[Qemu-devel] Re: [PATCH v4 04/15] pci: record which is written into pci configuration space

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

On Mon, Oct 18, 2010 at 12:17:45PM +0900, Isaku Yamahata wrote:
> record which is written into pci configuration space.
> introduce helper function to zero PCIDevice::written.
> They will be used later.
> 
> Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>

This really exposes an internal variable.
I really dislike this, and I don't think it's needed
at all: just make the bit writeable.
Commented on appropriate patches.

> ---
>  hw/pci.c |   10 ++++++++++
>  hw/pci.h |    5 +++++
>  2 files changed, 15 insertions(+), 0 deletions(-)
> 
> diff --git a/hw/pci.c b/hw/pci.c
> index 5954476..eca9324 100644
> --- a/hw/pci.c
> +++ b/hw/pci.c
> @@ -627,6 +627,7 @@ static void pci_config_alloc(PCIDevice *pci_dev)
>      pci_dev->cmask = qemu_mallocz(config_size);
>      pci_dev->wmask = qemu_mallocz(config_size);
>      pci_dev->w1cmask = qemu_mallocz(config_size);
> +    pci_dev->written = qemu_mallocz(config_size);
>      pci_dev->used = qemu_mallocz(config_size);
>  }
>  
> @@ -636,6 +637,7 @@ static void pci_config_free(PCIDevice *pci_dev)
>      qemu_free(pci_dev->cmask);
>      qemu_free(pci_dev->wmask);
>      qemu_free(pci_dev->w1cmask);
> +    qemu_free(pci_dev->written);
>      qemu_free(pci_dev->used);
>  }
>  
> @@ -1002,6 +1004,8 @@ void pci_default_write_config(PCIDevice *d, uint32_t addr, uint32_t val, int l)
>          assert(!(wmask & w1cmask));
>          d->config[addr + i] = (d->config[addr + i] & ~wmask) | (val & wmask);
>          d->config[addr + i] &= ~(val & w1cmask); /* W1C: Write 1 to Clear */
> +        d->written[addr + i] = val; /* record what is written for driver
> +                                       specific code */
>      }
>      if (ranges_overlap(addr, l, PCI_BASE_ADDRESS_0, 24) ||
>          ranges_overlap(addr, l, PCI_ROM_ADDRESS, 4) ||
> @@ -1013,6 +1017,12 @@ void pci_default_write_config(PCIDevice *d, uint32_t addr, uint32_t val, int l)
>          pci_update_irq_disabled(d, was_irq_disabled);
>  }
>  
> +void pci_clear_written_write_config(PCIDevice *d,
> +                                    uint32_t addr, uint32_t val, int l)
> +{
> +    memset(d->written + addr, 0, l);
> +}
> +
>  /***********************************************************/
>  /* generic PCI irq support */
>  
> diff --git a/hw/pci.h b/hw/pci.h
> index eafa9f3..7097817 100644
> --- a/hw/pci.h
> +++ b/hw/pci.h
> @@ -132,6 +132,9 @@ struct PCIDevice {
>      /* Used to implement RW1C(Write 1 to Clear) bytes */
>      uint8_t *w1cmask;
>  
> +    /* Used to record what value is written */
> +    uint8_t *written;
> +
>      /* Used to allocate config space for capabilities. */
>      uint8_t *used;
>  
> @@ -200,6 +203,8 @@ uint32_t pci_default_read_config(PCIDevice *d,
>                                   uint32_t address, int len);
>  void pci_default_write_config(PCIDevice *d,
>                                uint32_t address, uint32_t val, int len);
> +void pci_clear_written_write_config(PCIDevice *d,
> +                                    uint32_t addr, uint32_t val, int l);
>  void pci_device_save(PCIDevice *s, QEMUFile *f);
>  int pci_device_load(PCIDevice *s, QEMUFile *f);
>  
> -- 
> 1.7.1.1