Message ID | 20190906143021.28261-3-roger.pau@citrix.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | libxl: choose a sane default for HAP | expand |
On 06/09/2019 15:30, Roger Pau Monne wrote: > Current libxl code will always enable Hardware Assisted Paging (HAP), > expecting that the hypervisor will fallback to shadow if HAP is not > available. With the changes to the domain builder that's not the case "domain builder" is usually libxenguest. I'd suggest using DOMCTL_createdomain specifically to make it obvious that it was a hypervisor side change. otherwise, everything LGTM. This should probably be adjusted on commit. ~Andrew
Hi, On 9/6/19 3:30 PM, Roger Pau Monne wrote: > Current libxl code will always enable Hardware Assisted Paging (HAP), > expecting that the hypervisor will fallback to shadow if HAP is not > available. With the changes to the domain builder that's not the case > any longer, and the hypervisor will raise an error if HAP is not > available instead of silently falling back to shadow. > > In order to keep the previous functionality report whether HAP is > available or not in XEN_SYSCTL_physinfo, so that the toolstack can > select a sane default if there's no explicit user selection of whether > HAP should be used. > > Note that on ARM hardware HAP capability is always reported since it's NIT: s/ARM/Arm/ > a required feature in order to run Xen. > > Fixes: d0c0ba7d3de ('x86/hvm/domain: remove the 'hap_enabled' flag') > Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> > Reviewed-by: Paul Durrant <paul.durrant@citrix.com> > Acked-by: Jan Beulich <jbeulich@suse.com> For the Arm bits: Acked-by: Julien Grall <julien.grall@arm.com> Cheers,
Roger Pau Monne writes ("[PATCH v3 2/2] sysctl/libxl: choose a sane default for HAP"): > Current libxl code will always enable Hardware Assisted Paging (HAP), > expecting that the hypervisor will fallback to shadow if HAP is not > available. With the changes to the domain builder that's not the case > any longer, and the hypervisor will raise an error if HAP is not > available instead of silently falling back to shadow. > > In order to keep the previous functionality report whether HAP is > available or not in XEN_SYSCTL_physinfo, so that the toolstack can > select a sane default if there's no explicit user selection of whether > HAP should be used. > > Note that on ARM hardware HAP capability is always reported since it's > a required feature in order to run Xen. > > Fixes: d0c0ba7d3de ('x86/hvm/domain: remove the 'hap_enabled' flag') > Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> > Reviewed-by: Paul Durrant <paul.durrant@citrix.com> > Acked-by: Jan Beulich <jbeulich@suse.com> Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c index ec71574e99..5c0fcf320e 100644 --- a/tools/libxl/libxl.c +++ b/tools/libxl/libxl.c @@ -399,6 +399,7 @@ int libxl_get_physinfo(libxl_ctx *ctx, libxl_physinfo *physinfo) physinfo->cap_pv = !!(xcphysinfo.capabilities & XEN_SYSCTL_PHYSCAP_pv); physinfo->cap_hvm_directio = !!(xcphysinfo.capabilities & XEN_SYSCTL_PHYSCAP_directio); + physinfo->cap_hap = !!(xcphysinfo.capabilities & XEN_SYSCTL_PHYSCAP_hap); GC_FREE; return 0; diff --git a/tools/libxl/libxl.h b/tools/libxl/libxl.h index 9bacfb97f0..3ff67792a7 100644 --- a/tools/libxl/libxl.h +++ b/tools/libxl/libxl.h @@ -394,6 +394,13 @@ */ #define LIBXL_HAVE_EXTENDED_VKB 1 +/* + * LIBXL_HAVE_PHYSINFO_CAP_HAP indicates that libxl_physinfo has a cap_hap + * field that indicates whether the hardware supports Hardware Assisted + * Paging. + */ +#define LIBXL_HAVE_PHYSINFO_CAP_HAP 1 + /* * libxl ABI compatibility * diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c index 03ce166f4f..6a556dea8f 100644 --- a/tools/libxl/libxl_create.c +++ b/tools/libxl/libxl_create.c @@ -38,7 +38,13 @@ int libxl__domain_create_info_setdefault(libxl__gc *gc, libxl__arch_domain_create_info_setdefault(gc, c_info); if (c_info->type != LIBXL_DOMAIN_TYPE_PV) { - libxl_defbool_setdefault(&c_info->hap, true); + libxl_physinfo info; + int rc = libxl_get_physinfo(CTX, &info); + + if (rc) + return rc; + + 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 b61399ce36..9e1f8515d3 100644 --- a/tools/libxl/libxl_types.idl +++ b/tools/libxl/libxl_types.idl @@ -1025,6 +1025,7 @@ libxl_physinfo = Struct("physinfo", [ ("cap_hvm", bool), ("cap_pv", bool), ("cap_hvm_directio", bool), # No longer HVM specific + ("cap_hap", bool), ], dir=DIR_OUT) libxl_connectorinfo = Struct("connectorinfo", [ diff --git a/tools/xl/xl_info.c b/tools/xl/xl_info.c index 46d9c9f712..aa6724bc7f 100644 --- a/tools/xl/xl_info.c +++ b/tools/xl/xl_info.c @@ -210,11 +210,12 @@ 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\n", + maybe_printf("virt_caps :%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_pv && info.cap_hvm_directio ? " pv_directio" : "", + info.cap_hap ? " hap" : "" ); vinfo = libxl_get_version_info(ctx); diff --git a/xen/arch/arm/sysctl.c b/xen/arch/arm/sysctl.c index 92ac99c928..f87944e847 100644 --- a/xen/arch/arm/sysctl.c +++ b/xen/arch/arm/sysctl.c @@ -14,7 +14,7 @@ void arch_do_physinfo(struct xen_sysctl_physinfo *pi) { - pi->capabilities |= XEN_SYSCTL_PHYSCAP_hvm; + pi->capabilities |= XEN_SYSCTL_PHYSCAP_hvm | XEN_SYSCTL_PHYSCAP_hap; } long arch_do_sysctl(struct xen_sysctl *sysctl, diff --git a/xen/arch/x86/sysctl.c b/xen/arch/x86/sysctl.c index 7ec6174e6b..5777a05ffc 100644 --- a/xen/arch/x86/sysctl.c +++ b/xen/arch/x86/sysctl.c @@ -163,6 +163,8 @@ void arch_do_physinfo(struct xen_sysctl_physinfo *pi) pi->capabilities |= XEN_SYSCTL_PHYSCAP_hvm; if ( IS_ENABLED(CONFIG_PV) ) pi->capabilities |= XEN_SYSCTL_PHYSCAP_pv; + if ( hvm_hap_supported() ) + pi->capabilities |= XEN_SYSCTL_PHYSCAP_hap; } long arch_do_sysctl( diff --git a/xen/include/public/sysctl.h b/xen/include/public/sysctl.h index 36b3f8c429..e02d7ce4c6 100644 --- a/xen/include/public/sysctl.h +++ b/xen/include/public/sysctl.h @@ -90,6 +90,10 @@ struct xen_sysctl_tbuf_op { /* The platform supports direct access to I/O devices with IOMMU. */ #define _XEN_SYSCTL_PHYSCAP_directio 2 #define XEN_SYSCTL_PHYSCAP_directio (1u<<_XEN_SYSCTL_PHYSCAP_directio) +/* The platform supports Hardware Assisted Paging. */ +#define _XEN_SYSCTL_PHYSCAP_hap 3 +#define XEN_SYSCTL_PHYSCAP_hap (1u<<_XEN_SYSCTL_PHYSCAP_hap) + struct xen_sysctl_physinfo { uint32_t threads_per_core; uint32_t cores_per_socket;