From nobody Sun Sep 7 12:22:22 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 E1EDACDB465 for ; Mon, 16 Oct 2023 16:40:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234560AbjJPQkC (ORCPT ); Mon, 16 Oct 2023 12:40:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38184 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234657AbjJPQjF (ORCPT ); Mon, 16 Oct 2023 12:39:05 -0400 Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.136]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E7CA2D7B; Mon, 16 Oct 2023 09:17:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1697473078; x=1729009078; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=NT/toe0FHcz1FOQ9+qlRYuaeKyHzTK7eQLgyvz4j05U=; b=nxFszrH2A8pEUvTAxjkcrpZuLztiHHygTaIKmlqZr25Vh9eS70wYJ+xE NsP1TasfprRPQVDGfIsQRaAJJ4Z8IZXf821V+Or/KWOc9FyvNLY1uHUZ6 LVqqQHk4RMm1N3SSbpVpn86aTeUZnt813AHheBhfBQ5iWYf0ascIAcgaY YUpGkCM6V2J4dwpoP3PxApr7R8KPlsyQF2m6U8d/8/+90M5MgHKvxZ4p7 g3ZrrFZecuBojEfspwWQBXb9oR/+rhc188B09bGHbw9Oq5nCcpBXD8/64 dEGmR+G910QVj+MnQrTlTFjF5IB1mQrLrqIQ/AtMiVtJOZ9Z24Bi56FgW Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10865"; a="364921881" X-IronPort-AV: E=Sophos;i="6.03,229,1694761200"; d="scan'208";a="364921881" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Oct 2023 09:15:52 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10865"; a="846448202" X-IronPort-AV: E=Sophos;i="6.03,229,1694761200"; d="scan'208";a="846448202" Received: from ls.sc.intel.com (HELO localhost) ([172.25.112.31]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Oct 2023 09:15:52 -0700 From: isaku.yamahata@intel.com To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: isaku.yamahata@intel.com, isaku.yamahata@gmail.com, Paolo Bonzini , erdemaktas@google.com, Sean Christopherson , Sagi Shahar , David Matlack , Kai Huang , Zhi Wang , chen.bo@intel.com, hang.yuan@intel.com, tina.zhang@intel.com, Yang Weijiang Subject: [PATCH v16 067/116] KVM: TDX: Add TSX_CTRL msr into uret_msrs list Date: Mon, 16 Oct 2023 09:14:19 -0700 Message-Id: <0766a33268fa66b6f5e582d659e184d4eeacc837.1697471314.git.isaku.yamahata@intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: 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" From: Yang Weijiang TDX module resets the TSX_CTRL MSR to 0 at TD exit if TSX is enabled for TD. Or it preserves the TSX_CTRL MSR if TSX is disabled for TD. VMM can rely on uret_msrs mechanism to defer the reload of host value until exiting to user space. Signed-off-by: Yang Weijiang Signed-off-by: Isaku Yamahata --- arch/x86/kvm/vmx/tdx.c | 33 +++++++++++++++++++++++++++++++-- arch/x86/kvm/vmx/tdx.h | 8 ++++++++ 2 files changed, 39 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c index 87ed1a255c3b..b5493d6c7cdd 100644 --- a/arch/x86/kvm/vmx/tdx.c +++ b/arch/x86/kvm/vmx/tdx.c @@ -521,14 +521,21 @@ static struct tdx_uret_msr tdx_uret_msrs[] =3D { {.msr =3D MSR_LSTAR,}, {.msr =3D MSR_TSC_AUX,}, }; +static unsigned int tdx_uret_tsx_ctrl_slot; =20 -static void tdx_user_return_update_cache(void) +static void tdx_user_return_update_cache(struct kvm_vcpu *vcpu) { int i; =20 for (i =3D 0; i < ARRAY_SIZE(tdx_uret_msrs); i++) kvm_user_return_update_cache(tdx_uret_msrs[i].slot, tdx_uret_msrs[i].defval); + /* + * TSX_CTRL is reset to 0 if guest TSX is supported. Otherwise + * preserved. + */ + if (to_kvm_tdx(vcpu->kvm)->tsx_supported && tdx_uret_tsx_ctrl_slot !=3D -= 1) + kvm_user_return_update_cache(tdx_uret_tsx_ctrl_slot, 0); } =20 static void tdx_restore_host_xsave_state(struct kvm_vcpu *vcpu) @@ -623,7 +630,7 @@ fastpath_t tdx_vcpu_run(struct kvm_vcpu *vcpu) =20 tdx_vcpu_enter_exit(tdx); =20 - tdx_user_return_update_cache(); + tdx_user_return_update_cache(vcpu); tdx_restore_host_xsave_state(vcpu); tdx->host_state_need_restore =3D true; =20 @@ -1167,6 +1174,22 @@ static int setup_tdparams_xfam(struct kvm_cpuid2 *cp= uid, struct td_params *td_pa return 0; } =20 +static bool tdparams_tsx_supported(struct kvm_cpuid2 *cpuid) +{ + const struct kvm_cpuid_entry2 *entry; + u64 mask; + u32 ebx; + + entry =3D kvm_find_cpuid_entry2(cpuid->entries, cpuid->nent, 0x7, 0); + if (entry) + ebx =3D entry->ebx; + else + ebx =3D 0; + + mask =3D __feature_bit(X86_FEATURE_HLE) | __feature_bit(X86_FEATURE_RTM); + return ebx & mask; +} + static int setup_tdparams(struct kvm *kvm, struct td_params *td_params, struct kvm_tdx_init_vm *init_vm) { @@ -1212,6 +1235,7 @@ static int setup_tdparams(struct kvm *kvm, struct td_= params *td_params, MEMCPY_SAME_SIZE(td_params->mrowner, init_vm->mrowner); MEMCPY_SAME_SIZE(td_params->mrownerconfig, init_vm->mrownerconfig); =20 + to_kvm_tdx(kvm)->tsx_supported =3D tdparams_tsx_supported(cpuid); return 0; } =20 @@ -1875,6 +1899,11 @@ int __init tdx_hardware_setup(struct kvm_x86_ops *x8= 6_ops) return -EIO; } } + tdx_uret_tsx_ctrl_slot =3D kvm_find_user_return_msr(MSR_IA32_TSX_CTRL); + if (tdx_uret_tsx_ctrl_slot =3D=3D -1 && boot_cpu_has(X86_FEATURE_MSR_TSX_= CTRL)) { + pr_err("MSR_IA32_TSX_CTRL isn't included by kvm_find_user_return_msr\n"); + return -EIO; + } =20 max_pkgs =3D topology_max_packages(); tdx_mng_key_config_lock =3D kcalloc(max_pkgs, sizeof(*tdx_mng_key_config_= lock), diff --git a/arch/x86/kvm/vmx/tdx.h b/arch/x86/kvm/vmx/tdx.h index 610bd3f4e952..45f5c2744d78 100644 --- a/arch/x86/kvm/vmx/tdx.h +++ b/arch/x86/kvm/vmx/tdx.h @@ -17,6 +17,14 @@ struct kvm_tdx { u64 xfam; int hkid; =20 + /* + * Used on each TD-exit, see tdx_user_return_update_cache(). + * TSX_CTRL value on TD exit + * - set 0 if guest TSX enabled + * - preserved if guest TSX disabled + */ + bool tsx_supported; + hpa_t source_pa; =20 bool finalized; --=20 2.25.1