[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [PATCH v3 1/2] xen/pci: Defer initialization of MSI ops on HVM guests until after x2APIC has been set up



On 11/25/2014 07:06 AM, Stefano Stabellini wrote:
On Mon, 24 Nov 2014, Boris Ostrovsky wrote:
If the hardware supports APIC virtualization we may decide not to use pirqs
and instead use APIC/x2APIC directly, meaning that we don't want to set
x86_msi.setup_msi_irqs and x86_msi.teardown_msi_irq to Xen-specific routines.
However, x2APIC is not set up by the time pci_xen_hvm_init() is called so we
need to postpone setting these ops until later, when we know which APIC mode
is used.

(Note that currently x2APIC is never initialized on HVM guests. This may
change in the future)
I take that this is safe because no MSIs can be received at this point
(apic_post_init), right?


Yes. At the time apic_post_init() is called PCI has not been probed yet.

-boris



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel


 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.