some questions about system calls in KVM/ARM

some questions about system calls in KVM/ARM

[孙晓阳]

[-- Attachment #1.1: Type: text/plain, Size: 438 bytes --]

Hello,
I am intersted in KVM/ARM and I am trying to do some work based on KVM/ARM.
But here is some questions :
1. if I set HCR.TGE=1, does the system calls will traps into hyp mode and
be handled by hyp_svc( arch/arm/kvm/interrupts.S)?
2. How can I get Guest OS's system call's number and address while issuing
swi instruction in Guest OS usr mode and trapped into Hyp mode?

Thank you very much!
Have a fine day!

Send from xiaoyangsun

[-- Attachment #1.2: Type: text/html, Size: 682 bytes --]

[-- Attachment #2: Type: text/plain, Size: 151 bytes --]

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

Re: some questions about system calls in KVM/ARM

[Christoffer Dall]

On Sun, May 03, 2015 at 11:37:29AM +0800, 孙晓阳 wrote:
> Hello,
> I am intersted in KVM/ARM and I am trying to do some work based on KVM/ARM.
> But here is some questions :
> 1. if I set HCR.TGE=1, does the system calls will traps into hyp mode and
> be handled by hyp_svc( arch/arm/kvm/interrupts.S)?

no, hyp_svc is only handling hypervisor calls from hyp mode itself.  All
traps to Hyp mode are handled in hyp_hvc.  See "Use of offset 0x14 in
the Hyp vector table" in Section B1.8.1 in the ARMv7 ARM (DDI 0406C.c).

> 2. How can I get Guest OS's system call's number and address while issuing
> swi instruction in Guest OS usr mode and trapped into Hyp mode?

You have to know the ABI of the guest os and decode whatever
register/immediate used by that.

-Christoffer
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm