From patchwork Fri Jul 26 22:59:04 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roman Kisel X-Patchwork-Id: 13743241 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 568C3C3DA4A for ; Fri, 26 Jul 2024 23:00:17 +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=WFxhd+9RO4zGcRAHUQgDgONPVosLPQEEwR7xsvUdJIE=; b=PoYVqhr7jIUBH9WhhLr4PAQMqq Uk187DhoywKOdLiUQm7q7y4s9Cf5xa6ZIY4od/KK7pb+4PUcyt+By/PoQQ+dtHKxr8JXxFNI4A7Kl APQb8F8GPPFghtcvA2h4b0lGGPPyR01/YOjINQ25uJT9tpO31mIXiaJ0PPF2LUpcG7Lf4jwKs/9Mr DNwrkYUlWgl8VvWSw3EgPbzq3FXetQPHUniS3q5NGCTA6DI+w7/MJA/CkIYSoyX/oNQXaE08A3Jyr GD6QQ5qzizAwETMMgcLx6mtA6uq3XsjRv5CNSzP6vePiTC6n58cwowH8a1ytHC4BUkEkygPUlmi1w YUtQW8HQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sXTuo-00000005HU5-34OH; Fri, 26 Jul 2024 22:59:58 +0000 Received: from linux.microsoft.com ([13.77.154.182]) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sXTuN-00000005HGm-0ioe for linux-arm-kernel@lists.infradead.org; Fri, 26 Jul 2024 22:59:32 +0000 Received: from romank-3650.corp.microsoft.com (unknown [131.107.159.62]) by linux.microsoft.com (Postfix) with ESMTPSA id 2ABEC20B7177; Fri, 26 Jul 2024 15:59:28 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 2ABEC20B7177 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1722034768; bh=WFxhd+9RO4zGcRAHUQgDgONPVosLPQEEwR7xsvUdJIE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ooH+d9b/veU9GXEUGc1iFPvDL8E0ekXCc57TFGFw0fK31DgQKrUK1o7HmfnsmfYR7 kP//lNqDHHiUgdttFp2PWPsdhVSKaByiDO7b54XFkwFXZZ2x5SJFhHNcZALkVH1efF C4z1JtgXGDyzfqEeQzxZOv+39xhSCGNZ6RsZxvK8= From: Roman Kisel To: arnd@arndb.de, bhelgaas@google.com, bp@alien8.de, catalin.marinas@arm.com, dave.hansen@linux.intel.com, decui@microsoft.com, haiyangz@microsoft.com, hpa@zytor.com, kw@linux.com, kys@microsoft.com, lenb@kernel.org, lpieralisi@kernel.org, mingo@redhat.com, rafael@kernel.org, robh@kernel.org, tglx@linutronix.de, wei.liu@kernel.org, will@kernel.org, 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, ssengar@microsoft.com, sunilmut@microsoft.com, vdso@hexbites.dev Subject: [PATCH v3 1/7] arm64: hyperv: Use SMC to detect hypervisor presence Date: Fri, 26 Jul 2024 15:59:04 -0700 Message-Id: <20240726225910.1912537-2-romank@linux.microsoft.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240726225910.1912537-1-romank@linux.microsoft.com> References: <20240726225910.1912537-1-romank@linux.microsoft.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240726_155931_401744_8E182490 X-CRM114-Status: GOOD ( 15.20 ) 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, use the new SMC added recently to Hyper-V to use in the non-ACPI case. Signed-off-by: Roman Kisel Acked-by: Wei Liu --- arch/arm64/hyperv/mshyperv.c | 36 ++++++++++++++++++++++++++----- arch/arm64/include/asm/mshyperv.h | 5 +++++ 2 files changed, 36 insertions(+), 5 deletions(-) diff --git a/arch/arm64/hyperv/mshyperv.c b/arch/arm64/hyperv/mshyperv.c index b1a4de4eee29..341f98312667 100644 --- a/arch/arm64/hyperv/mshyperv.c +++ b/arch/arm64/hyperv/mshyperv.c @@ -27,6 +27,34 @@ int hv_get_hypervisor_version(union hv_hypervisor_version_info *info) return 0; } +static bool hyperv_detect_via_acpi(void) +{ + if (acpi_disabled) + return false; +#if IS_ENABLED(CONFIG_ACPI) + /* Hypervisor ID is only available in ACPI v6+. */ + if (acpi_gbl_FADT.header.revision < 6) + return false; + return strncmp((char *)&acpi_gbl_FADT.hypervisor_id, "MsHyperV", 8) == 0; +#else + return false; +#endif +} + +static bool hyperv_detect_via_smc(void) +{ + struct arm_smccc_res res = {}; + + if (arm_smccc_1_1_get_conduit() != SMCCC_CONDUIT_HVC) + return false; + arm_smccc_1_1_hvc(ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID, &res); + + return res.a0 == ARM_SMCCC_VENDOR_HYP_UID_HYPERV_REG_0 && + res.a1 == ARM_SMCCC_VENDOR_HYP_UID_HYPERV_REG_1 && + res.a2 == ARM_SMCCC_VENDOR_HYP_UID_HYPERV_REG_2 && + res.a3 == ARM_SMCCC_VENDOR_HYP_UID_HYPERV_REG_3; +} + static int __init hyperv_init(void) { struct hv_get_vp_registers_output result; @@ -35,13 +63,11 @@ 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_smc()) return 0; /* Setup the guest ID */ diff --git a/arch/arm64/include/asm/mshyperv.h b/arch/arm64/include/asm/mshyperv.h index a975e1a689dd..a7a3586f7cb1 100644 --- a/arch/arm64/include/asm/mshyperv.h +++ b/arch/arm64/include/asm/mshyperv.h @@ -51,4 +51,9 @@ static inline u64 hv_get_msr(unsigned int reg) #include +#define ARM_SMCCC_VENDOR_HYP_UID_HYPERV_REG_0 0x7948734d +#define ARM_SMCCC_VENDOR_HYP_UID_HYPERV_REG_1 0x56726570 +#define ARM_SMCCC_VENDOR_HYP_UID_HYPERV_REG_2 0 +#define ARM_SMCCC_VENDOR_HYP_UID_HYPERV_REG_3 0 + #endif