Re: [Crash-utility] [PATCH] vmware_vmss: read vCPUs regs and show them in 'bt'
On Wed, Mar 21, 2018 at 10:44:47AM -0400, Dave Anderson wrote:
----- Original Message -----
> VMSS dump files contain the state of each vCPU at the time of suspending
> the VM. This change enables 'crash' to read some relevant registers from
> each vCPU state and display them in 'bt'.
That's very helpful. I'm not sure why VMware never did anything like that
in the original patch.
And now that there finally is a VMSS_DUMPFILE() indicator, it would be helpful
to at least display *something* w/respect to the dumpfile contents as viewed from
"help -D". If you bring up the session with "crash -d1" you will
see a bunch
of stuff from the dumpfile, although I'm not sure whether all of it would be
useful during runtime. But if nothing else, at least indicate what kind of
dumpfile it is, and anything else that might be useful.
Also, I just noticed that original patch from VMware does not display the
VMWARE_VMSS bit in pc->flag as show by "help -p". Can you add that too?
I didn't pay any attention to the "help" command. I'm going to
implement
the VMWARE_VMSS bit in pc->flag, and also the "help -r" output, which
seems quite straightforward having all the registers already properly
placed in vmssregs64.
As for "help -D", I think we could implement a function that iterates
through groups and tags present in the VMSS, printing names, sizes and
values (for non-block tags). Basically, it'd be the same thing that
"vmware_vmss_init" does, but unconditionally printing the info without
touching anything else. Does this makes sense to you?
> calculation for VMSS dump files.
Will that require the KASLR helper patch as a prerequisite?
Yes, otherwise we'd need to duplicate "calc_kaslr_offset" and all the
related functions.
Sergio.