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=1793714506; b=OE1fhaXUEW1MiQiy+fQOeuvFh8PSDvOcdGsveWGP5O7rGC4E+eVcVN92YBjjA9mchr9f AO7xyRyRL5E4NdiGtaHNeKxxy5SuMoV9EwSct0Bzlrhp7WEUa1qX54INU3AixHpyUWxhi gYXCi9Ge+D+QZN/8jrOQz8mEvSNww8DyIAF/4XbbETIw07Fk2o5cTHvziWr7mWqMhUUiC DTMfPh7JmjotmWpjSStwlZcN1g2yE3RnRRVeDHleYJ4sFvc81B/PpTO6iNPSXA99/5QIC 0l1cYy/ESegEVXWv4sclBDVsHmk9TCnn4HF78Wa/mPYh8pAQS3f49qzPU9OFPbTxhCQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793714506; 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=aoEz3XDvNbQleGg7AGotOLvdqQR5gJ3dWjYehkJVEAg=; b=TjP+2PkKyGLutHrl2VC9AUNLNziDcMhaz4hG69Uh9IDrScxkewkUF/VIxxKX8J1bBQrx iuf/TkD9nI9dLNVU7sU7HSTg/bQR8UMqHBJlsIPKVt+KilBQyfOku176XQ8JpbW3DE5MA gcJItq/Md5/Qw+GDebBp2+zbktzsx+gzGJ7m5qStaseNPcM51deVeiN4n44+DQRvbQ6fa 3jrFH+KxZ79t3it1NTUjnO3VXUGD+DTYeC2XFu0x3yZCEyVUZO/M7VD/+JQssbh1BO6tG mZxnZMuw/YnWAEkz4QY00z0FvQdUKXDiTTx6B4jeXNfLrH7272mjf4OEHuN/GE6zd9w== 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=YwBrmiMc; 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 854756082BE5; Tue, 3 Nov 2026 14:01:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 854756082BE5 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=YwBrmiMc 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 4989C1595; Tue, 3 Nov 2026 06:01:40 -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 32A593F673; Tue, 3 Nov 2026 06:01:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1793714503; bh=wIZLjMr9MrBhBElX8/30eyxmo0F41I4lrfTa+wBa7tQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=YwBrmiMcxgxgc/oqB40Ht/y8m8LlWct0YtdnpHGGvzDuec16EtV7NY+oHv/hCetja 2f6zsYjxlTcIoz6eOMhAtSEfc75BbV73NZgTZSmw9FZPhcLeJhcnrlIilEq0T1jk4E 8CZPmtRTgv3jpFSsvkXhvGT+Q5XvXx7Avzo3Mwb8= Date: Tue, 3 Nov 2026 14:01:38 +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-kernel@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: On Mon, Nov 02, 2026 at 11:27:37AM -0800, Kameron Carr wrote: > On 11/2/2026 4:12 AM, Catalin Marinas wrote: > > 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. > > Thank you for your review and suggestions. > Your clarification makes sense. > > Is this a "Reviewed-by" or an "Acked-by"? I don't usually ack the hyperv patches as I don't know enough about it but given that I commented on this particular patch in v5: Reviewed-by: Catalin Marinas -- Catalin