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 A4CB717BA7; Thu, 25 Jan 2024 09:15:33 +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=1706174133; cv=none; b=d+x3+pMyb2jZGaJE2sgWEPLDKbUsx81bh+IdO2wIuU8EsSd8dk/GRri8TKRM+AZG38a9tvRAhWWyL7RKTplg4jrA5B1TU2qwqqkx0JznlK2i+Mk3DhY1+ifZWwrGDnUL8mq/W06gdzWEnc9MQnKprxTMEl/iq2jsYXgGzM+X8oo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706174133; c=relaxed/simple; bh=K9lYZvrqdgnYP3UGmpgkuK/YqJ3JhSr/K1XaHoW8CxE=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References: MIME-Version:Content-Type; b=gvskvTaQYsKMrZFyxbuEbQ0M2RekiYJvNt5CMR+xK8gAJgOVvGGPRYVBDYhyfUtEhpo8CaSOiQd/AvxA4QPA2gTsMROU9r7/duzGRmbhfb4lH5FApuU/OurQL62gkP7EAJ01oj3NUQC+gNLd76e2spp9mRcpMyiltmliR1mQPcc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=H6xYevna; 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="H6xYevna" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 173B7C433F1; Thu, 25 Jan 2024 09:15:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1706174133; bh=K9lYZvrqdgnYP3UGmpgkuK/YqJ3JhSr/K1XaHoW8CxE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=H6xYevnalxh+Yn9zgKcLDclQWboRoKYZnaeI9f0xI0v5QeE9+nR6XqeEbJDS3elwZ 1bbOvyg6ryhmWj3xrtkWS0ThR+2teDkJLKotLGjqGDhoE84/LuZINLgQeDBd9tlcOs HHVt82WzbIvBG4tcV/Jmdx9fagCK84ZwlHOm7c29IOIa3Kk7JVGrBdVjEDqt8NTVCx gbi+u6usmihayMcll8JN3NPoILuDuMZDvOoCQJVwyAla53tbhapcBB4E/VdZEnoIIx 2ObNGH4/V4Pj+eeqkT7p8AuCTOub3r1jouC3c2SlWrPbyMZdXEZZUGKivgxm16xgBX rqzMg++Fl/d6Q== 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 1rSvpa-00EfA8-RV; Thu, 25 Jan 2024 09:15:30 +0000 Date: Thu, 25 Jan 2024 09:15:30 +0000 Message-ID: <867cjx93kd.wl-maz@kernel.org> From: Marc Zyngier To: Oliver Upton Cc: kvmarm@lists.linux.dev, kvm@vger.kernel.org, James Morse , Suzuki K Poulose , Zenghui Yu , Raghavendra Rao Ananta , Jing Zhang Subject: Re: [PATCH 04/15] KVM: arm64: vgic-its: Walk the LPI xarray in vgic_copy_lpi_list() In-Reply-To: <20240124204909.105952-5-oliver.upton@linux.dev> References: <20240124204909.105952-1-oliver.upton@linux.dev> <20240124204909.105952-5-oliver.upton@linux.dev> 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/29.1 (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: oliver.upton@linux.dev, kvmarm@lists.linux.dev, kvm@vger.kernel.org, james.morse@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, rananta@google.com, jingzhangos@google.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false On Wed, 24 Jan 2024 20:48:58 +0000, Oliver Upton wrote: > > Start iterating the LPI xarray in anticipation of removing the LPI > linked-list. > > Signed-off-by: Oliver Upton > --- > arch/arm64/kvm/vgic/vgic-its.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/kvm/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c > index f152d670113f..a2d95a279798 100644 > --- a/arch/arm64/kvm/vgic/vgic-its.c > +++ b/arch/arm64/kvm/vgic/vgic-its.c > @@ -332,6 +332,7 @@ static int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq, > int vgic_copy_lpi_list(struct kvm *kvm, struct kvm_vcpu *vcpu, u32 **intid_ptr) > { > struct vgic_dist *dist = &kvm->arch.vgic; > + XA_STATE(xas, &dist->lpi_xa, 0); Why 0? LPIs start at 8192 (aka GIC_LPI_OFFSET), so it'd probably make sense to use that. > struct vgic_irq *irq; > unsigned long flags; > u32 *intids; > @@ -350,7 +351,9 @@ int vgic_copy_lpi_list(struct kvm *kvm, struct kvm_vcpu *vcpu, u32 **intid_ptr) > return -ENOMEM; > > raw_spin_lock_irqsave(&dist->lpi_list_lock, flags); > - list_for_each_entry(irq, &dist->lpi_list_head, lpi_list) { > + rcu_read_lock(); > + > + xas_for_each(&xas, irq, U32_MAX) { Similar thing: we advertise 16 bits of ID space (described as INTERRUPT_ID_BITS_ITS), so capping at that level would make it more understandable. > if (i == irq_count) > break; > /* We don't need to "get" the IRQ, as we hold the list lock. */ > @@ -358,6 +361,8 @@ int vgic_copy_lpi_list(struct kvm *kvm, struct kvm_vcpu *vcpu, u32 **intid_ptr) > continue; > intids[i++] = irq->intid; > } > + > + rcu_read_unlock(); > raw_spin_unlock_irqrestore(&dist->lpi_list_lock, flags); > > *intid_ptr = intids; Thanks, M. -- Without deviation from the norm, progress is not possible.