Re: [PATCH] KVM: PPC: Book3S HV: XIVE: fix page offset when clearing ESB pages

[Paul Mackerras <paulus@ozlabs.org>]

On Tue, May 28, 2019 at 11:13:24PM +0200, Cédric Le Goater wrote:
> Under XIVE, the ESB pages of an interrupt are used for interrupt
> management (EOI) and triggering. They are made available to guests
> through a mapping of the XIVE KVM device.
> 
> When a device is passed-through, the passthru_irq helpers,
> kvmppc_xive_set_mapped() and kvmppc_xive_clr_mapped(), clear the ESB
> pages of the guest IRQ number being mapped and let the VM fault
> handler repopulate with the correct page.
> 
> The ESB pages are mapped at offset 4 (KVM_XIVE_ESB_PAGE_OFFSET) in the
> KVM device mapping. Unfortunately, this offset was not taken into
> account when clearing the pages. This lead to issues with the
> passthrough devices for which the interrupts were not functional under
> some guest configuration (tg3 and single CPU) or in any configuration
> (e1000e adapter).
> 
> Signed-off-by: Cédric Le Goater <clg@kaod.org>

Thanks, patch applied to my kvm-ppc-fixes branch.

Paul.