On 02/24/2010 12:28 PM, Jan Kiszka wrote:
Jan Kiszka wrote:
Avi Kivity wrote:
On 02/24/2010 12:13 PM, Jan Kiszka wrote:
I see. Won't we hit the same issue when we call pic functions from
atomic context during the guest entry sequence?
If there are such call paths, for sure. What concrete path(s) do you
have in mind?
vcpu_enter_guest() -> inject_pending_event() ->
kvm_cpu_{has,get}_interrupt() -> various pic functions if you're unlucky.
But do they kick anyone or just check/pull information? Never saw any
warnings during my tests last year (granted: with older -rt and kvm
versions).
Mmh, they could if there is> 1 IRQ pending. Guess this just never
triggered in real life due to typical APIC use and low IRQ load during
PIC times in my tests.
We could just ignore the wakeup in this path. It's called in vcpu
context, so obviously the vcpu is awake and kicking it will only hurt
your feet.
Longer term, we should clear up this mess. One possible path is to move
the pic/lapic/injection stuff out of the the critical section, and use
vcpu->requests to close the race between querying the pic/lapic and
entering the guest.
--
error compiling committee.c: too many arguments to function
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