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 92A9F22FF22; Tue, 11 Mar 2025 09:59:53 +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=1741687193; cv=none; b=QhI5odKsuc9Ezt4KDBBgYM0PQ1DuzThyKRGG9F6Cn+s20dtlFYQxqibnaAcgixwdoJdQ42s+LFH90PK4p6SmF1/Ax4ogkX5f1Jivic35lUM5px3JPxINyfBl8yX9PA0r5iDSiwrgEN2d/dfE12DzrFyqhr0FiuC80yzVoDoUDoE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741687193; c=relaxed/simple; bh=zsOBPexXIma9FbHuX3ibpi1OjULOqW0uLKONM/kuVVU=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References: MIME-Version:Content-Type; b=nPbrx35R88dEMn2ka12NXXUYi2YdQCnVr6eBFs3QpKAm3f4gw5uSd+sawdyzRNaO3V4cIYuIa+b7yPeT6hCXdr7dzy9EIiNJx/vM29u3b63W61Q2VgxDtV/A3ietGcuJx7JZRucA1dXfyeORmcQPeYGz2olohwvZUtrQnMfWFBQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VG+tVE2G; 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="VG+tVE2G" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1BDADC4CEE9; Tue, 11 Mar 2025 09:59:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1741687193; bh=zsOBPexXIma9FbHuX3ibpi1OjULOqW0uLKONM/kuVVU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=VG+tVE2GzVsRb2JLul75HRtiRbXVhMMo4dxouYOHV1ATfkBNftFJxqRlhNgGrt4Bg 8vXYNEQkZEHXksDzgCVF/Yyx8hIt91AxQNxWIk89I5AqHIGU4eJhD3Pq53mR/y341v UYHr2jy1GiMEAPviiRXQLPCUWgZRLBHH9GFNhH+S0hl1qMwW2pQ75WmAq2zxa7BoRc HRdcHfn4o6MLMcknCGBnQ8umntBPefnWVLRwMF2suzzgDNx4UCGvuSZ1XOzPE2s4sN KDke/58ap/xklW+Bl71/yrmJriKNh4CjEL0i4lfQ6viZOLUgeFrHfGY01Gmg8LN0o9 MAaKmoA2pBEMA== 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 1trwOt-00CTwt-2K; Tue, 11 Mar 2025 09:59:51 +0000 Date: Tue, 11 Mar 2025 09:59:50 +0000 Message-ID: <86tt7zopk9.wl-maz@kernel.org> From: Marc Zyngier To: Zhenyu Ye Cc: , , , , , , , , , , , Subject: Re: [PATCH v1 3/5] arm64/kvm: using ioctl to enable/disable the HDBSS feature In-Reply-To: <20250311040321.1460-4-yezhenyu2@huawei.com> References: <20250311040321.1460-1-yezhenyu2@huawei.com> <20250311040321.1460-4-yezhenyu2@huawei.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: yezhenyu2@huawei.com, yuzenghui@huawei.com, will@kernel.org, oliver.upton@linux.dev, catalin.marinas@arm.com, joey.gouly@arm.com, linux-kernel@vger.kernel.org, xiexiangyou@huawei.com, zhengchuan@huawei.com, wangzhou1@hisilicon.com, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, kvmarm@lists.linux.dev X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false +1 on everything Oliver said. Additionally: On Tue, 11 Mar 2025 04:03:19 +0000, Zhenyu Ye wrote: > > diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c > index 1f55b0c7b11d..9c11e2292b1e 100644 > --- a/arch/arm64/kvm/mmu.c > +++ b/arch/arm64/kvm/mmu.c > @@ -1703,6 +1703,9 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, > if (writable) > prot |= KVM_PGTABLE_PROT_W; > > + if (kvm->enable_hdbss && logging_active) > + prot |= KVM_PGTABLE_PROT_DBM; > + This looks totally wrong. If the page is defined as R/O (KVM_PGTABLE_PROT_W not being set), setting the DBM flag makes it writable anyway (the W bit is the Dirty bit). Hello, memory corruption? overall, this patch is a total mess, and needs to be split to have the runtime logic on one side, and the userspace API on the other. Don't mix the two. Thanks, M. -- Without deviation from the norm, progress is not possible.