On 19.05.2025 21:23, dm...@proton.me wrote: > From: Denis Mukhin <dmuk...@ford.com> > > Currently, hypervisor code has two different non-system domain ID allocation > implementations: > > (a) Sequential IDs allocation in dom0less Arm code based on max_init_domid; > > (b) Sequential IDs allocation in XEN_DOMCTL_createdomain; does not use > max_init_domid (both Arm and x86). > > It makes sense to have a common helper code for such task across architectures > (Arm and x86) and between dom0less / toolstack domU allocation. > > Wrap the domain ID allocation as an arch-independent function domid_alloc() in > common/domain.c based on the bitmap. > > Allocation algorithm: > - If an explicit domain ID is provided, verify its availability and use it if > ID is not used; > - If DOMID_INVALID is provided, perform an exhaustive search within > [0..CONFIG_MAX_DOMID-1] range, starting from the last used domain ID.
CONFIG_MAX_DOMID first appears in patch 3 afaics, and hence doesn't want mentioning here, yet. That patch,for eample, may never make it into the tree (and thus the description here may be confusing to future readers). > --- a/xen/common/domain.c > +++ b/xen/common/domain.c > @@ -66,6 +66,12 @@ DEFINE_RCU_READ_LOCK(domlist_read_lock); > static struct domain *domain_hash[DOMAIN_HASH_SIZE]; > struct domain *domain_list; > > +/* Non-system domain ID allocator. */ > +#define CONFIG_MAX_DOMID DOMID_FIRST_RESERVED Oh, wait - you're actually introducing such an identifier. Please don't. It's bad enough that we still have a few CONFIG_* left which aren't Kconfig-controlled. We don't want any new ones. Jan
