Re: [PATCH v4 12/30] hw/core: Introduce proxy-pic

[Philippe Mathieu-Daudé]

On 21/12/22 17:59, Bernhard Beschow wrote:
> Having a proxy PIC allows for ISA PICs to be created and wired up in
> southbridges. This is especially useful for PIIX3 for two reasons:
> First, the southbridge doesn't need to care about the virtualization
> technology used (KVM, TCG, Xen) due to in-IRQs (where devices get
> attached) and out-IRQs (which will trigger the IRQs of the respective
> virtzalization technology) are separated. Second, since the in-IRQs are
> populated with fully initialized qemu_irq's, they can already be wired
> up inside PIIX3.
>
> Signed-off-by: Bernhard Beschow <shentey@gmail.com>
> Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
> Message-Id: <20221022150508.26830-15-shentey@gmail.com>
> ---
>   MAINTAINERS                 |  2 ++
>   hw/core/Kconfig             |  3 ++
>   hw/core/meson.build         |  1 +
>   hw/core/proxy-pic.c         | 70 +++++++++++++++++++++++++++++++++++++
>   include/hw/core/proxy-pic.h | 54 ++++++++++++++++++++++++++++
>   5 files changed, 130 insertions(+)
>   create mode 100644 hw/core/proxy-pic.c
>   create mode 100644 include/hw/core/proxy-pic.h

Please enable scripts/git.orderfile.

> diff --git a/include/hw/core/proxy-pic.h b/include/hw/core/proxy-pic.h
> new file mode 100644
> index 0000000000..0eb40c478a
> --- /dev/null
> +++ b/include/hw/core/proxy-pic.h
> @@ -0,0 +1,54 @@
> +/*
> + * Proxy interrupt controller device.
> + *
> + * Copyright (c) 2022 Bernhard Beschow <shentey@gmail.com>
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a copy
> + * of this software and associated documentation files (the "Software"), to 
> deal
> + * in the Software without restriction, including without limitation the rights
> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> + * copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
> FROM,
> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> + * THE SOFTWARE.

This is the MIT license right? Do you mind adding a SPDX tag along?

 * SPDX-License-Identifier: MIT

> + */
> +
> +#ifndef HW_PROXY_PIC_H
> +#define HW_PROXY_PIC_H
> +
> +#include "hw/qdev-core.h"
> +#include "qom/object.h"
> +#include "hw/irq.h"
> +
> +#define TYPE_PROXY_PIC "proxy-pic"
> +OBJECT_DECLARE_SIMPLE_TYPE(ProxyPICState, PROXY_PIC)
> +
> +#define MAX_PROXY_PIC_LINES 16
> +
> +/**
> + * This is a simple device which has 16 pairs of GPIO input and output lines.
> + * Any change on an input line is forwarded to the respective output.
> + *
> + * QEMU interface:
> + *  + 16 unnamed GPIO inputs: the input lines
> + *  + 16 unnamed GPIO outputs: the output lines
> + */

Why restrict to 16 and not use a class property and allocate
on the heap? See TYPE_SPLIT_IRQ for example.

> +struct ProxyPICState {
> +    /*< private >*/
> +    struct DeviceState parent_obj;
> +    /*< public >*/
> +
> +    qemu_irq in_irqs[MAX_PROXY_PIC_LINES];
> +    qemu_irq out_irqs[MAX_PROXY_PIC_LINES];
> +};
> +
> +#endif /* HW_PROXY_PIC_H */