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 9F3A5C74A5B for ; Thu, 23 Mar 2023 21:30:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231152AbjCWVaE (ORCPT ); Thu, 23 Mar 2023 17:30:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46722 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229877AbjCWVaD (ORCPT ); Thu, 23 Mar 2023 17:30:03 -0400 Received: from mail-pl1-x64a.google.com (mail-pl1-x64a.google.com [IPv6:2607:f8b0:4864:20::64a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4AE60E057 for ; Thu, 23 Mar 2023 14:30:02 -0700 (PDT) Received: by mail-pl1-x64a.google.com with SMTP id p9-20020a170902e74900b001a1c7b2e7afso85114plf.0 for ; Thu, 23 Mar 2023 14:30:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; t=1679607002; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=1hgyyqWHdWQ1oKWLENS4QWpBGzNOk+HCg4Piu7zsWyU=; b=VC7vJHPl1u5wfacX2P96EJMqxgdSZCWjffPShMCpQhljCD3q+t/IY0PHFHLJW4x0rg +HUDJHI6x2Zm8AabFW6vVbOnzu6DEnBnDF8hA/Gx/5+DnxfbTHNRqKr2cEm0aaDOBO9u dgmwTme9PRlWV7UJYxpoT83rNbX85E39qDw4ieJOvwpVZxbzEvV2fx+5MKoQK0kM2THC sXcRyv/9Jq8YDQV/UxeLZCcDiV49HZbyGzj/HrC1m0QGz6aDedUFPgnuTqbMvIxvkP2Q BpUu+LPB+KrLPtxSyPnZExIW/h/mAPUQavZXHdZXYsn/OGoeD/vFMVCN6nPodhS8X7hp OtxQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1679607002; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=1hgyyqWHdWQ1oKWLENS4QWpBGzNOk+HCg4Piu7zsWyU=; b=jDl5s7E0NJeoUFCzJmMx0JHw9GJLYMiI5Sp/mjT58Rs+t5t2pxyHFEqTRCNLT0rnTu dNpbULUYhHHUoFTMxFSv4E3vlC0BPJQ6S8H7n+AKVVXV3BViq1oapaBLgfZNMJi9c13s LzCefbGT/W+W82gxtXUnlXPVPOOr+rkAp6iGAbxsXAZl1R7EA68vclB3cJkmCXmKrMNY coI2UCcagpbeJS+7xdEC0iuScOfqhvnMdX6I5cRJPUQmz/zPeVVvXTRsQSz/CNZYzi2v drByiaHgmYcrc60D8SNutt27kwZ/Rg08pfHuFC8mgHN/NVs7q4LupitFU4eq7qwpqov8 41Xw== X-Gm-Message-State: AAQBX9fTSCvhj+15rBtTawq8em6GXTJW2Fgt6t5X1BJ3KcG5cqEVYBzW vdGr2A7Z+7Wv3aswI+CTzfPMOlxXF+Q= X-Google-Smtp-Source: AKy350ZQnCo8AtrV1rzzvVI7iZec6PUQD5nZ08WSU0xLErpgfXhjzMSb1qzaV/S6LpA7CAz7kPank1DSvSg= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a05:6a00:1781:b0:593:fcfb:208b with SMTP id s1-20020a056a00178100b00593fcfb208bmr466647pfg.3.1679607001861; Thu, 23 Mar 2023 14:30:01 -0700 (PDT) Date: Thu, 23 Mar 2023 14:30:00 -0700 In-Reply-To: Mime-Version: 1.0 References: <20230224223607.1580880-1-aaronlewis@google.com> <20230224223607.1580880-3-aaronlewis@google.com> Message-ID: Subject: Re: [PATCH v3 2/8] KVM: x86: Clear all supported MPX xfeatures if they are not all set From: Sean Christopherson To: Mingwei Zhang Cc: Aaron Lewis , kvm@vger.kernel.org, pbonzini@redhat.com, jmattson@google.com Content-Type: text/plain; charset="us-ascii" Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Thu, Mar 23, 2023, Mingwei Zhang wrote: > > > static inline u64 kvm_get_filtered_xcr0(void) > > > { > > > - return kvm_caps.supported_xcr0 & xstate_get_guest_group_perm(); > > > + u64 supported_xcr0 = kvm_caps.supported_xcr0; > > > + > > > + BUILD_BUG_ON(XFEATURE_MASK_USER_DYNAMIC != XFEATURE_MASK_XTILE_DATA); > > > + > > > + if (supported_xcr0 & XFEATURE_MASK_USER_DYNAMIC) { > > > + supported_xcr0 &= xstate_get_guest_group_perm(); > > > + > > > + /* > > > + * Treat XTILE_CFG as unsupported if the current process isn't > > > + * allowed to use XTILE_DATA, as attempting to set XTILE_CFG in > > > + * XCR0 without setting XTILE_DATA is architecturally illegal. > > > + */ > > > + if (!(supported_xcr0 & XFEATURE_MASK_XTILE_DATA)) > > > + supported_xcr0 &= XFEATURE_MASK_XTILE_CFG; > > > > should be this? supported_xcr0 &= ~XFEATURE_MASK_XTILE_CFG; > > > > > > > + } > > > + return supported_xcr0; > > > } > Also, a minor opinion: shall we use permitted_xcr0 instead of > supported_xcr0 to be consistent with other places? This way, it is > clear that supported_xcr0 is (almost) never changing. permitted_xcr0, > as its name suggested, will be subject to permission change. Ya, works for me.