From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 64CDBC4727F for ; Thu, 1 Oct 2020 13:06:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0CC3020B1F for ; Thu, 1 Oct 2020 13:06:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="QYMELtic" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732301AbgJANGN (ORCPT ); Thu, 1 Oct 2020 09:06:13 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:42255 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731952AbgJANF6 (ORCPT ); Thu, 1 Oct 2020 09:05:58 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1601557556; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=EML2yVy00qzvw0yduBf60TTMc1E88Fj3kk+iIdNVqTo=; b=QYMELtichj9IhxeqWePcXsB1A0k7qJL51cGhLa2M8jvsb9olB44COVTvmz5iJXsQ+CLv8j PvxKPP93Jz4MNp5mbZN4HoivPypLb0q0WXvW4Vdggkh0lWpDMqL5+4R1vEC3GZpvDpVqaX /SViakn7/i89W8gaI2LXrm3r3Sb+IZ4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-296-VpXeiEgiNvOn3_liXVOkpQ-1; Thu, 01 Oct 2020 09:05:54 -0400 X-MC-Unique: VpXeiEgiNvOn3_liXVOkpQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 907EA18C5201; Thu, 1 Oct 2020 13:05:53 +0000 (UTC) Received: from vitty.brq.redhat.com (unknown [10.40.195.161]) by smtp.corp.redhat.com (Postfix) with ESMTP id 42EE45C1CF; Thu, 1 Oct 2020 13:05:51 +0000 (UTC) From: Vitaly Kuznetsov To: kvm@vger.kernel.org, Paolo Bonzini Cc: Sean Christopherson , Wanpeng Li , Jim Mattson , "Dr . David Alan Gilbert" , Wei Huang , linux-kernel@vger.kernel.org Subject: [PATCH 2/3] KVM: x86: allocate vcpu->arch.cpuid_entries dynamically Date: Thu, 1 Oct 2020 15:05:40 +0200 Message-Id: <20201001130541.1398392-3-vkuznets@redhat.com> In-Reply-To: <20201001130541.1398392-1-vkuznets@redhat.com> References: <20201001130541.1398392-1-vkuznets@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The current limit for guest CPUID leaves (KVM_MAX_CPUID_ENTRIES, 80) is reported to be insufficient but before we bump it let's switch to allocating vcpu->arch.cpuid_entries[] array dynamically. Currently, 'struct kvm_cpuid_entry2' is 40 bytes so vcpu->arch.cpuid_entries is 3200 bytes which accounts for 1/4 of the whole 'struct kvm_vcpu_arch' but having it pre-allocated (for all vCPUs which we also pre-allocate) gives us no real benefits. Another plus of the dynamic allocation is that we now do kvm_check_cpuid() check before we assign anything to vcpu->arch.cpuid_nent/cpuid_entries so no changes are made in case the check fails. Opportunistically remove unneeded 'out' labels from kvm_vcpu_ioctl_set_cpuid()/kvm_vcpu_ioctl_set_cpuid2() and return directly whenever possible. Signed-off-by: Vitaly Kuznetsov --- arch/x86/include/asm/kvm_host.h | 2 +- arch/x86/kvm/cpuid.c | 89 +++++++++++++++++++-------------- arch/x86/kvm/x86.c | 1 + 3 files changed, 53 insertions(+), 39 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index d0f77235da92..7d259e21ea04 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -637,7 +637,7 @@ struct kvm_vcpu_arch { int halt_request; /* real mode on Intel only */ int cpuid_nent; - struct kvm_cpuid_entry2 cpuid_entries[KVM_MAX_CPUID_ENTRIES]; + struct kvm_cpuid_entry2 *cpuid_entries; int maxphyaddr; int max_tdp_level; diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 529348ddedc1..3fe20c4da0a6 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -210,46 +210,53 @@ int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry __user *entries) { int r, i; - struct kvm_cpuid_entry *cpuid_entries = NULL; + struct kvm_cpuid_entry *e = NULL; + struct kvm_cpuid_entry2 *e2 = NULL; - r = -E2BIG; if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) - goto out; + return -E2BIG; + if (cpuid->nent) { - cpuid_entries = vmemdup_user(entries, - array_size(sizeof(struct kvm_cpuid_entry), - cpuid->nent)); - if (IS_ERR(cpuid_entries)) { - r = PTR_ERR(cpuid_entries); - goto out; + e = vmemdup_user(entries, array_size(sizeof(*e), cpuid->nent)); + if (IS_ERR(e)) + return PTR_ERR(e); + + e2 = kvmalloc_array(cpuid->nent, sizeof(*e2), GFP_KERNEL_ACCOUNT); + if (!e2) { + r = -ENOMEM; + goto out_free_cpuid; } } for (i = 0; i < cpuid->nent; i++) { - vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function; - vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax; - vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx; - vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx; - vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx; - vcpu->arch.cpuid_entries[i].index = 0; - vcpu->arch.cpuid_entries[i].flags = 0; - vcpu->arch.cpuid_entries[i].padding[0] = 0; - vcpu->arch.cpuid_entries[i].padding[1] = 0; - vcpu->arch.cpuid_entries[i].padding[2] = 0; + e2[i].function = e[i].function; + e2[i].eax = e[i].eax; + e2[i].ebx = e[i].ebx; + e2[i].ecx = e[i].ecx; + e2[i].edx = e[i].edx; + e2[i].index = 0; + e2[i].flags = 0; + e2[i].padding[0] = 0; + e2[i].padding[1] = 0; + e2[i].padding[2] = 0; } - vcpu->arch.cpuid_nent = cpuid->nent; - r = kvm_check_cpuid(vcpu->arch.cpuid_entries, cpuid->nent); + + r = kvm_check_cpuid(e2, cpuid->nent); if (r) { - vcpu->arch.cpuid_nent = 0; - kvfree(cpuid_entries); - goto out; + kvfree(e2); + goto out_free_cpuid; } + kvfree(vcpu->arch.cpuid_entries); + vcpu->arch.cpuid_entries = e2; + vcpu->arch.cpuid_nent = cpuid->nent; + cpuid_fix_nx_cap(vcpu); kvm_update_cpuid_runtime(vcpu); kvm_vcpu_after_set_cpuid(vcpu); - kvfree(cpuid_entries); -out: +out_free_cpuid: + kvfree(e); + return r; } @@ -257,26 +264,32 @@ int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid, struct kvm_cpuid_entry2 __user *entries) { + struct kvm_cpuid_entry2 *e2 = NULL; int r; - r = -E2BIG; if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) - goto out; - r = -EFAULT; - if (copy_from_user(&vcpu->arch.cpuid_entries, entries, - cpuid->nent * sizeof(struct kvm_cpuid_entry2))) - goto out; - vcpu->arch.cpuid_nent = cpuid->nent; - r = kvm_check_cpuid(vcpu->arch.cpuid_entries, cpuid->nent); + return -E2BIG; + + if (cpuid->nent) { + e2 = vmemdup_user(entries, array_size(sizeof(*e2), cpuid->nent)); + if (IS_ERR(e2)) + return PTR_ERR(e2); + } + + r = kvm_check_cpuid(e2, cpuid->nent); if (r) { - vcpu->arch.cpuid_nent = 0; - goto out; + kvfree(e2); + return r; } + kvfree(vcpu->arch.cpuid_entries); + vcpu->arch.cpuid_entries = e2; + vcpu->arch.cpuid_nent = cpuid->nent; + kvm_update_cpuid_runtime(vcpu); kvm_vcpu_after_set_cpuid(vcpu); -out: - return r; + + return 0; } int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu, diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index c4015a43cc8a..f8ed1bde18af 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -9877,6 +9877,7 @@ void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu) kvm_mmu_destroy(vcpu); srcu_read_unlock(&vcpu->kvm->srcu, idx); free_page((unsigned long)vcpu->arch.pio_data); + kvfree(vcpu->arch.cpuid_entries); if (!lapic_in_kernel(vcpu)) static_key_slow_dec(&kvm_no_apic_vcpu); } -- 2.25.4