From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta1.migadu.com (out-59.mta1.migadu.com [95.215.58.59]) (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 4B89A3B2FFC for ; Mon, 17 Aug 2026 10:32:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.59 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786962771; cv=none; b=k29hwFKIDek6hmy+zOkb5GsH03U4zuDV+d3by8xk/ELZvOhre1u2VlmD5gShhDQjAUMoh1gKBuWbo3Y2FoMrEFr59OyevZhP+iFPhKaDrBOSXqira51qztt2NzeDqBWL7eGEwu9bdCjB7ex2C0AyDonmtApE/wUy1sLNJ6IVRB8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786962771; c=relaxed/simple; bh=+Voqs9fAmTLL/s31z+dkjB9bPNGxddhWAjF+IcSVPVE=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=UGtzB6pdouAPtHFfbqYAGI4MDRaKugNo/6ZZRo+Tant07EeEBUpiPYjCMkHG2d+V6K+y/fHfVcturIrp/K3LRSzt+TXZWX6xMYz08fa8Ql1QFxalRmrB6AaXi9c7YEEBzDHRQZ9pDCCXm+N/m9exk/7c1Rnrw8JYalECn20XEBA= 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=FoF1b/Hs; arc=none smtp.client-ip=95.215.58.59 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="FoF1b/Hs" X-Envelope-To: kvmarm@lists.linux.dev DKIM-Signature: a=rsa-sha256; bh=+Voqs9fAmTLL/s31z+dkjB9bPNGxddhWAjF+IcSVPVE=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1786962766; v=1; x=1787567566; b=FoF1b/Hsy2TRdJ2C0KsApUN5kPhnPO+RebhnRmetmjNMvDjUwHZ4pVfkT9fQ8gKdgM+t4d9k jzkHI2AhmWMhQNXbimV5I7JBUmHFuvJ2PBE8JI3yDNS/gsEUNzW5IBoqISst0gFqe+CYTGyJY1D aaIzfTmUIkocvZx9VmUzBoDA= X-Envelope-To: kvmarm@lists.linux.dev Received: from claudy.lan (37.156.72.212) by smtp.migadu.com with ESMTPS id dd3bab2071ab8f95; Mon, 17 Aug 2026 10:32:46 +0000 X-Migadu-Flow: FLOW_OUT From: Fuad Tabba To: Marc Zyngier , Oliver Upton , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org Cc: Fuad Tabba , Will Deacon , Catalin Marinas , Joey Gouly , Suzuki K Poulose , Zenghui Yu , Sascha Bischoff Subject: [PATCH v2 3/4] KVM: arm64: vgic: Do not access the GICv5 CPU interface from EL1 Date: Mon, 17 Aug 2026 11:32:27 +0100 Message-Id: <20260817103228.1203140-4-fuad.tabba@linux.dev> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20260817103228.1203140-1-fuad.tabba@linux.dev> References: <20260817103228.1203140-1-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 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. Require VHE for GICv5 as for GICv3. Fixes: 9b8e3d4ca0e73 ("KVM: arm64: gic-v5: Implement GICv5 load/put and save/restore") Reviewed-by: Sascha Bischoff Signed-off-by: Fuad Tabba --- arch/arm64/kvm/vgic/vgic.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c index 74bace10a22ed..df58c0042ed63 100644 --- a/arch/arm64/kvm/vgic/vgic.c +++ b/arch/arm64/kvm/vgic/vgic.c @@ -1042,11 +1042,15 @@ static void vgic_flush_lr_state(struct kvm_vcpu *vcpu) static inline bool can_access_vgic_from_kernel(void) { /* - * GICv2 can always be accessed from the kernel because it is - * memory-mapped, and VHE systems can access GICv3 EL2 system - * registers. + * GICv3 and GICv5 drive the CPU interface through EL2 system + * registers, so only VHE reaches them from the kernel. GICv2 is + * memory-mapped and always reachable. */ - return !static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif) || has_vhe(); + if (kvm_vgic_global_state.type == VGIC_V5 || + static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) + return has_vhe(); + + return true; } static inline void vgic_save_state(struct kvm_vcpu *vcpu) -- 2.39.5