Re: [RFC PATCH] x86, entry: Switch stacks on a paranoid entry from userspace

Re: [RFC PATCH] x86, entry: Switch stacks on a paranoid entry from userspace

[Borislav Petkov]

On Thu, Nov 13, 2014 at 12:31:30AM +0000, Luck, Tony wrote:
> > Is this something I can try under KVM?
> 
> I don't know if KVM has a way to simulate a machine check event.

I've been thinking about it recently too - adding MCA functionality to
qemu/kvm could be very useful, especially the thresholding stuff, for
testing RAS kernel code.

-- 
Regards/Gruss,
    Boris.

Sent from a fat crate under my desk. Formatting is fine.
--

Re: [RFC PATCH] x86, entry: Switch stacks on a paranoid entry from userspace

[Borislav Petkov]

On Thu, Nov 13, 2014 at 11:59:37AM +0100, Borislav Petkov wrote:
> I've been thinking about it recently too - adding MCA functionality to
> qemu/kvm could be very useful, especially the thresholding stuff, for
> testing RAS kernel code.

Btw, qemu monitor has a mce injection command with which I was able
to tickle some response from the guest kernel. I'll play more with it
tomorrow and try to tickle a response from the memory failure code.

[  195.328466] Disabling lock debugging due to kernel taint
[  195.328466] [Hardware Error]: System Fatal error.
[  195.328466] [Hardware Error]: CPU:1 (10:2:3) MC4_STATUS[Over|UE|MiscV|PCC|AddrV|UECC]: 0xfe002000001f012b
[  195.328466] [Hardware Error]: MC4_ADDR: 0x0000000000000000
[  195.328466] [Hardware Error]: MC4 Error (node 1): ECC Error in the Probe Filter directory.
[  195.328466] [Hardware Error]: cache level: L3/GEN, tx: GEN, mem-tx: WR
[  195.328466] mce: [Hardware Error]: CPU 1: Machine Check Exception: 3 Bank 4: fe002000001f012b
[  195.328466] mce: [Hardware Error]: RIP 10:<ffffffff8100e0b5> {default_idle+0x25/0x240}
[  195.328466] mce: [Hardware Error]: TSC b9e2f56f95 MISC d1d1dad1deadbeef 
[  195.328466] mce: [Hardware Error]: PROCESSOR 2:100f23 TIME 1415915466 SOCKET 1 APIC 1 microcode 1000065
[  195.328466] [Hardware Error]: System Fatal error.
[  195.328466] [Hardware Error]: CPU:1 (10:2:3) MC4_STATUS[Over|UE|MiscV|PCC|AddrV|UECC]: 0xfe002000001f012b
[  195.328466] [Hardware Error]: MC4_ADDR: 0x0000000000000000
[  195.328466] [Hardware Error]: MC4 Error (node 1): ECC Error in the Probe Filter directory.
[  195.328466] [Hardware Error]: cache level: L3/GEN, tx: GEN, mem-tx: WR
[  195.328466] mce: [Hardware Error]: Machine check: Invalid
[  195.328466] Kernel panic - not syncing: Fatal machine check on current CPU
[  195.328466] Kernel Offset: 0x0 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffff9fffffff)
[  195.328466] ---[ end Kernel panic - not syncing: Fatal machine check on current CPU

-- 
Regards/Gruss,
    Boris.

Sent from a fat crate under my desk. Formatting is fine.
--