On 12/12/2022 16:26, David Woodhouse wrote:
On Mon, 2022-12-12 at 16:16 +0000, Paul Durrant wrote:
On 09/12/2022 09:56, David Woodhouse wrote:
From: Ankur Arora <ankur.a.ar...@oracle.com>
The HVM_PARAM_CALLBACK_IRQ parameter controls the system-wide event
channel upcall method. The vector support is handled by KVM internally,
when the evtchn_upcall_pending field in the vcpu_info is set.
The GSI and PCI_INTX delivery methods are not supported. yet; those
need to simulate a level-triggered event on the I/OAPIC.
That's gonna be somewhat limiting if anyone runs a Windows guest with
upcall vector support turned off... which is an option at:
https://xenbits.xen.org/gitweb/?p=pvdrivers/win/xenbus.git;a=blob;f=src/xenbus/evtchn.c;;hb=HEAD#l1928
Sure. And as you know, I also added the 'xen_no_vector_callback' option
to the Linux command line to allow for that mode to be tested with
Linux too: https://git.kernel.org/torvalds/c/b36b0fe96a
The GSI and PCI_INTX modes will be added in time, but not yet.
Ok, but maybe worth calling out the limitation in the commit comment for
those wishing to kick the tyres.
Paul
