Re: [Qemu-arm] [PATCH] Correct CPACR reset value for v7 cores

[Peter Maydell]

On 22 May 2018 at 20:06, Cédric Le Goater <address@hidden> wrote:
> On 05/22/2018 07:37 PM, Peter Maydell wrote:
>> This is sufficient that a save-and-reload while the romulus-bmc
>> machine is in the bootloader will work. On the other hand if
>> I do a save-and-reload after the kernel has started booting
>> then we get the classic "guest hang after reload", so some
>> state is still not being transferred somewhere (probably in
>> a device in the machine model?)
>
> I see the problem. Bizarre.

Usually it means that something in the path from timer device
through to the CPU has failed to save-and-reload the state
that it needs to, so that when the timer fires post-reload
it doesn't actually cause a CPU interrupt. You can probably
debug by putting a breakpoint on whatever looks like a likely
timer device's 'set the irq line' function and stepping
through to figure out what's happening.

(You're not using trustzone, are you? I know of a bug with
migration of cpus with TZ enabled which I'm probably going to
look at later this week)

thanks
-- PMM