[v4,0/3] Rationalize usage of xc_domain_getinfo{,list}()

Message

Alejandro Vallejo May 9, 2023, 4:07 p.m. UTC

The first 4 patches of v2 already made it to staging. v4 includes a fix
so libxl preserves its previous error handling behaviour and a style change

Original cover letter:

xc_domain_getinfo() returns the list of domains with domid >= first_domid.
It does so by repeatedly invoking XEN_DOMCTL_getdomaininfo, which leads to
unintuitive behaviour (asking for domid=1 might succeed returning domid=2).
Furthermore, N hypercalls are required whereas the equivalent functionality
can be achieved using with XEN_SYSCTL_getdomaininfo.

Ideally, we want a DOMCTL interface that operates over a single precisely
specified domain and a SYSCTL interface that can be used for bulk queries.

All callers of xc_domain_getinfo() that are better off using SYSCTL are
migrated to use that instead. That includes callers performing domain
discovery and those requesting info for more than 1 domain per hypercall.

A new xc_domain_getinfo_single() is introduced with stricter semantics than
xc_domain_getinfo() (failing if domid isn't found) to migrate the rest to.

With no callers left the xc_dominfo_t structure and the xc_domain_getinfo()
call itself can be cleanly removed, and the DOMCTL interface simplified to
only use its fastpath.

With the DOMCTL ammended, the new xc_domain_getinfo_single() drops its
stricter check, becoming a simple wrapper to invoke the hypercall itself.

Alejandro Vallejo (3):
  tools: Modify single-domid callers of xc_domain_getinfolist()
  tools: Use new xc function for some xc_domain_getinfo() calls
  domctl: Modify XEN_DOMCTL_getdomaininfo to fail if domid is not found

 tools/console/client/main.c             |  7 +--
 tools/debugger/kdd/kdd-xen.c            |  5 +-
 tools/include/xenctrl.h                 | 43 -------------
 tools/libs/ctrl/xc_domain.c             | 82 ++-----------------------
 tools/libs/ctrl/xc_pagetab.c            |  7 +--
 tools/libs/ctrl/xc_private.c            |  9 +--
 tools/libs/ctrl/xc_private.h            |  7 ++-
 tools/libs/guest/xg_core.c              | 23 +++----
 tools/libs/guest/xg_core.h              |  6 +-
 tools/libs/guest/xg_core_arm.c          | 10 +--
 tools/libs/guest/xg_core_x86.c          | 18 +++---
 tools/libs/guest/xg_cpuid_x86.c         | 40 ++++++------
 tools/libs/guest/xg_dom_boot.c          | 16 ++---
 tools/libs/guest/xg_domain.c            |  8 +--
 tools/libs/guest/xg_offline_page.c      | 12 ++--
 tools/libs/guest/xg_private.h           |  1 +
 tools/libs/guest/xg_resume.c            | 20 +++---
 tools/libs/guest/xg_sr_common.h         |  2 +-
 tools/libs/guest/xg_sr_restore.c        | 17 ++---
 tools/libs/guest/xg_sr_restore_x86_pv.c |  2 +-
 tools/libs/guest/xg_sr_save.c           | 27 ++++----
 tools/libs/guest/xg_sr_save_x86_pv.c    |  6 +-
 tools/libs/light/libxl_dom.c            | 17 ++---
 tools/libs/light/libxl_dom_suspend.c    |  7 +--
 tools/libs/light/libxl_domain.c         | 18 +++---
 tools/libs/light/libxl_mem.c            |  4 +-
 tools/libs/light/libxl_sched.c          | 30 ++++-----
 tools/libs/light/libxl_x86_acpi.c       |  6 +-
 tools/misc/xen-hvmcrash.c               |  6 +-
 tools/misc/xen-lowmemd.c                |  6 +-
 tools/misc/xen-mfndump.c                | 22 +++----
 tools/misc/xen-vmtrace.c                |  6 +-
 tools/ocaml/libs/xc/xenctrl_stubs.c     |  6 +-
 tools/vchan/vchan-socket-proxy.c        |  6 +-
 tools/xenpaging/xenpaging.c             | 10 +--
 tools/xenstore/xenstored_domain.c       | 15 +++--
 tools/xentrace/xenctx.c                 |  8 +--
 xen/common/domctl.c                     | 32 +---------
 38 files changed, 190 insertions(+), 377 deletions(-)