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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5E84EC87FC9 for ; Tue, 29 Jul 2025 18:05:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To: Content-Transfer-Encoding:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=40dRevb3+VbSqC7PTRUcFwY+Be9Qk1uzZ2DAmm4HBNw=; b=YYQo7Bc4jO8WgOfaFvqUbVdv8p fHvk2viEl88JZt1/aulx5a1KoQ4K576deN4VugTRNfRb347sdxmT/O5guZMBYfe1+AcEQxbtjy+/5 Xd9K5RCnSq+3Tud8dDrEEPl24f5QDfVFrRHoUmHkT2543oA5L+fc4e6MA5CEVuOo/ssFC+He/rQUj nvFAtLiHZUueboeSkBGNSAtQD78GIf2w7fhTiv31wA66R5Ec4vUgFNuysJM1cIAWm04K+ubvY80dp UU6aMt6oETdh4RW2Eo0JeYICuSnD8f/pkUfWP1ERrlILkdO2NVtnDyqwFeMOrtYtmPi6Fm7SWPYwh 0wED/VvQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1ugohm-0000000HPsg-15gq; Tue, 29 Jul 2025 18:05:38 +0000 Received: from out-180.mta0.migadu.com ([2001:41d0:1004:224b::b4]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1ugofH-0000000HPj6-1yFO for linux-arm-kernel@lists.infradead.org; Tue, 29 Jul 2025 18:03:06 +0000 Date: Tue, 29 Jul 2025 11:02:51 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1753812179; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=40dRevb3+VbSqC7PTRUcFwY+Be9Qk1uzZ2DAmm4HBNw=; b=GmGwuBcwRjVOq4k7VEaTkmwB4av+swJA7Ghf530CDjC3cjGYHKELbUrsUe5cNnN0x2nl8u crfORW5dyCulim6P3KozhWBhcHoTKE7BsYNr7i2eGyjitZ6rDF2Lw5vnNxVZxxelul6ht+ VdArZIn5ZLyadHML5z3tqLhb03CgPcU= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Oliver Upton To: Raghavendra Rao Ananta Cc: Marc Zyngier , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Subject: Re: [PATCH] KVM: arm64: Set/unset vGIC v4 forwarding if direct IRQs are supported Message-ID: References: <20250728223710.129440-1-rananta@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Migadu-Flow: FLOW_OUT X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250729_110303_720262_F5B65C2E X-CRM114-Status: GOOD ( 22.90 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Jul 29, 2025 at 09:56:12AM -0700, Raghavendra Rao Ananta wrote: > On Tue, Jul 29, 2025 at 7:37 AM Oliver Upton wrote: > > > > Hi Raghu, > > > > Thanks for reporting this so quickly :) > > > > On Mon, Jul 28, 2025 at 10:37:10PM +0000, Raghavendra Rao Ananta wrote: > > > diff --git a/arch/arm64/kvm/vgic/vgic-v4.c b/arch/arm64/kvm/vgic/vgic-v4.c > > > index e7e284d47a77..873a190bcff7 100644 > > > --- a/arch/arm64/kvm/vgic/vgic-v4.c > > > +++ b/arch/arm64/kvm/vgic/vgic-v4.c > > > @@ -433,7 +433,7 @@ int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq, > > > unsigned long flags; > > > int ret = 0; > > > > > > - if (!vgic_supports_direct_msis(kvm)) > > > + if (!vgic_supports_direct_irqs(kvm)) > > > return 0; > > > > > > /* > > > @@ -533,7 +533,7 @@ int kvm_vgic_v4_unset_forwarding(struct kvm *kvm, int host_irq) > > > unsigned long flags; > > > int ret = 0; > > > > > > - if (!vgic_supports_direct_msis(kvm)) > > > + if (!vgic_supports_direct_irqs(kvm)) > > > return 0; > > > > I'm not sure this is what we want, since a precondition of actually > > doing vLPI injection is the guest having an ITS. Could you try the > > following? > > > > Thanks, > > Oliver > > > > diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v3.c b/arch/arm64/kvm/vgic/vgic-mmio-v3.c > > index a3ef185209e9..70d50c77e5dc 100644 > > --- a/arch/arm64/kvm/vgic/vgic-mmio-v3.c > > +++ b/arch/arm64/kvm/vgic/vgic-mmio-v3.c > > @@ -50,6 +50,14 @@ bool vgic_has_its(struct kvm *kvm) > > > > bool vgic_supports_direct_msis(struct kvm *kvm) > > { > > + /* > > + * Deliberately conflate vLPI and vSGI support on GICv4.1 hardware, > > + * indirectly allowing userspace to control whether or not vPEs are > > + * allocated for the VM. > > + */ > > + if (system_supports_direct_sgis() && !vgic_supports_direct_sgis(kvm)) > > + return false; > > + > > return kvm_vgic_global_state.has_gicv4 && vgic_has_its(kvm); > > } > > > > diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h > > index 1384a04c0784..de1c1d3261c3 100644 > > --- a/arch/arm64/kvm/vgic/vgic.h > > +++ b/arch/arm64/kvm/vgic/vgic.h > > @@ -396,15 +396,7 @@ bool vgic_supports_direct_sgis(struct kvm *kvm); > > > > static inline bool vgic_supports_direct_irqs(struct kvm *kvm) > > { > > - /* > > - * Deliberately conflate vLPI and vSGI support on GICv4.1 hardware, > > - * indirectly allowing userspace to control whether or not vPEs are > > - * allocated for the VM. > > - */ > > - if (system_supports_direct_sgis()) > > - return vgic_supports_direct_sgis(kvm); > > - > > - return vgic_supports_direct_msis(kvm); > > + return vgic_supports_direct_msis(kvm) || vgic_supports_direct_sgis(kvm); > > } > > > > int vgic_v4_init(struct kvm *kvm); > > Yes, the diff seems fine (tested as well). Would you be pushing a v2 > or do you want me to (on your behalf)? Go ahead and respin this diff, thanks! Oliver