Re: [Qemu-devel] [RFC PATCH] spapr/irq: force XICS interrupt mode on non P9 machines
On Mon, 18 Mar 2019 07:27:59 +0100 Cédric Le Goater wrote: > On 3/18/19 2:52 AM, David Gibson wrote: > > On Sun, Mar 17, 2019 at 09:33:42PM +0100, Cédric Le Goater wrote: > >> There is no need to propose the 'dual' interrupt mode interrupt device > >> on POWER7/8 machines and the XIVE mode will not operate. Simply force > >> XICS in this case. > >> > >> This makes the check in spapr_machine_init() redundant on XIVE-only > >> machines. > >> > >> Signed-off-by: Cédric Le Goater > > > > This is not my preferred approach. If the user explicitly selects > > xive or dual mode with a POWER8 cpu, we should hard error, rather than > > forcing a different mode from the one requested. > > I though so. > > > We do need to make sure we default to xics mode with POWER8, even on > > new machine types. > > That's the problem. > > When parsing the options, in the machine instance_init(), we don't > know the CPU type. > Yes but you still can have spapr_irq_init() to report an error, and we have: /* Set up Interrupt Controller before we create the VCPUs */ spapr_irq_init(spapr, _fatal); Some remarks below. > C. > > >> --- > >> hw/ppc/spapr_irq.c | 10 ++ > >> 1 file changed, 10 insertions(+) > >> > >> diff --git a/hw/ppc/spapr_irq.c b/hw/ppc/spapr_irq.c > >> index f2ca1bb66c9d..d27ae68915a1 100644 > >> --- a/hw/ppc/spapr_irq.c > >> +++ b/hw/ppc/spapr_irq.c > >> @@ -16,6 +16,7 @@ > >> #include "hw/ppc/spapr_xive.h" > >> #include "hw/ppc/xics.h" > >> #include "hw/ppc/xics_spapr.h" > >> +#include "cpu-models.h" > >> #include "sysemu/kvm.h" > >> > >> #include "trace.h" > >> @@ -655,6 +656,7 @@ SpaprIrq spapr_irq_dual = { > >> void spapr_irq_init(SpaprMachineState *spapr, Error **errp) > >> { > >> MachineState *machine = MACHINE(spapr); > >> +Error *local_err = NULL; > >> > >> if (machine_kernel_irqchip_split(machine)) { > >> error_setg(errp, "kernel_irqchip split mode not supported on > >> pseries"); > >> @@ -667,6 +669,14 @@ void spapr_irq_init(SpaprMachineState *spapr, Error > >> **errp) > >> return; > >> } > >> > >> +/* Force XICS on non P9 machines */ > >> +if (!ppc_type_check_compat(machine->cpu_type, > >> CPU_POWERPC_LOGICAL_3_00, > >> + 0, spapr->max_compat_pvr)) { This also takes into account a POWER9 (or newer) CPU running in architected power8 (or less) mode, which is a good thing. Maybe this should be mentioned in the changelog for clarity. > >> +error_setg(_err, "forcing XICS interrupt controller"); > >> +warn_report_err(local_err); BTW, at this point, local_err is a dangling pointer. If some future change causes the variable to be passed again to error_setg(), QEMU will abort. A better practice would be to set local_err to NULL if you don't return right away. Also, instead of doing error_setg()+warn_report_err(), you could just call warn_report() directly, without involving an error variable. Anyway, in the present case you just need to error_setg(errp) and return. > >> +spapr->irq = _irq_xics; > >> +} > >> + > >> /* Initialize the MSI IRQ allocator. */ > >> if (!SPAPR_MACHINE_GET_CLASS(spapr)->legacy_irq_allocation) { > >> spapr_irq_msi_init(spapr, spapr->irq->nr_msis); > > >
Re: [Qemu-devel] [RFC PATCH] spapr/irq: force XICS interrupt mode on non P9 machines
On 3/18/19 2:52 AM, David Gibson wrote: > On Sun, Mar 17, 2019 at 09:33:42PM +0100, Cédric Le Goater wrote: >> There is no need to propose the 'dual' interrupt mode interrupt device >> on POWER7/8 machines and the XIVE mode will not operate. Simply force >> XICS in this case. >> >> This makes the check in spapr_machine_init() redundant on XIVE-only >> machines. >> >> Signed-off-by: Cédric Le Goater > > This is not my preferred approach. If the user explicitly selects > xive or dual mode with a POWER8 cpu, we should hard error, rather than > forcing a different mode from the one requested. I though so. > We do need to make sure we default to xics mode with POWER8, even on > new machine types. That's the problem. When parsing the options, in the machine instance_init(), we don't know the CPU type. C. >> --- >> hw/ppc/spapr_irq.c | 10 ++ >> 1 file changed, 10 insertions(+) >> >> diff --git a/hw/ppc/spapr_irq.c b/hw/ppc/spapr_irq.c >> index f2ca1bb66c9d..d27ae68915a1 100644 >> --- a/hw/ppc/spapr_irq.c >> +++ b/hw/ppc/spapr_irq.c >> @@ -16,6 +16,7 @@ >> #include "hw/ppc/spapr_xive.h" >> #include "hw/ppc/xics.h" >> #include "hw/ppc/xics_spapr.h" >> +#include "cpu-models.h" >> #include "sysemu/kvm.h" >> >> #include "trace.h" >> @@ -655,6 +656,7 @@ SpaprIrq spapr_irq_dual = { >> void spapr_irq_init(SpaprMachineState *spapr, Error **errp) >> { >> MachineState *machine = MACHINE(spapr); >> +Error *local_err = NULL; >> >> if (machine_kernel_irqchip_split(machine)) { >> error_setg(errp, "kernel_irqchip split mode not supported on >> pseries"); >> @@ -667,6 +669,14 @@ void spapr_irq_init(SpaprMachineState *spapr, Error >> **errp) >> return; >> } >> >> +/* Force XICS on non P9 machines */ >> +if (!ppc_type_check_compat(machine->cpu_type, CPU_POWERPC_LOGICAL_3_00, >> + 0, spapr->max_compat_pvr)) { >> +error_setg(_err, "forcing XICS interrupt controller"); >> +warn_report_err(local_err); >> +spapr->irq = _irq_xics; >> +} >> + >> /* Initialize the MSI IRQ allocator. */ >> if (!SPAPR_MACHINE_GET_CLASS(spapr)->legacy_irq_allocation) { >> spapr_irq_msi_init(spapr, spapr->irq->nr_msis); >
Re: [Qemu-devel] [RFC PATCH] spapr/irq: force XICS interrupt mode on non P9 machines
On Sun, Mar 17, 2019 at 09:33:42PM +0100, Cédric Le Goater wrote: > There is no need to propose the 'dual' interrupt mode interrupt device > on POWER7/8 machines and the XIVE mode will not operate. Simply force > XICS in this case. > > This makes the check in spapr_machine_init() redundant on XIVE-only > machines. > > Signed-off-by: Cédric Le Goater This is not my preferred approach. If the user explicitly selects xive or dual mode with a POWER8 cpu, we should hard error, rather than forcing a different mode from the one requested. We do need to make sure we default to xics mode with POWER8, even on new machine types. > --- > hw/ppc/spapr_irq.c | 10 ++ > 1 file changed, 10 insertions(+) > > diff --git a/hw/ppc/spapr_irq.c b/hw/ppc/spapr_irq.c > index f2ca1bb66c9d..d27ae68915a1 100644 > --- a/hw/ppc/spapr_irq.c > +++ b/hw/ppc/spapr_irq.c > @@ -16,6 +16,7 @@ > #include "hw/ppc/spapr_xive.h" > #include "hw/ppc/xics.h" > #include "hw/ppc/xics_spapr.h" > +#include "cpu-models.h" > #include "sysemu/kvm.h" > > #include "trace.h" > @@ -655,6 +656,7 @@ SpaprIrq spapr_irq_dual = { > void spapr_irq_init(SpaprMachineState *spapr, Error **errp) > { > MachineState *machine = MACHINE(spapr); > +Error *local_err = NULL; > > if (machine_kernel_irqchip_split(machine)) { > error_setg(errp, "kernel_irqchip split mode not supported on > pseries"); > @@ -667,6 +669,14 @@ void spapr_irq_init(SpaprMachineState *spapr, Error > **errp) > return; > } > > +/* Force XICS on non P9 machines */ > +if (!ppc_type_check_compat(machine->cpu_type, CPU_POWERPC_LOGICAL_3_00, > + 0, spapr->max_compat_pvr)) { > +error_setg(_err, "forcing XICS interrupt controller"); > +warn_report_err(local_err); > +spapr->irq = _irq_xics; > +} > + > /* Initialize the MSI IRQ allocator. */ > if (!SPAPR_MACHINE_GET_CLASS(spapr)->legacy_irq_allocation) { > spapr_irq_msi_init(spapr, spapr->irq->nr_msis); -- 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 signature.asc Description: PGP signature
[Qemu-devel] [RFC PATCH] spapr/irq: force XICS interrupt mode on non P9 machines
There is no need to propose the 'dual' interrupt mode interrupt device on POWER7/8 machines and the XIVE mode will not operate. Simply force XICS in this case. This makes the check in spapr_machine_init() redundant on XIVE-only machines. Signed-off-by: Cédric Le Goater --- hw/ppc/spapr_irq.c | 10 ++ 1 file changed, 10 insertions(+) diff --git a/hw/ppc/spapr_irq.c b/hw/ppc/spapr_irq.c index f2ca1bb66c9d..d27ae68915a1 100644 --- a/hw/ppc/spapr_irq.c +++ b/hw/ppc/spapr_irq.c @@ -16,6 +16,7 @@ #include "hw/ppc/spapr_xive.h" #include "hw/ppc/xics.h" #include "hw/ppc/xics_spapr.h" +#include "cpu-models.h" #include "sysemu/kvm.h" #include "trace.h" @@ -655,6 +656,7 @@ SpaprIrq spapr_irq_dual = { void spapr_irq_init(SpaprMachineState *spapr, Error **errp) { MachineState *machine = MACHINE(spapr); +Error *local_err = NULL; if (machine_kernel_irqchip_split(machine)) { error_setg(errp, "kernel_irqchip split mode not supported on pseries"); @@ -667,6 +669,14 @@ void spapr_irq_init(SpaprMachineState *spapr, Error **errp) return; } +/* Force XICS on non P9 machines */ +if (!ppc_type_check_compat(machine->cpu_type, CPU_POWERPC_LOGICAL_3_00, + 0, spapr->max_compat_pvr)) { +error_setg(_err, "forcing XICS interrupt controller"); +warn_report_err(local_err); +spapr->irq = _irq_xics; +} + /* Initialize the MSI IRQ allocator. */ if (!SPAPR_MACHINE_GET_CLASS(spapr)->legacy_irq_allocation) { spapr_irq_msi_init(spapr, spapr->irq->nr_msis); -- 2.20.1