On Fri, 2011-04-29 at 11:05 +0200, Jan Kiszka wrote:
> Ensure that accesses exceeding PCI_CAPABILITY_LIST and
> PCI_INTERRUPT_LINE+PIN hit the real device in areas we do not
> virtualize. Again, we do not optimize these checks and accesses a lot,
> they are considered to be slow paths.
>
> Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
> ---
> hw/device-assignment.c | 34 +++++++++++++++++++++++++++++-----
> 1 files changed, 29 insertions(+), 5 deletions(-)
>
> diff --git a/hw/device-assignment.c b/hw/device-assignment.c
> index cea072e..37c77e3 100644
> --- a/hw/device-assignment.c
> +++ b/hw/device-assignment.c
> @@ -442,7 +442,29 @@ static void assigned_dev_pci_write_config(PCIDevice *d, uint32_t address,
> ranges_overlap(address, len, PCI_INTERRUPT_LINE, 2)) {
> /* used for update-mappings (BAR emulation) */
> pci_default_write_config(d, address, val, len);
> - return;
> +
> + /* Ensure that writes to overlapping areas we don't virtualize still
> + * hit the device. */
> + switch (address) {
> + case PCI_CAPABILITY_LIST:
> + if (len > 1) {
> + len -= 1;
> + address += 1;
> + val >>= 8;
> + break; /* continue writing to the device */
> + }
> + return;
> + case PCI_INTERRUPT_LINE:
> + if (len > 2) {
> + len -= 2;
> + address += 2;
> + val >>= 16;
> + break; /* continue writing to the device */
> + }
> + return;
> + default:
> + return;
> + }
> }
It seems like we could be more symmetric with the below read. Maybe
something like:
if (ranges_overlap(address, len, PCI_BASE_ADDRESS_0, 24) ||
ranges_overlap(address, len, PCI_ROM_ADDRESS, 4)) {
pci_default_write_config(d, address, val, len);
return;
} else if (ranges_overlap(address, len, PCI_CAPABILITY_LIST, 1) ||
ranges_overlap(address, len, PCI_INTERRUPT_LINE, 2)) {
uint32_t real_val = assigned_dev_pci_read(d, address, len);
pci_default_write_config(d, address, val, len);
val = merge_bits(val, real_val, address, len, PCI_CAPABILITY_LIST, 0xff);
val = merge_bits(val, real_val, address, len, PCI_INTERRUPT_LINE, 0xffff);
}
We might write out to real hardware when we could avoid it, but I don't
think it matters. Thanks,
Alex
> DEBUG("NON BAR (%x.%x): address=%04x val=0x%08x len=%d\n",
> @@ -467,7 +489,7 @@ again:
> static uint32_t assigned_dev_pci_read_config(PCIDevice *d, uint32_t address,
> int len)
> {
> - uint32_t val = 0;
> + uint32_t val = 0, virt_val;
> int fd;
> ssize_t ret;
> AssignedDevice *pci_dev = DO_UPCAST(AssignedDevice, dev, d);
> @@ -484,12 +506,10 @@ static uint32_t assigned_dev_pci_read_config(PCIDevice *d, uint32_t address,
> * - vendor & device ID
> * - base address registers
> * - ROM base address & capability pointer
> - * - interrupt line & pin
> */
> if (ranges_overlap(address, len, PCI_VENDOR_ID, 4) ||
> ranges_overlap(address, len, PCI_BASE_ADDRESS_0, 24) ||
> - ranges_overlap(address, len, PCI_ROM_ADDRESS, 5) ||
> - ranges_overlap(address, len, PCI_INTERRUPT_LINE, 2)) {
> + ranges_overlap(address, len, PCI_ROM_ADDRESS, 4)) {
> 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);
> @@ -523,6 +543,10 @@ do_log:
> address, len, PCI_COMMAND, 0xffff);
> }
>
> + virt_val = pci_default_read_config(d, address, len);
> + val = merge_bits(val, virt_val, address, len, PCI_CAPABILITY_LIST, 0xff);
> + val = merge_bits(val, virt_val, address, len, PCI_INTERRUPT_LINE, 0xffff);
> +
> if (!pci_dev->cap.available) {
> /* kill the special capabilities */
> if (address == PCI_COMMAND && len == 4) {
--
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