iommu/amd: Explicitly bail from enable_iommus_vapic() when in legacy mode

Bail early from enable_iommus_vapic() if IOMMUs are configured for either
of the legacy modes, as it's absurdly difficult to see that
iommu_ga_log_enable() is guaranteed to fail because iommu_init_ga_log()
skips allocating the ga_log.

Opportunistically have iommu_ga_log_enable() WARN if it's called without
IOMMUs being configured to support AVIC/vAPIC.

Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
This commit is contained in:
Sean Christopherson 2025-03-14 20:09:28 -07:00 • committed by Joerg Roedel
commit b30e046cfd