From patchwork Wed Jan 29 09:58:51 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Adrian Hunter X-Patchwork-Id: 13953581 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.12]) (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 D41741AE005; Wed, 29 Jan 2025 09:59:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.12 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738144793; cv=none; b=XyY5n03K/RFoP+8KgR2bchnrpTVnlD9F2agb5QD1o1fMv7bKu5gFJJZUS7J2TA1/3CWmY0ymWQN613QOnp63RGAudDyJ348KJF0P1YJmG/iRRo9CqjFRPq+AICJEnLf+ygOW1iKmVf4TLggKTK5zW8r9dh+CMjF7VNkoift9Bho= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738144793; c=relaxed/simple; bh=n+Q6EGUmpUH8fNKUFT8UiTcL8EopaupqREmb3UuQXPo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=L211SR77Rm494HsptHG4IZzXyNuJXUXjvaULHeWtZj+xLRGlObhjjunt5RJQ8v/lUo4XCZFX+Au0FgHGqKfhYzyW9T4kvIzEpw1TMGEHBzhsBolAUeQi4kW4qKvsBqMFgbwShyWv1aadYLrpWULuAsdugjkj8saeVSPiBoEj5l4= 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=AmXsVM7I; arc=none smtp.client-ip=198.175.65.12 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="AmXsVM7I" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1738144792; x=1769680792; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=n+Q6EGUmpUH8fNKUFT8UiTcL8EopaupqREmb3UuQXPo=; b=AmXsVM7IUEPBVEuEvSMpVFomL5MgOJILoa9DFgSxyxjhUufZgep3Hm8Z Lijn6SyT+TOS/H+aYxvx5RE/h1u3hcL3qXXNiN1NPXEBrKXpjPROpsbBA pDYk0NPvholX65bAyIRX2IWjKSYD0/j9rZay42tYpJ3rtiPOuYQ/ir421 aFEz1OiZzyXLHo1gKwL0ZYPS6id4/w/s0qtQ2VUEsrJZvtdkp7ZGQmwva bAI7aIkJOgIfmcCQI5Kfwr371tECY+W3iGXnpqop+G5V/uZU15QHCrUTG +lda1KnF6SW3O5XSQ+CnnDZm7rgP6LDzX+2d29PmDy6RVszpKO5OHCZZe A==; X-CSE-ConnectionGUID: 7xeyoXgqTVWfkUzUIJWWLA== X-CSE-MsgGUID: HOan9eIdSyOWtB0Ws6GqWw== X-IronPort-AV: E=McAfee;i="6700,10204,11329"; a="50035991" X-IronPort-AV: E=Sophos;i="6.13,243,1732608000"; d="scan'208";a="50035991" Received: from fmviesa002.fm.intel.com ([10.60.135.142]) by orvoesa104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Jan 2025 01:59:29 -0800 X-CSE-ConnectionGUID: 94/HuDFFR3m9H4ywczsHqQ== X-CSE-MsgGUID: m3EY/jQ0RLSAZ1+0RGMEYg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.12,224,1728975600"; d="scan'208";a="132262652" Received: from ahunter6-mobl1.ger.corp.intel.com (HELO ahunter-VirtualBox.ger.corp.intel.com) ([10.246.0.178]) by fmviesa002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Jan 2025 01:59:25 -0800 From: Adrian Hunter To: pbonzini@redhat.com, seanjc@google.com Cc: kvm@vger.kernel.org, rick.p.edgecombe@intel.com, kai.huang@intel.com, adrian.hunter@intel.com, reinette.chatre@intel.com, xiaoyao.li@intel.com, tony.lindgren@linux.intel.com, binbin.wu@linux.intel.com, dmatlack@google.com, isaku.yamahata@intel.com, nik.borisov@suse.com, linux-kernel@vger.kernel.org, yan.y.zhao@intel.com, chao.gao@intel.com, weijiang.yang@intel.com Subject: [PATCH V2 02/12] KVM: x86: Allow the use of kvm_load_host_xsave_state() with guest_state_protected Date: Wed, 29 Jan 2025 11:58:51 +0200 Message-ID: <20250129095902.16391-3-adrian.hunter@intel.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250129095902.16391-1-adrian.hunter@intel.com> References: <20250129095902.16391-1-adrian.hunter@intel.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki From: Sean Christopherson Allow the use of kvm_load_host_xsave_state() with vcpu->arch.guest_state_protected == true. This will allow TDX to reuse kvm_load_host_xsave_state() instead of creating its own version. For consistency, amend kvm_load_guest_xsave_state() also. Ensure that guest state that kvm_load_host_xsave_state() depends upon, such as MSR_IA32_XSS, cannot be changed by user space, if guest_state_protected. [Adrian: wrote commit message] Link: https://lore.kernel.org/r/Z2GiQS_RmYeHU09L@google.com Signed-off-by: Sean Christopherson Signed-off-by: Adrian Hunter --- TD vcpu enter/exit v2: - New patch --- arch/x86/kvm/svm/svm.c | 7 +++++-- arch/x86/kvm/x86.c | 18 +++++++++++------- 2 files changed, 16 insertions(+), 9 deletions(-) diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 7640a84e554a..b4bcfe15ad5e 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -4253,7 +4253,9 @@ static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu, svm_set_dr6(svm, DR6_ACTIVE_LOW); clgi(); - kvm_load_guest_xsave_state(vcpu); + + if (!vcpu->arch.guest_state_protected) + kvm_load_guest_xsave_state(vcpu); kvm_wait_lapic_expire(vcpu); @@ -4282,7 +4284,8 @@ static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu, if (unlikely(svm->vmcb->control.exit_code == SVM_EXIT_NMI)) kvm_before_interrupt(vcpu, KVM_HANDLING_NMI); - kvm_load_host_xsave_state(vcpu); + if (!vcpu->arch.guest_state_protected) + kvm_load_host_xsave_state(vcpu); stgi(); /* Any pending NMI will happen here */ diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index bbb6b7f40b3a..5cf9f023fd4b 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1169,11 +1169,9 @@ EXPORT_SYMBOL_GPL(kvm_lmsw); void kvm_load_guest_xsave_state(struct kvm_vcpu *vcpu) { - if (vcpu->arch.guest_state_protected) - return; + WARN_ON_ONCE(vcpu->arch.guest_state_protected); if (kvm_is_cr4_bit_set(vcpu, X86_CR4_OSXSAVE)) { - if (vcpu->arch.xcr0 != kvm_host.xcr0) xsetbv(XCR_XFEATURE_ENABLED_MASK, vcpu->arch.xcr0); @@ -1192,13 +1190,11 @@ EXPORT_SYMBOL_GPL(kvm_load_guest_xsave_state); void kvm_load_host_xsave_state(struct kvm_vcpu *vcpu) { - if (vcpu->arch.guest_state_protected) - return; - if (cpu_feature_enabled(X86_FEATURE_PKU) && ((vcpu->arch.xcr0 & XFEATURE_MASK_PKRU) || kvm_is_cr4_bit_set(vcpu, X86_CR4_PKE))) { - vcpu->arch.pkru = rdpkru(); + if (!vcpu->arch.guest_state_protected) + vcpu->arch.pkru = rdpkru(); if (vcpu->arch.pkru != vcpu->arch.host_pkru) wrpkru(vcpu->arch.host_pkru); } @@ -3916,6 +3912,10 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) if (!msr_info->host_initiated && !guest_cpuid_has(vcpu, X86_FEATURE_XSAVES)) return 1; + + if (vcpu->arch.guest_state_protected) + return 1; + /* * KVM supports exposing PT to the guest, but does not support * IA32_XSS[bit 8]. Guests have to use RDMSR/WRMSR rather than @@ -4375,6 +4375,10 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) if (!msr_info->host_initiated && !guest_cpuid_has(vcpu, X86_FEATURE_XSAVES)) return 1; + + if (vcpu->arch.guest_state_protected) + return 1; + msr_info->data = vcpu->arch.ia32_xss; break; case MSR_K7_CLK_CTL: