On 18.11.2022 13:19, Marek Marczykowski-Górecki wrote: > On Fri, Nov 18, 2022 at 08:20:14AM +0100, Jan Beulich wrote: >> On 17.11.2022 18:31, Marek Marczykowski-Górecki wrote: >>> On Thu, Nov 17, 2022 at 05:34:36PM +0100, Jan Beulich wrote: >>>> Which in turn raises the question: Do you need to handle reads >>>> in the new code in the first place? >>> >>> The page not being mapped is also the reason why I do need to handle >>> reads too. >> >> Just for my own clarity: You mean "not mapped to qemu" here? > > No, to the HVM domain (in p2m). Xen (outside of MSI-X specific code for > HVM) doesn't know where those reads should be from.
Hmm, I was expecting them to be mapped r/o to the guest, but perhaps I'm misremembering. Clearly both ept_p2m_type_to_flags() and p2m_type_to_flags() take mmio_ro_ranges into consideration, which is what I was basing my understanding on (without having looked at other places in detail). Jan
