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 865C321ADA3; Thu, 8 May 2025 15:44:15 +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=1746719058; cv=none; b=MC1XV9OhvEzEO2j202lCNveGKLid0ApaPdtvIax79rz02iT36QG7VIDAUTMXZ4IxUViHNP9LQl+z9QD4kQ9JLsDmpZPm0vBAssDFc4Yd5wKdCM6ZvRSKY3QoMO94Q4GrGV1XBclo27fX/SL/Jf3SN6g6YIAN8xbw7izBJImdzDw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746719058; c=relaxed/simple; bh=KB1/oizvpQsTeqTJKHIr+4TjWtU21XbIcDWxYq/GjaI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Bk8arP74ajjI5pkWnk3nYC36OL67eqV38wsZ+P0gvNtt/t4r8ShnEQSxUHqjS6rmBEZf4zRsvsX3lsWmc5Fo/rgH+Wl5gyBioZ1/H/+lMGqUyDzsvOvGdS/sPNZMVYJ7pzku5tgkVesuVKVij4UFmuOXDT/59rrYeApwX91niV8= 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=kk2qc85P; 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="kk2qc85P" Received: from [10.137.184.60] (unknown [131.107.1.188]) by linux.microsoft.com (Postfix) with ESMTPSA id D9B7D2115DCD; Thu, 8 May 2025 08:44:14 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com D9B7D2115DCD DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1746719055; bh=YjfYKDh2NdzjhE/wrp8l29NjvPHl77ttab2YnyaGfew=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=kk2qc85P0SF4cDpyPqzBQ/kgxMQ6DpNMSZuA3RgSErU+p7sF9EJrzHpFZp0V4KZnM G4rjdVBkhQ8o/0YuaXCp0t6enF/kc2xRZIyIePwosb22yHs4uSlIKlqXaKFIo2qN5U 3fbVIigBjLMPdcQRHbRtxnOT0CnFiJ9Edy7MvSM4= Message-ID: <1edea7f4-5ad2-4103-8eb5-9d5d9f0c7b0d@linux.microsoft.com> Date: Thu, 8 May 2025 08:44:14 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] Drivers: hv: Introduce mshv_vtl driver To: Saurabh Singh Sengar , Naman Jain , KY Srinivasan , Haiyang Zhang , Wei Liu , Dexuan Cui Cc: Anirudh Rayabharam , Saurabh Sengar , Stanislav Kinsburskii , Nuno Das Neves , "linux-kernel@vger.kernel.org" , "linux-hyperv@vger.kernel.org" References: <20250506084937.624680-1-namjain@linux.microsoft.com> <29edc00e-9797-4f4a-83b3-0b4158c94a16@linux.microsoft.com> Content-Language: en-US From: Roman Kisel In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 5/7/2025 8:00 PM, Saurabh Singh Sengar wrote: >> >> On 5/7/2025 4:21 AM, Naman Jain wrote: >>> >>> >> >> [...] >> >>> >>> >>>>> +        return -EINVAL; >>>>> +    if (copy_from_user(payload, (void __user *)message.payload_ptr, >>>>> +               message.payload_size)) >>>>> +        return -EFAULT; >>>>> + >>>>> +    return hv_post_message((union >>>> >>>> This function definition is in separate file which can be build as >>>> independent module, this will cause problem while linking . Try >>>> building with CONFIG_HYPERV=m and check. >>>> >>>> - Saurabh >>> >>> Thanks for reviewing Saurabh. As CONFIG_HYPERV can be set to 'm' >>> and CONFIG_MSHV_VTL depends on it, changing CONFIG_MSHV_VTL to >>> tristate and a few tweaks in Makefile will fix this issue. This will >>> ensure that mshv_vtl is also built as a module when hyperv is built as a >> module. >>> >>> I'll take care of this in next version. >> >> Let me ask for a clarification. How would the system boot if CONFIG_HYPERV >> is set to m? The arch parts are going to be still compiled-in, correct? >> Otherwise I don't see how that would initialize. >> >> I am thinking who would load Hyper-V modules on the system that requires >> Hyper-V here. It is understandable that distro's build Hyper-V as a module. >> That way, they don't have to load anything when there is no Hyper-V. Here, it >> is Hyper-V in and out, what do we need to fix? > > We need to fix compilation - for everyone. You seem to know for whom it is broken, would be great to share this knowledge. When CONFIG_MSHV_VTL is set to "m", OpenHCL will break down without additional work. So why do we need to be able to build that as a module, to let someone build the firmware that doesn't work? So far the request comes off as absurd to me. > > - Saurabh > >> >>> >>> here is the diff for reference: >>> diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig index >>> 57dcfcb69b88..c7f21b483377 100644 >>> --- a/drivers/hv/Kconfig >>> +++ b/drivers/hv/Kconfig >>> @@ -73,7 +73,7 @@ config MSHV_ROOT >>>           If unsure, say N. >>> >>>  config MSHV_VTL >>> -       bool "Microsoft Hyper-V VTL driver" >>> +       tristate "Microsoft Hyper-V VTL driver" >>>         depends on HYPERV && X86_64 >>>         depends on TRANSPARENT_HUGEPAGE >>>         depends on OF >>> diff --git a/drivers/hv/Makefile b/drivers/hv/Makefile index >>> 5e785dae08cc..c53a0df746b7 100644 >>> --- a/drivers/hv/Makefile >>> +++ b/drivers/hv/Makefile >>> @@ -15,9 +15,11 @@ hv_vmbus-$(CONFIG_HYPERV_TESTING)    += >>> hv_debugfs.o >>>  hv_utils-y := hv_util.o hv_kvp.o hv_snapshot.o hv_utils_transport.o >>>  mshv_root-y := mshv_root_main.o mshv_synic.o mshv_eventfd.o >>> mshv_irq.o \ >>>                mshv_root_hv_call.o mshv_portid_table.o >>> +mshv_vtl-y := mshv_vtl_main.o >>> >>>  # Code that must be built-in >>>  obj-$(subst m,y,$(CONFIG_HYPERV)) += hv_common.o -obj-$(subst >>> m,y,$(CONFIG_MSHV_ROOT)) += hv_proc.o mshv_common.o >>> - >>> -mshv_vtl-y := mshv_vtl_main.o mshv_common.o >>> +obj-$(subst m,y,$(CONFIG_MSHV_ROOT)) += hv_proc.o ifneq >>> +($(CONFIG_MSHV_ROOT) $(CONFIG_MSHV_VTL),) >>> +    obj-y += mshv_common.o >>> +endif >>> >>> Regards, >>> Naman >> >> -- >> Thank you, >> Roman > -- Thank you, Roman