Messages in this thread | | | Date | Fri, 10 Dec 2021 08:30:28 -0400 | From | Jason Gunthorpe <> | Subject | Re: [patch 21/32] NTB/msi: Convert to msi_on_each_desc() |
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On Fri, Dec 10, 2021 at 07:36:12AM +0000, Tian, Kevin wrote:
> /* > * The MSIX mappable capability informs that MSIX data of a BAR can be mmapped > * which allows direct access to non-MSIX registers which happened to be within > * the same system page. > * > * Even though the userspace gets direct access to the MSIX data, the existing > * VFIO_DEVICE_SET_IRQS interface must still be used for MSIX configuration. ^^^^^^^^^^^^^^^^^^^^^
It is this I think we don't want, there should be no hypervisor involvment on installing the addr/data pair
Guessing by what I saw in PPC there is a hypercall to install a MSI and the guest never touches the page even though it is mapped. Presumably there is some IR like thing making this secured
PPC has the same basic problem, I think they have a hypercall to install a MSI, not a hypercall to provision a generic addr/data pair.
Jason
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