Re: [PATCH 1/5] pci-assign: Clean up assigned_dev_pci_read/write_config

[Alex Williamson <alex.williamson@redhat.com>]

On Tue, 2010-12-14 at 00:25 +0100, Jan Kiszka wrote:
> From: Jan Kiszka <jan.kiszka@siemens.com>
> 
> Use rages_overlap and proper constants to match the access range against
> regions that need special handling. This also fixes yet uncaught
> high-byte write access to the command register. Moreover, use more
> constants instead of magic numbers.
> 
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> ---
>  hw/device-assignment.c |   39 +++++++++++++++++++++++++++++----------
>  1 files changed, 29 insertions(+), 10 deletions(-)

A long overdue cleanup, looks good.

Acked-by: Alex Williamson <alex.williamson@redhat.com>

> diff --git a/hw/device-assignment.c b/hw/device-assignment.c
> index 50c6408..bc3a57b 100644
> --- a/hw/device-assignment.c
> +++ b/hw/device-assignment.c
> @@ -438,13 +438,20 @@ static void assigned_dev_pci_write_config(PCIDevice *d, uint32_t address,
>          return assigned_device_pci_cap_write_config(d, address, val, len);
>      }
>  
> -    if (address == 0x4) {
> +    if (ranges_overlap(address, len, PCI_COMMAND, 2)) {
>          pci_default_write_config(d, address, val, len);
>          /* Continue to program the card */
>      }
>  
> -    if ((address >= 0x10 && address <= 0x24) || address == 0x30 ||
> -        address == 0x34 || address == 0x3c || address == 0x3d) {
> +    /*
> +     * Catch access to
> +     *  - base address registers
> +     *  - ROM base address & capability pointer
> +     *  - interrupt line & pin
> +     */
> +    if (ranges_overlap(address, len, PCI_BASE_ADDRESS_0, 24) ||
> +        ranges_overlap(address, len, PCI_ROM_ADDRESS, 8) ||
> +        ranges_overlap(address, len, PCI_INTERRUPT_LINE, 2)) {
>          /* used for update-mappings (BAR emulation) */
>          pci_default_write_config(d, address, val, len);
>          return;
> @@ -484,9 +491,20 @@ static uint32_t assigned_dev_pci_read_config(PCIDevice *d, uint32_t address,
>          return val;
>      }
>  
> -    if (address < 0x4 || (pci_dev->need_emulate_cmd && address == 0x4) ||
> -	(address >= 0x10 && address <= 0x24) || address == 0x30 ||
> -        address == 0x34 || address == 0x3c || address == 0x3d) {
> +    /*
> +     * Catch access to
> +     *  - vendor & device ID
> +     *  - command register (if emulation needed)
> +     *  - base address registers
> +     *  - ROM base address & capability pointer
> +     *  - interrupt line & pin
> +     */
> +    if (ranges_overlap(address, len, PCI_VENDOR_ID, 4) ||
> +        (pci_dev->need_emulate_cmd &&
> +         ranges_overlap(address, len, PCI_COMMAND, 2)) ||
> +        ranges_overlap(address, len, PCI_BASE_ADDRESS_0, 24) ||
> +        ranges_overlap(address, len, PCI_ROM_ADDRESS, 8) ||
> +        ranges_overlap(address, len, PCI_INTERRUPT_LINE, 2)) {
>          val = pci_default_read_config(d, address, len);
>          DEBUG("(%x.%x): address=%04x val=0x%08x len=%d\n",
>                (d->devfn >> 3) & 0x1F, (d->devfn & 0x7), address, val, len);
> @@ -517,10 +535,11 @@ do_log:
>  
>      if (!pci_dev->cap.available) {
>          /* kill the special capabilities */
> -        if (address == 4 && len == 4)
> -            val &= ~0x100000;
> -        else if (address == 6)
> -            val &= ~0x10;
> +        if (address == PCI_COMMAND && len == 4) {
> +            val &= ~(PCI_STATUS_CAP_LIST << 16);
> +        } else if (address == PCI_STATUS) {
> +            val &= ~PCI_STATUS_CAP_LIST;
> +        }
>      }
>  
>      return val;