Commit 3fe4f0fc authored by Cédric Le Goater's avatar Cédric Le Goater Committed by David Gibson
Browse files

spapr/rtas: do not reset the MSR in stop-self command 



When a CPU is stopped with the 'stop-self' RTAS call, its state
'halted' is switched to 1 and, in this case, the MSR is not taken into
account anymore in the cpu_has_work() routine. Only the pending
hardware interrupts are checked with their LPCR:PECE* enablement bit.

The CPU is now also protected from the decrementer interrupt by the
LPCR:PECE* bits which are disabled in the 'stop-self' RTAS
call. Reseting the MSR is pointless.

Signed-off-by: default avatarCédric Le Goater <clg@kaod.org>
Reviewed-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
parent d6322252

hw/ppc/spapr_rtas.c

+0 −10
Original line number Diff line number Diff line
@@ -206,16 +206,6 @@ static void rtas_stop_self(PowerPCCPU *cpu, sPAPRMachineState *spapr, 


    cs->halted = 1;

    qemu_cpu_kick(cs);

    /*

     * While stopping a CPU, the guest calls H_CPPR which

     * effectively disables interrupts on XICS level.

     * However decrementer interrupts in TCG can still

     * wake the CPU up so here we disable interrupts in MSR

     * as well.

     * As rtas_start_cpu() resets the whole MSR anyway, there is

     * no need to bother with specific bits, we just clear it.

     */

    env->msr = 0;



    /* Disable Power-saving mode Exit Cause exceptions for the CPU.

     * This could deliver an interrupt on a dying CPU and crash the