From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta0.migadu.com (out-247.mta0.migadu.com [91.218.175.247]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 82B3E3321C2 for ; Tue, 22 Sep 2026 07:38:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.247 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790062726; cv=none; b=WxmdDG8t0W0UJHFTIvStBOSWz9awei9vHbVqM5lCcGCobtTioRTcE8ya/nMKA+vNc89d8SroXvnilo2tYq+PPo6GUKVczIEvX6weoq4sjbJ+s3zcgVeQwkFWEWGZmKfX69yT0bjcVPeVBvUgRvQfVRy4e09iWjCxr6VWg6w2VhY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790062726; c=relaxed/simple; bh=KUW89faoHHYWgqCz8nIDgkYnfX7c9yryPkJWlGTaNK8=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=mD6eGORsNSIJv4D0PW3ehn52NP7915GN3MCYFMD5zwLI3WAevFz5Jf26IAmehp+4xvna80+yYy/XBk9jLVu9QsrdvvQjO1MkpbCiR1VEN0UHZ/uajHEKGUnFYz3kKtl0C+D+za2yiteM3Od8kZmxRfsokboOIIZR24d9GlOBNX4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=OSYdRr0f; arc=none smtp.client-ip=91.218.175.247 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="OSYdRr0f" X-Envelope-To: kvmarm@lists.linux.dev DKIM-Signature: a=rsa-sha256; bh=KUW89faoHHYWgqCz8nIDgkYnfX7c9yryPkJWlGTaNK8=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1790062722; v=1; x=1790667522; b=OSYdRr0fGPy2D1S9U6xWX44CKWx8Jjqulhl3rC8oOpJmHxUI/awWk1r6QZM5OP8myxIOJ4ok 2VV1cRSlHUw7Cr9E/KDDuOLQwAgl7TzHbTaEVNDqnjdxaKfCAp9QoqQDs/jNsYTS73ONi/G8Xal nsdXNFzMKRDOT0gXbXJuvH1M= X-Envelope-To: kvmarm@lists.linux.dev Received: by smtp.migadu.com with ESMTPS id 2b90d64f45864352; Tue, 22 Sep 2026 07:38:42 +0000 X-Mizu-Trace-ID: 2b90d64f45864352 X-Migadu-Flow: FLOW_OUT From: Fuad Tabba To: maz@kernel.org, oupton@kernel.org, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org Cc: catalin.marinas@arm.com, will@kernel.org, joey.gouly@arm.com, seiden@linux.ibm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, mark.rutland@arm.com, vdonnefort@google.com, qperret@google.com, Sascha.Bischoff@arm.com, steven.price@arm.com Subject: Re: [PATCH 6/7] KVM: arm64: vgic: Do not access the GICv5 CPU interface from EL1 Date: Tue, 22 Sep 2026 08:38:37 +0100 Message-Id: <20260922073837.705872-1-fuad.tabba@linux.dev> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20260915123846.2317931-7-fuad.tabba@linux.dev> References: <20260915123846.2317931-1-fuad.tabba@linux.dev> <20260915123846.2317931-7-fuad.tabba@linux.dev> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Hi, On Tue, 15 Sep 2026 13:38:45 +0100, Fuad Tabba wrote: > can_access_vgic_from_kernel() excludes only the GICv3 system register > interface, so on a native GICv5 system without FEAT_GCIE_LEGACY it > returns true under nVHE. The kernel then saves and restores the CPU > interface from EL1, where ICH_VMCR_EL2 and the ICH_PPI_* registers are > UNDEFINED, and the nVHE world switch already does that work at EL2. FWIW, I've since run this on the FVP GICv5 model (support_virtualization=1, kvm-arm.mode=nvhe). On kvmarm/next at 23ddf997ab16b the vgic_v5 selftest oopses the host at the first KVM_RUN: Internal error: Oops - Undefined instruction: 0000000002000000 [#1] SMP pc : __vgic_v5_restore_ppi_state+0x10/0x9c lr : vgic_v5_restore_state+0x28/0x3c Code: d503245f a941240a d0012448 91160108 (d51cca0a) d51cca0a is the ICH_PPI_DVIR0_EL2 write, from EL1. With this patch applied the same run passes. Cheers, /fuad