| Message ID | 1459413561-30745-12-git-send-email-bharata@linux.vnet.ibm.com |
|---|---|
| State | New |
| Headers | show |
Quoting Bharata B Rao (2016-03-31 03:39:20) > XICS is setup for each CPU during initialization. Provide a routine > to undo the same when CPU is unplugged. While here, move ss->cs management > into xics from xics_kvm since there is nothing KVM specific in it. > Also ensure xics reset doesn't set irq for CPUs that are already unplugged. > > This allows reboot of a VM that has undergone CPU hotplug and unplug > to work correctly. > > Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> > Reviewed-by: David Gibson <david@gibson.dropbear.id.au> > --- > hw/intc/xics.c | 14 ++++++++++++++ > hw/intc/xics_kvm.c | 8 ++++---- > include/hw/ppc/xics.h | 1 + > 3 files changed, 19 insertions(+), 4 deletions(-) > > diff --git a/hw/intc/xics.c b/hw/intc/xics.c > index 213a370..9fdb551 100644 > --- a/hw/intc/xics.c > +++ b/hw/intc/xics.c > @@ -45,6 +45,18 @@ static int get_cpu_index_by_dt_id(int cpu_dt_id) > return -1; > } > > +void xics_cpu_destroy(XICSState *icp, PowerPCCPU *cpu) > +{ > + CPUState *cs = CPU(cpu); > + ICPState *ss = &icp->ss[cs->cpu_index]; > + If the following assertion is false, I think you'd get an OOB before you reached it due to the assignment above. > + assert(cs->cpu_index < icp->nr_servers); > + assert(cs == ss->cs); > + > + ss->output = NULL; > + ss->cs = NULL; > +} > +
On Tue, Apr 05, 2016 at 07:24:39PM -0500, Michael Roth wrote: > Quoting Bharata B Rao (2016-03-31 03:39:20) > > XICS is setup for each CPU during initialization. Provide a routine > > to undo the same when CPU is unplugged. While here, move ss->cs management > > into xics from xics_kvm since there is nothing KVM specific in it. > > Also ensure xics reset doesn't set irq for CPUs that are already unplugged. > > > > This allows reboot of a VM that has undergone CPU hotplug and unplug > > to work correctly. > > > > Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> > > Reviewed-by: David Gibson <david@gibson.dropbear.id.au> > > --- > > hw/intc/xics.c | 14 ++++++++++++++ > > hw/intc/xics_kvm.c | 8 ++++---- > > include/hw/ppc/xics.h | 1 + > > 3 files changed, 19 insertions(+), 4 deletions(-) > > > > diff --git a/hw/intc/xics.c b/hw/intc/xics.c > > index 213a370..9fdb551 100644 > > --- a/hw/intc/xics.c > > +++ b/hw/intc/xics.c > > @@ -45,6 +45,18 @@ static int get_cpu_index_by_dt_id(int cpu_dt_id) > > return -1; > > } > > > > +void xics_cpu_destroy(XICSState *icp, PowerPCCPU *cpu) > > +{ > > + CPUState *cs = CPU(cpu); > > + ICPState *ss = &icp->ss[cs->cpu_index]; > > + > > If the following assertion is false, I think you'd get an OOB before you > reached it due to the assignment above. It should be ok. The assignment above will compute an out of bounds address, but it doesn't dereference it. > > + assert(cs->cpu_index < icp->nr_servers); > > + assert(cs == ss->cs); > > + > > + ss->output = NULL; > > + ss->cs = NULL; > > +} > > + >
Quoting David Gibson (2016-04-05 19:43:46) > On Tue, Apr 05, 2016 at 07:24:39PM -0500, Michael Roth wrote: > > Quoting Bharata B Rao (2016-03-31 03:39:20) > > > XICS is setup for each CPU during initialization. Provide a routine > > > to undo the same when CPU is unplugged. While here, move ss->cs management > > > into xics from xics_kvm since there is nothing KVM specific in it. > > > Also ensure xics reset doesn't set irq for CPUs that are already unplugged. > > > > > > This allows reboot of a VM that has undergone CPU hotplug and unplug > > > to work correctly. > > > > > > Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> > > > Reviewed-by: David Gibson <david@gibson.dropbear.id.au> > > > --- > > > hw/intc/xics.c | 14 ++++++++++++++ > > > hw/intc/xics_kvm.c | 8 ++++---- > > > include/hw/ppc/xics.h | 1 + > > > 3 files changed, 19 insertions(+), 4 deletions(-) > > > > > > diff --git a/hw/intc/xics.c b/hw/intc/xics.c > > > index 213a370..9fdb551 100644 > > > --- a/hw/intc/xics.c > > > +++ b/hw/intc/xics.c > > > @@ -45,6 +45,18 @@ static int get_cpu_index_by_dt_id(int cpu_dt_id) > > > return -1; > > > } > > > > > > +void xics_cpu_destroy(XICSState *icp, PowerPCCPU *cpu) > > > +{ > > > + CPUState *cs = CPU(cpu); > > > + ICPState *ss = &icp->ss[cs->cpu_index]; > > > + > > > > If the following assertion is false, I think you'd get an OOB before you > > reached it due to the assignment above. > > It should be ok. The assignment above will compute an out of bounds > address, but it doesn't dereference it. Ahh, right. I was thinking there was an actual access for some reason. I might still prefer moving the assignment after the assert from a stylistic standpoint, in case other variables get introduced in the future that rely on *ss. Just a nit though. > > > > + assert(cs->cpu_index < icp->nr_servers); > > > + assert(cs == ss->cs); > > > + > > > + ss->output = NULL; > > > + ss->cs = NULL; > > > +} > > > + > > > > -- > David Gibson | I'll have my music baroque, and my code > david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ > | _way_ _around_! > http://www.ozlabs.org/~dgibson
diff --git a/hw/intc/xics.c b/hw/intc/xics.c index 213a370..9fdb551 100644 --- a/hw/intc/xics.c +++ b/hw/intc/xics.c @@ -45,6 +45,18 @@ static int get_cpu_index_by_dt_id(int cpu_dt_id) return -1; } +void xics_cpu_destroy(XICSState *icp, PowerPCCPU *cpu) +{ + CPUState *cs = CPU(cpu); + ICPState *ss = &icp->ss[cs->cpu_index]; + + assert(cs->cpu_index < icp->nr_servers); + assert(cs == ss->cs); + + ss->output = NULL; + ss->cs = NULL; +} + void xics_cpu_setup(XICSState *icp, PowerPCCPU *cpu) { CPUState *cs = CPU(cpu); @@ -54,6 +66,8 @@ void xics_cpu_setup(XICSState *icp, PowerPCCPU *cpu) assert(cs->cpu_index < icp->nr_servers); + ss->cs = cs; + if (info->cpu_setup) { info->cpu_setup(icp, cpu); } diff --git a/hw/intc/xics_kvm.c b/hw/intc/xics_kvm.c index 9fe0667..7aab4a1 100644 --- a/hw/intc/xics_kvm.c +++ b/hw/intc/xics_kvm.c @@ -110,8 +110,10 @@ static void icp_kvm_reset(DeviceState *dev) icp->pending_priority = 0xff; icp->mfrr = 0xff; - /* Make all outputs are deasserted */ - qemu_set_irq(icp->output, 0); + /* Make all outputs as deasserted only if the CPU thread is in use */ + if (icp->output) { + qemu_set_irq(icp->output, 0); + } icp_set_kvm_state(icp, 1); } @@ -344,8 +346,6 @@ static void xics_kvm_cpu_setup(XICSState *icp, PowerPCCPU *cpu) if (icpkvm->kernel_xics_fd != -1) { int ret; - ss->cs = cs; - ret = kvm_vcpu_enable_cap(cs, KVM_CAP_IRQ_XICS, 0, icpkvm->kernel_xics_fd, kvm_arch_vcpu_id(cs)); if (ret < 0) { diff --git a/include/hw/ppc/xics.h b/include/hw/ppc/xics.h index f60b06a..9091054 100644 --- a/include/hw/ppc/xics.h +++ b/include/hw/ppc/xics.h @@ -167,5 +167,6 @@ int xics_alloc_block(XICSState *icp, int src, int num, bool lsi, bool align, void xics_free(XICSState *icp, int irq, int num); void xics_cpu_setup(XICSState *icp, PowerPCCPU *cpu); +void xics_cpu_destroy(XICSState *icp, PowerPCCPU *cpu); #endif /* __XICS_H__ */