From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id ED2DA606A324 for ; Mon, 2 Nov 2026 19:27:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=1iLIQ4IT; dkim=pass (1024-bit key, unprotected) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.a=rsa-sha256 header.s=default header.b=TO39YtUd 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-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Unsubscribe-Post: List-Owner; bh=9R7rn27BTvQI3HlJKKfu8p/MBYgn8iEr6X7HO0Xk9Xo=; b=1iLIQ4ITZYzFg0 sD2PAjvpG0eRgflJCmZ9sU0NaDLJ5KnO7j84SWSz0JAUFF9mklY2rHTFkQZmBw8BRbQWMRiHzYYCo lA3AWR/ysq2/lCNemjQ4yZIYu2Qgd1xBbth+NVX9y+WwplFTDsLvwOcMDljWxI4ASUNSbnFZtd4Fr VvS1eBuf0gNdM58TAjnraLkV2sFY/xDgORl1J0dAxROAFzzDvgzyxmSwHxQcrNJb1q/029xiy+qSp AXSoJonVMCo+05VLiWKg25J+n/K8+07h1WQh5571hEk6aw0vWv/u/LxE9JiyNIUNyOyGPDvNUeLHW J5L8F6lNA/kGUzNXaN+g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xNxgt-0000000069r-46UR; Mon, 02 Nov 2026 19:27:35 +0000 Received: from linux.microsoft.com ([13.77.154.182]) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xNxgs-0000000069C-01z5 for linux-arm-kernel@lists.infradead.org; Mon, 02 Nov 2026 19:27:35 +0000 Received: from [10.4.158.9] (unknown [131.107.174.137]) by linux.microsoft.com (Postfix) with ESMTPSA id 6549D20B7166; Mon, 2 Nov 2026 11:27:18 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 6549D20B7166 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1793647638; bh=9R7rn27BTvQI3HlJKKfu8p/MBYgn8iEr6X7HO0Xk9Xo=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=TO39YtUd3Cf/StF0QdPN6j/y4FbKs8B4iukuDInUIKTsVQ1LEzXCfdknb5uZ9yR6g 3ho611vKzzuwp3vFYIg+aRD3vGJGC8lACS0ButV7faA5pYvf3tsTfix5VvL1wLluTa L28VqbIrKkdSC4GVW4GL5tz22IwvjhYGEzwbQOdg= Message-ID: Date: Mon, 2 Nov 2026 11:27:37 -0800 X-Archived-By: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v6 2/6] arm64: hyperv: Detect Hyper-V via RSI host call in CCA Realms To: Catalin Marinas 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 References: <20261031001412.4150488-1-kameroncarr@linux.microsoft.com> <20261031001412.4150488-3-kameroncarr@linux.microsoft.com> Content-Language: en-US From: Kameron Carr In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-12.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261102_112734_073296_FA0FF363 X-CRM114-Status: GOOD ( 12.58 ) X-Spam-Score: -2.1 (--) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" 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"? -- Regards, Kameron