Re: [RFC PATCH 3/3] arch/x86/acrn: add hypercall for acrn_hypervisor

[Zhao, Yakui]

On 2019年03月25日 16:30, Thomas Gleixner wrote:

On Mon, 25 Mar 2019, Zhao, Yakui wrote:

-----Original Message-----
From: Thomas Gleixner [mailto:t...@linutronix.de]
Sent: Saturday, March 23, 2019 12:02 AM
To: Zhao, Yakui <yakui.z...@intel.com>
Cc: linux-kernel@vger.kernel.org; x...@kernel.org; Chen, Jason CJ
<jason.cj.c...@intel.com>
Subject: Re: [RFC PATCH 3/3] arch/x86/acrn: add hypercall for acrn_hypervisor

Can you please fix your mail client not to copy the full email headers on
the reply?

The simple: On $DATE, someone wrote: like the below is sufficient.

thanks for the reminder.

+static inline long acrn_hypercall0(unsigned long hcall_id) {
+
+       /* x86-64 System V ABI register usage */

Well, yes. But can you please provide a link to the hypercall specification in 
the
changelog?

Also instead of repeating the same comment over and over, explain the calling
convention in a top level comment.

This is the low-level implementation of low-level hypercall. It is similar to
Kvm_hypercall1/2/3 in arch/x86/include/asm/kvm_para.h.
Does it make sense that the below comments are added before acrn_hypercall0/1/2?
/*
  * Hypercalls for ACRN Guest
  *
  * Hypercall number is passed in r8 register.
  * Return value will be placed in rax.
  * Up to 2 arguments are passed in rdi, rsi.
  */

Yes, that's much more helpful.

Thanks,

        tglx