linux-kernel - Re: [PATCH] KVM: Loongarch: Remove undefined a6 argument comment for kvm

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]

Message-ID: <a9245b66-be6e-7211-49dd-a9a2d23ec2cf@loongson.cn>
Date: Fri, 26 Jul 2024 11:34:55 +0800
From: maobibo <maobibo@...ngson.cn>
To: Huacai Chen <chenhuacai@...nel.org>
Cc: Dandan Zhang <zhangdandan@...ontech.com>, zhaotianrui@...ngson.cn,
 kernel@...0n.name, kvm@...r.kernel.org, loongarch@...ts.linux.dev,
 linux-kernel@...r.kernel.org, wangyuli@...ontech.com,
 Wentao Guan <guanwentao@...ontech.com>
Subject: Re: [PATCH] KVM: Loongarch: Remove undefined a6 argument comment for
 kvm_hypercall



On 2024/7/26 上午10:55, Huacai Chen wrote:
> On Fri, Jul 26, 2024 at 9:49 AM maobibo <maobibo@...ngson.cn> wrote:
>>
>>
>>
>> On 2024/7/25 下午9:48, Dandan Zhang wrote:
>>> The kvm_hypercall set for LoongArch is limited to a1-a5.
>>> The mention of a6 in the comment is undefined that needs to be rectified.
>>>
>>> Signed-off-by: Wentao Guan <guanwentao@...ontech.com>
>>> Signed-off-by: Dandan Zhang <zhangdandan@...ontech.com>
>>> ---
>>>    arch/loongarch/include/asm/kvm_para.h | 4 ++--
>>>    1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/arch/loongarch/include/asm/kvm_para.h b/arch/loongarch/include/asm/kvm_para.h
>>> index 335fb86778e2..43ec61589e6c 100644
>>> --- a/arch/loongarch/include/asm/kvm_para.h
>>> +++ b/arch/loongarch/include/asm/kvm_para.h
>>> @@ -39,9 +39,9 @@ struct kvm_steal_time {
>>>     * Hypercall interface for KVM hypervisor
>>>     *
>>>     * a0: function identifier
>>> - * a1-a6: args
>>> + * a1-a5: args
>>>     * Return value will be placed in a0.
>>> - * Up to 6 arguments are passed in a1, a2, a3, a4, a5, a6.
>>> + * Up to 5 arguments are passed in a1, a2, a3, a4, a5.
>>>     */
>>>    static __always_inline long kvm_hypercall0(u64 fid)
>>>    {
>>>
>>
>> Dandan,
>>
>> Nice catch. In future hypercall abi may expand such as the number of
>> input register and output register, or async hypercall function if there
>> is really such requirement.
>>
>> Anyway the modification is deserved and it is enough to use now, thanks
>> for doing it.
>>
>> Reviewed-by: Bibo Mao <maobibo@...ngson.cn>
> Maybe it is better to implement kvm_hypercall6() than remove a6 now?
That is one option also. The main reason is that there is no such 
requirement in near future :(, I prefer to removing the annotation and 
keeping it clean.

Regards
Bibo Mao
> 
> Huacai
>>