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 AFCADEDF16E for ; Fri, 13 Feb 2026 14:38:29 +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:Content-Type:Cc:To:From: Subject:Message-ID:References:Mime-Version:In-Reply-To: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=ZI3PiRBCJaOtbE31TrtopwnjhpEV4zI9W7Z3S9kmPS8=; b=BWOhtK58/VSLHLw7LqjX3WyrSi sPcAL2lSby0A4y1IGLXeE9ZVJMSrLZ8f4Fa21boC8tFHU6soFpEvpSN1JcuYUVKi6wRdI4yereg6h W1pojfG7orQDXVWQv+i5sNEqgDLVzGE64lPwxGYMWslVjpybgQeHF7PVNXUMzCFE02A3hJ6K32bHW SRdGk26Ssuo0yxFYsJ/rsYn/EcqijUWInmDhIuDFC1rmqzPGLHtRZHZSKVRwGcq3kF1ukRhdenhwR D5rZ7xHNlRmO2zfBUXPp+qLWTd5S1r/qFamRoSQ12L3DLeSvgVYOzdOLCmes+2MjypSgOtjwO4U/p GTLGI1ag==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vquJM-00000003XvC-3FJB; Fri, 13 Feb 2026 14:38:24 +0000 Received: from mail-wm1-x34a.google.com ([2a00:1450:4864:20::34a]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vquJH-00000003XsW-30BB for linux-arm-kernel@lists.infradead.org; Fri, 13 Feb 2026 14:38:21 +0000 Received: by mail-wm1-x34a.google.com with SMTP id 5b1f17b1804b1-4836c819456so13083125e9.3 for ; Fri, 13 Feb 2026 06:38:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1770993497; x=1771598297; darn=lists.infradead.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=ZI3PiRBCJaOtbE31TrtopwnjhpEV4zI9W7Z3S9kmPS8=; b=D0nXGcp0Qd3ehEfFpoEJKAwlPXpdwnIm/0+TaUn05woBy70TaQd4Vmhr1FIn1BwZ9W F4Sxl53BOLw95VEQsQel0shZK8b4vlQzAzDgprHVYkmQE27BrZp3klvOSEqc4JKE8Xm1 7ShZ8q+JBLvlXW1mgsgWi4AVJAsBCf/wr0DEeSEdcK4vDBsynw89ADAAkysuvnuxRUpG hfSsfhx8s+psdwb67VnqSt1qnxazX18QkSg0s4KAIdwDdWx/xMC6N6qksvo0W7i1F40I WpZgJnhd7YRXqrGZADg0kuhwu99WVxcCodnx8hwClc3ZB6wxrIkNY3ZSmTblWE6Vs5Xm bj4w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1770993497; x=1771598297; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=ZI3PiRBCJaOtbE31TrtopwnjhpEV4zI9W7Z3S9kmPS8=; b=WhXc54x/F2dSw0Z5j94LmuMbNhkBdyQakqVyYQqHlOXt0XG5DSCcSweTEwvXwVLseB 3NToE1PqRQsrlfqac8SSzrEwXO0YsiII++rKhPsy+88guP57de2/nSOCG3qnpTp7iAxV Dfz9G2zFAbR6XrmGuWlVXhe9II3oddaDgMtvkkprKypKYrOt+XvpQXzWZaO6mSomYKMj XQ92kcWJPm4C+tqVpCOGSxMCsV4ocFrsWl21jckevW6UipBEooCyc6vwiojdnrF1IE2b AuGF5ix0vNKelr3umRe1x5cHD3mlLJH6mke1Ck9AV9v+sUhgUvjrEhZT4NVOdFyLNGSx HfAA== X-Forwarded-Encrypted: i=1; AJvYcCVm7w22c0ORR4TThWoezhnCs2ztMJqKsDu866266Fftfx8mZ7GGQwqwDI3ww5k3k+Z3utyt7cagWklj1mUjXxSp@lists.infradead.org X-Gm-Message-State: AOJu0YySfiHupgVbSJXJYCdcSchn/Ex/b1vhE12k/yGDeN8NrUidasvv l7SCI25zzrcltNXPYbh/R/c8ktqlhY0GgFGt9Ucwwq7kVUVh/TLPdjTb1KAOti7rh8VYPs2aN29 q4A== X-Received: from wmbz20.prod.google.com ([2002:a05:600c:c094:b0:47b:d5ad:dd7f]) (user=tabba job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:474e:b0:480:4be7:4f53 with SMTP id 5b1f17b1804b1-48371095fa6mr56214175e9.31.1770993497276; Fri, 13 Feb 2026 06:38:17 -0800 (PST) Date: Fri, 13 Feb 2026 14:38:12 +0000 In-Reply-To: <20260213143815.1732675-1-tabba@google.com> Mime-Version: 1.0 References: <20260213143815.1732675-1-tabba@google.com> X-Mailer: git-send-email 2.53.0.273.g2a3d683680-goog Message-ID: <20260213143815.1732675-2-tabba@google.com> Subject: [PATCH v2 1/4] KVM: arm64: Hide S1POE from guests when not supported by the host From: Fuad Tabba To: kvm@vger.kernel.org, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org Cc: maz@kernel.org, oliver.upton@linux.dev, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, catalin.marinas@arm.com, will@kernel.org, tabba@google.com, stable@vger.kernel.org Content-Type: text/plain; charset="UTF-8" X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260213_063819_766118_885F627A X-CRM114-Status: GOOD ( 12.50 ) 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 When CONFIG_ARM64_POE is disabled, KVM does not save/restore POR_EL1. However, ID_AA64MMFR3_EL1 sanitisation currently exposes the feature to guests whenever the hardware supports it, ignoring the host kernel configuration. If a guest detects this feature and attempts to use it, the host will fail to context-switch POR_EL1, potentially leading to state corruption. Fix this by masking ID_AA64MMFR3_EL1.S1POE in the sanitised system registers, preventing KVM from advertising the feature when the host does not support it (i.e. system_supports_poe() is false). Fixes: 70ed7238297f ("KVM: arm64: Sanitise ID_AA64MMFR3_EL1") Signed-off-by: Fuad Tabba --- arch/arm64/kvm/sys_regs.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 88a57ca36d96..237e8bd1cf29 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1816,6 +1816,9 @@ static u64 __kvm_read_sanitised_id_reg(const struct kvm_vcpu *vcpu, ID_AA64MMFR3_EL1_SCTLRX | ID_AA64MMFR3_EL1_S1POE | ID_AA64MMFR3_EL1_S1PIE; + + if (!system_supports_poe()) + val &= ~ID_AA64MMFR3_EL1_S1POE; break; case SYS_ID_MMFR4_EL1: val &= ~ID_MMFR4_EL1_CCIDX; -- 2.53.0.273.g2a3d683680-goog