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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 99C7FC433F5 for ; Wed, 11 May 2022 11:23:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237450AbiEKLXb (ORCPT ); Wed, 11 May 2022 07:23:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51276 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236759AbiEKLXa (ORCPT ); Wed, 11 May 2022 07:23:30 -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 ESMTP id DF60122EA51 for ; Wed, 11 May 2022 04:23:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1652268208; 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=zt0OS1hGFRD4C8YQzVy36UKvcvKZE0+pTjEjsVa3aIA=; b=E91M0lIessdMoa4DRl1YQi0swo7Dx3UNdHAHaqCIP7oC+jBke0xlfqP4rkrrNB6EzII8RZ BLrtHu8xZCwaNpqFUZiJfhyK7aen8XCiNJTlzeDCidMGzoJEplzdLHGqwvJe8/212qf2GX bVQbd9fen6G63P8yTKULsBiPfDDqK0Y= 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-499-aBRYLjheOGOwuBZJVWavkA-1; Wed, 11 May 2022 07:23:22 -0400 X-MC-Unique: aBRYLjheOGOwuBZJVWavkA-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 6246D80B920; Wed, 11 May 2022 11:23:22 +0000 (UTC) Received: from starship (unknown [10.40.192.26]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1F6C2438BDB; Wed, 11 May 2022 11:23:19 +0000 (UTC) Message-ID: Subject: Re: [PATCH v3 05/34] KVM: x86: hyper-v: Expose support for extended gva ranges for flush hypercalls From: Maxim Levitsky To: Vitaly Kuznetsov , kvm@vger.kernel.org, Paolo Bonzini Cc: Sean Christopherson , Wanpeng Li , Jim Mattson , Michael Kelley , Siddharth Chandrasekaran , linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org Date: Wed, 11 May 2022 14:23:18 +0300 In-Reply-To: <20220414132013.1588929-6-vkuznets@redhat.com> References: <20220414132013.1588929-1-vkuznets@redhat.com> <20220414132013.1588929-6-vkuznets@redhat.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.36.5 (3.36.5-2.fc32) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.85 on 10.11.54.9 Precedence: bulk List-ID: X-Mailing-List: linux-hyperv@vger.kernel.org On Thu, 2022-04-14 at 15:19 +0200, Vitaly Kuznetsov wrote: > Extended GVA ranges support bit seems to indicate whether lower 12 > bits of GVA can be used to specify up to 4095 additional consequent > GVAs to flush. This is somewhat described in TLFS. > > Previously, KVM was handling HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST{,EX} > requests by flushing the whole VPID so technically, extended GVA > ranges were already supported. As such requests are handled more > gently now, advertizing support for extended ranges starts making > sense to reduce the size of TLB flush requests. > > Signed-off-by: Vitaly Kuznetsov > --- > arch/x86/include/asm/hyperv-tlfs.h | 2 ++ > arch/x86/kvm/hyperv.c | 1 + > 2 files changed, 3 insertions(+) > > diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h > index 0a9407dc0859..5225a85c08c3 100644 > --- a/arch/x86/include/asm/hyperv-tlfs.h > +++ b/arch/x86/include/asm/hyperv-tlfs.h > @@ -61,6 +61,8 @@ > #define HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE BIT(10) > /* Support for debug MSRs available */ > #define HV_FEATURE_DEBUG_MSRS_AVAILABLE BIT(11) > +/* Support for extended gva ranges for flush hypercalls available */ > +#define HV_FEATURE_EXT_GVA_RANGES_FLUSH BIT(14) > /* > * Support for returning hypercall output block via XMM > * registers is available > diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c > index 759e1a16e5c3..1a6f9628cee9 100644 > --- a/arch/x86/kvm/hyperv.c > +++ b/arch/x86/kvm/hyperv.c > @@ -2702,6 +2702,7 @@ int kvm_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid, > ent->ebx |= HV_DEBUGGING; > ent->edx |= HV_X64_GUEST_DEBUGGING_AVAILABLE; > ent->edx |= HV_FEATURE_DEBUG_MSRS_AVAILABLE; > + ent->edx |= HV_FEATURE_EXT_GVA_RANGES_FLUSH; > > /* > * Direct Synthetic timers only make sense with in-kernel I do think that we need to ask Microsoft to document this, since from the spec (v6.0b) the only mention of this is "Bit 14: ExtendedGvaRangesForFlushVirtualAddressListAvailable" Reviewed-by: Maxim Levitsky Best regards, Maxim Levitsky