Re: [patch 0/3] x86/PCI/MSI: Make sure that irq reservation mode works everywhere

From: Bjorn Helgaas
Date: Fri Oct 20 2017 - 19:01:37 EST


On Tue, Oct 17, 2017 at 09:54:56AM +0200, Thomas Gleixner wrote:
> Dexuan reported that the recent rework of the vector allocation mode in x86
> broke HyperV PCI passtrough because the rework missed to add the
> MSI_FLAG_MUST_REACTIVATE flag to the HyperV/PCI interrupt domain info.
>
> The simple solution would be to set the flag in the HyperV/PCI driver but
> it's better to make this generic and let the PCI/MSI core code set the flag
> when reservation mode is enabled. That ensures that future users of this
> wont trip over the same problem.
>
> Thanks,
>
> tglx
>
> ---
> arch/x86/Kconfig | 2 +-
> arch/x86/kernel/apic/msi.c | 5 ++---
> drivers/pci/msi.c | 2 ++
> kernel/irq/Kconfig | 3 +++
> 4 files changed, 8 insertions(+), 4 deletions(-)

This mentions 4900be83602b ("x86/vector/msi: Switch to global reservation
mode"), which I don't have, so I assume it's an x86 thing. So I guess
you'll probably merge this via the same tree?

Here's my ack for the PCI part:

Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>