Re: [PATCH RESEND] kvm: make kvm_vcpu_(un)map dependency on CONFIG_HAS_IOMEM explicit

[Michal Kubecek]

On Mon, May 20, 2019 at 03:45:29PM -0700, Bjorn Andersson wrote:
> On Mon, May 20, 2019 at 9:44 AM Michal Kubecek <mkubecek@xxxxxxx> wrote:
> >
> > Recently introduced functions kvm_vcpu_map() and kvm_vcpu_unmap() call
> > memremap() and memunmap() which are only available if HAS_IOMEM is enabled
> > but this dependency is not explicit, so that the build fails with HAS_IOMEM
> > disabled.
> >
> > As both function are only used on x86 where HAS_IOMEM is always enabled,
> > the easiest fix seems to be to only provide them when HAS_IOMEM is enabled.
> >
> > Fixes: e45adf665a53 ("KVM: Introduce a new guest mapping API")
> > Signed-off-by: Michal Kubecek <mkubecek@xxxxxxx>
> 
> Hi Michal,
> 
> I see the same build issue on arm64 and as CONFIG_HAS_IOMEM is set
> there this patch has no effect on solving that. Instead I had to
> include linux/io.h in kvm_main.c to make it compile.

This sounds like a different problem which was already resolved in
mainline by commit c011d23ba046 ("kvm: fix compilation on aarch64")
which is present in v5.2-rc1. The issue I'm trying to address is link
time failure (unresolved reference to memremap()/memunmap()) when
CONFIG_HAS_IOMEM is disabled (in our case it affects a special
minimalistic s390x config for zfcpdump).

Michal