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 BA0CDC369B2 for ; Mon, 14 Apr 2025 22:54:10 +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-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=NYi43WhtS1hVthbgtuaLVNWnlw3+yXhxoNWNK/Qb6Jg=; b=zN2//KC8G4bei0QMdufORoVdBe E0sZgDdbrGK2DXtYG0wgzsvdDAWt0AFrt3qpsz2+mNq33ND4g61VwuVo9/Q2DWYEhGKRW4p3ipqKu YJWPsRpyxZFwcGzYdRshYdlAlxmrZ7AgBSmTd6IssgV3LyVkUsvgxvpWen7exY87ptAfQJvtkqZUX /xlI/5RVtqY0YHyvNoKMZUKWV9xv8sbJt+bCR9SyrIAMJKvR24BWt4kbL3oOGnItNCPx+a8v86j9O xLCbnigNd4JqboxqOOZHqtnS78n01w8StGHWe9/LFc1nH5YEf0v6d/a7fUMfwbnxdqgFtpPwKeMQd W5EE+ymA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1u4Sgi-00000003mZ7-2F3j; Mon, 14 Apr 2025 22:54:00 +0000 Received: from linux.microsoft.com ([13.77.154.182]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1u4SaD-00000003l2q-3AAu for linux-arm-kernel@lists.infradead.org; Mon, 14 Apr 2025 22:47:20 +0000 Received: from romank-3650.corp.microsoft.com (unknown [131.107.159.188]) by linux.microsoft.com (Postfix) with ESMTPSA id 9D7CF210C42D; Mon, 14 Apr 2025 15:47:15 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 9D7CF210C42D DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1744670835; bh=NYi43WhtS1hVthbgtuaLVNWnlw3+yXhxoNWNK/Qb6Jg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FOZ335NEPx1NnMrhoMAyeAlWfWIw/LtKYiNBBk0X0NRof/x+k37UKIbRtvWAiV88R 6s6uqWrG6LuFFUR2ekZSO9z0fgE9DMa5B4gAwBqGAjVzP7mecGMmYJ1qjp12aZORE7 3tXtmvohB+dh4XBKgmZUN2qIFOilUz00BouvElAk= From: Roman Kisel To: arnd@arndb.de, bhelgaas@google.com, bp@alien8.de, catalin.marinas@arm.com, conor+dt@kernel.org, dan.carpenter@linaro.org, dave.hansen@linux.intel.com, decui@microsoft.com, haiyangz@microsoft.com, hpa@zytor.com, joey.gouly@arm.com, krzk+dt@kernel.org, kw@linux.com, kys@microsoft.com, lenb@kernel.org, lpieralisi@kernel.org, manivannan.sadhasivam@linaro.org, mark.rutland@arm.com, maz@kernel.org, mingo@redhat.com, oliver.upton@linux.dev, rafael@kernel.org, robh@kernel.org, rafael.j.wysocki@intel.com, ssengar@linux.microsoft.com, sudeep.holla@arm.com, suzuki.poulose@arm.com, tglx@linutronix.de, wei.liu@kernel.org, will@kernel.org, yuzenghui@huawei.com, devicetree@vger.kernel.org, kvmarm@lists.linux.dev, linux-acpi@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, x86@kernel.org Cc: apais@microsoft.com, benhill@microsoft.com, bperkins@microsoft.com, sunilmut@microsoft.com Subject: [PATCH hyperv-next v8 02/11] arm64: hyperv: Use SMCCC to detect hypervisor presence Date: Mon, 14 Apr 2025 15:47:04 -0700 Message-ID: <20250414224713.1866095-3-romank@linux.microsoft.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250414224713.1866095-1-romank@linux.microsoft.com> References: <20250414224713.1866095-1-romank@linux.microsoft.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250414_154717_842384_ECB87589 X-CRM114-Status: GOOD ( 15.30 ) 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 The arm64 Hyper-V startup path relies on ACPI to detect running under a Hyper-V compatible hypervisor. That doesn't work on non-ACPI systems. Hoist the ACPI detection logic into a separate function. Then use the vendor-specific hypervisor service call (implemented recently in Hyper-V) via SMCCC in the non-ACPI case. Signed-off-by: Roman Kisel --- arch/arm64/hyperv/mshyperv.c | 50 ++++++++++++++++++++++++++++++++---- 1 file changed, 45 insertions(+), 5 deletions(-) diff --git a/arch/arm64/hyperv/mshyperv.c b/arch/arm64/hyperv/mshyperv.c index 4e27cc29c79e..21458b6338aa 100644 --- a/arch/arm64/hyperv/mshyperv.c +++ b/arch/arm64/hyperv/mshyperv.c @@ -28,6 +28,48 @@ int hv_get_hypervisor_version(union hv_hypervisor_version_info *info) } EXPORT_SYMBOL_GPL(hv_get_hypervisor_version); +#ifdef CONFIG_ACPI + +static bool __init hyperv_detect_via_acpi(void) +{ + if (acpi_disabled) + return false; + /* + * Hypervisor ID is only available in ACPI v6+, and the + * structure layout was extended in v6 to accommodate that + * new field. + * + * At the very minimum, this check makes sure not to read + * past the FADT structure. + * + * It is also needed to catch running in some unknown + * non-Hyper-V environment that has ACPI 5.x or less. + * In such a case, it can't be Hyper-V. + */ + if (acpi_gbl_FADT.header.revision < 6) + return false; + return strncmp((char *)&acpi_gbl_FADT.hypervisor_id, "MsHyperV", 8) == 0; +} + +#else + +static bool __init hyperv_detect_via_acpi(void) +{ + return false; +} + +#endif + +static bool __init hyperv_detect_via_smccc(void) +{ + uuid_t hyperv_uuid = UUID_INIT( + 0x58ba324d, 0x6447, 0x24cd, + 0x75, 0x6c, 0xef, 0x8e, + 0x24, 0x70, 0x59, 0x16); + + return arm_smccc_hypervisor_has_uuid(&hyperv_uuid); +} + static int __init hyperv_init(void) { struct hv_get_vp_registers_output result; @@ -36,13 +78,11 @@ static int __init hyperv_init(void) /* * Allow for a kernel built with CONFIG_HYPERV to be running in - * a non-Hyper-V environment, including on DT instead of ACPI. + * a non-Hyper-V environment. + * * In such cases, do nothing and return success. */ - if (acpi_disabled) - return 0; - - if (strncmp((char *)&acpi_gbl_FADT.hypervisor_id, "MsHyperV", 8)) + if (!hyperv_detect_via_acpi() && !hyperv_detect_via_smccc()) return 0; /* Setup the guest ID */ -- 2.43.0