RE: [RFC PATCH v1] powerpc/prom_init: disable XIVE in Secure VM.

On Wed, Mar 04, 2020 at 11:59:48AM +0100, Greg Kurz wrote:

On Tue, 3 Mar 2020 10:56:45 -0800
Ram Pai [off-list ref] wrote:

quoted

On Tue, Mar 03, 2020 at 06:45:20PM +0100, Greg Kurz wrote:

....snip.

quoted

quoted

This patch would allow at least to answer Cedric's question about
kernel_irqchip=off, since this looks like the only thing needed
to make it work.

hmm.. I am not sure. Are you saying
(a) patch the guest kernel to share the event queue page
(b) run the qemu with "kernel_irqchip=off"
(c) and the guest kernel with "svm=on"

and it should all work?

Yes.

Ok. 

(1) applied the patch which shares the EQ-page with the hypervisor.
(2) set "kernel_irqchip=off"
(3) set "ic-mode=xive"
(4) set "svm=on" on the kernel command line.
(5) no changes to the hypervisor and ultravisor.

And Boom it works!.   So you were right.


I am sending out the patch for (1) above ASAP.

Thanks,
RP