[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen stable-4.16] libs/guest: introduce support for setting guest MSRs
commit c5eadfe0d083dd6ace4f82c924996b3cf2deea00 Author: Roger Pau Monne <roger.pau@xxxxxxxxxx> AuthorDate: Tue Jul 25 15:05:53 2023 +0200 Commit: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> CommitDate: Tue Aug 8 16:02:54 2023 +0100 libs/guest: introduce support for setting guest MSRs Like it's done with CPUID, introduce support for passing MSR values to xc_cpuid_apply_policy(). The chosen format for expressing MSR policy data matches the current one used for CPUID. Note that existing callers of xc_cpuid_apply_policy() can pass NULL as the value for the newly introduced 'msr' parameter in order to preserve the same functionality, and in fact that's done in libxl on this patch. Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx> Acked-by: Anthony PERARD <anthony.perard@xxxxxxxxxx> (cherry picked from commit ed742cf1b65c822759833027ca5cbb087c506a41) --- tools/include/xenctrl.h | 21 ++++- tools/libs/guest/xg_cpuid_x86.c | 170 +++++++++++++++++++++++++++++++++++++++- tools/libs/light/libxl_cpuid.c | 2 +- 3 files changed, 189 insertions(+), 4 deletions(-) diff --git a/tools/include/xenctrl.h b/tools/include/xenctrl.h index 893ae39e4a..ebf21ee215 100644 --- a/tools/include/xenctrl.h +++ b/tools/include/xenctrl.h @@ -1829,6 +1829,21 @@ struct xc_xend_cpuid { char *policy[4]; }; +/* + * MSR policy data. + * + * The format of the policy string is the following: + * '1' -> force to 1 + * '0' -> force to 0 + * 'x' -> we don't care (use default) + * 'k' -> pass through host value + */ +struct xc_msr { + uint32_t index; + char policy[65]; +}; +#define XC_MSR_INPUT_UNUSED 0xffffffffu + /* * Make adjustments to the CPUID settings for a domain. * @@ -1840,13 +1855,15 @@ struct xc_xend_cpuid { * Either pass a full new @featureset (and @nr_features), or adjust individual * features (@pae, @itsc, @nested_virt). * - * Then (optionally) apply legacy XEND overrides (@xend) to the result. + * Then (optionally) apply legacy XEND CPUID overrides (@xend) or MSR (@msr) + * to the result. */ int xc_cpuid_apply_policy(xc_interface *xch, uint32_t domid, bool restore, const uint32_t *featureset, unsigned int nr_features, bool pae, bool itsc, - bool nested_virt, const struct xc_xend_cpuid *xend); + bool nested_virt, const struct xc_xend_cpuid *xend, + const struct xc_msr *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/xg_cpuid_x86.c b/tools/libs/guest/xg_cpuid_x86.c index c04f2b90d4..26197e1a5b 100644 --- a/tools/libs/guest/xg_cpuid_x86.c +++ b/tools/libs/guest/xg_cpuid_x86.c @@ -423,10 +423,171 @@ static int xc_cpuid_xend_policy( return rc; } +static int compare_msr(const void *l, const void *r) +{ + const xen_msr_entry_t *lhs = l; + const xen_msr_entry_t *rhs = r; + + if ( lhs->idx == rhs->idx ) + return 0; + + return lhs->idx < rhs->idx ? -1 : 1; +} + +static xen_msr_entry_t *find_msr( + xen_msr_entry_t *msrs, unsigned int nr_msrs, + uint32_t index) +{ + const xen_msr_entry_t key = { .idx = index }; + + return bsearch(&key, msrs, nr_msrs, sizeof(*msrs), compare_msr); +} + + +static int xc_msr_policy(xc_interface *xch, domid_t domid, + const struct xc_msr *msr) +{ + int rc; + bool hvm; + xc_dominfo_t di; + unsigned int nr_leaves, nr_msrs; + uint32_t err_leaf = -1, err_subleaf = -1, err_msr = -1; + /* + * Three full policies. The host, default for the domain type, + * and domain current. + */ + xen_msr_entry_t *host = NULL, *def = NULL, *cur = NULL; + unsigned int nr_host, nr_def, nr_cur; + + if ( xc_domain_getinfo(xch, domid, 1, &di) != 1 || + di.domid != domid ) + { + ERROR("Failed to obtain d%d info", domid); + rc = -ESRCH; + goto out; + } + hvm = di.hvm; + + rc = xc_cpu_policy_get_size(xch, &nr_leaves, &nr_msrs); + if ( rc ) + { + PERROR("Failed to obtain policy info size"); + rc = -errno; + goto out; + } + + if ( (host = calloc(nr_msrs, sizeof(*host))) == NULL || + (def = calloc(nr_msrs, sizeof(*def))) == NULL || + (cur = calloc(nr_msrs, sizeof(*cur))) == NULL ) + { + ERROR("Unable to allocate memory for %u CPUID leaves", nr_leaves); + rc = -ENOMEM; + goto out; + } + + /* Get the domain's current policy. */ + nr_leaves = 0; + nr_cur = nr_msrs; + rc = get_domain_cpu_policy(xch, domid, &nr_leaves, NULL, &nr_cur, cur); + if ( rc ) + { + PERROR("Failed to obtain d%d current policy", domid); + rc = -errno; + goto out; + } + + /* Get the domain type's default policy. */ + nr_leaves = 0; + nr_def = nr_msrs; + rc = get_system_cpu_policy(xch, hvm ? XEN_SYSCTL_cpu_policy_hvm_default + : XEN_SYSCTL_cpu_policy_pv_default, + &nr_leaves, NULL, &nr_def, def); + if ( rc ) + { + PERROR("Failed to obtain %s def policy", hvm ? "hvm" : "pv"); + rc = -errno; + goto out; + } + + /* Get the host policy. */ + nr_leaves = 0; + nr_host = nr_msrs; + rc = get_system_cpu_policy(xch, XEN_SYSCTL_cpu_policy_host, + &nr_leaves, NULL, &nr_host, host); + if ( rc ) + { + PERROR("Failed to obtain host policy"); + rc = -errno; + goto out; + } + + for ( ; msr->index != XC_MSR_INPUT_UNUSED; ++msr ) + { + xen_msr_entry_t *cur_msr = find_msr(cur, nr_cur, msr->index); + const xen_msr_entry_t *def_msr = find_msr(def, nr_def, msr->index); + const xen_msr_entry_t *host_msr = find_msr(host, nr_host, msr->index); + unsigned int i; + + if ( cur_msr == NULL || def_msr == NULL || host_msr == NULL ) + { + ERROR("Missing MSR %#x", msr->index); + rc = -ENOENT; + goto out; + } + + for ( i = 0; i < ARRAY_SIZE(msr->policy) - 1; i++ ) + { + bool val; + + if ( msr->policy[i] == '1' ) + val = true; + else if ( msr->policy[i] == '0' ) + val = false; + else if ( msr->policy[i] == 'x' ) + val = test_bit(63 - i, &def_msr->val); + else if ( msr->policy[i] == 'k' ) + val = test_bit(63 - i, &host_msr->val); + else + { + ERROR("MSR index %#x: bad character '%c' in policy string '%s'", + msr->index, msr->policy[i], msr->policy); + rc = -EINVAL; + goto out; + } + + if ( val ) + set_bit(63 - i, &cur_msr->val); + else + clear_bit(63 - i, &cur_msr->val); + } + } + + /* Feed the transformed policy back up to Xen. */ + rc = xc_set_domain_cpu_policy(xch, domid, 0, NULL, nr_cur, cur, + &err_leaf, &err_subleaf, &err_msr); + if ( rc ) + { + PERROR("Failed to set d%d's policy (err leaf %#x, subleaf %#x, msr %#x)", + domid, err_leaf, err_subleaf, err_msr); + rc = -errno; + goto out; + } + + /* Success! */ + + out: + free(cur); + free(def); + free(host); + + return rc; +} + int xc_cpuid_apply_policy(xc_interface *xch, uint32_t domid, bool restore, const uint32_t *featureset, unsigned int nr_features, bool pae, bool itsc, bool nested_virt, - const struct xc_xend_cpuid *xend) + const struct xc_xend_cpuid *xend, + const struct xc_msr *msr) { int rc; xc_dominfo_t di; @@ -667,6 +828,13 @@ int xc_cpuid_apply_policy(xc_interface *xch, uint32_t domid, bool restore, if ( xend && (rc = xc_cpuid_xend_policy(xch, domid, xend)) ) goto out; + if ( msr ) + { + rc = xc_msr_policy(xch, domid, msr); + if ( rc ) + goto out; + } + rc = 0; out: diff --git a/tools/libs/light/libxl_cpuid.c b/tools/libs/light/libxl_cpuid.c index b4eacc2bd5..0d876342e3 100644 --- a/tools/libs/light/libxl_cpuid.c +++ b/tools/libs/light/libxl_cpuid.c @@ -489,7 +489,7 @@ int libxl__cpuid_legacy(libxl_ctx *ctx, uint32_t domid, bool restore, info->tsc_mode == LIBXL_TSC_MODE_ALWAYS_EMULATE); r = xc_cpuid_apply_policy(ctx->xch, domid, restore, NULL, 0, - pae, itsc, nested_virt, info->cpuid); + pae, itsc, nested_virt, info->cpuid, NULL); if (r) LOGEVD(ERROR, -r, domid, "Failed to apply CPUID policy"); -- generated by git-patchbot for /home/xen/git/xen.git#stable-4.16
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