Re: [PATCH v3] pc: Implement -no-hpet as sugar for -machine hpet=on

[Paolo Bonzini]

On 21/10/20 16:47, Eduardo Habkost wrote:
> Get rid of yet another global variable.
> 
> The default will be hpet=on only if CONFIG_HPET=y.
> 
> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
> ---
> Changes v2 -> v3:
> * Revert v2 changes (use "hpet" property), plus:
> * Default to hpet=off if CONFIG_HPET=n
> * Error out if creation of HPET device fails and hpet=on
> 
> Changes v1 -> v2:
> * Rename property to "allow-hpet" to make its semantic clearer,
>   as it won't make sure HPET is created if CONFIG_HPET=n
> * Use qdev_new(TYPE_HPET) at pc_basic_device_init()
> ---
>  include/hw/i386/pc.h  |  1 +
>  include/hw/i386/x86.h |  3 ---
>  hw/i386/pc.c          | 61 +++++++++++++++++++++++++++++--------------
>  hw/i386/pc_piix.c     |  2 +-
>  softmmu/vl.c          |  4 +--
>  5 files changed, 46 insertions(+), 25 deletions(-)
> 
> diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
> index 84639d0ebc..911e460097 100644
> --- a/include/hw/i386/pc.h
> +++ b/include/hw/i386/pc.h
> @@ -43,6 +43,7 @@ typedef struct PCMachineState {
>      bool smbus_enabled;
>      bool sata_enabled;
>      bool pit_enabled;
> +    bool hpet_enabled;
>  
>      /* NUMA information: */
>      uint64_t numa_nodes;
> diff --git a/include/hw/i386/x86.h b/include/hw/i386/x86.h
> index d5dcf7a07f..4e66a15ff5 100644
> --- a/include/hw/i386/x86.h
> +++ b/include/hw/i386/x86.h
> @@ -124,7 +124,4 @@ qemu_irq x86_allocate_cpu_irq(void);
>  void gsi_handler(void *opaque, int n, int level);
>  void ioapic_init_gsi(GSIState *gsi_state, const char *parent_name);
>  
> -/* hpet.c */
> -extern int no_hpet;
> -
>  #endif
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index 4e323755d0..416fb0e0f6 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -1142,28 +1142,31 @@ void pc_basic_device_init(struct PCMachineState *pcms,
>       * Without KVM_CAP_PIT_STATE2, we cannot switch off the in-kernel PIT
>       * when the HPET wants to take over. Thus we have to disable the latter.
>       */
> -    if (!no_hpet && (!kvm_irqchip_in_kernel() || kvm_has_pit_state2())) {
> +    if (pcms->hpet_enabled && (!kvm_irqchip_in_kernel() ||
> +                               kvm_has_pit_state2())) {
>          hpet = qdev_try_new(TYPE_HPET);
> -        if (hpet) {
> -            /* For pc-piix-*, hpet's intcap is always IRQ2. For pc-q35-1.7
> -             * and earlier, use IRQ2 for compat. Otherwise, use IRQ16~23,
> -             * IRQ8 and IRQ2.
> -             */
> -            uint8_t compat = object_property_get_uint(OBJECT(hpet),
> -                    HPET_INTCAP, NULL);
> -            if (!compat) {
> -                qdev_prop_set_uint32(hpet, HPET_INTCAP, hpet_irqs);
> -            }
> -            sysbus_realize_and_unref(SYS_BUS_DEVICE(hpet), &error_fatal);
> -            sysbus_mmio_map(SYS_BUS_DEVICE(hpet), 0, HPET_BASE);
> +        if (!hpet) {
> +            error_report("couldn't create HPET device");
> +            exit(1);
> +        }
> +        /* For pc-piix-*, hpet's intcap is always IRQ2. For pc-q35-1.7
> +            * and earlier, use IRQ2 for compat. Otherwise, use IRQ16~23,
> +            * IRQ8 and IRQ2.
> +            */
> +        uint8_t compat = object_property_get_uint(OBJECT(hpet),
> +                HPET_INTCAP, NULL);
> +        if (!compat) {
> +            qdev_prop_set_uint32(hpet, HPET_INTCAP, hpet_irqs);
> +        }
> +        sysbus_realize_and_unref(SYS_BUS_DEVICE(hpet), &error_fatal);
> +        sysbus_mmio_map(SYS_BUS_DEVICE(hpet), 0, HPET_BASE);
>  
> -            for (i = 0; i < GSI_NUM_PINS; i++) {
> -                sysbus_connect_irq(SYS_BUS_DEVICE(hpet), i, gsi[i]);
> -            }
> -            pit_isa_irq = -1;
> -            pit_alt_irq = qdev_get_gpio_in(hpet, HPET_LEGACY_PIT_INT);
> -            rtc_irq = qdev_get_gpio_in(hpet, HPET_LEGACY_RTC_INT);
> +        for (i = 0; i < GSI_NUM_PINS; i++) {
> +            sysbus_connect_irq(SYS_BUS_DEVICE(hpet), i, gsi[i]);
>          }
> +        pit_isa_irq = -1;
> +        pit_alt_irq = qdev_get_gpio_in(hpet, HPET_LEGACY_PIT_INT);
> +        rtc_irq = qdev_get_gpio_in(hpet, HPET_LEGACY_RTC_INT);
>      }
>      *rtc_state = mc146818_rtc_init(isa_bus, 2000, rtc_irq);
>  
> @@ -1535,6 +1538,20 @@ static void pc_machine_set_pit(Object *obj, bool 
> value, Error **errp)
>      pcms->pit_enabled = value;
>  }
>  
> +static bool pc_machine_get_hpet(Object *obj, Error **errp)
> +{
> +    PCMachineState *pcms = PC_MACHINE(obj);
> +
> +    return pcms->hpet_enabled;
> +}
> +
> +static void pc_machine_set_hpet(Object *obj, bool value, Error **errp)
> +{
> +    PCMachineState *pcms = PC_MACHINE(obj);
> +
> +    pcms->hpet_enabled = value;
> +}
> +
>  static void pc_machine_get_max_ram_below_4g(Object *obj, Visitor *v,
>                                              const char *name, void *opaque,
>                                              Error **errp)
> @@ -1585,6 +1602,9 @@ static void pc_machine_initfn(Object *obj)
>      pcms->smbus_enabled = true;
>      pcms->sata_enabled = true;
>      pcms->pit_enabled = true;
> +#ifdef CONFIG_HPET
> +    pcms->hpet_enabled = true;
> +#endif
>  
>      pc_system_flash_create(pcms);
>      pcms->pcspk = isa_new(TYPE_PC_SPEAKER);
> @@ -1705,6 +1725,9 @@ static void pc_machine_class_init(ObjectClass *oc, void 
> *data)
>  
>      object_class_property_add_bool(oc, PC_MACHINE_PIT,
>          pc_machine_get_pit, pc_machine_set_pit);
> +
> +    object_class_property_add_bool(oc, "hpet",
> +        pc_machine_get_hpet, pc_machine_set_hpet);
>  }
>  
>  static const TypeInfo pc_machine_info = {
> diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
> index 0cf22a57ad..13d1628f13 100644
> --- a/hw/i386/pc_piix.c
> +++ b/hw/i386/pc_piix.c
> @@ -216,7 +216,7 @@ static void pc_init1(MachineState *machine,
>          i440fx_state = NULL;
>          isa_bus = isa_bus_new(NULL, get_system_memory(), system_io,
>                                &error_abort);
> -        no_hpet = 1;
> +        pcms->hpet_enabled = false;
>      }
>      isa_bus_irqs(isa_bus, x86ms->gsi);
>  
> diff --git a/softmmu/vl.c b/softmmu/vl.c
> index cb476aa70b..c2281f45a8 100644
> --- a/softmmu/vl.c
> +++ b/softmmu/vl.c
> @@ -146,7 +146,6 @@ static Chardev **serial_hds;
>  Chardev *parallel_hds[MAX_PARALLEL_PORTS];
>  int win2k_install_hack = 0;
>  int singlestep = 0;
> -int no_hpet = 0;
>  int fd_bootchk = 1;
>  static int no_reboot;
>  int no_shutdown = 0;
> @@ -3562,7 +3561,8 @@ void qemu_init(int argc, char **argv, char **envp)
>                  qemu_opts_parse_noisily(olist, "acpi=off", false);
>                  break;
>              case QEMU_OPTION_no_hpet:
> -                no_hpet = 1;
> +                olist = qemu_find_opts("machine");
> +                qemu_opts_parse_noisily(olist, "hpet=off", false);
>                  break;
>              case QEMU_OPTION_no_reboot:
>                  no_reboot = 1;
> 

Acked-by: Paolo Bonzini <pbonzini@redhat.com>

Thanks!

Paolo