On 18.01.2016 05:24, David Gibson wrote:
> The spapr_alloc_htab() and spapr_reset_htab() functions currently handle
> all errors with error_setg(&error_abort, ...).
>
> But really, the callers are really better placed to decide on the error
> handling. So, instead make the functions use the error propagation
> infrastructure.
>
> In the callers we change to &error_fatal instead of &error_abort, since
> this can be triggered by a bad configuration or kernel error rather than
> indicating a programming error in qemu.
>
> While we're at it improve the messages themselves a bit, and clean up the
> indentation a little.
>
> Signed-off-by: David Gibson <da...@gibson.dropbear.id.au>
> ---
> hw/ppc/spapr.c | 24 ++++++++++++++++--------
> 1 file changed, 16 insertions(+), 8 deletions(-)
>
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index b7fd09a..d28e349 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -1016,7 +1016,7 @@ static void emulate_spapr_hypercall(PowerPCCPU *cpu)
> #define CLEAN_HPTE(_hpte) ((*(uint64_t *)(_hpte)) &=
> tswap64(~HPTE64_V_HPTE_DIRTY))
> #define DIRTY_HPTE(_hpte) ((*(uint64_t *)(_hpte)) |=
> tswap64(HPTE64_V_HPTE_DIRTY))
>
> -static void spapr_alloc_htab(sPAPRMachineState *spapr)
> +static void spapr_alloc_htab(sPAPRMachineState *spapr, Error **errp)
> {
> long shift;
> int index;
> @@ -1031,7 +1031,8 @@ static void spapr_alloc_htab(sPAPRMachineState *spapr)
> * For HV KVM, host kernel will return -ENOMEM when requested
> * HTAB size can't be allocated.
> */
> - error_setg(&error_abort, "Failed to allocate HTAB of requested size,
> try with smaller maxmem");
> + error_setg_errno(errp, -shift,
> + "Error allocating KVM hash page table, try smaller
> maxmem");
> } else if (shift > 0) {
> /*
> * Kernel handles htab, we don't need to allocate one
> @@ -1040,7 +1041,10 @@ static void spapr_alloc_htab(sPAPRMachineState *spapr)
> * but we don't allow booting of such guests.
> */
> if (shift != spapr->htab_shift) {
> - error_setg(&error_abort, "Failed to allocate HTAB of requested
> size, try with smaller maxmem");
> + error_setg(errp,
> + "Small allocation for KVM hash page table (%ld < %"
> + PRIu32 "), try smaller maxmem",
> + shift, spapr->htab_shift);
Maybe you should add an "return" statement here - theoretically you do
not want to continue with "kvmppc_kern_htab = true" in case of errors.
(practically this does not happen because errp = error_fatal, but in
case the caller gets changed, this might introduce subtle errors otherwise)
> }
>
> spapr->htab_shift = shift;
> @@ -1064,17 +1068,21 @@ static void spapr_alloc_htab(sPAPRMachineState *spapr)
> * If host kernel has allocated HTAB, KVM_PPC_ALLOCATE_HTAB ioctl is
> * used to clear HTAB. Otherwise QEMU-allocated HTAB is cleared manually.
> */
> -static void spapr_reset_htab(sPAPRMachineState *spapr)
> +static void spapr_reset_htab(sPAPRMachineState *spapr, Error **errp)
> {
> long shift;
> int index;
>
> shift = kvmppc_reset_htab(spapr->htab_shift);
> if (shift < 0) {
> - error_setg(&error_abort, "Failed to reset HTAB");
> + error_setg_errno(errp, -shift,
> + "Error resetting KVM hash page table, try smaller
> maxmem");
dito, better do an "return" here...
> } else if (shift > 0) {
> if (shift != spapr->htab_shift) {
> - error_setg(&error_abort, "Requested HTAB allocation failed
> during reset");
> + error_setg(errp,
> + "Reduced size on reset of KVM hash page table (%ld < %"
> + PRIu32 "), try smaller maxmem",
> + shift, spapr->htab_shift);
... and here.
> }
>
> /* Tell readers to update their file descriptor */
> @@ -1145,7 +1153,7 @@ static void ppc_spapr_reset(void)
> foreach_dynamic_sysbus_device(find_unknown_sysbus_device, NULL);
>
> /* Reset the hash table & recalc the RMA */
> - spapr_reset_htab(spapr);
> + spapr_reset_htab(spapr, &error_fatal);
>
> qemu_devices_reset();
>
> @@ -1792,7 +1800,7 @@ static void ppc_spapr_init(MachineState *machine)
> }
> spapr->htab_shift++;
> }
> - spapr_alloc_htab(spapr);
> + spapr_alloc_htab(spapr, &error_fatal);
>
> /* Set up Interrupt Controller before we create the VCPUs */
> spapr->icp = xics_system_init(machine,
>
Thomas
