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 1B51CCCD1BE for ; Wed, 22 Oct 2025 07:05:12 +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-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=6XSSTLCS1TZ0ZhjGf5BQOvNt71mRr5p/Fed2+JopWuw=; b=mT/Srj9Gx5LsYMzE6Ny/gn3nRW +Jlr55yk4J28/Cc8e6++ma1KErFMb0PPqC3rRUbU14j0IUlRWlymQTh1VUzhk8n45PMqNrbVKxFyS V+ZpVEARfa973PNAt4rRUOtMRrhWDPLKIuORW6P26YVIbZXzcij1BfBq70C2IS32djjcF5x+WTLzb 8d7ddK+FDBKZC9w96JsvA0kivX98nZP38hX0fgXmmLuEDsbtfJRfV/tfn05O6bSVrIXLCZ21tfwdE QrtRayg9SvAr2yPeGYWssfEC1+rSCwch+XEtYKTdb0LSgEqJoh+23g3ZLr54bsE2l1Gni+pZFG3UZ m+9QfTlw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vBSu9-00000001mzb-2D55; Wed, 22 Oct 2025 07:05:05 +0000 Received: from out-183.mta0.migadu.com ([91.218.175.183]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vBSu6-00000001myp-40jD for linux-arm-kernel@lists.infradead.org; Wed, 22 Oct 2025 07:05:04 +0000 Date: Wed, 22 Oct 2025 00:04:55 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1761116700; 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: in-reply-to:in-reply-to:references:references; bh=6XSSTLCS1TZ0ZhjGf5BQOvNt71mRr5p/Fed2+JopWuw=; b=o/ARPoIjdXq6DC7H4kMGg4IR7zH3Hgd+Sg9m5PjudMvw7zpP2FrsbHRwuTGQIg9fo+7VjT WTVtZRRdybkM+TAP2GoWyEkmZyzF7wMMWGEHT7FSeIB/zIXpG0/IfptMg2Xu+vv86JonuS E3DxBLhe4VLPTAuSc4NwP7tpk1EzbC0= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Oliver Upton To: Marc Zyngier Cc: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, Joey Gouly , Suzuki K Poulose , Zenghui Yu , Peter Maydell Subject: Re: [PATCH 2/3] KVM: arm64: Set ID_{AA64PFR0,PFR1}_EL1.GIC when GICv3 is configured Message-ID: References: <20251013083207.518998-1-maz@kernel.org> <20251013083207.518998-3-maz@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251013083207.518998-3-maz@kernel.org> X-Migadu-Flow: FLOW_OUT X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251022_000503_162888_7AE748BF X-CRM114-Status: GOOD ( 14.73 ) 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 Mon, Oct 13, 2025 at 09:32:06AM +0100, Marc Zyngier wrote: > Drive the idreg fields indicating the presence of GICv3 directly from > the vgic code. This avoids having to do any sort of runtime clearing > of the idreg. > > Fixes: 5cb57a1aff755 ("KVM: arm64: Zero ID_AA64PFR0_EL1.GIC when no GICv3 is presented to the guest") > Signed-off-by: Marc Zyngier > --- > arch/arm64/kvm/vgic/vgic-init.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c > index 4c3c0d82e4760..2c518b0a4d81b 100644 > --- a/arch/arm64/kvm/vgic/vgic-init.c > +++ b/arch/arm64/kvm/vgic/vgic-init.c > @@ -161,10 +161,16 @@ int kvm_vgic_create(struct kvm *kvm, u32 type) > > kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF; > > - if (type == KVM_DEV_TYPE_ARM_VGIC_V2) > + *__vm_id_reg(&kvm->arch, SYS_ID_AA64PFR0_EL1) &= ~ID_AA64PFR0_EL1_GIC; > + *__vm_id_reg(&kvm->arch, SYS_ID_PFR1_EL1) &= ~ID_PFR1_EL1_GIC; I'd prefer this to be done as a kvm_read_vm_id_reg() / kvm_set_vm_id_reg(), if only to ensure this flow hits the config_lock lockdep assertion like other writers of the ID registers. Thanks, Oliver