On Tue, 17 Apr 2018 17:17:20 +1000 David Gibson <da...@gibson.dropbear.id.au> wrote:
> To prevent spurious wakeups on cpus that are supposed to be disabled, we > need to clear the LPCR bits which control certain wakeup events. > spapr_cpu_reset() has separate cases here for boot and non-boot (initially > inactive) cpus. rtas_start_cpu() then turns the LPCR bits on when the > non-boot cpus are activated. > > But explicit checks against first_cpu are not how we usually do things: > instead spapr_cpu_reset() generally sets things up for non-boot (inactive) > cpus, then spapr_machine_reset() and/or rtas_start_cpu() override as > necessary. > > So, do that instead. Because the LPCR activation is identical for boot > cpus and non-boot cpus just activated with rtas_start_cpu() we can put the > code common in spapr_cpu_set_entry_state(). > > Signed-off-by: David Gibson <da...@gibson.dropbear.id.au> > --- Ok, ok, I hadn't seen this patch yet when I commented on patch 5 :) Reviewed-by: Greg Kurz <gr...@kaod.org> > hw/ppc/spapr_cpu_core.c | 22 +++++++--------------- > hw/ppc/spapr_rtas.c | 4 ---- > 2 files changed, 7 insertions(+), 19 deletions(-) > > diff --git a/hw/ppc/spapr_cpu_core.c b/hw/ppc/spapr_cpu_core.c > index ecd40dbf03..8be0265d04 100644 > --- a/hw/ppc/spapr_cpu_core.c > +++ b/hw/ppc/spapr_cpu_core.c > @@ -52,28 +52,17 @@ static void spapr_cpu_reset(void *opaque) > * Clearing VPM0 will also cause us to use RMOR in mmu-hash64.c for > * real mode accesses, which thankfully defaults to 0 and isn't > * accessible in guest mode. > + * > + * Disable Power-saving mode Exit Cause exceptions for the CPU, so > + * we don't get spurious wakups before an RTAS start-cpu call. > */ > - lpcr &= ~(LPCR_VPM0 | LPCR_VPM1 | LPCR_ISL | LPCR_KBV); > + lpcr &= ~(LPCR_VPM0 | LPCR_VPM1 | LPCR_ISL | LPCR_KBV | pcc->lpcr_pm); > lpcr |= LPCR_LPES0 | LPCR_LPES1; > > /* Set RMLS to the max (ie, 16G) */ > lpcr &= ~LPCR_RMLS; > lpcr |= 1ull << LPCR_RMLS_SHIFT; > > - /* Only enable Power-saving mode Exit Cause exceptions on the boot > - * CPU. The RTAS command start-cpu will enable them on secondaries. > - */ > - if (cs == first_cpu) { > - lpcr |= pcc->lpcr_pm; > - } > - > - /* Disable Power-saving mode Exit Cause exceptions for the CPU. > - * This can cause issues when rebooting the guest if a secondary > - * is awaken */ > - if (cs != first_cpu) { > - lpcr &= ~pcc->lpcr_pm; > - } > - > ppc_store_lpcr(cpu, lpcr); > > /* Set a full AMOR so guest can use the AMR as it sees fit */ > @@ -82,11 +71,14 @@ static void spapr_cpu_reset(void *opaque) > > void spapr_cpu_set_entry_state(PowerPCCPU *cpu, target_ulong nip, > target_ulong r3) > { > + PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cpu); > CPUPPCState *env = &cpu->env; > > env->nip = SPAPR_ENTRY_POINT; > env->gpr[3] = r3; > CPU(cpu)->halted = 0; > + /* Enable Power-saving mode Exit Cause exceptions */ > + ppc_store_lpcr(cpu, env->spr[SPR_LPCR] | pcc->lpcr_pm); > } > > static void spapr_cpu_destroy(PowerPCCPU *cpu) > diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c > index d79aa44467..e720d54eb5 100644 > --- a/hw/ppc/spapr_rtas.c > +++ b/hw/ppc/spapr_rtas.c > @@ -162,7 +162,6 @@ static void rtas_start_cpu(PowerPCCPU *cpu_, > sPAPRMachineState *spapr, > if (cpu != NULL) { > CPUState *cs = CPU(cpu); > CPUPPCState *env = &cpu->env; > - PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cpu); > > if (!cs->halted) { > rtas_st(rets, 0, RTAS_OUT_HW_ERROR); > @@ -178,9 +177,6 @@ static void rtas_start_cpu(PowerPCCPU *cpu_, > sPAPRMachineState *spapr, > > env->msr = (1ULL << MSR_SF) | (1ULL << MSR_ME); > > - /* Enable Power-saving mode Exit Cause exceptions for the new CPU */ > - env->spr[SPR_LPCR] |= pcc->lpcr_pm; > - > spapr_cpu_set_endianness(cpu); > spapr_cpu_update_tb_offset(cpu); >