Re: [PATCH v4 3/7] ccid: build smartcard as module - Philippe Mathieu-Daudé

From: "Philippe Mathieu-Daudé" <philmd@redhat.com>
To: "Gerd Hoffmann" <kraxel@redhat.com>,
	qemu-devel@nongnu.org, "Paolo Bonzini" <pbonzini@redhat.com>,
	"Daniel P. Berrangé" <berrange@redhat.com>
Cc: dinechin@redhat.com, Eduardo Habkost <ehabkost@redhat.com>
Subject: Re: [PATCH v4 3/7] ccid: build smartcard as module
Date: Tue, 23 Jun 2020 17:28:55 +0200	[thread overview]
Message-ID: <434be3b8-8ed0-d27b-99c7-e682b0dc4c02@redhat.com> (raw)
In-Reply-To: <20200622135601.12433-4-kraxel@redhat.com>

Hi Gerd,

On 6/22/20 3:55 PM, Gerd Hoffmann wrote:
> Drops libcacard.so dependency from core qemu.
> 
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> ---
>  Makefile.objs        | 1 +
>  hw/core/qdev.c       | 2 ++
>  hw/Makefile.objs     | 1 +
>  hw/usb/Makefile.objs | 4 +++-
>  4 files changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/Makefile.objs b/Makefile.objs
> index 7ce2588b89a3..ca555ede0710 100644
> --- a/Makefile.objs
> +++ b/Makefile.objs
> @@ -59,6 +59,7 @@ common-obj-y += migration/
>  common-obj-y += audio/
>  common-obj-m += audio/
>  common-obj-y += hw/
> +common-obj-m += hw/
>  
>  common-obj-y += replay/
>  
> diff --git a/hw/core/qdev.c b/hw/core/qdev.c
> index 6119e25e0eeb..d6459e4aa8e8 100644
> --- a/hw/core/qdev.c
> +++ b/hw/core/qdev.c
> @@ -172,6 +172,8 @@ static struct {
>      const char *type;
>      const char *mod;
>  } const hwmodules[] = {
> +    { .type = "ccid-card-passthru",    .mod = "usb-smartcard"         },
> +    { .type = "ccid-card-emulated",    .mod = "usb-smartcard"         },

We want to use type definitions here (such TYPE_CCID_PASSTHRU),
as we don't guaranty them stable.

We don't want to include various "hw/x/y.h" in this core file.

Since there is a relation between QOM type and the module,
can we store/use the module name in the TypeInfo declaration?

  static const TypeInfo passthru_card_info = {
      .name          = TYPE_CCID_PASSTHRU,
      .parent        = TYPE_CCID_CARD,
      .instance_size = sizeof(PassthruState),
      .class_init    = passthru_class_initfn,
      .module_name   = "usb-smartcard",        <=====
  };

Actually this modularization is not specific to QDEV
and can be used to all QOM right? I.e:

  static const TypeInfo qcrypto_tls_creds_x509_info = {
      .parent = TYPE_QCRYPTO_TLS_CREDS,
      .name = TYPE_QCRYPTO_TLS_CREDS_X509,
      .module_name = "gnu-tls",
      ...
  }

>  };
>  
>  static bool qdev_module_loaded_all;
> diff --git a/hw/Makefile.objs b/hw/Makefile.objs
> index 4cbe5e4e57d6..af8fd9a510ed 100644
> --- a/hw/Makefile.objs
> +++ b/hw/Makefile.objs
> @@ -43,4 +43,5 @@ devices-dirs-y += smbios/
>  endif
>  
>  common-obj-y += $(devices-dirs-y)
> +common-obj-m += usb/
>  obj-y += $(devices-dirs-y)
> diff --git a/hw/usb/Makefile.objs b/hw/usb/Makefile.objs
> index fa5c3fa1b877..3c5b3d4fadd3 100644
> --- a/hw/usb/Makefile.objs
> +++ b/hw/usb/Makefile.objs
> @@ -29,11 +29,13 @@ common-obj-$(CONFIG_USB_NETWORK)      += dev-network.o
>  
>  ifeq ($(CONFIG_USB_SMARTCARD),y)
>  common-obj-y                          += dev-smartcard-reader.o
> -common-obj-$(CONFIG_SMARTCARD)        += smartcard.mo
> +ifeq ($(CONFIG_SMARTCARD),y)
> +common-obj-m                          += smartcard.mo
>  smartcard.mo-objs := ccid-card-passthru.o ccid-card-emulated.o
>  smartcard.mo-cflags := $(SMARTCARD_CFLAGS)
>  smartcard.mo-libs := $(SMARTCARD_LIBS)
>  endif
> +endif
>  
>  ifeq ($(CONFIG_POSIX),y)
>  common-obj-$(CONFIG_USB_STORAGE_MTP)  += dev-mtp.o
> 