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Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1s7J8e-00000002W2S-0sbc; Wed, 15 May 2024 18:14:04 +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 1s7J8O-00000002Vsk-2JIW for linux-arm-kernel@lists.infradead.org; Wed, 15 May 2024 18:13:54 +0000 Received: from [10.137.186.190] (unknown [131.107.159.62]) by linux.microsoft.com (Postfix) with ESMTPSA id 6509120BE570; Wed, 15 May 2024 11:13:47 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 6509120BE570 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1715796827; bh=AHKWJF8nm5miX2UApnb2dUoKaj7GWJg9H8YznRUr3R8=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=ixc5rLLCMkyJtA4esUykBJndyXziXrYCLkwz2FnP/ZdCeuabNttOFqDrzl3//5WH1 RpyncfDZtLMba7fV/Cex+ptU4+jvM4OU/0fvdxCSmAwWwxHm4yihZcBayA/xIwveVu msKnaup6NO7XdgsxzMmrlbO7EnZnBGIcLMSGK3S8= Message-ID: Date: Wed, 15 May 2024 11:13:47 -0700 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 4/6] arm64/hyperv: Boot in a Virtual Trust Level To: Michael Kelley , "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: "ssengar@microsoft.com" , "sunilmut@microsoft.com" , "vdso@hexbites.dev" References: <20240514224508.212318-1-romank@linux.microsoft.com> <20240514224508.212318-5-romank@linux.microsoft.com> Content-Language: en-US From: Roman Kisel In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240515_111350_002317_B3B5A1B2 X-CRM114-Status: GOOD ( 32.30 ) 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: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 5/15/2024 6:39 AM, Michael Kelley wrote: > From: Roman Kisel Sent: Tuesday, May 14, 2024 3:44 PM >> >> To run in the VTL mode, Hyper-V drivers have to know what >> VTL the system boots in, and the arm64/hyperv code does not >> update the variable that stores the value. >> >> Update the variable to enable the Hyper-V drivers to boot >> in the VTL mode and print the VTL the code runs in. >> >> Signed-off-by: Roman Kisel >> --- >> arch/arm64/hyperv/Makefile | 1 + >> arch/arm64/hyperv/hv_vtl.c | 19 +++++++++++++++++++ >> arch/arm64/hyperv/mshyperv.c | 6 ++++++ >> arch/arm64/include/asm/mshyperv.h | 8 ++++++++ >> arch/x86/hyperv/hv_vtl.c | 2 +- >> 5 files changed, 35 insertions(+), 1 deletion(-) >> create mode 100644 arch/arm64/hyperv/hv_vtl.c >> >> diff --git a/arch/arm64/hyperv/Makefile b/arch/arm64/hyperv/Makefile >> index 87c31c001da9..9701a837a6e1 100644 >> --- a/arch/arm64/hyperv/Makefile >> +++ b/arch/arm64/hyperv/Makefile >> @@ -1,2 +1,3 @@ >> # SPDX-License-Identifier: GPL-2.0 >> obj-y := hv_core.o mshyperv.o >> +obj-$(CONFIG_HYPERV_VTL_MODE) += hv_vtl.o >> diff --git a/arch/arm64/hyperv/hv_vtl.c b/arch/arm64/hyperv/hv_vtl.c >> new file mode 100644 >> index 000000000000..9b44cc49594c >> --- /dev/null >> +++ b/arch/arm64/hyperv/hv_vtl.c >> @@ -0,0 +1,19 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> +/* >> + * Copyright (C) 2023, Microsoft, Inc. >> + * >> + * Author : Roman Kisel >> + */ >> + >> +#include >> + >> +void __init hv_vtl_init_platform(void) >> +{ >> + pr_info("Linux runs in Hyper-V Virtual Trust Level %d\n", ms_hyperv.vtl); >> +} >> + >> +int __init hv_vtl_early_init(void) >> +{ >> + return 0; >> +} >> +early_initcall(hv_vtl_early_init); >> diff --git a/arch/arm64/hyperv/mshyperv.c b/arch/arm64/hyperv/mshyperv.c >> index 208a3bcb9686..cbde483b167a 100644 >> --- a/arch/arm64/hyperv/mshyperv.c >> +++ b/arch/arm64/hyperv/mshyperv.c >> @@ -96,6 +96,12 @@ static int __init hyperv_init(void) >> return ret; >> } >> >> + /* Find the VTL */ >> + ms_hyperv.vtl = get_vtl(); >> + if (ms_hyperv.vtl > 0) /* non default VTL */ >> + hv_vtl_early_init(); > > Since hv_vtl_early_init() doesn't do anything on arm64, is the above > and the empty implementation of hv_vtl_early_init() really needed? > I thought maybe a subsequent patch in this series would populate > hv_vtl_early_init() to do something, but I didn't see such. I realize > the functions hv_vtl_init_platform() and hv_vtl_early_init() parallel > equivalent functions on x86, but I'd say drop hv_vtl_early_init() on > arm64 if it isn't needed. > > Note too that the naming on the x86 side is arguably a bit messed > up. hv_vtl_init_platform() runs *before* hv_vtl_early_init(). But > typically in the Linux kernel, functions with "early init" in the name > run very early in boot, and that's not the case here. hv_vtl_init_platform() > is actually the function that runs very early in boot, but its name is > set up to parallel ms_hyperv_init_platform(), which calls it. On the > x86 side, I'd would argue for renaming hv_vtl_init_platform() to > hv_vtl_early_init(), and then hv_vtl_early_init() becomes hv_vtl_init(). > But that's probably a separate patch. Here on arm64, perhaps all > you need is hv_vtl_init(). > I'll clean that up, appreciate the thorough explanation! > Michael > >> + >> + hv_vtl_init_platform(); >> ms_hyperv_late_init(); >> >> hyperv_initialized = true; >> diff --git a/arch/arm64/include/asm/mshyperv.h >> b/arch/arm64/include/asm/mshyperv.h >> index a975e1a689dd..4a8ff6be389c 100644 >> --- a/arch/arm64/include/asm/mshyperv.h >> +++ b/arch/arm64/include/asm/mshyperv.h >> @@ -49,6 +49,14 @@ static inline u64 hv_get_msr(unsigned int reg) >> ARM_SMCCC_OWNER_VENDOR_HYP, \ >> HV_SMCCC_FUNC_NUMBER) >> >> +#ifdef CONFIG_HYPERV_VTL_MODE >> +void __init hv_vtl_init_platform(void); >> +int __init hv_vtl_early_init(void); >> +#else >> +static inline void __init hv_vtl_init_platform(void) {} >> +static inline int __init hv_vtl_early_init(void) { return 0; } >> +#endif >> + >> #include >> >> #endif >> diff --git a/arch/x86/hyperv/hv_vtl.c b/arch/x86/hyperv/hv_vtl.c >> index 92bd5a55f093..ae3105375a12 100644 >> --- a/arch/x86/hyperv/hv_vtl.c >> +++ b/arch/x86/hyperv/hv_vtl.c >> @@ -19,7 +19,7 @@ static struct real_mode_header hv_vtl_real_mode_header; >> >> void __init hv_vtl_init_platform(void) >> { >> - pr_info("Linux runs in Hyper-V Virtual Trust Level\n"); >> + pr_info("Linux runs in Hyper-V Virtual Trust Level %d\n", ms_hyperv.vtl); >> >> x86_platform.realmode_reserve = x86_init_noop; >> x86_platform.realmode_init = x86_init_noop; >> -- >> 2.45.0 >> -- Thank you, Roman _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel