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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen master] libs/guest: introduce support for setting guest MSRs
commit ed742cf1b65c822759833027ca5cbb087c506a41
Author: Roger Pau Monne <roger.pau@xxxxxxxxxx>
AuthorDate: Tue Jul 25 15:05:53 2023 +0200
Commit: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Wed Jul 26 10:56:27 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>
---
tools/include/xenctrl.h | 21 ++++-
tools/libs/guest/xg_cpuid_x86.c | 169 +++++++++++++++++++++++++++++++++++++++-
tools/libs/light/libxl_cpuid.c | 2 +-
3 files changed, 188 insertions(+), 4 deletions(-)
diff --git a/tools/include/xenctrl.h b/tools/include/xenctrl.h
index dba33d5d0f..faec1dd824 100644
--- a/tools/include/xenctrl.h
+++ b/tools/include/xenctrl.h
@@ -1822,6 +1822,21 @@ 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.
*
@@ -1833,13 +1848,15 @@ 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 5b035223f4..f2b1e80901 100644
--- a/tools/libs/guest/xg_cpuid_x86.c
+++ b/tools/libs/guest/xg_cpuid_x86.c
@@ -423,10 +423,170 @@ 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_domaininfo_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 ( (rc = xc_domain_getinfo_single(xch, domid, &di)) < 0 )
+ {
+ PERROR("Failed to obtain d%d info", domid);
+ rc = -errno;
+ goto out;
+ }
+ hvm = di.flags & XEN_DOMINF_hvm_guest;
+
+ 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;
bool hvm;
@@ -663,6 +823,13 @@ 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 f5ce9f9795..c96aeb3bce 100644
--- a/tools/libs/light/libxl_cpuid.c
+++ b/tools/libs/light/libxl_cpuid.c
@@ -502,7 +502,7 @@ 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#master
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