On Sat, Jul 19, 2014 at 06:55:48PM +0200, Jan Kiszka wrote:
> From: Jan Kiszka <jan.kis...@siemens.com>
>
> The spec says (and real HW confirms this) that, if the bus master bit
> is 0, the device will not generate any PCI accesses. MSI and MSI-X
> messages fall among these.
>
> Signed-off-by: Jan Kiszka <jan.kis...@siemens.com>
I guess an alternative is for callers to check before
invoking msi_notify. Please note is this is only option
when using e.g. irqfd, so this has some advantages.
Is there a specific device that is affected by this?
I would expect drivers to disable msi before clearing
bus master bit ...
> ---
> hw/pci/msi.c | 4 ++++
> hw/pci/msix.c | 4 ++++
> 2 files changed, 8 insertions(+)
>
> diff --git a/hw/pci/msi.c b/hw/pci/msi.c
> index a4a3040..36b651b 100644
> --- a/hw/pci/msi.c
> +++ b/hw/pci/msi.c
> @@ -285,6 +285,10 @@ void msi_notify(PCIDevice *dev, unsigned int vector)
> return;
> }
>
> + if (!(pci_get_word(dev->config + PCI_COMMAND) & PCI_COMMAND_MASTER)) {
> + return;
> + }
> +
> msg = msi_get_message(dev, vector);
>
> MSI_DEV_PRINTF(dev,
> diff --git a/hw/pci/msix.c b/hw/pci/msix.c
> index 5c49bfc..c77ae7d 100644
> --- a/hw/pci/msix.c
> +++ b/hw/pci/msix.c
> @@ -437,6 +437,10 @@ void msix_notify(PCIDevice *dev, unsigned vector)
> return;
> }
>
> + if (!(pci_get_word(dev->config + PCI_COMMAND) & PCI_COMMAND_MASTER)) {
> + return;
> + }
> +
> msg = msix_get_message(dev, vector);
>
> stl_le_phys(&address_space_memory, msg.address, msg.data);
> --
> 1.8.1.1.298.ge7eed54
>
