From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id D34E91A0BF3 for ; Fri, 7 Nov 2025 10:06:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762509989; cv=none; b=UlJ4cW+qkyWPUgZEao3JYg9a1oIMd96ca4QOA0L7OoirIqHlRFERJzO55Yv72tS2cOnXMLSfZ/frwbjf/xyxKuQnvndLYFekjfTCk8A6/bAkU+pA5urAsghsS8RpIQdg4Ga/c56e6aLSgu2w2QuxYSPAa4D0Z6L9CncwWRk2/mE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762509989; c=relaxed/simple; bh=e1JOdRzLeuWX3PVxN52agD5YetnAyZ0LklkuKw8GlZM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=aFS7h+boi9HFKT+70QncswtxxSkX+3l9faG2wFisQz/TDh1Ft2KUfeNamD3hEzwEceIQqYV6i+jk3gMW2QQP4OztyWjsCVDUxA+8lZj5zCfLtERArrHXPx9ha49Pu4GFR9NXbe7CCzao9kDdJGEeOkPsiPwskYnuHemOuA+24e8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 7C75E14BF; Fri, 7 Nov 2025 02:06:18 -0800 (PST) Received: from [10.1.197.1] (ewhatever.cambridge.arm.com [10.1.197.1]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 496A53F66E; Fri, 7 Nov 2025 02:06:25 -0800 (PST) Message-ID: <264b9f2d-5fca-4fda-a0ce-1b0223906560@arm.com> Date: Fri, 7 Nov 2025 10:06:23 +0000 Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 0/3] KVM: arm64: Fix handling of ID_PFR1_EL1.GIC To: Marc Zyngier , kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org Cc: Joey Gouly , Oliver Upton , Zenghui Yu , Peter Maydell References: <20251030122707.2033690-1-maz@kernel.org> Content-Language: en-US From: Suzuki K Poulose In-Reply-To: <20251030122707.2033690-1-maz@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Hi Marc On 30/10/2025 12:27, Marc Zyngier wrote: > Peter reported[0] that restoring a GICv2 VM fails badly, and correctly > points out that ID_PFR1_EL1.GIC isn't writable, while its 64bit > equivalent is. I broke that in 6.12. > > The other thing is that fixing the ID regs at runtime isn't great. > specially when we could adjust them at the point where the GIC gets > created. > > This small series aims at fixing these issues. I've only tagged the > first one as a stable candidate. But, all 3 patches have the same Fixes tag, was that intentional ? Otherwise looks good. Suzuki With these fixes, I can happily > save/restore a GICv2 VM (both 32 and 64bit) on my trusty Synquacer. > > * From v1 [1]: > > - Make all 32bit ID regs writable > > - Use official accessors to manipulate ID regs > > - Rebased on 6.18-rc3 > > [0] https://lore.kernel.org/r/CAFEAcA8TpQduexT=8rdRYC=yxm_073COjzgWJAvc26_T+-F5vA@mail.gmail.com > [3] https://lore.kernel.org/r/20251013083207.518998-1-maz@kernel.org > > Marc Zyngier (3): > KVM: arm64: Make all 32bit ID registers fully writable > KVM: arm64: Set ID_{AA64PFR0,PFR1}_EL1.GIC when GICv3 is configured > KVM: arm64: Limit clearing of ID_{AA64PFR0,PFR1}_EL1.GIC to userspace > irqchip > > arch/arm64/kvm/sys_regs.c | 71 ++++++++++++++++++--------------- > arch/arm64/kvm/vgic/vgic-init.c | 14 ++++++- > 2 files changed, 50 insertions(+), 35 deletions(-) >