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=-23.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, 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_IN_DEF_DKIM_WL autolearn=ham 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 DE466C4338F for ; Mon, 2 Aug 2021 10:31:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BE5D86023B for ; Mon, 2 Aug 2021 10:31:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233185AbhHBKbN (ORCPT ); Mon, 2 Aug 2021 06:31:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46280 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231357AbhHBKbM (ORCPT ); Mon, 2 Aug 2021 06:31:12 -0400 Received: from mail-ej1-x633.google.com (mail-ej1-x633.google.com [IPv6:2a00:1450:4864:20::633]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 20616C06175F for ; Mon, 2 Aug 2021 03:31:03 -0700 (PDT) Received: by mail-ej1-x633.google.com with SMTP id nd39so30113667ejc.5 for ; Mon, 02 Aug 2021 03:31:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=yGVEq9B5bByjRAfhMPs/aPNjzWR9vo1LM/IsDeZ/fw4=; b=NhuObWYcT4Ws0XBuXGzohVpUDGBsWLH4oX9MHLm87mGm0eyOzT5PsB+WKSYrCavXnr qPixW7MErBufFuWbaYkRUJLEeTDLjpSj7MFMfR1Xso+L8nRPbtdbfotRZGLumNl7gTJu R0K3BmV36cB5GI09hubxsKpuY4ThUI2+rMpsfE5o64afsQ72esreblTgFkjibXtlmMmC EOTGmpbqO5PirVRv9RmsdqwM9/ewHqzGMXXQIFHScsTHHJch8eRpXGFveDSELD035UZv ly9DrFt1gVzB0onpWLtIl7mzSfGMj9juv9pLca65D6xEx30TGFE6r4dxjouj1wJMNPkd 48lg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=yGVEq9B5bByjRAfhMPs/aPNjzWR9vo1LM/IsDeZ/fw4=; b=sH7blzMK1JiA3MIZE2VY/zWESxntGejHLs/Baj1u7b2C5A6ijxj5PXu0GUAgJYKRcV cgRBGzYbLyA869O71hMw44ZFg//H6iFr03k1DXZjDgRQ6C9sQzJAjZQMb3Vrd8zzPPBB g5Vg6Dgq4bBwrD1/L4bBSocgyqHxbyBHiteqc2IvgOY6Bt7F/ivyWzez3fN6FUQfp7UY nBzczc0A3KmMZw8oxJtB3QdI7z4fZfoORP3Y/aEBp/4CQgaBiwdaDsDWMUTBIfgk6gFi vG2KOUkS8KqLC06X+RxPNVNKKplzRi3SctlEvDAsX30VVltXsaaLnLP5lDklpWwX0len 0UjA== X-Gm-Message-State: AOAM531DNw8Y5qr6TLZgk9PAovGt2cEX2MMEI3CltRLkorwwJQeDix1q xlNKI8TRliQ4gatpw46eIz3DcyFXhvooTx/iBAtQfA== X-Google-Smtp-Source: ABdhPJwELrHM8KMcxJgMtc2//RdcfHO0BBsraGRqwLVekJXAVvzXhMzTKx/LaOqiF+bS/C2fHPTkVM4G1T50Hhsf+GE= X-Received: by 2002:a17:906:2441:: with SMTP id a1mr13848525ejb.550.1627900261494; Mon, 02 Aug 2021 03:31:01 -0700 (PDT) MIME-Version: 1.0 References: <20210729132818.4091769-1-qperret@google.com> <20210729132818.4091769-13-qperret@google.com> In-Reply-To: <20210729132818.4091769-13-qperret@google.com> From: Fuad Tabba Date: Mon, 2 Aug 2021 12:30:25 +0200 Message-ID: Subject: Re: [PATCH v3 12/21] KVM: arm64: Add helpers to tag shared pages in SW bits To: Quentin Perret Cc: maz@kernel.org, james.morse@arm.com, alexandru.elisei@arm.com, suzuki.poulose@arm.com, catalin.marinas@arm.com, will@kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, ardb@kernel.org, qwandor@google.com, dbrazdil@google.com, kernel-team@android.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Quentin, On Thu, Jul 29, 2021 at 3:28 PM Quentin Perret wrote: > > We will soon start annotating shared pages in page-tables in nVHE > protected mode. Define all the states in which a page can be (owned, > shared and owned, shared and borrowed), and provide helpers allowing to > convert this into SW bits annotations using the matching prot > attributes. > > Signed-off-by: Quentin Perret > --- > arch/arm64/kvm/hyp/include/nvhe/mem_protect.h | 26 +++++++++++++++++++ > 1 file changed, 26 insertions(+) > > diff --git a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h > index 9c227d87c36d..ae355bfd8c01 100644 > --- a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h > +++ b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h > @@ -12,6 +12,32 @@ > #include > #include > > +/* > + * SW bits 0-1 are reserved to track the memory ownership state of each page: > + * 00: The page is owned solely by the page-table owner. nit: solely -> exclusively, because "exclusive" is the more common term in context of shared resources > + * 01: The page is owned by the page-table owner, but is shared > + * with another entity. > + * 10: The page is shared with, but not owned by the page-table owner. > + * 11: Reserved for future use (lending). > + */ > +enum pkvm_page_state { > + PKVM_PAGE_OWNED = 0ULL, > + PKVM_PAGE_SHARED_OWNED = KVM_PGTABLE_PROT_SW0, > + PKVM_PAGE_SHARED_BORROWED = KVM_PGTABLE_PROT_SW1, > +}; > + > +#define PKVM_PAGE_STATE_PROT_MASK (KVM_PGTABLE_PROT_SW0 | KVM_PGTABLE_PROT_SW1) > +static inline enum kvm_pgtable_prot pkvm_mkstate(enum kvm_pgtable_prot prot, > + enum pkvm_page_state state) > +{ > + return (prot & ~PKVM_PAGE_STATE_PROT_MASK) | state; > +} > + > +static inline enum pkvm_page_state pkvm_getstate(enum kvm_pgtable_prot prot) > +{ > + return prot & PKVM_PAGE_STATE_PROT_MASK; > +} > + I think that this encoding is pretty neat and easy to follow. Reviewed-by: Fuad Tabba Thanks, /fuad > struct host_kvm { > struct kvm_arch arch; > struct kvm_pgtable pgt; > -- > 2.32.0.432.gabb21c7263-goog >