Hi Stefano,
On 12/03/2021 23:16, Stefano Stabellini wrote:
Introduce two feature flags to tell the domain whether it is
direct-mapped or not. It allows the guest kernel to make informed
decisions on things such as swiotlb-xen enablement.
The introduction of both flags (XENFEAT_direct_mapped and
XENFEAT_not_direct_mapped) allows the guest kernel to avoid any
guesswork if one of the two is present, or fallback to the current
checks if neither of them is present.
XENFEAT_direct_mapped is always set for not auto-translated guests.
For auto-translated guests, only Dom0 on ARM is direct-mapped. Also,
see is_domain_direct_mapped() which refers to auto-translated guests:
xen/include/asm-arm/domain.h:is_domain_direct_mapped
xen/include/asm-x86/domain.h:is_domain_direct_mapped
Signed-off-by: Stefano Stabellini <[email protected]>
Reviewed-by: Julien Grall <[email protected]>
Cheers,
--
Julien Grall
