On Mon, 8 Feb 2016 09:31:49 +0100 Greg Kurz <[email protected]> wrote:
> On Mon, 8 Feb 2016 11:45:19 +1000 > David Gibson <[email protected]> wrote: > > > On Fri, Feb 05, 2016 at 09:43:40AM +0100, Greg Kurz wrote: > > > From: Brian W. Hart <[email protected]> > > > > > > xics_alloc_block() does not return a clear error code when it > > > fails to allocate a block of interrupts. Instead it returns the > > > base interrupt number minus 1. This change updates it to return a > > > clear -1 in case of failure (following the example of xics_alloc()). > > > > > > The two callers of xics_alloc_block() are updated to check for > > > a negative return as an error. They had previously checked for > > > a 0 return as an error, which wrongly treated most failures as > > > successes. > > > > > > Fixes: bee763dbfb8cfceea112131970da07f215f293a6 > > > Signed-off-by: Brian W. Hart <[email protected]> > > > [only pass src and num to trace_xics_alloc_block_failed_no_left, > > > added trace_xics_alloc_block_failed_no_left definition to trace-events] > > > Signed-off-by: Greg Kurz <[email protected]> > > > > Hrm, it would probably be better to give xics_alloc_block() an Error > > ** argument so it can report errors using the new API. > > > > Sure. I can rework the patch to do so. > The trace_xics_alloc_block_failed_no_left trace is more a debugging thing than an error to be reported to the user. Also, rtas_ibm_change_msi() already has a meaningful error message: error_report("Cannot allocate MSIs for device %x", config_addr); So in the end, I'm not sure about the benefit of passing an Error ** down to xics_alloc_block(). > > TBH the whole xics_alloc_block() interface is kind of dubious, or at > > least the ics_find_free_block() part of it. Dynamically allocating > > irqs to devices is basically awful for migration, so it's better to > > have fixed allocations of all interrupts at the machine level. > > > > I agree about the extra complexity, but isn't it the purpose of > the ibm,change-msi RTAS call ? I'm not sure to understand what you > are suggesting... > And anyway, even if the decision is made one day to have fixed allocations, shouldn't we consider fixing this bug first ? Cheers. -- Greg > > > > > --- > > > hw/intc/xics.c | 10 ++++++---- > > > hw/ppc/spapr_pci.c | 9 +++++---- > > > trace-events | 1 + > > > 3 files changed, 12 insertions(+), 8 deletions(-) > > > > > > diff --git a/hw/intc/xics.c b/hw/intc/xics.c > > > index cd91ddc4d1d9..3bb77ff96e7b 100644 > > > --- a/hw/intc/xics.c > > > +++ b/hw/intc/xics.c > > > @@ -763,11 +763,13 @@ int xics_alloc_block(XICSState *icp, int src, int > > > num, bool lsi, bool align) > > > } else { > > > first = ics_find_free_block(ics, num, 1); > > > } > > > + if (first < 0) { > > > + trace_xics_alloc_block_failed_no_left(src, num); > > > + return -1; > > > + } > > > > > > - if (first >= 0) { > > > - for (i = first; i < first + num; ++i) { > > > - ics_set_irq_type(ics, i, lsi); > > > - } > > > + for (i = first; i < first + num; ++i) { > > > + ics_set_irq_type(ics, i, lsi); > > > } > > > first += ics->offset; > > > > > > diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c > > > index cca9257fecc5..ba33cee2a465 100644 > > > --- a/hw/ppc/spapr_pci.c > > > +++ b/hw/ppc/spapr_pci.c > > > @@ -275,7 +275,8 @@ static void rtas_ibm_change_msi(PowerPCCPU *cpu, > > > sPAPRMachineState *spapr, > > > unsigned int req_num = rtas_ld(args, 4); /* 0 == remove all */ > > > unsigned int seq_num = rtas_ld(args, 5); > > > unsigned int ret_intr_type; > > > - unsigned int irq, max_irqs = 0, num = 0; > > > + unsigned int max_irqs = 0, num = 0; > > > + int irq; > > > sPAPRPHBState *phb = NULL; > > > PCIDevice *pdev = NULL; > > > spapr_pci_msi *msi; > > > @@ -354,7 +355,7 @@ static void rtas_ibm_change_msi(PowerPCCPU *cpu, > > > sPAPRMachineState *spapr, > > > /* Allocate MSIs */ > > > irq = xics_alloc_block(spapr->icp, 0, req_num, false, > > > ret_intr_type == RTAS_TYPE_MSI); > > > - if (!irq) { > > > + if (irq < 0) { > > > error_report("Cannot allocate MSIs for device %x", config_addr); > > > rtas_st(rets, 0, RTAS_OUT_HW_ERROR); > > > return; > > > @@ -1359,10 +1360,10 @@ static void spapr_phb_realize(DeviceState *dev, > > > Error **errp) > > > > > > /* Initialize the LSI table */ > > > for (i = 0; i < PCI_NUM_PINS; i++) { > > > - uint32_t irq; > > > + int32_t irq; > > > > > > irq = xics_alloc_block(spapr->icp, 0, 1, true, false); > > > - if (!irq) { > > > + if (irq < 0) { > > > error_setg(errp, "spapr_allocate_lsi failed"); > > > return; > > > } > > > diff --git a/trace-events b/trace-events > > > index c9ac144ceee4..07b0250aaf11 100644 > > > --- a/trace-events > > > +++ b/trace-events > > > @@ -1393,6 +1393,7 @@ xics_alloc(int src, int irq) "source#%d, irq %d" > > > xics_alloc_failed_hint(int src, int irq) "source#%d, irq %d is already > > > in use" > > > xics_alloc_failed_no_left(int src) "source#%d, no irq left" > > > xics_alloc_block(int src, int first, int num, bool lsi, int align) > > > "source#%d, first irq %d, %d irqs, lsi=%d, alignnum %d" > > > +xics_alloc_block_failed_no_left(int src, int num) "source#%d, cannot > > > find %d consecutive irqs" > > > xics_ics_free(int src, int irq, int num) "Source#%d, first irq %d, %d > > > irqs" > > > xics_ics_free_warn(int src, int irq) "Source#%d, irq %d is already free" > > > > > > > > >
