From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=217.140.110.172 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793621550; b=MdgDJDiE8++VDl4wslIoxTod4gtXbcUvLxm3YGF8HzT+itMwDDhsyMotqbcSMRp9a8wo R91TSnORA2Tu1hXo46NXb2b/aCH14IRzdlEleU9OfjfPgaPZJSHZlvVidSmFT85AvYNLT CYqq0JOfP1KgUfjdcQvil3VCm/tofHugP0O4vEU6W9WcrhfZkUQ3nXvp6f0wPBn5MwXLO Jr1QeLtzncE/jQGGySYD9XI1crX8+wvZpAGBIct4LJ1+sidf2sglRebRrbPSdBkFaFu2e q/vs7Hjay++P91A87C5ArGZrfGvcWNIKMeIDi/Ax2TZEiqgjdzvtQiLWX0dfOZh53JA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793621550; h=DMARC-Filter:Received:Received:DKIM-Signature:Date:From:To:Cc: Subject:Message-ID:References:MIME-Version:Content-Type: Content-Disposition:In-Reply-To; bh=42kWpsG9Z6lrlCHz9cuZnhbJ9wiLjaLNz5DpNtMKtpU=; b=KEWo9Gtq2wVl8vYpnuPuNpc8OFN4Qsi5P8LRbH7RSClHkhC2pO7n1ggrO1194IyfkJyd wXk5yEasPsGgmO4zysuoDKrlBvSEoaSrVo8x+nL6G/iCpcPbsVwkEFCLBgxBmxPFoS+1p 8rDPHKVf+NyedTZs8xorjD4TMMxAftU6Eu3IEeqxjEAA/R+QbA/nA7agV6qDY5+Hn1Kvt I6JhTKP7gpHT+tGBsx1xMSR0WB2ro5HUTQKOkyZ5Tq2h0MYFWEgOeJk0vK7ruSLf3bhm8 jKIc0xyntCZCCsT/ZxFRVJeLzw4wWcgY+vkzL3QjhN1TW9dReQRkX2lROKLBF+Uj6GQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass header.d=arm.com header.i=@arm.com header.a=rsa-sha256 header.s=foss header.b=lET5Iiwm; arc=none smtp.remote-ip=217.140.110.172 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 924AB606A324; Mon, 2 Nov 2026 12:12:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 924AB606A324 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 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=arm.com header.i=@arm.com header.a=rsa-sha256 header.s=foss header.b=lET5Iiwm 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 D8CBE153B; Mon, 2 Nov 2026 04:12:25 -0800 (PST) Received: from arm.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 258A73F59E; Mon, 2 Nov 2026 04:12:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1793621548; bh=LDLkhtz2J8kntAj62nqHKUXzSrEajnevTEiXeI9yeaA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=lET5IiwmXEcuJA3mJ7t/gUqnS0VPO7JCdGNxr0QsWHhd4sv5NHofA/ZHd5Z/g2OFK C4D2e3pSJmF97NDdhXdPHU9XbNr2LyxExsHN2futubQMCfp6EXS0Hf1fb/tvYlnBIG Ab1SR41yNpxvRZTecGKGt6tmMDPlI186uS1SMNcI= Date: Mon, 2 Nov 2026 12:12:24 +0000 From: Catalin Marinas To: Kameron Carr Cc: decui@microsoft.com, haiyangz@microsoft.com, mhklinux@outlook.com, wei.liu@kernel.org, arnd@arndb.de, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, lpieralisi@kernel.org, mark.rutland@arm.com, sudeep.holla@kernel.org, thuth@redhat.com, will@kernel.org Subject: Re: [PATCH v6 2/6] arm64: hyperv: Detect Hyper-V via RSI host call in CCA Realms Message-ID: References: <20261031001412.4150488-1-kameroncarr@linux.microsoft.com> <20261031001412.4150488-3-kameroncarr@linux.microsoft.com> X-Mailing-List: linux-arch@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261031001412.4150488-3-kameroncarr@linux.microsoft.com> On Fri, Oct 30, 2026 at 05:14:08PM -0700, Kameron Carr wrote: > When booting without ACPI, hyperv_detect_via_smccc() detects Hyper-V by > querying the SMCCC vendor hypervisor UID. In an Arm CCA Realm the SMCCC > call is handled by the RMM rather than by the hypervisor, so the > query never reaches Hyper-V and detection fails. > > When running in a Realm, forward ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID > to the host with RSI_HOST_CALL instead, which is how Hyper-V hypercalls > are issued from a Realm. > > This is done in the Hyper-V code rather than in the generic > arm_smccc_hypervisor_has_uuid() because the other users expect different > behavior. > > hyperv_init() is an early_initcall and runs before the secondary CPUs > are brought up, so a single __initdata host call structure is used > without locking. > > ACPI-based detection and non-Realm guests are unaffected. > > Signed-off-by: Kameron Carr This works for me, thanks. I replied to Dexuan clarifying my objection to v5 do the UUID check generically. -- Catalin