| Message ID | 20190910152538.36921-2-roger.pau@citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v4,1/2] sysctl/libxl: choose a sane default for HAP | expand |
On 10.09.2019 17:25, Roger Pau Monne wrote: > Report whether shadow paging is supported by the hypervisor, since it > can be disabled at build time. > > Requested-by: Andrew Cooper <Andrew.Cooper3@citrix.com> > Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> The straightforward hypervisor part Acked-by: Jan Beulich <jbeulich@suse.com> Jan
On 10/09/2019 16:25, Roger Pau Monne wrote: > diff --git a/tools/libxl/libxl.h b/tools/libxl/libxl.h > index 3ff67792a7..e8f5ebe929 100644 > --- a/tools/libxl/libxl.h > +++ b/tools/libxl/libxl.h > @@ -401,6 +401,12 @@ > */ > #define LIBXL_HAVE_PHYSINFO_CAP_HAP 1 > > +/* > + * LIBXL_HAVE_PHYSINFO_CAP_HAP indicates that libxl_physinfo has a cap_shadow > + * field that indicates whether software implemented paging is supported. > + */ > +#define LIBXL_HAVE_PHYSINFO_CAP_SHADOW 1 > + Is it really worth doing this, and not extending the previous define? Very little point having two going into the tree at the same time. > diff --git a/tools/ocaml/libs/xc/xenctrl.ml b/tools/ocaml/libs/xc/xenctrl.ml > index a5e77c943a..9f56e1df1a 100644 > --- a/tools/ocaml/libs/xc/xenctrl.ml > +++ b/tools/ocaml/libs/xc/xenctrl.ml > @@ -108,6 +108,7 @@ type physinfo_cap_flag = > | CAP_PV > | CAP_DirectIO > | CAP_hap > + | CAP_shadow Similarly as with HAP, this should at least be Shadow to match DirectIO. Can be fixed on commit. ~Andrew
Roger Pau Monne writes ("[PATCH v4 2/2] sysctl: report shadow paging capability"):
> Report whether shadow paging is supported by the hypervisor, since it
> can be disabled at build time.
...
> NB: I'm not sure the added check in
> libxl__domain_create_info_setdefault is that useful, or if it could be
> better placed somewhere else.
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
> + if (!info.cap_hap && !info.cap_shadow) {
> + LOG(ERROR, "neither hap nor shadow paging available");
> + return ERROR_INVAL;
> + }
> +
> libxl_defbool_setdefault(&c_info->hap, info.cap_hap);
I would have written
if (cap_hap) setdefault(info->hap, true);
else if (cap_shadow) setdefault(info->hap, false);
else bomb_out();
but the result is equivalent.
Ian.
diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c index 5c0fcf320e..57073c06d5 100644 --- a/tools/libxl/libxl.c +++ b/tools/libxl/libxl.c @@ -400,6 +400,8 @@ int libxl_get_physinfo(libxl_ctx *ctx, libxl_physinfo *physinfo) physinfo->cap_hvm_directio = !!(xcphysinfo.capabilities & XEN_SYSCTL_PHYSCAP_directio); physinfo->cap_hap = !!(xcphysinfo.capabilities & XEN_SYSCTL_PHYSCAP_hap); + physinfo->cap_shadow = + !!(xcphysinfo.capabilities & XEN_SYSCTL_PHYSCAP_shadow); GC_FREE; return 0; diff --git a/tools/libxl/libxl.h b/tools/libxl/libxl.h index 3ff67792a7..e8f5ebe929 100644 --- a/tools/libxl/libxl.h +++ b/tools/libxl/libxl.h @@ -401,6 +401,12 @@ */ #define LIBXL_HAVE_PHYSINFO_CAP_HAP 1 +/* + * LIBXL_HAVE_PHYSINFO_CAP_HAP indicates that libxl_physinfo has a cap_shadow + * field that indicates whether software implemented paging is supported. + */ +#define LIBXL_HAVE_PHYSINFO_CAP_SHADOW 1 + /* * libxl ABI compatibility * diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c index 3b45065597..47f10da465 100644 --- a/tools/libxl/libxl_create.c +++ b/tools/libxl/libxl_create.c @@ -44,6 +44,11 @@ int libxl__domain_create_info_setdefault(libxl__gc *gc, if (rc) return rc; + if (!info.cap_hap && !info.cap_shadow) { + LOG(ERROR, "neither hap nor shadow paging available"); + return ERROR_INVAL; + } + libxl_defbool_setdefault(&c_info->hap, info.cap_hap); libxl_defbool_setdefault(&c_info->oos, true); } diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl index 9e1f8515d3..6f431baec2 100644 --- a/tools/libxl/libxl_types.idl +++ b/tools/libxl/libxl_types.idl @@ -1026,6 +1026,7 @@ libxl_physinfo = Struct("physinfo", [ ("cap_pv", bool), ("cap_hvm_directio", bool), # No longer HVM specific ("cap_hap", bool), + ("cap_shadow", bool), ], dir=DIR_OUT) libxl_connectorinfo = Struct("connectorinfo", [ diff --git a/tools/ocaml/libs/xc/xenctrl.ml b/tools/ocaml/libs/xc/xenctrl.ml index a5e77c943a..9f56e1df1a 100644 --- a/tools/ocaml/libs/xc/xenctrl.ml +++ b/tools/ocaml/libs/xc/xenctrl.ml @@ -108,6 +108,7 @@ type physinfo_cap_flag = | CAP_PV | CAP_DirectIO | CAP_hap + | CAP_shadow type physinfo = { diff --git a/tools/ocaml/libs/xc/xenctrl.mli b/tools/ocaml/libs/xc/xenctrl.mli index e92256654b..e06c53d0fa 100644 --- a/tools/ocaml/libs/xc/xenctrl.mli +++ b/tools/ocaml/libs/xc/xenctrl.mli @@ -93,6 +93,7 @@ type physinfo_cap_flag = | CAP_PV | CAP_DirectIO | CAP_hap + | CAP_shadow type physinfo = { threads_per_core : int; cores_per_socket : int; diff --git a/tools/xl/xl_info.c b/tools/xl/xl_info.c index aa6724bc7f..148c4740ae 100644 --- a/tools/xl/xl_info.c +++ b/tools/xl/xl_info.c @@ -210,12 +210,13 @@ static void output_physinfo(void) info.hw_cap[4], info.hw_cap[5], info.hw_cap[6], info.hw_cap[7] ); - maybe_printf("virt_caps :%s%s%s%s%s\n", + maybe_printf("virt_caps :%s%s%s%s%s%s\n", info.cap_pv ? " pv" : "", info.cap_hvm ? " hvm" : "", info.cap_hvm && info.cap_hvm_directio ? " hvm_directio" : "", info.cap_pv && info.cap_hvm_directio ? " pv_directio" : "", - info.cap_hap ? " hap" : "" + info.cap_hap ? " hap" : "", + info.cap_shadow ? " shadow" : "" ); vinfo = libxl_get_version_info(ctx); diff --git a/xen/arch/x86/sysctl.c b/xen/arch/x86/sysctl.c index 5777a05ffc..50be0c722a 100644 --- a/xen/arch/x86/sysctl.c +++ b/xen/arch/x86/sysctl.c @@ -165,6 +165,8 @@ void arch_do_physinfo(struct xen_sysctl_physinfo *pi) pi->capabilities |= XEN_SYSCTL_PHYSCAP_pv; if ( hvm_hap_supported() ) pi->capabilities |= XEN_SYSCTL_PHYSCAP_hap; + if ( IS_ENABLED(CONFIG_SHADOW_PAGING) ) + pi->capabilities |= XEN_SYSCTL_PHYSCAP_shadow; } long arch_do_sysctl( diff --git a/xen/include/public/sysctl.h b/xen/include/public/sysctl.h index d4b455619c..e324442f92 100644 --- a/xen/include/public/sysctl.h +++ b/xen/include/public/sysctl.h @@ -93,9 +93,12 @@ struct xen_sysctl_tbuf_op { /* The platform supports Hardware Assisted Paging. */ #define _XEN_SYSCTL_PHYSCAP_hap 3 #define XEN_SYSCTL_PHYSCAP_hap (1u<<_XEN_SYSCTL_PHYSCAP_hap) +/* The platform supports software paging. */ +#define _XEN_SYSCTL_PHYSCAP_shadow 4 +#define XEN_SYSCTL_PHYSCAP_shadow (1u<<_XEN_SYSCTL_PHYSCAP_shadow) /* Max XEN_SYSCTL_PHYSCAP_* constant. Used for ABI checking. */ -#define XEN_SYSCTL_PHYSCAP_MAX XEN_SYSCTL_PHYSCAP_hap +#define XEN_SYSCTL_PHYSCAP_MAX XEN_SYSCTL_PHYSCAP_shadow struct xen_sysctl_physinfo { uint32_t threads_per_core;
Report whether shadow paging is supported by the hypervisor, since it can be disabled at build time. Requested-by: Andrew Cooper <Andrew.Cooper3@citrix.com> Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> --- NB: I'm not sure the added check in libxl__domain_create_info_setdefault is that useful, or if it could be better placed somewhere else. --- Changes since v3: - New in this version. --- tools/libxl/libxl.c | 2 ++ tools/libxl/libxl.h | 6 ++++++ tools/libxl/libxl_create.c | 5 +++++ tools/libxl/libxl_types.idl | 1 + tools/ocaml/libs/xc/xenctrl.ml | 1 + tools/ocaml/libs/xc/xenctrl.mli | 1 + tools/xl/xl_info.c | 5 +++-- xen/arch/x86/sysctl.c | 2 ++ xen/include/public/sysctl.h | 5 ++++- 9 files changed, 25 insertions(+), 3 deletions(-)