Re: [Qemu-devel] [PATCH v2] hw/i386: make IOMMUs configurable via default-configs/

[Thomas Huth]

On 12.03.2018 10:43, Paolo Bonzini wrote:
> Allow distributions to disable the Intel and/or AMD IOMMU devices.
> 
> Signed-off-by: Paolo Bonzini <address@hidden>
> ---
>         v1->v2: don't include x86-iommu.o unconditionally
> 
>  default-configs/i386-softmmu.mak   | 2 ++
>  default-configs/x86_64-softmmu.mak | 2 ++
>  hw/i386/Makefile.objs              | 4 ++--
>  3 files changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/default-configs/i386-softmmu.mak 
> b/default-configs/i386-softmmu.mak
> index 3326e3e0bb..9e5a29fa4a 100644
> --- a/default-configs/i386-softmmu.mak
> +++ b/default-configs/i386-softmmu.mak
> @@ -63,3 +63,5 @@ CONFIG_PXB=y
>  CONFIG_ACPI_VMGENID=y
>  CONFIG_FW_CFG_DMA=y
>  CONFIG_I2C=y
> +CONFIG_VTD=y
> +CONFIG_AMD_IOMMU=y
> diff --git a/default-configs/x86_64-softmmu.mak 
> b/default-configs/x86_64-softmmu.mak
> index 1c6cda1d9a..7baf91b921 100644
> --- a/default-configs/x86_64-softmmu.mak
> +++ b/default-configs/x86_64-softmmu.mak
> @@ -63,3 +63,5 @@ CONFIG_PXB=y
>  CONFIG_ACPI_VMGENID=y
>  CONFIG_FW_CFG_DMA=y
>  CONFIG_I2C=y
> +CONFIG_VTD=y
> +CONFIG_AMD_IOMMU=y
> diff --git a/hw/i386/Makefile.objs b/hw/i386/Makefile.objs
> index fd279e7584..fa87a14152 100644
> --- a/hw/i386/Makefile.objs
> +++ b/hw/i386/Makefile.objs
> @@ -2,8 +2,8 @@ obj-$(CONFIG_KVM) += kvm/
>  obj-y += multiboot.o
>  obj-y += pc.o pc_piix.o pc_q35.o
>  obj-y += pc_sysfw.o
> -obj-y += x86-iommu.o intel_iommu.o
> -obj-y += amd_iommu.o
> +obj-$(CONFIG_VTD) += x86-iommu.o intel_iommu.o
> +obj-$(CONFIG_AMD_IOMMU) += x86-iommu.o amd_iommu.o

The linker likely does not care if x86-iommu.o is included twice, but
wouldn't it be clearer to use this instead:

obj-$(call lor,$(CONFIG_VTD),$(CONFIG_AMD_IOMMU)) += x86-iommu.o

?

 Thomas