On Fri, 17 Jan 2025 at 18:29, Nicholas Piggin <[email protected]> wrote:

> Of the MSI-X PBA pending bits, the PCI Local Bus Specification says:
>
>   Software should never write, and should only read
>   Pending Bits. If software writes to Pending Bits, the
>   result is undefined.
>
> Log a GUEST_ERROR message if the PBA is written to by software.
>
> Cc: Michael S. Tsirkin <[email protected]>
> Cc: Marcel Apfelbaum <[email protected]>
> Cc: Dmitry Fleytman <[email protected]>
> Cc: Akihiko Odaki <[email protected]>
> Cc: Sriram Yagnaraman <[email protected]>
> Signed-off-by: Nicholas Piggin <[email protected]>
>

Reviewed-by: Phil Dennis-Jordan <[email protected]>


> ---
>  hw/pci/msix.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
>
> diff --git a/hw/pci/msix.c b/hw/pci/msix.c
> index 57ec7084a47..66f27b9d712 100644
> --- a/hw/pci/msix.c
> +++ b/hw/pci/msix.c
> @@ -15,6 +15,7 @@
>   */
>
>  #include "qemu/osdep.h"
> +#include "qemu/log.h"
>  #include "hw/pci/msi.h"
>  #include "hw/pci/msix.h"
>  #include "hw/pci/pci.h"
> @@ -260,6 +261,14 @@ static uint64_t msix_pba_mmio_read(void *opaque,
> hwaddr addr,
>  static void msix_pba_mmio_write(void *opaque, hwaddr addr,
>                                  uint64_t val, unsigned size)
>  {
> +    PCIDevice *dev = opaque;
> +
> +    qemu_log_mask(LOG_GUEST_ERROR,
> +                  "PCI [%s:%02x:%02x.%x] attempt to write to MSI-X "
> +                  "PBA at 0x%" FMT_PCIBUS ", ignoring.\n",
> +                  pci_root_bus_path(dev), pci_dev_bus_num(dev),
> +                  PCI_SLOT(dev->devfn), PCI_FUNC(dev->devfn),
> +                  addr);
>  }
>
>  static const MemoryRegionOps msix_pba_mmio_ops = {
> --
> 2.45.2
>
>
>

Reply via email to