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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 110D8C11F64 for ; Thu, 1 Jul 2021 15:41:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EFCAC61406 for ; Thu, 1 Jul 2021 15:41:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233986AbhGAPnu (ORCPT ); Thu, 1 Jul 2021 11:43:50 -0400 Received: from smtp-out1.suse.de ([195.135.220.28]:51806 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233728AbhGAPnl (ORCPT ); Thu, 1 Jul 2021 11:43:41 -0400 Received: from imap.suse.de (imap-alt.suse-dmz.suse.de [192.168.254.47]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id DE7C22290A; Thu, 1 Jul 2021 15:41:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1625154069; h=from:from:reply-to: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=EtpyeY2LWzLpUtmvOyclkqbU6bQLiiAIoIZDjZfdMyA=; b=BLyNKjT8T9o+8E3veyF+Ju4FmC9jvp/rK+mPprEg4pvXf1TTbamzNR/zf/twQOoemJSw3v shX6i2iyZuAGMjiUIpGWNJujh+nEMOICpvs2cfDS5LUVHHoQINPP/vmawyAEhDOIMAFxZn mpQjJcpbEgGYwO4wih8ceuoQJoUAOtU= Received: from imap3-int (imap-alt.suse-dmz.suse.de [192.168.254.47]) by imap.suse.de (Postfix) with ESMTP id 78EE211CD5; Thu, 1 Jul 2021 15:41:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1625154069; h=from:from:reply-to: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=EtpyeY2LWzLpUtmvOyclkqbU6bQLiiAIoIZDjZfdMyA=; b=BLyNKjT8T9o+8E3veyF+Ju4FmC9jvp/rK+mPprEg4pvXf1TTbamzNR/zf/twQOoemJSw3v shX6i2iyZuAGMjiUIpGWNJujh+nEMOICpvs2cfDS5LUVHHoQINPP/vmawyAEhDOIMAFxZn mpQjJcpbEgGYwO4wih8ceuoQJoUAOtU= Received: from director2.suse.de ([192.168.254.72]) by imap3-int with ESMTPSA id UA9wHBXi3WAOFwAALh3uQQ (envelope-from ); Thu, 01 Jul 2021 15:41:09 +0000 From: Juergen Gross To: linux-kernel@vger.kernel.org, x86@kernel.org, linux-doc@vger.kernel.org, kvm@vger.kernel.org Cc: Juergen Gross , Jonathan Corbet , Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" Subject: [PATCH 3/6] x86/kvm: add boot parameter for maximum vcpu-id Date: Thu, 1 Jul 2021 17:41:02 +0200 Message-Id: <20210701154105.23215-4-jgross@suse.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210701154105.23215-1-jgross@suse.com> References: <20210701154105.23215-1-jgross@suse.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Today the maximum vcpu-id of a kvm guest's vcpu on x86 systems is set via a #define in a header file. In order to support higher vcpu-ids without generally increasing the memory consumption of guests on the host (some guest structures contain arrays sized by KVM_MAX_VCPU_ID) add a boot parameter for selecting the maximum vcpu-id. Per default it will still be the current value of 1023, but it can be set manually to higher or lower values. This requires to allocate the arrays using KVM_MAX_VCPU_ID as the size dynamically. Signed-off-by: Juergen Gross --- Documentation/admin-guide/kernel-parameters.txt | 8 ++++++++ arch/x86/include/asm/kvm_host.h | 5 ++++- arch/x86/kvm/ioapic.c | 12 +++++++++++- arch/x86/kvm/ioapic.h | 4 ++-- arch/x86/kvm/x86.c | 3 +++ 5 files changed, 28 insertions(+), 4 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index cb89dbdedc46..99bfa53a2bbd 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2365,6 +2365,14 @@ feature (tagged TLBs) on capable Intel chips. Default is 1 (enabled) + kvm.max_vcpu_id= + [KVM,X86] Set the maximum allowed vcpu-id of a guest. + Some memory structure sizes depend on this value, so it + shouldn't be set too high. Note that each vcpu of a + guests needs to have a unique vcpu-id, so a single + guest can't have more vcpus than the set value + 1. + Default: 1023 + l1tf= [X86] Control mitigation of the L1TF vulnerability on affected CPUs diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 9c7ced0e3171..88b1ff898fb9 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -39,7 +39,8 @@ #define KVM_MAX_VCPUS 288 #define KVM_SOFT_MAX_VCPUS 240 -#define KVM_MAX_VCPU_ID 1023 +#define KVM_DEFAULT_MAX_VCPU_ID 1023 +#define KVM_MAX_VCPU_ID max_vcpu_id /* memory slots that are not exposed to userspace */ #define KVM_PRIVATE_MEM_SLOTS 3 @@ -1511,6 +1512,8 @@ extern u64 kvm_max_tsc_scaling_ratio; extern u64 kvm_default_tsc_scaling_ratio; /* bus lock detection supported? */ extern bool kvm_has_bus_lock_exit; +/* maximum vcpu-id */ +extern unsigned int max_vcpu_id; extern u64 kvm_mce_cap_supported; diff --git a/arch/x86/kvm/ioapic.c b/arch/x86/kvm/ioapic.c index ff005fe738a4..52e8ea90c914 100644 --- a/arch/x86/kvm/ioapic.c +++ b/arch/x86/kvm/ioapic.c @@ -685,11 +685,21 @@ static const struct kvm_io_device_ops ioapic_mmio_ops = { int kvm_ioapic_init(struct kvm *kvm) { struct kvm_ioapic *ioapic; + size_t sz; int ret; - ioapic = kzalloc(sizeof(struct kvm_ioapic), GFP_KERNEL_ACCOUNT); + sz = sizeof(struct kvm_ioapic) + + sizeof(*ioapic->rtc_status.dest_map.map) * + BITS_TO_LONGS(KVM_MAX_VCPU_ID + 1) + + sizeof(*ioapic->rtc_status.dest_map.vectors) * + (KVM_MAX_VCPU_ID + 1); + ioapic = kzalloc(sz, GFP_KERNEL_ACCOUNT); if (!ioapic) return -ENOMEM; + ioapic->rtc_status.dest_map.map = (void *)(ioapic + 1); + ioapic->rtc_status.dest_map.vectors = + (void *)(ioapic->rtc_status.dest_map.map + + BITS_TO_LONGS(KVM_MAX_VCPU_ID + 1)); spin_lock_init(&ioapic->lock); INIT_DELAYED_WORK(&ioapic->eoi_inject, kvm_ioapic_eoi_inject_work); kvm->arch.vioapic = ioapic; diff --git a/arch/x86/kvm/ioapic.h b/arch/x86/kvm/ioapic.h index bbd4a5d18b5d..623a3c5afad7 100644 --- a/arch/x86/kvm/ioapic.h +++ b/arch/x86/kvm/ioapic.h @@ -39,13 +39,13 @@ struct kvm_vcpu; struct dest_map { /* vcpu bitmap where IRQ has been sent */ - DECLARE_BITMAP(map, KVM_MAX_VCPU_ID + 1); + unsigned long *map; /* * Vector sent to a given vcpu, only valid when * the vcpu's bit in map is set */ - u8 vectors[KVM_MAX_VCPU_ID + 1]; + u8 *vectors; }; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index e0f4a46649d7..0390d90fd360 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -177,6 +177,9 @@ module_param(force_emulation_prefix, bool, S_IRUGO); int __read_mostly pi_inject_timer = -1; module_param(pi_inject_timer, bint, S_IRUGO | S_IWUSR); +unsigned int __read_mostly max_vcpu_id = KVM_DEFAULT_MAX_VCPU_ID; +module_param(max_vcpu_id, uint, S_IRUGO); + /* * Restoring the host value for MSRs that are only consumed when running in * usermode, e.g. SYSCALL MSRs and TSC_AUX, can be deferred until the CPU -- 2.26.2