Re: [PATCH] xen-pciback: Allow setting PCI_MSIX_FLAGS_MASKALL too

[Jan Beulich]

On 14.11.2022 11:31, Marek Marczykowski-Górecki wrote:
> When Xen domain configures MSI-X, the usual approach is to enable MSI-X
> together with masking all of them via the config space, then fill the
> table and only then clear PCI_MSIX_FLAGS_MASKALL. Allow doing this via
> QEMU running in a stub domain.
> 
> Previously, when changing PCI_MSIX_FLAGS_MASKALL was not allowed, the
> whole write was aborted, preventing change to the PCI_MSIX_FLAGS_ENABLE
> bit too.
> 
> Note the Xen hypervisor intercepts this write anyway, and may keep the
> PCI_MSIX_FLAGS_MASKALL bit set if it wishes to. It will store the
> guest-requested state and will apply it eventually.
> 
> Signed-off-by: Marek Marczykowski-Górecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx>

Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>