Re: [PATCH 22/24] x86/entry: Implement and use do_paranoid_entry() and paranoid_exit()

From: Joerg Roedel
Date: Thu Sep 02 2021 - 08:29:58 EST


On Thu, Sep 02, 2021 at 07:58:51PM +0800, Lai Jiangshan wrote:
> Oh, #VC will need to switch stack. I think we need ASM code to switch
> stack since the original stack need to be "free" for next #VC.

Right, #VC switches off its IST stack to make it free for subsequent
#VCs. The switch mostly happens in C code already, see
vc_switch_off_ist(), only the actual RSP update is still ASM.

Regards,

Joerg