From patchwork Fri Dec 17 15:29:49 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jing Liu X-Patchwork-Id: 12685101 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 567ABC433EF for ; Fri, 17 Dec 2021 15:30:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238291AbhLQPaM (ORCPT ); Fri, 17 Dec 2021 10:30:12 -0500 Received: from mga03.intel.com ([134.134.136.65]:10852 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238222AbhLQPaG (ORCPT ); Fri, 17 Dec 2021 10:30:06 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1639755006; x=1671291006; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=Oudfdu6myNVjvoNfDhIoilt+uJCzFGHVxT+rvDPYbcw=; b=j1iwBUDiQL47pNPKRKxemujDYKX8ixqVtUDU/muQG1MQOwMANr/JzB25 jRf4GSlYXJapWKWqGdeBL/4ECdZy/wM6jQIzwuYNMxudU+I1pQRQtgPgB LxdJawtyl7EklzexfnzpkDxZLBm6tFNQItu6g4KVYphlhUGxEKsWR1ln2 b86/AIL9vk8lrgS7AFY4wFOWwnHFnqURaa9tZCUNnQ7h3EoSBbU69Xy6/ Vz7Dxer6if224LFqLbe7y9VWvsBeqtEJag0Bk7fhApmupc/q7Nrzuig3v 97yOlOfs7e4Rxl9C3S97JBY35N1N7W0obpIP/i1rliyXqdtLdyDLABbOg g==; X-IronPort-AV: E=McAfee;i="6200,9189,10200"; a="239723447" X-IronPort-AV: E=Sophos;i="5.88,213,1635231600"; d="scan'208";a="239723447" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Dec 2021 07:30:05 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.88,213,1635231600"; d="scan'208";a="615588422" Received: from 984fee00a228.jf.intel.com ([10.165.56.59]) by orsmga004.jf.intel.com with ESMTP; 17 Dec 2021 07:30:04 -0800 From: Jing Liu To: x86@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, pbonzini@redhat.com Cc: seanjc@google.com, jun.nakajima@intel.com, kevin.tian@intel.com, jing2.liu@linux.intel.com, jing2.liu@intel.com, guang.zeng@intel.com, wei.w.wang@intel.com, yang.zhong@intel.com Subject: [PATCH v2 09/23] kvm: x86: Enable dynamic XSAVE features at KVM_SET_CPUID2 Date: Fri, 17 Dec 2021 07:29:49 -0800 Message-Id: <20211217153003.1719189-10-jing2.liu@intel.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20211217153003.1719189-1-jing2.liu@intel.com> References: <20211217153003.1719189-1-jing2.liu@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Statically enable all xfeatures allowed by guest perm in KVM_SET_CPUID2, with fpstate buffer sized accordingly. This avoids run-time expansion in the emulation and restore path of XCR0 and XFD MSR [1]. Change kvm_vcpu_after_set_cpuid() to return error given fpstate reallocation may fail. [1] https://lore.kernel.org/all/20211214024948.048572883@linutronix.de/ Suggested-by: Thomas Gleixner Suggested-by: Paolo Bonzini Signed-off-by: Jing Liu --- arch/x86/kvm/cpuid.c | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index a068373a7fbd..eb5a5070accb 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -204,10 +204,12 @@ void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu) } EXPORT_SYMBOL_GPL(kvm_update_cpuid_runtime); -static void kvm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu) +static int kvm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu) { struct kvm_lapic *apic = vcpu->arch.apic; struct kvm_cpuid_entry2 *best; + u64 xfeatures; + int r; best = kvm_find_cpuid_entry(vcpu, 1, 0); if (best && apic) { @@ -222,9 +224,17 @@ static void kvm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu) best = kvm_find_cpuid_entry(vcpu, 0xD, 0); if (!best) vcpu->arch.guest_supported_xcr0 = 0; - else - vcpu->arch.guest_supported_xcr0 = - (best->eax | ((u64)best->edx << 32)) & supported_xcr0; + else { + xfeatures = best->eax | ((u64)best->edx << 32); + + vcpu->arch.guest_supported_xcr0 = xfeatures & supported_xcr0; + + if (xfeatures != vcpu->arch.guest_fpu.xfeatures) { + r = fpu_update_guest_perm_features(&vcpu->arch.guest_fpu); + if (r) + return r; + } + } /* * Bits 127:0 of the allowed SECS.ATTRIBUTES (CPUID.0x12.0x1) enumerate @@ -260,6 +270,8 @@ static void kvm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu) * adjustments to the reserved GPA bits. */ kvm_mmu_after_set_cpuid(vcpu); + + return 0; } int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu) @@ -301,9 +313,7 @@ static int kvm_set_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *e2, kvm_update_kvm_cpuid_base(vcpu); kvm_update_cpuid_runtime(vcpu); - kvm_vcpu_after_set_cpuid(vcpu); - - return 0; + return kvm_vcpu_after_set_cpuid(vcpu); } /* when an old userspace process fills a new kernel module */