From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 6A306168BD; Fri, 10 May 2024 17:04:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715360666; cv=none; b=uqbqAIGBT6HgEQp7MTNxQrSzxe1l8ek9NZaT003KrZdFjtF98MMame9bUftxtPVLuYzEJumIf8FOAcfaeNtYfZBVtGnwdigSzybMuGT8gw+Xqd7srfRQxLjrk9UTewGYZ/7QdUCPAN0BL3ysKsqx9x8hGSlwajdL0iiOiVs/93s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715360666; c=relaxed/simple; bh=W8ZlpyVfAQ2NmbLul5CfY32bP45vGBrmtSAre6V9Nrk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=r0feinKfrgGBmUestw7iJwjpxHNkqPdmr7IqM+e8ZwPwHSmd/xSEx5R7IaaZe3TevHErqxhhABSGzfIGTjbBp3JkCV1q97J9anW+VlcjMb/THWqP627kEiYSr6QmsS638A3EKQSSBd1CH9oi4W4IzL401HmP6g3cHDopXaWPUZE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=XN6g+rFX; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="XN6g+rFX" Received: from [192.168.49.54] (c-73-118-245-227.hsd1.wa.comcast.net [73.118.245.227]) by linux.microsoft.com (Postfix) with ESMTPSA id C1AA220B2C87; Fri, 10 May 2024 10:04:24 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com C1AA220B2C87 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1715360665; bh=D6rlDT4v0DLvneUWLv+DfcU6XBGP07Du9qcg/Pby8a8=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=XN6g+rFX+VYKAfFTaommksIyHGDKm1XYil5liTozTFlJkjQaqdtfXVr7iX72/HsPV ePInUOrUTvZwRweD7UyzSSs0PEQZAZNoOKuL+7Ki0BaqC9L3mTGAOURtVh0d1HB95p 3aKwDzBIHutXT9+Owql37VwUlFMplEyBMdsjKkyw= Message-ID: <46eae37e-0c0d-4963-a39c-c9f1d2318c85@linux.microsoft.com> Date: Fri, 10 May 2024 10:04:24 -0700 Precedence: bulk X-Mailing-List: linux-hyperv@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/6] arm64/hyperv: Support DeviceTree To: romank@linux.microsoft.com, kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, linux-hyperv@vger.kernel.org, rafael@kernel.org, lenb@kernel.org, linux-acpi@vger.kernel.org Cc: ssengar@microsoft.com, sunilmut@microsoft.com References: <20240510160602.1311352-1-romank@linux.microsoft.com> <20240510160602.1311352-2-romank@linux.microsoft.com> Content-Language: en-CA From: Easwar Hariharan In-Reply-To: <20240510160602.1311352-2-romank@linux.microsoft.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 5/10/2024 9:05 AM, romank@linux.microsoft.com wrote: > From: Roman Kisel > > Update the driver to support DeviceTree boot as well along with ACPI. > This enables the Virtual Trust Level platforms boot up on ARM64. > > Signed-off-by: Roman Kisel > --- > arch/arm64/hyperv/mshyperv.c | 34 +++++++++++++++++++++++++++++----- > 1 file changed, 29 insertions(+), 5 deletions(-) > > diff --git a/arch/arm64/hyperv/mshyperv.c b/arch/arm64/hyperv/mshyperv.c > index b1a4de4eee29..208a3bcb9686 100644 > --- a/arch/arm64/hyperv/mshyperv.c > +++ b/arch/arm64/hyperv/mshyperv.c > @@ -15,6 +15,9 @@ > #include > #include > #include > +#include > +#include > +#include > #include > > static bool hyperv_initialized; > @@ -27,6 +30,29 @@ int hv_get_hypervisor_version(union hv_hypervisor_version_info *info) > return 0; > } > > +static bool hyperv_detect_fdt(void) > +{ > +#ifdef CONFIG_OF > + const unsigned long hyp_node = of_get_flat_dt_subnode_by_name( > + of_get_flat_dt_root(), "hypervisor"); > + > + return (hyp_node != -FDT_ERR_NOTFOUND) && > + of_flat_dt_is_compatible(hyp_node, "microsoft,hyperv"); > +#else > + return false; > +#endif > +} > + > +static bool hyperv_detect_acpi(void) > +{ > +#ifdef CONFIG_ACPI > + return !acpi_disabled && > + !strncmp((char *)&acpi_gbl_FADT.hypervisor_id, "MsHyperV", 8); > +#else > + return false; > +#endif > +} > + Could using IS_ENABLED() allow collapsing these two functions into one hyperv_detect_fw()? I am wondering if #ifdef was explicitly chosen to allow for the code to be compiled in if CONFIG* is defined v/s IS_ENABLED() only being true if the CONFIG value is true. > static int __init hyperv_init(void) > { > struct hv_get_vp_registers_output result; > @@ -35,13 +61,11 @@ 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_fdt() && !hyperv_detect_acpi()) > return 0; > > /* Setup the guest ID */