From nobody Wed Dec 17 17:23:04 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 05F57C61DF4 for ; Fri, 24 Nov 2023 07:59:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345087AbjKXH7S (ORCPT ); Fri, 24 Nov 2023 02:59:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46424 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235132AbjKXH6i (ORCPT ); Fri, 24 Nov 2023 02:58:38 -0500 Received: from mgamail.intel.com (mgamail.intel.com [134.134.136.100]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BF1BE1710; Thu, 23 Nov 2023 23:58:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1700812724; x=1732348724; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=hoo4Iwqu83bRaL99m4ilvZ+WdOV6DreLDSnH/3fxOIs=; b=idHEpzN51+O7s0Wil+apR1RyXame7o6nVIkOi8n3PvFSY8bnZVHmFZe2 bMjPK8RQlLYpGBi8aB+WIj7kygbay63JKGL3zD/fpZMzQV+KwRi0UVN4m CWTwxLRxgVuitfj0TAbVOzlSmMehReDz0A41mkjQ26sxFsOWWqpAVqnmt 8EbBkBrXs86lhSJcIPXYF+emNcrA+wnVUUR1eU1X9aQy5KdkQpgiq5Ws+ FuspsKgO6gob6k2a0tLkC1zxxkcGBSLJz5p7Areytzr5nDJ7lFPmWZrpR zGEEuZ0Ml80RvBsyjUt8j1o4KpgHpT42k9A4wkPQpW4PCiqj8e9jZFcyJ w==; X-IronPort-AV: E=McAfee;i="6600,9927,10902"; a="458872319" X-IronPort-AV: E=Sophos;i="6.04,223,1695711600"; d="scan'208";a="458872319" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Nov 2023 23:58:38 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10902"; a="833629820" X-IronPort-AV: E=Sophos;i="6.04,223,1695711600"; d="scan'208";a="833629820" Received: from unknown (HELO embargo.jf.intel.com) ([10.165.9.183]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Nov 2023 23:58:38 -0800 From: Yang Weijiang To: seanjc@google.com, pbonzini@redhat.com, dave.hansen@intel.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: peterz@infradead.org, chao.gao@intel.com, rick.p.edgecombe@intel.com, mlevitsk@redhat.com, john.allen@amd.com, weijiang.yang@intel.com Subject: [PATCH v7 10/26] KVM: x86: Refine xsave-managed guest register/MSR reset handling Date: Fri, 24 Nov 2023 00:53:14 -0500 Message-Id: <20231124055330.138870-11-weijiang.yang@intel.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20231124055330.138870-1-weijiang.yang@intel.com> References: <20231124055330.138870-1-weijiang.yang@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Tweak the code a bit to facilitate resetting more xstate components in the future, e.g., adding CET's xstate-managed MSRs. No functional change intended. Signed-off-by: Yang Weijiang Reviewed-by: Maxim Levitsky --- arch/x86/kvm/x86.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index b9c2c0cd4cf5..16b4f2dd138a 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -12132,6 +12132,11 @@ void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu) static_branch_dec(&kvm_has_noapic_vcpu); } =20 +static inline bool is_xstate_reset_needed(void) +{ + return kvm_cpu_cap_has(X86_FEATURE_MPX); +} + void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) { struct kvm_cpuid_entry2 *cpuid_0x1; @@ -12189,7 +12194,7 @@ void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool ini= t_event) kvm_async_pf_hash_reset(vcpu); vcpu->arch.apf.halted =3D false; =20 - if (vcpu->arch.guest_fpu.fpstate && kvm_mpx_supported()) { + if (vcpu->arch.guest_fpu.fpstate && is_xstate_reset_needed()) { struct fpstate *fpstate =3D vcpu->arch.guest_fpu.fpstate; =20 /* @@ -12199,8 +12204,12 @@ void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool in= it_event) if (init_event) kvm_put_guest_fpu(vcpu); =20 - fpstate_clear_xstate_component(fpstate, XFEATURE_BNDREGS); - fpstate_clear_xstate_component(fpstate, XFEATURE_BNDCSR); + if (kvm_cpu_cap_has(X86_FEATURE_MPX)) { + fpstate_clear_xstate_component(fpstate, + XFEATURE_BNDREGS); + fpstate_clear_xstate_component(fpstate, + XFEATURE_BNDCSR); + } =20 if (init_event) kvm_load_guest_fpu(vcpu); --=20 2.27.0