| Message ID | 1611182952-9941-5-git-send-email-boris.ostrovsky@oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Permit fault-less access to non-emulated MSRs | expand |
On Wed, Jan 20, 2021 at 05:49:12PM -0500, Boris Ostrovsky wrote: > When creating a guest, if ignore_msrs option has been specified, > apply it to guest's MSR policy. > > Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Acked-by: Wei Liu <wl@xen.org>
Hi Boris, On 20/01/2021 22:49, Boris Ostrovsky wrote: > diff --git a/tools/libs/light/libxl_dom.c b/tools/libs/light/libxl_dom.c > index 19168572fd3e..1f2abf6679d7 100644 > --- a/tools/libs/light/libxl_dom.c > +++ b/tools/libs/light/libxl_dom.c > @@ -383,9 +383,10 @@ int libxl__build_pre(libxl__gc *gc, uint32_t domid, > /* Construct a CPUID policy, but only for brand new domains. Domains > * being migrated-in/restored have CPUID handled during the > * static_data_done() callback. */ > - if (!state->restore) > + if (!state->restore) { > libxl__cpuid_legacy(ctx, domid, false, info); > - > + libxl__msr_policy(ctx, domid, info); AFAICT, this is going to break compilation of the toolst on Arm because libxl__msr_policy(). However, I am a bit unsure whether we should define a stub for this on Arm. It feels to me it would be better to pass an extra boolean (restore) to libxl__arch_domain_create() and directly implement it there. Cheers,
On 1/22/21 4:56 AM, Julien Grall wrote: > Hi Boris, > > On 20/01/2021 22:49, Boris Ostrovsky wrote: >> diff --git a/tools/libs/light/libxl_dom.c b/tools/libs/light/libxl_dom.c >> index 19168572fd3e..1f2abf6679d7 100644 >> --- a/tools/libs/light/libxl_dom.c >> +++ b/tools/libs/light/libxl_dom.c >> @@ -383,9 +383,10 @@ int libxl__build_pre(libxl__gc *gc, uint32_t domid, >> /* Construct a CPUID policy, but only for brand new domains. Domains >> * being migrated-in/restored have CPUID handled during the >> * static_data_done() callback. */ >> - if (!state->restore) >> + if (!state->restore) { >> libxl__cpuid_legacy(ctx, domid, false, info); >> - >> + libxl__msr_policy(ctx, domid, info); > > AFAICT, this is going to break compilation of the toolst on Arm because libxl__msr_policy(). Yes, it will ;-( > > However, I am a bit unsure whether we should define a stub for this on Arm. It feels to me it would be better to pass an extra boolean (restore) to libxl__arch_domain_create() and directly implement it there. Yes. And move libxl__cpuid_legacy call there too then. -boris
On Wed, Jan 20, 2021 at 05:49:12PM -0500, Boris Ostrovsky wrote: > When creating a guest, if ignore_msrs option has been specified, > apply it to guest's MSR policy. > > Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> > --- > tools/include/xenctrl.h | 2 + > tools/libs/guest/Makefile | 1 + > tools/libs/guest/xg_msrs_x86.c | 110 ++++++++++++++++++++++++++++++++++++++ > tools/libs/light/libxl_dom.c | 5 +- > tools/libs/light/libxl_internal.h | 2 + > tools/libs/light/libxl_x86.c | 7 +++ > 6 files changed, 125 insertions(+), 2 deletions(-) > create mode 100644 tools/libs/guest/xg_msrs_x86.c > > diff --git a/tools/include/xenctrl.h b/tools/include/xenctrl.h > index 3796425e1eca..1d6a38e73dcf 100644 > --- a/tools/include/xenctrl.h > +++ b/tools/include/xenctrl.h > @@ -1835,6 +1835,8 @@ int xc_cpuid_apply_policy(xc_interface *xch, > const uint32_t *featureset, > unsigned int nr_features, bool pae, bool itsc, > bool nested_virt, const struct xc_xend_cpuid *xend); > +int xc_msr_apply_policy(xc_interface *xch, uint32_t domid, > + unsigned int ignore_msr); > int xc_mca_op(xc_interface *xch, struct xen_mc *mc); > int xc_mca_op_inject_v2(xc_interface *xch, unsigned int flags, > xc_cpumap_t cpumap, unsigned int nr_cpus); > diff --git a/tools/libs/guest/Makefile b/tools/libs/guest/Makefile > index 1c729040b337..452155ea0385 100644 > --- a/tools/libs/guest/Makefile > +++ b/tools/libs/guest/Makefile > @@ -56,6 +56,7 @@ SRCS-y += xg_dom_compat_linux.c > > SRCS-$(CONFIG_X86) += xg_dom_x86.c > SRCS-$(CONFIG_X86) += xg_cpuid_x86.c > +SRCS-$(CONFIG_X86) += xg_msrs_x86.c > SRCS-$(CONFIG_ARM) += xg_dom_arm.c > > ifeq ($(CONFIG_LIBXC_MINIOS),y) > diff --git a/tools/libs/guest/xg_msrs_x86.c b/tools/libs/guest/xg_msrs_x86.c > new file mode 100644 > index 000000000000..464ce9292ad8 > --- /dev/null > +++ b/tools/libs/guest/xg_msrs_x86.c > @@ -0,0 +1,110 @@ > +/****************************************************************************** > + * xc_msrs_x86.c > + * > + * Update MSR policy of a domain. > + * > + * Copyright (c) 2021, Oracle and/or its affiliates. > + * > + * This library is free software; you can redistribute it and/or > + * modify it under the terms of the GNU Lesser General Public > + * License as published by the Free Software Foundation; > + * version 2.1 of the License. > + * > + * This library is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + * Lesser General Public License for more details. > + * > + * You should have received a copy of the GNU Lesser General Public > + * License along with this library; If not, see <http://www.gnu.org/licenses/>. > + */ > + > +#include "xc_private.h" > +#include "xen/lib/x86/msr.h" > + > + > + > +int xc_msr_apply_policy(xc_interface *xch, uint32_t domid, unsigned int ignore_msr) > +{ > + int rc; > + unsigned int nr_leaves, nr_msrs; > + xen_msr_entry_t *msrs = NULL; > + struct msr_policy *p = NULL; > + xc_dominfo_t di; > + unsigned int err_leaf, err_subleaf, err_msr; > + > + if ( xc_domain_getinfo(xch, domid, 1, &di) != 1 || > + di.domid != domid ) > + { > + ERROR("Failed to obtain d%d info", domid); > + rc = -ESRCH; > + goto out; > + } > + > + rc = xc_get_cpu_policy_size(xch, &nr_leaves, &nr_msrs); > + if ( rc ) > + { > + PERROR("Failed to obtain policy info size"); > + rc = -errno; > + goto out; > + } > + > + rc = -ENOMEM; > + if ( (msrs = calloc(nr_msrs, sizeof(*msrs))) == NULL || > + (p = calloc(1, sizeof(*p))) == NULL ) > + goto out; > + > + /* Get the domain's default policy. */ > + nr_leaves = 0; > + rc = xc_get_system_cpu_policy(xch, di.hvm ? XEN_SYSCTL_cpu_policy_hvm_default > + : XEN_SYSCTL_cpu_policy_pv_default, > + &nr_leaves, NULL, &nr_msrs, msrs); > + if ( rc ) > + { > + PERROR("Failed to obtain %s default policy", di.hvm ? "hvm" : "pv"); > + rc = -errno; > + goto out; > + } Why not use xc_get_domain_cpu_policy instead so that you can avoid the call to xc_domain_getinfo? It would also seem safer, as you won't be discarding any adjustments made to the default policy by the hypervisor for this specific domain. Thanks, Roger.
On 2/18/21 6:48 AM, Roger Pau Monné wrote: > >> + /* Get the domain's default policy. */ >> + nr_leaves = 0; >> + rc = xc_get_system_cpu_policy(xch, di.hvm ? XEN_SYSCTL_cpu_policy_hvm_default >> + : XEN_SYSCTL_cpu_policy_pv_default, >> + &nr_leaves, NULL, &nr_msrs, msrs); >> + if ( rc ) >> + { >> + PERROR("Failed to obtain %s default policy", di.hvm ? "hvm" : "pv"); >> + rc = -errno; >> + goto out; >> + } > Why not use xc_get_domain_cpu_policy instead so that you can avoid the > call to xc_domain_getinfo? Yes, indeed. -boris > > It would also seem safer, as you won't be discarding any adjustments > made to the default policy by the hypervisor for this specific domain. > > Thanks, Roger.
diff --git a/tools/include/xenctrl.h b/tools/include/xenctrl.h index 3796425e1eca..1d6a38e73dcf 100644 --- a/tools/include/xenctrl.h +++ b/tools/include/xenctrl.h @@ -1835,6 +1835,8 @@ int xc_cpuid_apply_policy(xc_interface *xch, const uint32_t *featureset, unsigned int nr_features, bool pae, bool itsc, bool nested_virt, const struct xc_xend_cpuid *xend); +int xc_msr_apply_policy(xc_interface *xch, uint32_t domid, + unsigned int ignore_msr); int xc_mca_op(xc_interface *xch, struct xen_mc *mc); int xc_mca_op_inject_v2(xc_interface *xch, unsigned int flags, xc_cpumap_t cpumap, unsigned int nr_cpus); diff --git a/tools/libs/guest/Makefile b/tools/libs/guest/Makefile index 1c729040b337..452155ea0385 100644 --- a/tools/libs/guest/Makefile +++ b/tools/libs/guest/Makefile @@ -56,6 +56,7 @@ SRCS-y += xg_dom_compat_linux.c SRCS-$(CONFIG_X86) += xg_dom_x86.c SRCS-$(CONFIG_X86) += xg_cpuid_x86.c +SRCS-$(CONFIG_X86) += xg_msrs_x86.c SRCS-$(CONFIG_ARM) += xg_dom_arm.c ifeq ($(CONFIG_LIBXC_MINIOS),y) diff --git a/tools/libs/guest/xg_msrs_x86.c b/tools/libs/guest/xg_msrs_x86.c new file mode 100644 index 000000000000..464ce9292ad8 --- /dev/null +++ b/tools/libs/guest/xg_msrs_x86.c @@ -0,0 +1,110 @@ +/****************************************************************************** + * xc_msrs_x86.c + * + * Update MSR policy of a domain. + * + * Copyright (c) 2021, Oracle and/or its affiliates. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; + * version 2.1 of the License. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; If not, see <http://www.gnu.org/licenses/>. + */ + +#include "xc_private.h" +#include "xen/lib/x86/msr.h" + + + +int xc_msr_apply_policy(xc_interface *xch, uint32_t domid, unsigned int ignore_msr) +{ + int rc; + unsigned int nr_leaves, nr_msrs; + xen_msr_entry_t *msrs = NULL; + struct msr_policy *p = NULL; + xc_dominfo_t di; + unsigned int err_leaf, err_subleaf, err_msr; + + if ( xc_domain_getinfo(xch, domid, 1, &di) != 1 || + di.domid != domid ) + { + ERROR("Failed to obtain d%d info", domid); + rc = -ESRCH; + goto out; + } + + rc = xc_get_cpu_policy_size(xch, &nr_leaves, &nr_msrs); + if ( rc ) + { + PERROR("Failed to obtain policy info size"); + rc = -errno; + goto out; + } + + rc = -ENOMEM; + if ( (msrs = calloc(nr_msrs, sizeof(*msrs))) == NULL || + (p = calloc(1, sizeof(*p))) == NULL ) + goto out; + + /* Get the domain's default policy. */ + nr_leaves = 0; + rc = xc_get_system_cpu_policy(xch, di.hvm ? XEN_SYSCTL_cpu_policy_hvm_default + : XEN_SYSCTL_cpu_policy_pv_default, + &nr_leaves, NULL, &nr_msrs, msrs); + if ( rc ) + { + PERROR("Failed to obtain %s default policy", di.hvm ? "hvm" : "pv"); + rc = -errno; + goto out; + } + + rc = x86_msr_copy_from_buffer(p, msrs, nr_msrs, &err_msr); + if ( rc ) + { + ERROR("Failed to deserialise MSR (err msr %#x) (%d = %s)", + err_msr, -rc, strerror(-rc)); + goto out; + } + + p->ignore_msrs = ignore_msr; + + rc = x86_msr_copy_to_buffer(p, msrs, &nr_msrs); + if ( rc ) + { + ERROR("Failed to serialise MSR (%d = %s)", -rc, strerror(-rc)); + goto out; + } + + nr_leaves = 0; + rc = xc_set_domain_cpu_policy(xch, domid, nr_leaves, NULL, nr_msrs, msrs, + &err_leaf, &err_subleaf, &err_msr); + if ( rc ) + { + PERROR("Failed to set d%d's MSR policy (err leaf %#x, subleaf %#x, msr %#x)", + domid, err_leaf, err_subleaf, err_msr); + rc = -errno; + } + +out: + free(msrs); + free(p); + + return rc; +} + +/* + * Local variables: + * mode: C + * c-basic-offset: 4 + * indent-tabs-mode: nil + * End: + */ + diff --git a/tools/libs/light/libxl_dom.c b/tools/libs/light/libxl_dom.c index 19168572fd3e..1f2abf6679d7 100644 --- a/tools/libs/light/libxl_dom.c +++ b/tools/libs/light/libxl_dom.c @@ -383,9 +383,10 @@ int libxl__build_pre(libxl__gc *gc, uint32_t domid, /* Construct a CPUID policy, but only for brand new domains. Domains * being migrated-in/restored have CPUID handled during the * static_data_done() callback. */ - if (!state->restore) + if (!state->restore) { libxl__cpuid_legacy(ctx, domid, false, info); - + libxl__msr_policy(ctx, domid, info); + } return rc; } diff --git a/tools/libs/light/libxl_internal.h b/tools/libs/light/libxl_internal.h index c79523ba9248..4f369e6a6f14 100644 --- a/tools/libs/light/libxl_internal.h +++ b/tools/libs/light/libxl_internal.h @@ -2054,6 +2054,8 @@ _hidden char *libxl__object_to_json(libxl_ctx *ctx, const char *type, _hidden void libxl__cpuid_legacy(libxl_ctx *ctx, uint32_t domid, bool retore, libxl_domain_build_info *info); +_hidden void libxl__msr_policy(libxl_ctx *ctx, uint32_t domid, + libxl_domain_build_info *info); /* Calls poll() again - useful to check whether a signaled condition * is still true. Cannot fail. Returns currently-true revents. */ diff --git a/tools/libs/light/libxl_x86.c b/tools/libs/light/libxl_x86.c index 86d272999d67..92ec1da77139 100644 --- a/tools/libs/light/libxl_x86.c +++ b/tools/libs/light/libxl_x86.c @@ -1,5 +1,6 @@ #include "libxl_internal.h" #include "libxl_arch.h" +#include "xen/lib/x86/msr.h" int libxl__arch_domain_prepare_config(libxl__gc *gc, libxl_domain_config *d_config, @@ -838,6 +839,12 @@ int libxl__arch_passthrough_mode_setdefault(libxl__gc *gc, return rc; } +void libxl__msr_policy(libxl_ctx *ctx, uint32_t domid, + libxl_domain_build_info *info) +{ + if (info->ignore_msrs != LIBXL_IGNORE_MSRS_NEVER) + xc_msr_apply_policy(ctx->xch, domid, info->ignore_msrs); +} /* * Local variables:
When creating a guest, if ignore_msrs option has been specified, apply it to guest's MSR policy. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> --- tools/include/xenctrl.h | 2 + tools/libs/guest/Makefile | 1 + tools/libs/guest/xg_msrs_x86.c | 110 ++++++++++++++++++++++++++++++++++++++ tools/libs/light/libxl_dom.c | 5 +- tools/libs/light/libxl_internal.h | 2 + tools/libs/light/libxl_x86.c | 7 +++ 6 files changed, 125 insertions(+), 2 deletions(-) create mode 100644 tools/libs/guest/xg_msrs_x86.c