From patchwork Tue Oct 10 16:02:50 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vitaly Kuznetsov X-Patchwork-Id: 13415732 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 8F23BCD8CA5 for ; Tue, 10 Oct 2023 16:04:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233760AbjJJQED (ORCPT ); Tue, 10 Oct 2023 12:04:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54184 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233705AbjJJQD6 (ORCPT ); Tue, 10 Oct 2023 12:03:58 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CA76FCA for ; Tue, 10 Oct 2023 09:03:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1696953791; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=prXnsQoLnnAumc7wrBTC9PXl8VFIdNti/eoAvkFE+lo=; b=F9YowIf+aj5mEHdFJ6MU48PrndeUEiv6XDUplBbk0WA945+pYSmtFx1jG3YscEPs7g1Py3 bL25WjTPFg1ZDbQwQCU3whluodMoTmT9oFH3ac5qJAh39PwsnyFYZYS0GpyYNVlG1lO8P+ QFVVWVZ6CsRa29v5tmwUIZYMpw3lxhc= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-471-yXu5rYv0Nv2HM7RbZkTUHQ-1; Tue, 10 Oct 2023 12:03:03 -0400 X-MC-Unique: yXu5rYv0Nv2HM7RbZkTUHQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 56865185A79B; Tue, 10 Oct 2023 16:03:03 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.45.226.166]) by smtp.corp.redhat.com (Postfix) with ESMTP id 85FAD158; Tue, 10 Oct 2023 16:03:02 +0000 (UTC) From: Vitaly Kuznetsov To: kvm@vger.kernel.org, Paolo Bonzini , Sean Christopherson Cc: linux-kernel@vger.kernel.org Subject: [PATCH RFC 01/11] KVM: x86: xen: Remove unneeded xen context from struct kvm_arch when !CONFIG_KVM_XEN Date: Tue, 10 Oct 2023 18:02:50 +0200 Message-ID: <20231010160300.1136799-2-vkuznets@redhat.com> In-Reply-To: <20231010160300.1136799-1-vkuznets@redhat.com> References: <20231010160300.1136799-1-vkuznets@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.1 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Saving a few bytes of memory per KVM VM is certainly great but what's more important is the ability to see where the code accesses Xen emulation context while CONFIG_KVM_XEN is not enabled. Currently, kvm_cpu_get_extint() is the only such place and it is harmless: kvm_xen_has_interrupt() always returns '0' when !CONFIG_KVM_XEN. No functional change intended. Signed-off-by: Vitaly Kuznetsov Reviewed-by: Maxim Levitsky --- arch/x86/include/asm/kvm_host.h | 5 +++++ arch/x86/kvm/irq.c | 2 ++ 2 files changed, 7 insertions(+) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 17715cb8731d..e5d4b8a44630 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1126,6 +1126,7 @@ struct msr_bitmap_range { unsigned long *bitmap; }; +#ifdef CONFIG_KVM_XEN /* Xen emulation context */ struct kvm_xen { struct mutex xen_lock; @@ -1137,6 +1138,7 @@ struct kvm_xen { struct idr evtchn_ports; unsigned long poll_mask[BITS_TO_LONGS(KVM_MAX_VCPUS)]; }; +#endif enum kvm_irqchip_mode { KVM_IRQCHIP_NONE, @@ -1338,7 +1340,10 @@ struct kvm_arch { struct hlist_head mask_notifier_list; struct kvm_hv hyperv; + +#ifdef CONFIG_KVM_XEN struct kvm_xen xen; +#endif bool backwards_tsc_observed; bool boot_vcpu_runs_old_kvmclock; diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c index b2c397dd2bc6..ad9ca8a60144 100644 --- a/arch/x86/kvm/irq.c +++ b/arch/x86/kvm/irq.c @@ -118,8 +118,10 @@ static int kvm_cpu_get_extint(struct kvm_vcpu *v) if (!lapic_in_kernel(v)) return v->arch.interrupt.nr; +#ifdef CONFIG_KVM_XEN if (kvm_xen_has_interrupt(v)) return v->kvm->arch.xen.upcall_vector; +#endif if (irqchip_split(v->kvm)) { int vector = v->arch.pending_external_vector;