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[34.168.104.7]) by smtp.gmail.com with ESMTPSA id f5-20020a655505000000b00434760ee36asm7850505pgr.16.2022.11.09.14.42.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 09 Nov 2022 14:42:14 -0800 (PST) Date: Wed, 9 Nov 2022 22:42:10 +0000 From: Sean Christopherson To: Ben Gardon Subject: Re: [PATCH v5 09/14] KVM: arm64: Atomically update stage 2 leaf attributes in parallel walks Message-ID: References: <20221107215644.1895162-1-oliver.upton@linux.dev> <20221107215644.1895162-10-oliver.upton@linux.dev> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: Cc: kvm@vger.kernel.org, Marc Zyngier , Will Deacon , kvmarm@lists.linux.dev, David Matlack , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu On Wed, Nov 09, 2022, Ben Gardon wrote: > On Mon, Nov 7, 2022 at 1:58 PM Oliver Upton wrote: > > @@ -1054,7 +1066,7 @@ kvm_pte_t kvm_pgtable_stage2_mkold(struct kvm_pgtable *pgt, u64 addr) > > bool kvm_pgtable_stage2_is_young(struct kvm_pgtable *pgt, u64 addr) > > { > > kvm_pte_t pte = 0; > > - stage2_update_leaf_attrs(pgt, addr, 1, 0, 0, &pte, NULL); > > + stage2_update_leaf_attrs(pgt, addr, 1, 0, 0, &pte, NULL, 0); > > Would be nice to have an enum for KVM_PGTABLE_WALK_EXCLUSIVE so this > doesn't just have to pass 0. That's also dangerous though since the param is a set of flags, not unique, arbitrary values. E.g. this won't do the expected thing if (flags & KVM_PGTABLE_WALK_EXCLUSIVE) I assume compilers would complain, but never say never when it comes to compilers :-) _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f53.google.com (mail-pj1-f53.google.com [209.85.216.53]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 67444107A7 for ; Wed, 9 Nov 2022 22:42:15 +0000 (UTC) Received: by mail-pj1-f53.google.com with SMTP id b1-20020a17090a7ac100b00213fde52d49so85441pjl.3 for ; Wed, 09 Nov 2022 14:42:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=ZKiMsUeXYzlgxWfF0WcmHUUjbEiQdWPsUbhG4FuUTvU=; b=cD4gLgROz4g4LtmSRbdLXGAjaJuR6pnQPfjazM0yU0Hn/lv/WT5o4Her5FZZKbaJvo 3llk8DYE2nZDW2sbqQRiQfbjE1ZapQwwU0U2Cv08c9Ebk8FU0i0XK4awq7K7iidJf8OH 3GcfjHTDxs/DR50LOoQvFL4LWTUNBDsk4dxtwc4SeMTKq2oVpauMgfCUNtsr3uNWy3cz RpG+CtA8bVTi2doo034FUCj8Kt6OAO4pYKClaQOLsbg15mz+DJmaYa7LRAgZji6biWZu +q6Wz7oH6l72tqHN4GUlfyDALVakTWYywy2upo+HFDthGSfQgKq+AvRIE4mmZZ0GudzA bgyg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=ZKiMsUeXYzlgxWfF0WcmHUUjbEiQdWPsUbhG4FuUTvU=; b=3JvRy4KfGdtSA/UFJHE/SSVRyjc/AurKTVVH9V9kvQdTcEqrAxaFyfL4jPLlPrIjPF ZAgnTfOFjMol3GdjI7aj0WSaFZlpolABqkX8h/JX89IRrTlrPgGtA3xD8c1OjTvcPTKw IjO1PpAXdEH4PwjvZ5TW44YVIvgAMCkS/RJU9EVEB6rQ+VNjbuxQMLPfEcgiOy5VT87g ghjCWOO8S1kGQN+HTK21U2pR2GuSNuiLRTt2uipwE64wIlyv4bLy4bIynCRvMbIfw+di SL7Tj1CszQ3zA4DjxPASv05FHbuZugGbIWJEQx/RoVpee5RMTRfRUxEqr2d8E6Be/0RK 4t7g== X-Gm-Message-State: ACrzQf2D6PwrvmSgutcHRa5NBOW/2rdCOvNzyCPlijqFaXgm54Nr+Z5t Q/BQq/r/4GcIcE2+7IKkX8bK5A== X-Google-Smtp-Source: AMsMyM7VhBvIBJZq8DOffvWOeCdh5Qe5jEL63Uu0jploe/nMqN4VkZSgtUrZB0hVopNblvbQ13kL9w== X-Received: by 2002:a17:902:e811:b0:186:8a61:ea76 with SMTP id u17-20020a170902e81100b001868a61ea76mr63663058plg.10.1668033734747; Wed, 09 Nov 2022 14:42:14 -0800 (PST) Received: from google.com (7.104.168.34.bc.googleusercontent.com. [34.168.104.7]) by smtp.gmail.com with ESMTPSA id f5-20020a655505000000b00434760ee36asm7850505pgr.16.2022.11.09.14.42.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 09 Nov 2022 14:42:14 -0800 (PST) Date: Wed, 9 Nov 2022 22:42:10 +0000 From: Sean Christopherson To: Ben Gardon Cc: Oliver Upton , Marc Zyngier , James Morse , Alexandru Elisei , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, Reiji Watanabe , Ricardo Koller , David Matlack , Quentin Perret , Gavin Shan , Peter Xu , Will Deacon , kvmarm@lists.linux.dev Subject: Re: [PATCH v5 09/14] KVM: arm64: Atomically update stage 2 leaf attributes in parallel walks Message-ID: References: <20221107215644.1895162-1-oliver.upton@linux.dev> <20221107215644.1895162-10-oliver.upton@linux.dev> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Message-ID: <20221109224210.0uQwWuksReKykGZTknOzDpurgBgASDoKoLMxT5dYiaQ@z> On Wed, Nov 09, 2022, Ben Gardon wrote: > On Mon, Nov 7, 2022 at 1:58 PM Oliver Upton wrote: > > @@ -1054,7 +1066,7 @@ kvm_pte_t kvm_pgtable_stage2_mkold(struct kvm_pgtable *pgt, u64 addr) > > bool kvm_pgtable_stage2_is_young(struct kvm_pgtable *pgt, u64 addr) > > { > > kvm_pte_t pte = 0; > > - stage2_update_leaf_attrs(pgt, addr, 1, 0, 0, &pte, NULL); > > + stage2_update_leaf_attrs(pgt, addr, 1, 0, 0, &pte, NULL, 0); > > Would be nice to have an enum for KVM_PGTABLE_WALK_EXCLUSIVE so this > doesn't just have to pass 0. That's also dangerous though since the param is a set of flags, not unique, arbitrary values. E.g. this won't do the expected thing if (flags & KVM_PGTABLE_WALK_EXCLUSIVE) I assume compilers would complain, but never say never when it comes to compilers :-)