On 01/10/2019 10:07, Jan Beulich wrote: > The write-discard property of the type can't be represented in IOMMU > page table entries. Make sure the respective checks / tracking can't > race, by utilizing the domain lock. The other sides of the sharing/ > paging/log-dirty exclusion checks should subsequently perhaps also be > put under that lock then. > > This also fixes an unguarded d->arch.hvm access. > > Take the opportunity and also convert neighboring bool_t to bool in > struct hvm_domain. > > Signed-off-by: Jan Beulich <[email protected]> > Reviewed-by: Paul Durrant <[email protected]>
Leaving aside the logdirty change which is an automatic no from me in this form, I can't see how this change avoids regressing the status quo. Qemu really does set this flag for option ROMs, which will typically be the iPXE image for net booting. Currently, netbooting an HVM guest with device passed through to it does work, because it is part of XenServers basic testing. It is entirely possible that this only "works" as long as DMA doesn't touch the option ROM, and while this might not be ideal, it seems to be less bad behaviour than breaking existing VMs using this configuration. ~Andrew _______________________________________________ Xen-devel mailing list [email protected] https://lists.xenproject.org/mailman/listinfo/xen-devel
