From patchwork Mon Jan 22 23:53:44 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Isaku Yamahata X-Patchwork-Id: 13526514 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.11]) (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 5DA476A03C; Mon, 22 Jan 2024 23:55:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.11 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705967760; cv=none; b=vFypBrdCUMnONIkjQdbRvDEp7Svm9n6mR+pAFNKCjzLL1+q2lNpymv2P1RLAIWEDtocInfYp3AgMRUvuTrnDvtWOxRhoq9/UnvIrqMTjv0IyE2MqGErJiPNHB1WrZes0R+7CcLPm31TwO3Jwa6Pf19hOgcrY2zgyL/2IIML296Y= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705967760; c=relaxed/simple; bh=KyvBdpiFNRaGh+RsOiKazFrH6itFyy3pSM+Er3VqRVQ=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Zsb9Z4rihPw8mVRwjhH3wOCpneKxQ8UOxa/uewt8fFJFlEF/pmfqLmlHzbHmByfLo/CDHzN/Fa5Qe6cX1lbZ4ek1VZZSPXirc67ruz6GNnc8XmdK/03ZV1naTInE2xDbDwNr9KbIPaXI61Rbj4EpdIhJS0AYRPedk42KkUpgWzs= 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=A4zp94tK; arc=none smtp.client-ip=198.175.65.11 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="A4zp94tK" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1705967759; x=1737503759; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=KyvBdpiFNRaGh+RsOiKazFrH6itFyy3pSM+Er3VqRVQ=; b=A4zp94tKuNsurC2u9psjHAePxR9z1hRB+MwfbTPaL2eNRPRi/KLEg+qN fncfWuxfVJtFT+ibS5u/oq1V7L9oKhqq8tmv6FHe9iuCP7ZueLMFF9+Kg 3XoT24851qwudcgpk9UcRhNVYdV+tWnLSUtHgYMjSwemchlD5px4mAoHM GwJqZj6jYhD0DaTh5ZjzHbzY/IkP/YSDX0BurFI2nqI1bq8jcuzDOXL55 YSXigaADgLk007E6A3jOUInBpYZuIcBZgl/vuOC1f7iyo8k5LwSWlzIWH Y6imran/LvMZC8T5AbwBGje/wqovYYrIdoDe2rTiPjhwNcj8BSgKhQbVa w==; X-IronPort-AV: E=McAfee;i="6600,9927,10961"; a="8016513" X-IronPort-AV: E=Sophos;i="6.05,212,1701158400"; d="scan'208";a="8016513" Received: from fmviesa004.fm.intel.com ([10.60.135.144]) by orvoesa103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Jan 2024 15:55:41 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.05,212,1701158400"; d="scan'208";a="1468243" Received: from ls.sc.intel.com (HELO localhost) ([172.25.112.31]) by fmviesa004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Jan 2024 15:55:39 -0800 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 , Kai Huang , chen.bo@intel.com, hang.yuan@intel.com, tina.zhang@intel.com Subject: [PATCH v18 068/121] KVM: TDX: vcpu_run: save/restore host state(host kernel gs) Date: Mon, 22 Jan 2024 15:53:44 -0800 Message-Id: <2b3077927e39a71d4b903a9a91f6bc58c354f31b.1705965635.git.isaku.yamahata@intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Isaku Yamahata On entering/exiting TDX vcpu, Preserved or clobbered CPU state is different from VMX case. Add TDX hooks to save/restore host/guest CPU state. Save/restore kernel GS base MSR. Signed-off-by: Isaku Yamahata Reviewed-by: Paolo Bonzini --- arch/x86/kvm/vmx/main.c | 30 +++++++++++++++++++++++++-- arch/x86/kvm/vmx/tdx.c | 42 ++++++++++++++++++++++++++++++++++++++ arch/x86/kvm/vmx/tdx.h | 4 ++++ arch/x86/kvm/vmx/x86_ops.h | 4 ++++ 4 files changed, 78 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c index 89ab8411500d..661d858a529e 100644 --- a/arch/x86/kvm/vmx/main.c +++ b/arch/x86/kvm/vmx/main.c @@ -173,6 +173,32 @@ static void vt_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) vmx_vcpu_reset(vcpu, init_event); } +static void vt_prepare_switch_to_guest(struct kvm_vcpu *vcpu) +{ + /* + * All host state is saved/restored across SEAMCALL/SEAMRET, and the + * guest state of a TD is obviously off limits. Deferring MSRs and DRs + * is pointless because the TDX module needs to load *something* so as + * not to expose guest state. + */ + if (is_td_vcpu(vcpu)) { + tdx_prepare_switch_to_guest(vcpu); + return; + } + + vmx_prepare_switch_to_guest(vcpu); +} + +static void vt_vcpu_put(struct kvm_vcpu *vcpu) +{ + if (is_td_vcpu(vcpu)) { + tdx_vcpu_put(vcpu); + return; + } + + vmx_vcpu_put(vcpu); +} + static int vt_vcpu_pre_run(struct kvm_vcpu *vcpu) { if (is_td_vcpu(vcpu)) @@ -308,9 +334,9 @@ struct kvm_x86_ops vt_x86_ops __initdata = { .vcpu_free = vt_vcpu_free, .vcpu_reset = vt_vcpu_reset, - .prepare_switch_to_guest = vmx_prepare_switch_to_guest, + .prepare_switch_to_guest = vt_prepare_switch_to_guest, .vcpu_load = vmx_vcpu_load, - .vcpu_put = vmx_vcpu_put, + .vcpu_put = vt_vcpu_put, .update_exception_bitmap = vmx_update_exception_bitmap, .get_msr_feature = vmx_get_msr_feature, diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c index 5a64ac4fd5fb..903f4abb3543 100644 --- a/arch/x86/kvm/vmx/tdx.c +++ b/arch/x86/kvm/vmx/tdx.c @@ -1,5 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 #include +#include #include @@ -468,6 +469,7 @@ u8 tdx_get_mt_mask(struct kvm_vcpu *vcpu, gfn_t gfn, bool is_mmio) int tdx_vcpu_create(struct kvm_vcpu *vcpu) { struct kvm_tdx *kvm_tdx = to_kvm_tdx(vcpu->kvm); + struct vcpu_tdx *tdx = to_tdx(vcpu); /* * On cpu creation, cpuid entry is blank. Forcibly enable @@ -496,9 +498,47 @@ int tdx_vcpu_create(struct kvm_vcpu *vcpu) if ((kvm_tdx->xfam & XFEATURE_MASK_XTILE) == XFEATURE_MASK_XTILE) vcpu->arch.xfd_no_write_intercept = true; + tdx->host_state_need_save = true; + tdx->host_state_need_restore = false; + return 0; } +void tdx_prepare_switch_to_guest(struct kvm_vcpu *vcpu) +{ + struct vcpu_tdx *tdx = to_tdx(vcpu); + + if (!tdx->host_state_need_save) + return; + + if (likely(is_64bit_mm(current->mm))) + tdx->msr_host_kernel_gs_base = current->thread.gsbase; + else + tdx->msr_host_kernel_gs_base = read_msr(MSR_KERNEL_GS_BASE); + + tdx->host_state_need_save = false; +} + +static void tdx_prepare_switch_to_host(struct kvm_vcpu *vcpu) +{ + struct vcpu_tdx *tdx = to_tdx(vcpu); + + tdx->host_state_need_save = true; + if (!tdx->host_state_need_restore) + return; + + ++vcpu->stat.host_state_reload; + + wrmsrl(MSR_KERNEL_GS_BASE, tdx->msr_host_kernel_gs_base); + tdx->host_state_need_restore = false; +} + +void tdx_vcpu_put(struct kvm_vcpu *vcpu) +{ + vmx_vcpu_pi_put(vcpu); + tdx_prepare_switch_to_host(vcpu); +} + void tdx_vcpu_free(struct kvm_vcpu *vcpu) { struct vcpu_tdx *tdx = to_tdx(vcpu); @@ -619,6 +659,8 @@ fastpath_t tdx_vcpu_run(struct kvm_vcpu *vcpu) tdx_vcpu_enter_exit(tdx); + tdx->host_state_need_restore = true; + vcpu->arch.regs_avail &= ~VMX_REGS_LAZY_LOAD_SET; trace_kvm_exit(vcpu, KVM_ISA_VMX); diff --git a/arch/x86/kvm/vmx/tdx.h b/arch/x86/kvm/vmx/tdx.h index 45b0b88a9b28..2d3119c60a14 100644 --- a/arch/x86/kvm/vmx/tdx.h +++ b/arch/x86/kvm/vmx/tdx.h @@ -67,6 +67,10 @@ struct vcpu_tdx { bool initialized; + bool host_state_need_save; + bool host_state_need_restore; + u64 msr_host_kernel_gs_base; + /* * Dummy to make pmu_intel not corrupt memory. * TODO: Support PMU for TDX. Future work. diff --git a/arch/x86/kvm/vmx/x86_ops.h b/arch/x86/kvm/vmx/x86_ops.h index 9061284487e8..aa434fc28bc4 100644 --- a/arch/x86/kvm/vmx/x86_ops.h +++ b/arch/x86/kvm/vmx/x86_ops.h @@ -151,6 +151,8 @@ int tdx_vcpu_create(struct kvm_vcpu *vcpu); void tdx_vcpu_free(struct kvm_vcpu *vcpu); void tdx_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event); fastpath_t tdx_vcpu_run(struct kvm_vcpu *vcpu); +void tdx_prepare_switch_to_guest(struct kvm_vcpu *vcpu); +void tdx_vcpu_put(struct kvm_vcpu *vcpu); u8 tdx_get_mt_mask(struct kvm_vcpu *vcpu, gfn_t gfn, bool is_mmio); int tdx_vcpu_ioctl(struct kvm_vcpu *vcpu, void __user *argp); @@ -179,6 +181,8 @@ static inline int tdx_vcpu_create(struct kvm_vcpu *vcpu) { return -EOPNOTSUPP; } static inline void tdx_vcpu_free(struct kvm_vcpu *vcpu) {} static inline void tdx_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) {} static inline fastpath_t tdx_vcpu_run(struct kvm_vcpu *vcpu) { return EXIT_FASTPATH_NONE; } +static inline void tdx_prepare_switch_to_guest(struct kvm_vcpu *vcpu) {} +static inline void tdx_vcpu_put(struct kvm_vcpu *vcpu) {} static inline u8 tdx_get_mt_mask(struct kvm_vcpu *vcpu, gfn_t gfn, bool is_mmio) { return 0; } static inline int tdx_vcpu_ioctl(struct kvm_vcpu *vcpu, void __user *argp) { return -EOPNOTSUPP; }