From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id C441925A636; Fri, 17 Jan 2025 17:01:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737133308; cv=none; b=XbvmIu6vMXAlkLx+MvAOyVv/QJjIY72t3uQRg399m874JXmo8giYonWuozWGtdNtzGfNp8FBAXOOZYTEKaNQHNjvokTBmUd7JiGVn9VpqwQXaLSADGd/V6AzKXYZkEJCk+WU/cMgbibDbNJaFXHHEcQlcmBAMQrBNG/yy7kvLwM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737133308; c=relaxed/simple; bh=0L/L+VwLhP+2Nz4Sawes6nA9aPBfVtIcEpeDR3mt4zc=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=AWFaWVeJCRD/TRfgzy9RPazmKEukZswD7cS9bjHlHWDDSm+B/bLOrRKD+uFTtWrSGCsneEGqxogBoTgpQoBvSWj1iOqQ9yUHxMYkvde1Fm7P+GQrZ8jeHsU4uptFCvETt+rM57/RYOF+G+XKkSmqlDUdUyXvdLSBBMkQidSdMHA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=HS4WmeOg; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="HS4WmeOg" Received: from romank-3650.corp.microsoft.com (unknown [131.107.160.188]) by linux.microsoft.com (Postfix) with ESMTPSA id 11C7820BEBE1; Fri, 17 Jan 2025 09:01:42 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 11C7820BEBE1 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1737133304; bh=gSmaDm3F5c/wG4BQ++dl12j488dT0JYhFCB3CqlNhg8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HS4WmeOgnXuDYcJVkdO+Cau47LBdiWPRTYuWGWzHEfkXDleKE09vZg9dx0ZI/ry8E gxXP83hYcUsv2Km55FsdW+P2QlIICSYllQpe0YXGgpji50L+GgiM3mEL0ZcAhO38fh sc3v99rK9cVktCa/ZdF1aVyQglLLMp0sM/9QBgIQ= From: Roman Kisel To: namjain@linux.microsoft.com Cc: bp@alien8.de, dave.hansen@linux.intel.com, decui@microsoft.com, haiyangz@microsoft.com, kys@microsoft.com, linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, mingo@redhat.com, ssengar@linux.microsoft.com, tglx@linutronix.de, wei.liu@kernel.org, x86@kernel.org Subject: [PATCH] x86/hyperv/vtl: Stop kernel from probing VTL0 low memory Date: Fri, 17 Jan 2025 09:01:41 -0800 Message-Id: <20250117170141.1351283-1-romank@linux.microsoft.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250116061224.1701-1-namjain@linux.microsoft.com> References: <20250116061224.1701-1-namjain@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-hyperv@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit > For Linux, running in Hyper-V VTL (Virtual Trust Level), kernel in VTL2 > tries to access VTL0 low memory in probe_roms. This memory is not > described in the e820 map. Initialize probe_roms call to no-ops > during boot for VTL2 kernel to avoid this. The issue got identified > in OpenVMM which detects invalid accesses initiated from kernel running > in VTL2. > > Co-developed-by: Saurabh Sengar > Signed-off-by: Saurabh Sengar > Signed-off-by: Naman Jain > --- > arch/x86/hyperv/hv_vtl.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/x86/hyperv/hv_vtl.c b/arch/x86/hyperv/hv_vtl.c > index 4e1b1e3b5658..3f4e20d7b724 100644 > --- a/arch/x86/hyperv/hv_vtl.c > +++ b/arch/x86/hyperv/hv_vtl.c > @@ -30,6 +30,7 @@ void __init hv_vtl_init_platform(void) > x86_platform.realmode_init = x86_init_noop; > x86_init.irqs.pre_vector_init = x86_init_noop; > x86_init.timers.timer_init = x86_init_noop; > + x86_init.resources.probe_roms = x86_init_noop; > > /* Avoid searching for BIOS MP tables */ > x86_init.mpparse.find_mptable = x86_init_noop; > > base-commit: 37136bf5c3a6f6b686d74f41837a6406bec6b7bc > -- > 2.43.0 Thanks, Naman! Tested-by: Roman Kisel Reviewed-by: Roman Kisel