From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0EBA81AD3E3; Wed, 11 Sep 2024 16:10:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726071007; cv=none; b=IwBX1ivVkRpS0Ju5ftdpdOKHCGaZrH9VQqGJe5u42ncFSDayLylA1M7pf1MXmrg6J4XJo7Q49CGbsONq0I7cIiPaRIP8F8uBn6Rhm0R6C58JqZTXt5KQ1IvSswjvq0ZVPjh4SaFcZsZGwaH+1Qi10ODibVbpn5x1TQI1wTrV1kk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726071007; c=relaxed/simple; bh=n3zgqizMvbrvZLnqLGYPpKZnWKf0e2LcRkhxNBqsjvc=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References: MIME-Version:Content-Type; b=qdL2Dfo7P8besfxsWPFHwckcz8vvt3XkHvSOT4FuOZEmVuiwOi2LxpUZKzh+UB351PxDVE2ovpI0ZpyaJ0SDgFxx3cxZHNxO1S+OWRVDA2wG+0eHLBse/kwe9V5TqhMP860TTs75PgaTFTR91+mYlUYFj11iX/QASgc8UAOybI4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cJ53Rfrr; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="cJ53Rfrr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 869E0C4CED2; Wed, 11 Sep 2024 16:10:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1726071006; bh=n3zgqizMvbrvZLnqLGYPpKZnWKf0e2LcRkhxNBqsjvc=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=cJ53RfrrQgECSOr1FX3ZKvn4orPRiAmMck+nUrMh666hvi2GEN22z91zwZ4Z+sneY +uj0JblZ7PK7Odd8ykfsNE/l+y8mmTPpgQOCP3cFbBJx1c4vmm8CtyfwGfaCZLTVt0 oXb+zW8VucH1CKRAfPVHuPCht2De8GCYynT1C504U8ZeC3UoQwKeHv1itkCGfUNwDq BhqpyCkLaqveKVJLLF1Vp2Vkg1QxUO900uYtWxOGyWHm/h8ZQDsV4i4hWqECDE0ecX 3/f0xELPkXhc3RObMQtPKkWbiYdvEqVKUjrQB/Vpxo5GtaqATCtfzI01PzWwfhxjLt eDIEOJaDIne3g== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1soPuu-00CAxN-I5; Wed, 11 Sep 2024 17:10:04 +0100 Date: Wed, 11 Sep 2024 17:10:04 +0100 Message-ID: <86mske6ujn.wl-maz@kernel.org> From: Marc Zyngier To: Joey Gouly Cc: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, James Morse , Suzuki K Poulose , Oliver Upton , Zenghui Yu , Alexandru Elisei , Mark Brown Subject: Re: [PATCH v3 18/24] KVM: arm64: Split S1 permission evaluation into direct and hierarchical parts In-Reply-To: <20240911155128.GA1087252@e124191.cambridge.arm.com> References: <20240911135151.401193-1-maz@kernel.org> <20240911135151.401193-19-maz@kernel.org> <20240911141513.GA1080224@e124191.cambridge.arm.com> <86o74u6vzu.wl-maz@kernel.org> <20240911155128.GA1087252@e124191.cambridge.arm.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/29.4 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: joey.gouly@arm.com, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, james.morse@arm.com, suzuki.poulose@arm.com, oliver.upton@linux.dev, yuzenghui@huawei.com, alexandru.elisei@arm.com, broonie@kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false On Wed, 11 Sep 2024 16:51:28 +0100, Joey Gouly wrote: > > On Wed, Sep 11, 2024 at 04:38:45PM +0100, Marc Zyngier wrote: > > On Wed, 11 Sep 2024 15:15:13 +0100, > > Joey Gouly wrote: > > > > > > On Wed, Sep 11, 2024 at 02:51:45PM +0100, Marc Zyngier wrote: > > > > [...] > > > > > > +static void compute_s1_hierarchical_permissions(struct kvm_vcpu *vcpu, > > > > + struct s1_walk_info *wi, > > > > + struct s1_walk_result *wr, > > > > + struct s1_perms *s1p) > > > > +{ > > > > > > How about: > > > > > > if (wi->hpd) > > > return; > > > > I was hoping not to add anything like this, because all the table bits > > are 0 (we simply don't collect them), and thus don't have any effect. > > I just thought it was more obvious that they wouldn't apply in this case, don't > feel super strongly about it. If you want it to be obvious, how about this instead? diff --git a/arch/arm64/kvm/at.c b/arch/arm64/kvm/at.c index 8a5e1c4682619..fb9de5fc2cc26 100644 --- a/arch/arm64/kvm/at.c +++ b/arch/arm64/kvm/at.c @@ -985,7 +985,8 @@ static void compute_s1_permissions(struct kvm_vcpu *vcpu, u32 op, else compute_s1_indirect_permissions(vcpu, wi, wr, s1p); - compute_s1_hierarchical_permissions(vcpu, wi, wr, s1p); + if (!wi->hpd) + compute_s1_hierarchical_permissions(vcpu, wi, wr, s1p); if (op == OP_AT_S1E1RP || op == OP_AT_S1E1WP) { bool pan; Thanks, M. -- Without deviation from the norm, progress is not possible.