linux-kernel - Re: [PATCH] Drivers: hv: Use nested hypercall for post message and signal event

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 4 Apr 2023 09:56:59 -0700
From:   Nuno Das Neves <nunodasneves@...ux.microsoft.com>
To:     Olaf Hering <olaf@...fle.de>
Cc:     linux-hyperv@...r.kernel.org, linux-kernel@...r.kernel.org,
        mikelley@...rosoft.com, kys@...rosoft.com, wei.liu@...nel.org,
        haiyangz@...rosoft.com, decui@...rosoft.com
Subject: Re: [PATCH] Drivers: hv: Use nested hypercall for post message and
 signal event

On 4/3/2023 11:45 PM, Olaf Hering wrote:
> Mon,  3 Apr 2023 16:22:58 -0700 Nuno Das Neves <nunodasneves@...ux.microsoft.com>:
> 
>> Only relevant for x86; nested functionality is not available in ARM64.
> 
>> +#if defined(CONFIG_X86_64)
>> +	else if (hv_nested)
> 
> Should there be a hv_nested in the ARM64 code path?
> Looks like c4bdf94f97c86 provided such thing, so the Kconfig conditional could be removed.
> 
> Olaf

This will not compile on ARM64 without the guard, because hv_do_nested_hypercall and
hv_do_fast_nested_hypercall8 are not defined.
These are inline functions only defined in the x86 mshyperv.h header.

The alternative to these guards would be defining dummy inline functions for the nested
versions of hv_do_hypercall in the ARM64 mshyperv.h.
I could take that approach if it is preferable.