From nobody Wed Dec 24 21:49:50 2025 Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.120]) (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 CAC46171BC; Wed, 24 Jan 2024 02:42:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.55.52.120 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706064161; cv=none; b=AhAZ8YpcKlUrH8BU8kq4v7E01JpX10M8otlCPOTYD1UsiKH6ixnXFgWJ4riH9UgOHtlqIKe32Ffxn1Ed5jBJ0alY0m7NvLkhNSDeQTG34ybRwyrdC6iY2VGTr6BicxtKMcIQU+ed5K/HROCJ0NiXkFEl5wVPDY2QyIgge4qC/hM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706064161; c=relaxed/simple; bh=cxpPX3Wn0VREKtBeuHc/MZkj33xyM0sqH6UvdE/wBRo=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=T/bpQ2Oq51itYJDTgjul5LlKMC08SDBTmFcf9CWE1eJ02yX6DerK18H1yKipuwvIWoeFHhkudW2cmJ1nIvOflsvO6Xb0DpeOm3E6RspZZ3pyo6OapaERN2IuXJBPaKN73LOrCdrlhjbHfqX4nrKxBIAaFy1EWWYeIKkkJKMUjus= 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=jzIb/tY7; arc=none smtp.client-ip=192.55.52.120 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="jzIb/tY7" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1706064159; x=1737600159; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=cxpPX3Wn0VREKtBeuHc/MZkj33xyM0sqH6UvdE/wBRo=; b=jzIb/tY7JY9v72xklDRzq6stw171yM3YJ5nXSAYV9G0enQNgUIvFBKtP AyOtGxxbqekdBKOtVoxU4auKKNWpi/616w404wtiwnkaFanvy9I17BqGN yBgHnRRUY4dwGDGcTuBIr55A2x8jRzNUZ01NtoRfN2206o9x4rhDJdtv5 fKfhjK5F+ir3wm/OgoGzwK1fdTyR9N6tQVwaTLinq2aPCc4+Aqvs6x00e +uYeEhYiBPBVjWNd2H1ZNHCP66T8BBWF13ZEycWjJDHiU5mH0ScRepCWr KCSpmqplOj6PzcDzFXcI5KJYbTm1FXYgsPLemNj8dilsPiayaNFTkRX8/ w==; X-IronPort-AV: E=McAfee;i="6600,9927,10962"; a="400586478" X-IronPort-AV: E=Sophos;i="6.05,215,1701158400"; d="scan'208";a="400586478" Received: from fmviesa003.fm.intel.com ([10.60.135.143]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Jan 2024 18:42:35 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.05,215,1701158400"; d="scan'208";a="1825855" Received: from 984fee00a5ca.jf.intel.com ([10.165.9.183]) by fmviesa003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Jan 2024 18:42:35 -0800 From: Yang Weijiang To: seanjc@google.com, pbonzini@redhat.com, dave.hansen@intel.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org, yuan.yao@linux.intel.com 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 v9 10/27] KVM: x86: Refine xsave-managed guest register/MSR reset handling Date: Tue, 23 Jan 2024 18:41:43 -0800 Message-Id: <20240124024200.102792-11-weijiang.yang@intel.com> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20240124024200.102792-1-weijiang.yang@intel.com> References: <20240124024200.102792-1-weijiang.yang@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: quoted-printable 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 0e7dc3398293..3671f4868d1b 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -12205,6 +12205,11 @@ 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; @@ -12262,7 +12267,7 @@ 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 /* @@ -12272,8 +12277,12 @@ 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 2.39.3