Re: [PATCH-for-5.0 v3 6/6] hw/pci-host: Add Kconfig entry to select the IGD Passthrough Host Bridge

From: Paolo Bonzini <pbonzini@redhat.com>
To: "Philippe Mathieu-Daudé" <philmd@redhat.com>, qemu-devel@nongnu.org
Cc: Thomas Huth <thuth@redhat.com>,
	Stefano Stabellini <sstabellini@kernel.org>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	Paul Durrant <paul@xen.org>,
	Markus Armbruster <armbru@redhat.com>,
	Alex Williamson <alex.williamson@redhat.com>,
	Anthony Perard <anthony.perard@citrix.com>,
	xen-devel@lists.xenproject.org
Subject: Re: [PATCH-for-5.0 v3 6/6] hw/pci-host: Add Kconfig entry to select the IGD Passthrough Host Bridge
Date: Mon, 9 Dec 2019 11:39:28 +0100	[thread overview]
Message-ID: <0b4c7637-ffc1-102e-7f29-2568831eb20c@redhat.com> (raw)
In-Reply-To: <20191209095002.32194-7-philmd@redhat.com>

On 09/12/19 10:50, Philippe Mathieu-Daudé wrote:
> Add the XEN_IGD_PASSTHROUGH Kconfig option.
> 
> Xen build has that option selected by default. Non-Xen builds now
> have to select this feature manually.
> 
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
> v3: Only default with Xen (Alex Williamson)
> 
> I did not used 'depends on XEN' as suggested by Alex but
> 'default y if XEN', so one can build XEN without this feature
> (for example, on other ARCH than X86).
> ---
>  hw/pci-host/Kconfig       | 5 +++++
>  hw/pci-host/Makefile.objs | 2 +-
>  2 files changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/pci-host/Kconfig b/hw/pci-host/Kconfig
> index b0aa8351c4..24ba8ea046 100644
> --- a/hw/pci-host/Kconfig
> +++ b/hw/pci-host/Kconfig
> @@ -1,6 +1,11 @@
>  config PAM
>      bool
>  
> +config XEN_IGD_PASSTHROUGH
> +    bool
> +    default y if XEN
> +    select PCI_I440FX

Maybe "depends on PCI_I440FX" (so if somebody builds a Xen+KVM, q35-only
machine they don't get IGD passthrough).  I can do this when applying.

Paolo

> +
>  config PREP_PCI
>      bool
>      select PCI
> diff --git a/hw/pci-host/Makefile.objs b/hw/pci-host/Makefile.objs
> index fa6d1556c0..9c466fab01 100644
> --- a/hw/pci-host/Makefile.objs
> +++ b/hw/pci-host/Makefile.objs
> @@ -14,7 +14,7 @@ common-obj-$(CONFIG_VERSATILE_PCI) += versatile.o
>  common-obj-$(CONFIG_PCI_SABRE) += sabre.o
>  common-obj-$(CONFIG_FULONG) += bonito.o
>  common-obj-$(CONFIG_PCI_I440FX) += i440fx.o
> -common-obj-$(CONFIG_PCI_I440FX) += xen_igd_pt.o
> +common-obj-$(CONFIG_XEN_IGD_PASSTHROUGH) += xen_igd_pt.o
>  common-obj-$(CONFIG_PCI_EXPRESS_Q35) += q35.o
>  common-obj-$(CONFIG_PCI_EXPRESS_GENERIC_BRIDGE) += gpex.o
>  common-obj-$(CONFIG_PCI_EXPRESS_XILINX) += xilinx-pcie.o
> 