Re: [Qemu-devel] [BUGFIX][PATCH for 2.2 v3 1/1] -machine vmport=auto: Fix handling of VMWare ioport emulation for xen

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Nov 19, 2014 at 07:38:10PM -0500, Don Slutz wrote:
> c/s 9b23cfb76b3a5e9eb5cc899eaf2f46bc46d33ba4
> 
> or
> 
> c/s b154537ad07598377ebf98252fb7d2aff127983b
> 
> moved the testing of xen_enabled() from pc_init1() to
> pc_machine_initfn().
> 
> xen_enabled() does not return the correct value in
> pc_machine_initfn().
> 
> Changed vmport from a bool to an enum.  Added the value "auto" to do
> the old way.
> 
> Signed-off-by: Don Slutz <dslutz@verizon.com>

This looks fine to me. A couple of minor comments below.
Also this changes qapi schema file, let's get ack from maintainers -
my understanding is that just adding a definition there won't
affect any users, correct?


> ---
>  hw/i386/pc.c         | 23 ++++++++++++++---------
>  hw/i386/pc_piix.c    | 27 ++++++++++++++++++++++++++-
>  hw/i386/pc_q35.c     | 27 ++++++++++++++++++++++++++-
>  include/hw/i386/pc.h |  2 +-
>  qapi-schema.json     | 16 ++++++++++++++++
>  qemu-options.hx      |  8 +++++---
>  vl.c                 |  2 +-
>  7 files changed, 89 insertions(+), 16 deletions(-)
> 
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index 1205db8..2f68e4d 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -1711,18 +1711,23 @@ static void pc_machine_set_max_ram_below_4g(Object *obj, Visitor *v,
>      pcms->max_ram_below_4g = value;
>  }
>  
> -static bool pc_machine_get_vmport(Object *obj, Error **errp)
> +static void pc_machine_get_vmport(Object *obj, Visitor *v, void *opaque,
> +                                  const char *name, Error **errp)
>  {
>      PCMachineState *pcms = PC_MACHINE(obj);
> +    int vmport = pcms->vmport;
>  
> -    return pcms->vmport;
> +    visit_type_enum(v, &vmport, vmport_lookup, NULL, name, errp);
>  }
>  
> -static void pc_machine_set_vmport(Object *obj, bool value, Error **errp)
> +static void pc_machine_set_vmport(Object *obj, Visitor *v, void *opaque,
> +                                  const char *name, Error **errp)
>  {
>      PCMachineState *pcms = PC_MACHINE(obj);
> +    int vmport;
>  
> -    pcms->vmport = value;
> +    visit_type_enum(v, &vmport, vmport_lookup, NULL, name, errp);
> +    pcms->vmport = vmport;
>  }
>  
>  static void pc_machine_initfn(Object *obj)
> @@ -1737,11 +1742,11 @@ static void pc_machine_initfn(Object *obj)
>                          pc_machine_get_max_ram_below_4g,
>                          pc_machine_set_max_ram_below_4g,
>                          NULL, NULL, NULL);
> -    pcms->vmport = !xen_enabled();
> -    object_property_add_bool(obj, PC_MACHINE_VMPORT,
> -                             pc_machine_get_vmport,
> -                             pc_machine_set_vmport,
> -                             NULL);
> +    pcms->vmport = VMPORT_AUTO;
> +    object_property_add(obj, PC_MACHINE_VMPORT, "str",
> +                        pc_machine_get_vmport,
> +                        pc_machine_set_vmport,
> +                        NULL, NULL, NULL);
>  }
>  
>  static void pc_machine_class_init(ObjectClass *oc, void *data)
> diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
> index 7bb97a4..81a7b83 100644
> --- a/hw/i386/pc_piix.c
> +++ b/hw/i386/pc_piix.c
> @@ -101,6 +101,7 @@ static void pc_init1(MachineState *machine,
>      FWCfgState *fw_cfg = NULL;
>      PcGuestInfo *guest_info;
>      ram_addr_t lowmem;
> +    bool no_vmport;
>  
>      /* Check whether RAM fits below 4G (leaving 1/2 GByte for IO memory).
>       * If it doesn't, we need to split it in chunks below and above 4G.
> @@ -234,9 +235,33 @@ static void pc_init1(MachineState *machine,
>  
>      pc_vga_init(isa_bus, pci_enabled ? pci_bus : NULL);
>  

Probably should be assert(pc_machine->vmport != VMPORT_MAX) -
we never get any values except on/off/auto.

> +    if (xen_enabled()) {
> +        switch (pc_machine->vmport) {
> +        case VMPORT_MAX:
> +        case VMPORT_AUTO:
> +        case VMPORT_OFF:
> +            no_vmport = true;
> +            break;
> +        case VMPORT_ON:
> +            no_vmport = false;
> +            break;
> +        }
> +    } else {
> +        switch (pc_machine->vmport) {
> +        case VMPORT_MAX:
> +        case VMPORT_OFF:
> +            no_vmport = true;
> +            break;
> +        case VMPORT_AUTO:
> +        case VMPORT_ON:
> +            no_vmport = false;
> +            break;
> +        }
> +    }
> +

Can't above be moved to a function in pc.c, and be reused between piix
and q35? It's big enough to avoid open-coding, IMHO.


>      /* init basic PC hardware */
>      pc_basic_device_init(isa_bus, gsi, &rtc_state, &floppy,
> -                         !pc_machine->vmport, 0x4);
> +                         no_vmport, 0x4);
>  
>      pc_nic_init(isa_bus, pci_bus);
>  
> diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
> index 598e679..4f932d6 100644
> --- a/hw/i386/pc_q35.c
> +++ b/hw/i386/pc_q35.c
> @@ -88,6 +88,7 @@ static void pc_q35_init(MachineState *machine)
>      PcGuestInfo *guest_info;
>      ram_addr_t lowmem;
>      DriveInfo *hd[MAX_SATA_PORTS];
> +    bool no_vmport;
>  
>      /* Check whether RAM fits below 4G (leaving 1/2 GByte for IO memory
>       * and 256 Mbytes for PCI Express Enhanced Configuration Access Mapping
> @@ -242,9 +243,33 @@ static void pc_q35_init(MachineState *machine)
>  
>      pc_register_ferr_irq(gsi[13]);
>  
> +    if (xen_enabled()) {
> +        switch (pc_machine->vmport) {
> +        case VMPORT_MAX:
> +        case VMPORT_AUTO:
> +        case VMPORT_OFF:
> +            no_vmport = true;
> +            break;
> +        case VMPORT_ON:
> +            no_vmport = false;
> +            break;
> +        }
> +    } else {
> +        switch (pc_machine->vmport) {
> +        case VMPORT_MAX:
> +        case VMPORT_OFF:
> +            no_vmport = true;
> +            break;
> +        case VMPORT_AUTO:
> +        case VMPORT_ON:
> +            no_vmport = false;
> +            break;
> +        }
> +    }
> +
>      /* init basic PC hardware */
>      pc_basic_device_init(isa_bus, gsi, &rtc_state, &floppy,
> -                         !pc_machine->vmport, 0xff0104);
> +                         no_vmport, 0xff0104);
>  
>      /* connect pm stuff to lpc */
>      ich9_lpc_pm_init(lpc);
> diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
> index 7c3731f..d7d8f30 100644
> --- a/include/hw/i386/pc.h
> +++ b/include/hw/i386/pc.h
> @@ -37,7 +37,7 @@ struct PCMachineState {
>      ISADevice *rtc;
>  
>      uint64_t max_ram_below_4g;
> -    bool vmport;
> +    vmport vmport;
>  };
>  
>  #define PC_MACHINE_ACPI_DEVICE_PROP "acpi-device"
> diff --git a/qapi-schema.json b/qapi-schema.json
> index d0926d9..f7ee3ad 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -3513,3 +3513,19 @@
>  # Since: 2.1
>  ##
>  { 'command': 'rtc-reset-reinjection' }
> +
> +##
> +# @vmport
> +#
> +# An enumeration of the options on enabling of VMWare ioport emulation
> +#
> +# @auto: system selects the old default
> +#
> +# @on: provide the vmport device
> +#
> +# @off: do not provide the vmport device
> +#
> +# Since: 2.2
> +##
> +{ 'enum': 'vmport',


vmport as type name violates our coding style.
Should be VMPort.

But in fact, this is a generic OnOffAuto type, isn't it?
Maybe it should be named like this, and go into qapi/common.json?
I think it might be a good idea but it's not a must.

> +  'data': [ 'auto', 'on', 'off' ] }
> diff --git a/qemu-options.hx b/qemu-options.hx
> index da9851d..64af16d 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -33,7 +33,7 @@ DEF("machine", HAS_ARG, QEMU_OPTION_machine, \
>      "                property accel=accel1[:accel2[:...]] selects accelerator\n"
>      "                supported accelerators are kvm, xen, tcg (default: tcg)\n"
>      "                kernel_irqchip=on|off controls accelerated irqchip support\n"
> -    "                vmport=on|off controls emulation of vmport (default: on)\n"
> +    "                vmport=on|off|auto controls emulation of vmport (default: auto)\n"
>      "                kvm_shadow_mem=size of KVM shadow MMU\n"
>      "                dump-guest-core=on|off include guest memory in a core dump (default=on)\n"
>      "                mem-merge=on|off controls memory merge support (default: on)\n"
> @@ -52,8 +52,10 @@ than one accelerator specified, the next one is used if the previous one fails
>  to initialize.
>  @item kernel_irqchip=on|off
>  Enables in-kernel irqchip support for the chosen accelerator when available.
> -@item vmport=on|off
> -Enables emulation of VMWare IO port, for vmmouse etc. (enabled by default)
> +@item vmport=on|off|auto
> +Enables emulation of VMWare IO port, for vmmouse etc. auto says to select the
> +value based on accel. For accel=xen the default is off otherwise the default
> +is on.
>  @item kvm_shadow_mem=size
>  Defines the size of the KVM shadow MMU.
>  @item dump-guest-core=on|off
> diff --git a/vl.c b/vl.c
> index f4a6e5e..eb89d62 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -381,7 +381,7 @@ static QemuOptsList qemu_machine_opts = {
>              .help = "maximum ram below the 4G boundary (32bit boundary)",
>          }, {
>              .name = PC_MACHINE_VMPORT,
> -            .type = QEMU_OPT_BOOL,
> +            .type = QEMU_OPT_STRING,
>              .help = "Enable vmport (pc & q35)",
>          },{
>              .name = "iommu",
> -- 
> 1.8.4