xiaoyao Li --- --- arch/x86/kvm/x86.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index d94b59140c45..3d8422d1cd04 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4058,8 +4058,10 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm, (cap->args[0] & KVM_BUS_LOCK_DETECTION_EXIT)) break; - if (kvm_caps.has_bus_lock_exit && - cap->args[0] & KVM_BUS_LOCK_DETECTION_EXIT) + if (!kvm_caps.has_bus_lock_exit) + break; + + if (cap->args[0] & KVM_BUS_LOCK_DETECTION_EXIT) kvm->arch.bus_lock_detection_enabled = true; r = 0; break; -- 2.43.0