[lkml]   [2020]   [Mar]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH 41/70] x86/sev-es: Add Runtime #VC Exception Handler
On Thu, Mar 19, 2020 at 2:14 AM Joerg Roedel <> wrote:
> From: Tom Lendacky <>
> Add the handler for #VC exceptions invoked at runtime.

If I read this correctly, this does not use IST. If that's true, I
don't see how this can possibly work. There at least two nasty cases
that come to mind:

1. SYSCALL followed by NMI. The NMI IRET hack gets to #VC and we
explode. This is fixable by getting rid of the NMI EFLAGS.TF hack.

2. tools/testing/selftests/x86/mov_ss_trap_64. User code does MOV
(addr), SS; SYSCALL, where addr has a data breakpoint. We get #DB
promoted to #VC with no stack.

 \ /
  Last update: 2020-03-19 16:45    [W:0.606 / U:3.008 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site