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* [PATCH v4 00/10] libs/guest: new CPUID/MSR interface
@ 2021-05-07 11:04 Roger Pau Monne
  2021-05-07 11:04 ` [PATCH v4 01/10] libx86: introduce helper to fetch cpuid leaf Roger Pau Monne
                   ` (9 more replies)
  0 siblings, 10 replies; 15+ messages in thread
From: Roger Pau Monne @ 2021-05-07 11:04 UTC (permalink / raw)
  To: xen-devel
  Cc: Andrew Cooper, Roger Pau Monne, Jan Beulich, Wei Liu,
	Ian Jackson, Anthony PERARD

Hello,

The following series introduces a new CPUID/MSR interface for the
xenguest library. Such interface handles both CPUID and MSRs using the
same opaque object, and provides some helpers for the user to peek or
modify such data without exposing the backing type. This is useful for
future development as CPUID and MSRs are closely related, so it makes
handling those much easier if they are inside the same object (ie: a
change to a CPUID bit might expose or hide an MSR).

In this patch series libxl and other in tree users have been switched to
use the new interface, so it shouldn't result in any functional change
from a user point of view.

Note there are still some missing pieces likely. The way to modify CPUID
data is not ideal, as it requires fetching a leaf and modifying it
directly. We might want some kind of interface in order to set specific
CPUID features more easily, but that's to be discussed, and would be
done as a follow up series.

The addition of a helper to generate compatible policies given two
inputs has been removed from this iteration, sine Andrew Cooper has
posted a patch to set the foundation for that, and further work should
be done against that baseline.

Thanks, Roger.

Roger Pau Monne (10):
  libx86: introduce helper to fetch cpuid leaf
  libs/guest: allow fetching a specific CPUID leaf from a cpu policy
  libx86: introduce helper to fetch msr entry
  libs/guest: allow fetching a specific MSR entry from a cpu policy
  libs/guest: make a cpu policy compatible with older Xen versions
  libs/guest: introduce helper set cpu topology in cpu policy
  libs/guest: rework xc_cpuid_xend_policy
  libs/guest: apply a featureset into a cpu policy
  libs/{light,guest}: implement xc_cpuid_apply_policy in libxl
  libs/guest: (re)move xc_cpu_policy_apply_cpuid

 tools/include/libxl.h                    |   6 +-
 tools/include/xenctrl.h                  |  44 --
 tools/include/xenguest.h                 |  18 +
 tools/libs/guest/xg_cpuid_x86.c          | 633 ++++++++---------------
 tools/libs/light/libxl_cpuid.c           | 228 +++++++-
 tools/libs/light/libxl_internal.h        |  26 +
 tools/tests/cpu-policy/test-cpu-policy.c | 123 ++++-
 xen/arch/x86/cpuid.c                     |  55 +-
 xen/include/xen/lib/x86/cpuid.h          |  18 +
 xen/include/xen/lib/x86/msr.h            |  19 +-
 xen/lib/x86/cpuid.c                      |  51 ++
 xen/lib/x86/msr.c                        |  41 +-
 12 files changed, 717 insertions(+), 545 deletions(-)

-- 
2.31.1



^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH v4 01/10] libx86: introduce helper to fetch cpuid leaf
  2021-05-07 11:04 [PATCH v4 00/10] libs/guest: new CPUID/MSR interface Roger Pau Monne
@ 2021-05-07 11:04 ` Roger Pau Monne
  2021-05-07 11:04 ` [PATCH v4 02/10] libs/guest: allow fetching a specific CPUID leaf from a cpu policy Roger Pau Monne
                   ` (8 subsequent siblings)
  9 siblings, 0 replies; 15+ messages in thread
From: Roger Pau Monne @ 2021-05-07 11:04 UTC (permalink / raw)
  To: xen-devel
  Cc: Andrew Cooper, Roger Pau Monne, Jan Beulich, Wei Liu, Ian Jackson

Introduce a helper based on the current Xen guest_cpuid code in order
to fetch a cpuid leaf from a policy. The newly introduced function in
cpuid.c should not be directly called and instead the provided
x86_cpuid_get_leaf macro should be used that will properly deal with
const and non-const inputs.

Also add a test to check that the introduced helper doesn't go over
the bounds of the policy.

Note the code in x86_cpuid_copy_from_buffer is not switched to use the
new function because of the boundary checks against the max fields of
the policy, which might not be properly set at the point where
x86_cpuid_copy_from_buffer get called, for example when filling an
empty policy from scratch.

Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
---
Changes since v3:
 - New in this version.
---
Regarding safety of the usage of array_access_nospec to obtain a
pointer to an element of an array, there are already other instances
of this usage, for example in viridian_time_wrmsr, so I would assume
this is fine.
---
 tools/tests/cpu-policy/test-cpu-policy.c | 75 ++++++++++++++++++++++++
 xen/arch/x86/cpuid.c                     | 55 +++--------------
 xen/include/xen/lib/x86/cpuid.h          | 18 ++++++
 xen/lib/x86/cpuid.c                      | 51 ++++++++++++++++
 4 files changed, 151 insertions(+), 48 deletions(-)

diff --git a/tools/tests/cpu-policy/test-cpu-policy.c b/tools/tests/cpu-policy/test-cpu-policy.c
index 75973298dfd..81de9720c8d 100644
--- a/tools/tests/cpu-policy/test-cpu-policy.c
+++ b/tools/tests/cpu-policy/test-cpu-policy.c
@@ -670,6 +670,80 @@ static void test_cpuid_maximum_leaf_shrinking(void)
     }
 }
 
+static void test_cpuid_get_leaf_failure(void)
+{
+    static const struct test {
+        struct cpuid_policy p;
+        const char *name;
+        uint32_t leaf, subleaf;
+    } tests[] = {
+        /* Bound checking logic. */
+        {
+            .name = "Basic max leaf >= array size",
+            .p = {
+                .basic.max_leaf = CPUID_GUEST_NR_BASIC,
+            },
+        },
+        {
+            .name = "Feature max leaf >= array size",
+            .p = {
+                .basic.max_leaf = CPUID_GUEST_NR_BASIC - 1,
+                .feat.max_subleaf = CPUID_GUEST_NR_FEAT,
+            },
+            .leaf = 0x00000007,
+        },
+        {
+            .name = "Extended max leaf >= array size",
+            .p = {
+                .extd.max_leaf = 0x80000000 + CPUID_GUEST_NR_EXTD,
+            },
+            .leaf = 0x80000000,
+        },
+
+        {
+            .name = "Basic leaf >= max leaf",
+            .p = {
+                .basic.max_leaf = CPUID_GUEST_NR_BASIC - 1,
+            },
+            .leaf = CPUID_GUEST_NR_BASIC,
+        },
+        {
+            .name = "Feature leaf >= max leaf",
+            .p = {
+                .basic.max_leaf = CPUID_GUEST_NR_BASIC - 1,
+                .feat.max_subleaf = CPUID_GUEST_NR_FEAT - 1,
+            },
+            .leaf = 0x00000007,
+            .subleaf = CPUID_GUEST_NR_FEAT,
+        },
+        {
+            .name = "Extended leaf >= max leaf",
+            .p = {
+                .extd.max_leaf = 0x80000000 + CPUID_GUEST_NR_EXTD - 1,
+            },
+            .leaf = 0x80000000 + CPUID_GUEST_NR_EXTD,
+        },
+    };
+    const struct cpuid_policy pc;
+    const struct cpuid_leaf *lc;
+    struct cpuid_policy p;
+    struct cpuid_leaf *l;
+
+    /* Constness build test. */
+    lc = x86_cpuid_get_leaf(&pc, 0, 0);
+    l = x86_cpuid_get_leaf(&p, 0, 0);
+
+    printf("Testing CPUID get leaf bound checking:\n");
+
+    for ( size_t i = 0; i < ARRAY_SIZE(tests); ++i )
+    {
+        const struct test *t = &tests[i];
+
+        if ( x86_cpuid_get_leaf(&t->p, t->leaf, t->subleaf) )
+            fail("  Test %s get leaf fail\n", t->name);
+    }
+}
+
 static void test_is_compatible_success(void)
 {
     static struct test {
@@ -786,6 +860,7 @@ int main(int argc, char **argv)
     test_cpuid_deserialise_failure();
     test_cpuid_out_of_range_clearing();
     test_cpuid_maximum_leaf_shrinking();
+    test_cpuid_get_leaf_failure();
 
     test_msr_serialise_success();
     test_msr_deserialise_failure();
diff --git a/xen/arch/x86/cpuid.c b/xen/arch/x86/cpuid.c
index 752bf244ea3..f7481c3168d 100644
--- a/xen/arch/x86/cpuid.c
+++ b/xen/arch/x86/cpuid.c
@@ -779,48 +779,16 @@ void guest_cpuid(const struct vcpu *v, uint32_t leaf,
     switch ( leaf )
     {
     case 0 ... CPUID_GUEST_NR_BASIC - 1:
-        ASSERT(p->basic.max_leaf < ARRAY_SIZE(p->basic.raw));
-        if ( leaf > min_t(uint32_t, p->basic.max_leaf,
-                          ARRAY_SIZE(p->basic.raw) - 1) )
-            return;
-
-        switch ( leaf )
-        {
-        case 0x4:
-            if ( subleaf >= ARRAY_SIZE(p->cache.raw) )
-                return;
-
-            *res = array_access_nospec(p->cache.raw, subleaf);
-            break;
-
-        case 0x7:
-            ASSERT(p->feat.max_subleaf < ARRAY_SIZE(p->feat.raw));
-            if ( subleaf > min_t(uint32_t, p->feat.max_subleaf,
-                                 ARRAY_SIZE(p->feat.raw) - 1) )
-                return;
-
-            *res = array_access_nospec(p->feat.raw, subleaf);
-            break;
-
-        case 0xb:
-            if ( subleaf >= ARRAY_SIZE(p->topo.raw) )
-                return;
-
-            *res = array_access_nospec(p->topo.raw, subleaf);
-            break;
-
-        case XSTATE_CPUID:
-            if ( !p->basic.xsave || subleaf >= ARRAY_SIZE(p->xstate.raw) )
-                return;
+    case 0x80000000 ... 0x80000000 + CPUID_GUEST_NR_EXTD - 1:
+    {
+        const struct cpuid_leaf *tmp = x86_cpuid_get_leaf(p, leaf, subleaf);
 
-            *res = array_access_nospec(p->xstate.raw, subleaf);
-            break;
+        if ( !tmp )
+            return;
 
-        default:
-            *res = array_access_nospec(p->basic.raw, leaf);
-            break;
-        }
+        *res = *tmp;
         break;
+    }
 
     case 0x40000000 ... 0x400000ff:
         if ( is_viridian_domain(d) )
@@ -835,15 +803,6 @@ void guest_cpuid(const struct vcpu *v, uint32_t leaf,
     case 0x40000100 ... 0x400001ff:
         return cpuid_hypervisor_leaves(v, leaf, subleaf, res);
 
-    case 0x80000000 ... 0x80000000 + CPUID_GUEST_NR_EXTD - 1:
-        ASSERT((p->extd.max_leaf & 0xffff) < ARRAY_SIZE(p->extd.raw));
-        if ( (leaf & 0xffff) > min_t(uint32_t, p->extd.max_leaf & 0xffff,
-                                     ARRAY_SIZE(p->extd.raw) - 1) )
-            return;
-
-        *res = array_access_nospec(p->extd.raw, leaf & 0xffff);
-        break;
-
     default:
         return;
     }
diff --git a/xen/include/xen/lib/x86/cpuid.h b/xen/include/xen/lib/x86/cpuid.h
index 2300faf03e2..4e8797f9f5f 100644
--- a/xen/include/xen/lib/x86/cpuid.h
+++ b/xen/include/xen/lib/x86/cpuid.h
@@ -438,6 +438,24 @@ int x86_cpuid_copy_from_buffer(struct cpuid_policy *policy,
                                uint32_t nr_entries, uint32_t *err_leaf,
                                uint32_t *err_subleaf);
 
+/**
+ * Get a cpuid leaf from a policy object.
+ *
+ * @param policy      The cpuid_policy object.
+ * @param leaf        The leaf index.
+ * @param subleaf     The subleaf index.
+ * @returns a pointer to the requested leaf or NULL in case of error.
+ *
+ * The function will perform out of bound checks. Do not call this function
+ * directly and instead use x86_cpuid_get_leaf that will deal with both const
+ * and non-const policies returning a pointer with constness matching that of
+ * the input.
+ */
+const struct cpuid_leaf *_x86_cpuid_get_leaf(const struct cpuid_policy *p,
+                                             uint32_t leaf, uint32_t subleaf);
+#define x86_cpuid_get_leaf(p, l, s) \
+    ((__typeof__(&(p)->basic.raw[0]))_x86_cpuid_get_leaf(p, l, s))
+
 #endif /* !XEN_LIB_X86_CPUID_H */
 
 /*
diff --git a/xen/lib/x86/cpuid.c b/xen/lib/x86/cpuid.c
index 1409c254c8e..3637466ff9f 100644
--- a/xen/lib/x86/cpuid.c
+++ b/xen/lib/x86/cpuid.c
@@ -532,6 +532,57 @@ int x86_cpuid_copy_from_buffer(struct cpuid_policy *p,
     return -ERANGE;
 }
 
+const struct cpuid_leaf *_x86_cpuid_get_leaf(const struct cpuid_policy *p,
+                                             uint32_t leaf, uint32_t subleaf)
+{
+    switch ( leaf )
+    {
+    case 0 ... CPUID_GUEST_NR_BASIC - 1:
+        if ( p->basic.max_leaf >= ARRAY_SIZE(p->basic.raw) ||
+             leaf > p->basic.max_leaf )
+            return NULL;
+
+        switch ( leaf )
+        {
+        case 0x4:
+            if ( subleaf >= ARRAY_SIZE(p->cache.raw) )
+                return NULL;
+
+            return &array_access_nospec(p->cache.raw, subleaf);
+
+        case 0x7:
+            if ( p->feat.max_subleaf >= ARRAY_SIZE(p->feat.raw) ||
+                 subleaf > p->feat.max_subleaf )
+                return NULL;
+
+            return &array_access_nospec(p->feat.raw, subleaf);
+
+        case 0xb:
+            if ( subleaf >= ARRAY_SIZE(p->topo.raw) )
+                return NULL;
+
+            return &array_access_nospec(p->topo.raw, subleaf);
+
+        case 0xd:
+            if ( !p->basic.xsave || subleaf >= ARRAY_SIZE(p->xstate.raw) )
+                return NULL;
+
+            return &array_access_nospec(p->xstate.raw, subleaf);
+        }
+
+        return &array_access_nospec(p->basic.raw, leaf);
+
+    case 0x80000000 ... 0x80000000 + CPUID_GUEST_NR_EXTD - 1:
+        if ( (p->extd.max_leaf & 0xffff) >= ARRAY_SIZE(p->extd.raw) ||
+             leaf > p->extd.max_leaf )
+            return NULL;
+
+        return &array_access_nospec(p->extd.raw, leaf & 0xffff);
+    }
+
+    return NULL;
+}
+
 /*
  * Local variables:
  * mode: C
-- 
2.31.1



^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH v4 02/10] libs/guest: allow fetching a specific CPUID leaf from a cpu policy
  2021-05-07 11:04 [PATCH v4 00/10] libs/guest: new CPUID/MSR interface Roger Pau Monne
  2021-05-07 11:04 ` [PATCH v4 01/10] libx86: introduce helper to fetch cpuid leaf Roger Pau Monne
@ 2021-05-07 11:04 ` Roger Pau Monne
  2021-05-07 11:04 ` [PATCH v4 03/10] libx86: introduce helper to fetch msr entry Roger Pau Monne
                   ` (7 subsequent siblings)
  9 siblings, 0 replies; 15+ messages in thread
From: Roger Pau Monne @ 2021-05-07 11:04 UTC (permalink / raw)
  To: xen-devel; +Cc: Andrew Cooper, Roger Pau Monne, Ian Jackson, Wei Liu

Introduce an interface that returns a specific leaf/subleaf from a cpu
policy in xen_cpuid_leaf_t format.

This is useful to callers can peek data from the opaque
xc_cpu_policy_t type.

No caller of the interface introduced on this patch.

Note that callers of find_leaf need to be slightly adjusted to use the
new helper parameters.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
---
Changes since v3:
 - Use x86_cpuid_get_leaf.

Changes since v1:
 - Use find leaf.
---
 tools/include/xenguest.h        |  3 +++
 tools/libs/guest/xg_cpuid_x86.c | 23 +++++++++++++++++++++++
 2 files changed, 26 insertions(+)

diff --git a/tools/include/xenguest.h b/tools/include/xenguest.h
index 03c813a0d78..7001e04e88d 100644
--- a/tools/include/xenguest.h
+++ b/tools/include/xenguest.h
@@ -744,6 +744,9 @@ int xc_cpu_policy_update_cpuid(xc_interface *xch, xc_cpu_policy_t *policy,
                                uint32_t nr);
 int xc_cpu_policy_update_msrs(xc_interface *xch, xc_cpu_policy_t *policy,
                               const xen_msr_entry_t *msrs, uint32_t nr);
+int xc_cpu_policy_get_cpuid(xc_interface *xch, const xc_cpu_policy_t *policy,
+                            uint32_t leaf, uint32_t subleaf,
+                            xen_cpuid_leaf_t *out);
 
 /* Compatibility calculations. */
 bool xc_cpu_policy_is_compatible(xc_interface *xch, xc_cpu_policy_t *host,
diff --git a/tools/libs/guest/xg_cpuid_x86.c b/tools/libs/guest/xg_cpuid_x86.c
index 144b5a5aee6..460512d063b 100644
--- a/tools/libs/guest/xg_cpuid_x86.c
+++ b/tools/libs/guest/xg_cpuid_x86.c
@@ -860,6 +860,29 @@ int xc_cpu_policy_update_msrs(xc_interface *xch, xc_cpu_policy_t *policy,
     return rc;
 }
 
+int xc_cpu_policy_get_cpuid(xc_interface *xch, const xc_cpu_policy_t *policy,
+                            uint32_t leaf, uint32_t subleaf,
+                            xen_cpuid_leaf_t *out)
+{
+    const struct cpuid_leaf *tmp;
+
+    tmp = x86_cpuid_get_leaf(&policy->cpuid, leaf, subleaf);
+    if ( !tmp )
+    {
+        /* Unable to find a matching leaf. */
+        errno = ENOENT;
+        return -1;
+    }
+
+    out->leaf = leaf;
+    out->subleaf = subleaf;
+    out->a = tmp->a;
+    out->b = tmp->b;
+    out->c = tmp->c;
+    out->d = tmp->d;
+    return 0;
+}
+
 bool xc_cpu_policy_is_compatible(xc_interface *xch, xc_cpu_policy_t *host,
                                  xc_cpu_policy_t *guest)
 {
-- 
2.31.1



^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH v4 03/10] libx86: introduce helper to fetch msr entry
  2021-05-07 11:04 [PATCH v4 00/10] libs/guest: new CPUID/MSR interface Roger Pau Monne
  2021-05-07 11:04 ` [PATCH v4 01/10] libx86: introduce helper to fetch cpuid leaf Roger Pau Monne
  2021-05-07 11:04 ` [PATCH v4 02/10] libs/guest: allow fetching a specific CPUID leaf from a cpu policy Roger Pau Monne
@ 2021-05-07 11:04 ` Roger Pau Monne
  2021-05-17 15:43   ` Jan Beulich
  2021-05-07 11:04 ` [PATCH v4 04/10] libs/guest: allow fetching a specific MSR entry from a cpu policy Roger Pau Monne
                   ` (6 subsequent siblings)
  9 siblings, 1 reply; 15+ messages in thread
From: Roger Pau Monne @ 2021-05-07 11:04 UTC (permalink / raw)
  To: xen-devel
  Cc: Andrew Cooper, Roger Pau Monne, Jan Beulich, Wei Liu, Ian Jackson

Use such helper in order to replace the code in
x86_msr_copy_from_buffer. Note the introduced helper should not be
directly called and instead x86_msr_get_entry should be used that will
properly deal with const and non-const inputs.

Note this requires making the raw fields uint64_t so that it can
accommodate the maximum size of MSRs values, and in turn removing the
truncation tests.

Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
---
Changes since v3:
 - New in this version.
---
 tools/tests/cpu-policy/test-cpu-policy.c | 48 +++++++++++++++++++-----
 xen/include/xen/lib/x86/msr.h            | 19 +++++++++-
 xen/lib/x86/msr.c                        | 41 ++++++++++----------
 3 files changed, 75 insertions(+), 33 deletions(-)

diff --git a/tools/tests/cpu-policy/test-cpu-policy.c b/tools/tests/cpu-policy/test-cpu-policy.c
index 81de9720c8d..854883fbb39 100644
--- a/tools/tests/cpu-policy/test-cpu-policy.c
+++ b/tools/tests/cpu-policy/test-cpu-policy.c
@@ -389,16 +389,6 @@ static void test_msr_deserialise_failure(void)
             .msr = { .idx = 0xce, .flags = 1 },
             .rc = -EINVAL,
         },
-        {
-            .name = "truncated val",
-            .msr = { .idx = 0xce, .val = ~0ull },
-            .rc = -EOVERFLOW,
-        },
-        {
-            .name = "truncated val",
-            .msr = { .idx = 0x10a, .val = ~0ull },
-            .rc = -EOVERFLOW,
-        },
     };
 
     printf("Testing MSR deserialise failure:\n");
@@ -744,6 +734,43 @@ static void test_cpuid_get_leaf_failure(void)
     }
 }
 
+static void test_msr_get_entry(void)
+{
+    static const struct test {
+        const char *name;
+        unsigned int idx;
+        bool success;
+    } tests[] = {
+        {
+            .name = "bad msr index",
+            .idx = -1,
+        },
+        {
+            .name = "good msr index",
+            .idx = 0xce,
+            .success = true,
+        },
+    };
+    const struct msr_policy pc;
+    const uint64_t *ec;
+    struct msr_policy p;
+    uint64_t *e;
+
+    /* Constness build test. */
+    ec = x86_msr_get_entry(&pc, 0);
+    e = x86_msr_get_entry(&p, 0);
+
+    printf("Testing MSR get leaf:\n");
+
+    for ( size_t i = 0; i < ARRAY_SIZE(tests); ++i )
+    {
+        const struct test *t = &tests[i];
+
+        if ( !!x86_msr_get_entry(&pc, t->idx) != t->success )
+            fail("  Test %s failed\n", t->name);
+    }
+}
+
 static void test_is_compatible_success(void)
 {
     static struct test {
@@ -864,6 +891,7 @@ int main(int argc, char **argv)
 
     test_msr_serialise_success();
     test_msr_deserialise_failure();
+    test_msr_get_entry();
 
     test_is_compatible_success();
     test_is_compatible_failure();
diff --git a/xen/include/xen/lib/x86/msr.h b/xen/include/xen/lib/x86/msr.h
index 48ba4a59c03..9d5bcfad886 100644
--- a/xen/include/xen/lib/x86/msr.h
+++ b/xen/include/xen/lib/x86/msr.h
@@ -17,7 +17,7 @@ struct msr_policy
      * is dependent on real hardware support.
      */
     union {
-        uint32_t raw;
+        uint64_t raw;
         struct {
             uint32_t :31;
             bool cpuid_faulting:1;
@@ -32,7 +32,7 @@ struct msr_policy
      * fixed in hardware.
      */
     union {
-        uint32_t raw;
+        uint64_t raw;
         struct {
             bool rdcl_no:1;
             bool ibrs_all:1;
@@ -91,6 +91,21 @@ int x86_msr_copy_from_buffer(struct msr_policy *policy,
                              const msr_entry_buffer_t msrs, uint32_t nr_entries,
                              uint32_t *err_msr);
 
+/**
+ * Get a MSR entry from a policy object.
+ *
+ * @param policy      The msr_policy object.
+ * @param idx         The index.
+ * @returns a pointer to the requested leaf or NULL in case of error.
+ *
+ * Do not call this function directly and instead use x86_msr_get_entry that
+ * will deal with both const and non-const policies returning a pointer with
+ * constness matching that of the input.
+ */
+const uint64_t *_x86_msr_get_entry(const struct msr_policy *policy,
+                                   uint32_t idx);
+#define x86_msr_get_entry(p, i) \
+    ((__typeof__(&(p)->platform_info.raw))_x86_msr_get_entry(p, i))
 #endif /* !XEN_LIB_X86_MSR_H */
 
 /*
diff --git a/xen/lib/x86/msr.c b/xen/lib/x86/msr.c
index 7d71e92a380..4b5e3553e34 100644
--- a/xen/lib/x86/msr.c
+++ b/xen/lib/x86/msr.c
@@ -74,6 +74,8 @@ int x86_msr_copy_from_buffer(struct msr_policy *p,
 
     for ( i = 0; i < nr_entries; i++ )
     {
+        uint64_t *val;
+
         if ( copy_from_buffer_offset(&data, msrs, i, 1) )
             return -EFAULT;
 
@@ -83,31 +85,13 @@ int x86_msr_copy_from_buffer(struct msr_policy *p,
             goto err;
         }
 
-        switch ( data.idx )
+        val = x86_msr_get_entry(p, data.idx);
+        if ( !val )
         {
-            /*
-             * Assign data.val to p->field, checking for truncation if the
-             * backing storage for field is smaller than uint64_t
-             */
-#define ASSIGN(field)                             \
-({                                                \
-    if ( (typeof(p->field))data.val != data.val ) \
-    {                                             \
-        rc = -EOVERFLOW;                          \
-        goto err;                                 \
-    }                                             \
-    p->field = data.val;                          \
-})
-
-        case MSR_INTEL_PLATFORM_INFO: ASSIGN(platform_info.raw); break;
-        case MSR_ARCH_CAPABILITIES:   ASSIGN(arch_caps.raw);     break;
-
-#undef ASSIGN
-
-        default:
             rc = -ERANGE;
             goto err;
         }
+        *val = data.val;
     }
 
     return 0;
@@ -119,6 +103,21 @@ int x86_msr_copy_from_buffer(struct msr_policy *p,
     return rc;
 }
 
+const uint64_t *_x86_msr_get_entry(const struct msr_policy *policy,
+                                   uint32_t idx)
+{
+    switch ( idx )
+    {
+    case MSR_INTEL_PLATFORM_INFO:
+        return &policy->platform_info.raw;
+
+    case MSR_ARCH_CAPABILITIES:
+        return &policy->arch_caps.raw;
+    }
+
+    return NULL;
+}
+
 /*
  * Local variables:
  * mode: C
-- 
2.31.1



^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH v4 04/10] libs/guest: allow fetching a specific MSR entry from a cpu policy
  2021-05-07 11:04 [PATCH v4 00/10] libs/guest: new CPUID/MSR interface Roger Pau Monne
                   ` (2 preceding siblings ...)
  2021-05-07 11:04 ` [PATCH v4 03/10] libx86: introduce helper to fetch msr entry Roger Pau Monne
@ 2021-05-07 11:04 ` Roger Pau Monne
  2021-05-07 11:04 ` [PATCH v4 05/10] libs/guest: make a cpu policy compatible with older Xen versions Roger Pau Monne
                   ` (5 subsequent siblings)
  9 siblings, 0 replies; 15+ messages in thread
From: Roger Pau Monne @ 2021-05-07 11:04 UTC (permalink / raw)
  To: xen-devel; +Cc: Andrew Cooper, Roger Pau Monne, Ian Jackson, Wei Liu

Introduce an interface that returns a specific MSR entry from a cpu
policy in xen_msr_entry_t format.

This is useful to callers can peek data from the opaque
xc_cpu_policy_t type.

No caller of the interface introduced on this patch.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
---
Changes since v3:
 - Use x86_msr_get_entry.

Changes since v1:
 - Introduce a helper to perform a binary search of the MSR entries
   array.
---
 tools/include/xenguest.h        |  2 ++
 tools/libs/guest/xg_cpuid_x86.c | 20 ++++++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/tools/include/xenguest.h b/tools/include/xenguest.h
index 7001e04e88d..8e8461b0660 100644
--- a/tools/include/xenguest.h
+++ b/tools/include/xenguest.h
@@ -747,6 +747,8 @@ int xc_cpu_policy_update_msrs(xc_interface *xch, xc_cpu_policy_t *policy,
 int xc_cpu_policy_get_cpuid(xc_interface *xch, const xc_cpu_policy_t *policy,
                             uint32_t leaf, uint32_t subleaf,
                             xen_cpuid_leaf_t *out);
+int xc_cpu_policy_get_msr(xc_interface *xch, const xc_cpu_policy_t *policy,
+                          uint32_t msr, xen_msr_entry_t *out);
 
 /* Compatibility calculations. */
 bool xc_cpu_policy_is_compatible(xc_interface *xch, xc_cpu_policy_t *host,
diff --git a/tools/libs/guest/xg_cpuid_x86.c b/tools/libs/guest/xg_cpuid_x86.c
index 460512d063b..cdfc79a86e7 100644
--- a/tools/libs/guest/xg_cpuid_x86.c
+++ b/tools/libs/guest/xg_cpuid_x86.c
@@ -883,6 +883,26 @@ int xc_cpu_policy_get_cpuid(xc_interface *xch, const xc_cpu_policy_t *policy,
     return 0;
 }
 
+int xc_cpu_policy_get_msr(xc_interface *xch, const xc_cpu_policy_t *policy,
+                          uint32_t msr, xen_msr_entry_t *out)
+{
+    const uint64_t *val;
+
+    *out = (xen_msr_entry_t){};
+
+    val = x86_msr_get_entry(&policy->msr, msr);
+    if ( !val )
+    {
+        errno = ENOENT;
+        return -1;
+    }
+
+    out->idx = msr;
+    out->val = *val;
+
+    return 0;
+}
+
 bool xc_cpu_policy_is_compatible(xc_interface *xch, xc_cpu_policy_t *host,
                                  xc_cpu_policy_t *guest)
 {
-- 
2.31.1



^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH v4 05/10] libs/guest: make a cpu policy compatible with older Xen versions
  2021-05-07 11:04 [PATCH v4 00/10] libs/guest: new CPUID/MSR interface Roger Pau Monne
                   ` (3 preceding siblings ...)
  2021-05-07 11:04 ` [PATCH v4 04/10] libs/guest: allow fetching a specific MSR entry from a cpu policy Roger Pau Monne
@ 2021-05-07 11:04 ` Roger Pau Monne
  2021-05-07 11:04 ` [PATCH v4 06/10] libs/guest: introduce helper set cpu topology in cpu policy Roger Pau Monne
                   ` (4 subsequent siblings)
  9 siblings, 0 replies; 15+ messages in thread
From: Roger Pau Monne @ 2021-05-07 11:04 UTC (permalink / raw)
  To: xen-devel; +Cc: Andrew Cooper, Roger Pau Monne, Ian Jackson, Wei Liu

Older Xen versions used to expose some CPUID bits which are no longer
exposed by default. In order to keep a compatible behavior with
guests migrated from versions of Xen that don't encode the CPUID data
on the migration stream introduce a function that sets the same bits
as older Xen versions.

This is pulled out from xc_cpuid_apply_policy which already has this
logic present.

No functional change intended.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
---
Changes since v3:
 - Rename function to xc_cpu_policy_make_compat_4_12.

Changes since v1:
 - Move comments and explicitly mention pre-4.13 Xen.
---
 tools/include/xenguest.h        |  4 +++
 tools/libs/guest/xg_cpuid_x86.c | 58 ++++++++++++++++++++++++---------
 2 files changed, 47 insertions(+), 15 deletions(-)

diff --git a/tools/include/xenguest.h b/tools/include/xenguest.h
index 8e8461b0660..576e976d069 100644
--- a/tools/include/xenguest.h
+++ b/tools/include/xenguest.h
@@ -754,6 +754,10 @@ int xc_cpu_policy_get_msr(xc_interface *xch, const xc_cpu_policy_t *policy,
 bool xc_cpu_policy_is_compatible(xc_interface *xch, xc_cpu_policy_t *host,
                                  xc_cpu_policy_t *guest);
 
+/* Make a policy compatible with pre-4.13 Xen versions. */
+int xc_cpu_policy_make_compat_4_12(xc_interface *xch, xc_cpu_policy_t *policy,
+                                   bool hvm);
+
 int xc_get_cpu_levelling_caps(xc_interface *xch, uint32_t *caps);
 int xc_get_cpu_featureset(xc_interface *xch, uint32_t index,
                           uint32_t *nr_features, uint32_t *featureset);
diff --git a/tools/libs/guest/xg_cpuid_x86.c b/tools/libs/guest/xg_cpuid_x86.c
index cdfc79a86e7..fccbc54a400 100644
--- a/tools/libs/guest/xg_cpuid_x86.c
+++ b/tools/libs/guest/xg_cpuid_x86.c
@@ -441,6 +441,7 @@ int xc_cpuid_apply_policy(xc_interface *xch, uint32_t domid, bool restore,
     unsigned int i, nr_leaves, nr_msrs;
     xen_cpuid_leaf_t *leaves = NULL;
     struct cpuid_policy *p = NULL;
+    struct xc_cpu_policy policy = { };
     uint32_t err_leaf = -1, err_subleaf = -1, err_msr = -1;
     uint32_t host_featureset[FEATURESET_NR_ENTRIES] = {};
     uint32_t len = ARRAY_SIZE(host_featureset);
@@ -505,21 +506,9 @@ int xc_cpuid_apply_policy(xc_interface *xch, uint32_t domid, bool restore,
 
     if ( restore )
     {
-        /*
-         * Account for feature which have been disabled by default since Xen 4.13,
-         * so migrated-in VM's don't risk seeing features disappearing.
-         */
-        p->basic.rdrand = test_bit(X86_FEATURE_RDRAND, host_featureset);
-
-        if ( di.hvm )
-        {
-            p->feat.mpx = test_bit(X86_FEATURE_MPX, host_featureset);
-        }
-
-        /* Clamp maximum leaves to the ones supported on 4.12. */
-        p->basic.max_leaf = min(p->basic.max_leaf, 0xdu);
-        p->feat.max_subleaf = 0;
-        p->extd.max_leaf = min(p->extd.max_leaf, 0x1cu);
+        policy.cpuid = *p;
+        xc_cpu_policy_make_compat_4_12(xch, &policy, di.hvm);
+        *p = policy.cpuid;
     }
 
     if ( featureset )
@@ -921,3 +910,42 @@ bool xc_cpu_policy_is_compatible(xc_interface *xch, xc_cpu_policy_t *host,
 
     return false;
 }
+
+int xc_cpu_policy_make_compat_4_12(xc_interface *xch, xc_cpu_policy_t *policy,
+                                   bool hvm)
+{
+    xc_cpu_policy_t *host;
+    int rc;
+
+    host = xc_cpu_policy_init();
+    if ( !host )
+    {
+        errno = ENOMEM;
+        return -1;
+    }
+
+    rc = xc_cpu_policy_get_system(xch, XEN_SYSCTL_cpu_policy_host, host);
+    if ( rc )
+    {
+        ERROR("Failed to get host policy");
+        goto out;
+    }
+
+    /*
+     * Account for features which have been disabled by default since Xen 4.13,
+     * so migrated-in VM's don't risk seeing features disappearing.
+     */
+    policy->cpuid.basic.rdrand = host->cpuid.basic.rdrand;
+
+    if ( hvm )
+        policy->cpuid.feat.mpx = host->cpuid.feat.mpx;
+
+    /* Clamp maximum leaves to the ones supported on pre-4.13. */
+    policy->cpuid.basic.max_leaf = min(policy->cpuid.basic.max_leaf, 0xdu);
+    policy->cpuid.feat.max_subleaf = 0;
+    policy->cpuid.extd.max_leaf = min(policy->cpuid.extd.max_leaf, 0x1cu);
+
+ out:
+    xc_cpu_policy_destroy(host);
+    return rc;
+}
-- 
2.31.1



^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH v4 06/10] libs/guest: introduce helper set cpu topology in cpu policy
  2021-05-07 11:04 [PATCH v4 00/10] libs/guest: new CPUID/MSR interface Roger Pau Monne
                   ` (4 preceding siblings ...)
  2021-05-07 11:04 ` [PATCH v4 05/10] libs/guest: make a cpu policy compatible with older Xen versions Roger Pau Monne
@ 2021-05-07 11:04 ` Roger Pau Monne
  2021-05-07 11:04 ` [PATCH v4 07/10] libs/guest: rework xc_cpuid_xend_policy Roger Pau Monne
                   ` (3 subsequent siblings)
  9 siblings, 0 replies; 15+ messages in thread
From: Roger Pau Monne @ 2021-05-07 11:04 UTC (permalink / raw)
  To: xen-devel; +Cc: Andrew Cooper, Roger Pau Monne, Ian Jackson, Wei Liu

This logic is pulled out from xc_cpuid_apply_policy and placed into a
separate helper. Note the legacy part of the introduced function, as
long term Xen will require a proper topology setter function capable
of expressing a more diverse set of topologies.

No functional change intended.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
---
 - s/xc_cpu_policy_topology/xc_cpu_policy_legacy_topology/
---
 tools/include/xenguest.h        |   4 +
 tools/libs/guest/xg_cpuid_x86.c | 182 +++++++++++++++++---------------
 2 files changed, 103 insertions(+), 83 deletions(-)

diff --git a/tools/include/xenguest.h b/tools/include/xenguest.h
index 576e976d069..6fe01ae292b 100644
--- a/tools/include/xenguest.h
+++ b/tools/include/xenguest.h
@@ -758,6 +758,10 @@ bool xc_cpu_policy_is_compatible(xc_interface *xch, xc_cpu_policy_t *host,
 int xc_cpu_policy_make_compat_4_12(xc_interface *xch, xc_cpu_policy_t *policy,
                                    bool hvm);
 
+/* Setup the legacy policy topology. */
+int xc_cpu_policy_legacy_topology(xc_interface *xch, xc_cpu_policy_t *policy,
+                                  bool hvm);
+
 int xc_get_cpu_levelling_caps(xc_interface *xch, uint32_t *caps);
 int xc_get_cpu_featureset(xc_interface *xch, uint32_t index,
                           uint32_t *nr_features, uint32_t *featureset);
diff --git a/tools/libs/guest/xg_cpuid_x86.c b/tools/libs/guest/xg_cpuid_x86.c
index fccbc54a400..2c89c59cccb 100644
--- a/tools/libs/guest/xg_cpuid_x86.c
+++ b/tools/libs/guest/xg_cpuid_x86.c
@@ -438,13 +438,11 @@ int xc_cpuid_apply_policy(xc_interface *xch, uint32_t domid, bool restore,
 {
     int rc;
     xc_dominfo_t di;
-    unsigned int i, nr_leaves, nr_msrs;
+    unsigned int nr_leaves, nr_msrs;
     xen_cpuid_leaf_t *leaves = NULL;
     struct cpuid_policy *p = NULL;
     struct xc_cpu_policy policy = { };
     uint32_t err_leaf = -1, err_subleaf = -1, err_msr = -1;
-    uint32_t host_featureset[FEATURESET_NR_ENTRIES] = {};
-    uint32_t len = ARRAY_SIZE(host_featureset);
 
     if ( xc_domain_getinfo(xch, domid, 1, &di) != 1 ||
          di.domid != domid )
@@ -467,22 +465,6 @@ int xc_cpuid_apply_policy(xc_interface *xch, uint32_t domid, bool restore,
          (p = calloc(1, sizeof(*p))) == NULL )
         goto out;
 
-    /* Get the host policy. */
-    rc = xc_get_cpu_featureset(xch, XEN_SYSCTL_cpu_featureset_host,
-                               &len, host_featureset);
-    if ( rc )
-    {
-        /* Tolerate "buffer too small", as we've got the bits we need. */
-        if ( errno == ENOBUFS )
-            rc = 0;
-        else
-        {
-            PERROR("Failed to obtain host featureset");
-            rc = -errno;
-            goto out;
-        }
-    }
-
     /* Get the domain's default policy. */
     nr_msrs = 0;
     rc = get_system_cpu_policy(xch, di.hvm ? XEN_SYSCTL_cpu_policy_hvm_default
@@ -566,70 +548,11 @@ int xc_cpuid_apply_policy(xc_interface *xch, uint32_t domid, bool restore,
         }
     }
 
-    if ( !di.hvm )
-    {
-        /*
-         * On hardware without CPUID Faulting, PV guests see real topology.
-         * As a consequence, they also need to see the host htt/cmp fields.
-         */
-        p->basic.htt       = test_bit(X86_FEATURE_HTT, host_featureset);
-        p->extd.cmp_legacy = test_bit(X86_FEATURE_CMP_LEGACY, host_featureset);
-    }
-    else
-    {
-        /*
-         * Topology for HVM guests is entirely controlled by Xen.  For now, we
-         * hardcode APIC_ID = vcpu_id * 2 to give the illusion of no SMT.
-         */
-        p->basic.htt = true;
-        p->extd.cmp_legacy = false;
-
-        /*
-         * Leaf 1 EBX[23:16] is Maximum Logical Processors Per Package.
-         * Update to reflect vLAPIC_ID = vCPU_ID * 2, but make sure to avoid
-         * overflow.
-         */
-        if ( !(p->basic.lppp & 0x80) )
-            p->basic.lppp *= 2;
-
-        switch ( p->x86_vendor )
-        {
-        case X86_VENDOR_INTEL:
-            for ( i = 0; (p->cache.subleaf[i].type &&
-                          i < ARRAY_SIZE(p->cache.raw)); ++i )
-            {
-                p->cache.subleaf[i].cores_per_package =
-                    (p->cache.subleaf[i].cores_per_package << 1) | 1;
-                p->cache.subleaf[i].threads_per_cache = 0;
-            }
-            break;
-
-        case X86_VENDOR_AMD:
-        case X86_VENDOR_HYGON:
-            /*
-             * Leaf 0x80000008 ECX[15:12] is ApicIdCoreSize.
-             * Leaf 0x80000008 ECX[7:0] is NumberOfCores (minus one).
-             * Update to reflect vLAPIC_ID = vCPU_ID * 2.  But avoid
-             * - overflow,
-             * - going out of sync with leaf 1 EBX[23:16],
-             * - incrementing ApicIdCoreSize when it's zero (which changes the
-             *   meaning of bits 7:0).
-             *
-             * UPDATE: I addition to avoiding overflow, some
-             * proprietary operating systems have trouble with
-             * apic_id_size values greater than 7.  Limit the value to
-             * 7 for now.
-             */
-            if ( p->extd.nc < 0x7f )
-            {
-                if ( p->extd.apic_id_size != 0 && p->extd.apic_id_size < 0x7 )
-                    p->extd.apic_id_size++;
-
-                p->extd.nc = (p->extd.nc << 1) | 1;
-            }
-            break;
-        }
-    }
+    policy.cpuid = *p;
+    rc = xc_cpu_policy_legacy_topology(xch, &policy, di.hvm);
+    if ( rc )
+        goto out;
+    *p = policy.cpuid;
 
     rc = x86_cpuid_copy_to_buffer(p, leaves, &nr_leaves);
     if ( rc )
@@ -949,3 +872,96 @@ int xc_cpu_policy_make_compat_4_12(xc_interface *xch, xc_cpu_policy_t *policy,
     xc_cpu_policy_destroy(host);
     return rc;
 }
+
+int xc_cpu_policy_legacy_topology(xc_interface *xch, xc_cpu_policy_t *policy,
+                                  bool hvm)
+{
+    if ( !hvm )
+    {
+        xc_cpu_policy_t *host;
+        int rc;
+
+        host = xc_cpu_policy_init();
+        if ( !host )
+        {
+            errno = ENOMEM;
+            return -1;
+        }
+
+        rc = xc_cpu_policy_get_system(xch, XEN_SYSCTL_cpu_policy_host, host);
+        if ( rc )
+        {
+            ERROR("Failed to get host policy");
+            xc_cpu_policy_destroy(host);
+            return rc;
+        }
+
+
+        /*
+         * On hardware without CPUID Faulting, PV guests see real topology.
+         * As a consequence, they also need to see the host htt/cmp fields.
+         */
+        policy->cpuid.basic.htt = host->cpuid.basic.htt;
+        policy->cpuid.extd.cmp_legacy = host->cpuid.extd.cmp_legacy;
+    }
+    else
+    {
+        unsigned int i;
+
+        /*
+         * Topology for HVM guests is entirely controlled by Xen.  For now, we
+         * hardcode APIC_ID = vcpu_id * 2 to give the illusion of no SMT.
+         */
+        policy->cpuid.basic.htt = true;
+        policy->cpuid.extd.cmp_legacy = false;
+
+        /*
+         * Leaf 1 EBX[23:16] is Maximum Logical Processors Per Package.
+         * Update to reflect vLAPIC_ID = vCPU_ID * 2, but make sure to avoid
+         * overflow.
+         */
+        if ( !(policy->cpuid.basic.lppp & 0x80) )
+            policy->cpuid.basic.lppp *= 2;
+
+        switch ( policy->cpuid.x86_vendor )
+        {
+        case X86_VENDOR_INTEL:
+            for ( i = 0; (policy->cpuid.cache.subleaf[i].type &&
+                          i < ARRAY_SIZE(policy->cpuid.cache.raw)); ++i )
+            {
+                policy->cpuid.cache.subleaf[i].cores_per_package =
+                  (policy->cpuid.cache.subleaf[i].cores_per_package << 1) | 1;
+                policy->cpuid.cache.subleaf[i].threads_per_cache = 0;
+            }
+            break;
+
+        case X86_VENDOR_AMD:
+        case X86_VENDOR_HYGON:
+            /*
+             * Leaf 0x80000008 ECX[15:12] is ApicIdCoreSize.
+             * Leaf 0x80000008 ECX[7:0] is NumberOfCores (minus one).
+             * Update to reflect vLAPIC_ID = vCPU_ID * 2.  But avoid
+             * - overflow,
+             * - going out of sync with leaf 1 EBX[23:16],
+             * - incrementing ApicIdCoreSize when it's zero (which changes the
+             *   meaning of bits 7:0).
+             *
+             * UPDATE: I addition to avoiding overflow, some
+             * proprietary operating systems have trouble with
+             * apic_id_size values greater than 7.  Limit the value to
+             * 7 for now.
+             */
+            if ( policy->cpuid.extd.nc < 0x7f )
+            {
+                if ( policy->cpuid.extd.apic_id_size != 0 &&
+                     policy->cpuid.extd.apic_id_size < 0x7 )
+                    policy->cpuid.extd.apic_id_size++;
+
+                policy->cpuid.extd.nc = (policy->cpuid.extd.nc << 1) | 1;
+            }
+            break;
+        }
+    }
+
+    return 0;
+}
-- 
2.31.1



^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH v4 07/10] libs/guest: rework xc_cpuid_xend_policy
  2021-05-07 11:04 [PATCH v4 00/10] libs/guest: new CPUID/MSR interface Roger Pau Monne
                   ` (5 preceding siblings ...)
  2021-05-07 11:04 ` [PATCH v4 06/10] libs/guest: introduce helper set cpu topology in cpu policy Roger Pau Monne
@ 2021-05-07 11:04 ` Roger Pau Monne
  2021-05-07 11:04 ` [PATCH v4 08/10] libs/guest: apply a featureset into a cpu policy Roger Pau Monne
                   ` (2 subsequent siblings)
  9 siblings, 0 replies; 15+ messages in thread
From: Roger Pau Monne @ 2021-05-07 11:04 UTC (permalink / raw)
  To: xen-devel; +Cc: Andrew Cooper, Roger Pau Monne, Ian Jackson, Wei Liu

Rename xc_cpuid_xend_policy to xc_cpu_policy_apply_cpuid and make it
public. Modify the function internally to use the new xc_cpu_policy_*
set of functions. Also don't apply the passed policy to a domain
directly, and instead modify the provided xc_cpu_policy_t. The caller
will be responsible of applying the modified cpu policy to the domain.

Note that further patches will end up removing this function, as the
callers should have the necessary helpers to modify an xc_cpu_policy_t
themselves.

The find_leaf helper and related comparison function is also removed,
as it's no longer needed to search for cpuid leafs as finding the
matching leaves is now done using xc_cpu_policy_get_cpuid.

No functional change intended.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
---
Changes since v3:
 - Drop find_leaf and comparison helper.
---
 tools/include/xenguest.h        |   4 +
 tools/libs/guest/xg_cpuid_x86.c | 200 +++++++++++++-------------------
 2 files changed, 83 insertions(+), 121 deletions(-)

diff --git a/tools/include/xenguest.h b/tools/include/xenguest.h
index 6fe01ae292b..3e2fe7f3654 100644
--- a/tools/include/xenguest.h
+++ b/tools/include/xenguest.h
@@ -762,6 +762,10 @@ int xc_cpu_policy_make_compat_4_12(xc_interface *xch, xc_cpu_policy_t *policy,
 int xc_cpu_policy_legacy_topology(xc_interface *xch, xc_cpu_policy_t *policy,
                                   bool hvm);
 
+/* Apply an xc_xend_cpuid object to the policy. */
+int xc_cpu_policy_apply_cpuid(xc_interface *xch, xc_cpu_policy_t *policy,
+                              const struct xc_xend_cpuid *cpuid, bool hvm);
+
 int xc_get_cpu_levelling_caps(xc_interface *xch, uint32_t *caps);
 int xc_get_cpu_featureset(xc_interface *xch, uint32_t index,
                           uint32_t *nr_features, uint32_t *featureset);
diff --git a/tools/libs/guest/xg_cpuid_x86.c b/tools/libs/guest/xg_cpuid_x86.c
index 2c89c59cccb..65b49753d3e 100644
--- a/tools/libs/guest/xg_cpuid_x86.c
+++ b/tools/libs/guest/xg_cpuid_x86.c
@@ -263,144 +263,107 @@ int xc_set_domain_cpu_policy(xc_interface *xch, uint32_t domid,
     return ret;
 }
 
-static int compare_leaves(const void *l, const void *r)
-{
-    const xen_cpuid_leaf_t *lhs = l;
-    const xen_cpuid_leaf_t *rhs = r;
-
-    if ( lhs->leaf != rhs->leaf )
-        return lhs->leaf < rhs->leaf ? -1 : 1;
-
-    if ( lhs->subleaf != rhs->subleaf )
-        return lhs->subleaf < rhs->subleaf ? -1 : 1;
-
-    return 0;
-}
-
-static xen_cpuid_leaf_t *find_leaf(
-    xen_cpuid_leaf_t *leaves, unsigned int nr_leaves,
-    const struct xc_xend_cpuid *xend)
-{
-    const xen_cpuid_leaf_t key = { xend->leaf, xend->subleaf };
-
-    return bsearch(&key, leaves, nr_leaves, sizeof(*leaves), compare_leaves);
-}
-
-static int xc_cpuid_xend_policy(
-    xc_interface *xch, uint32_t domid, const struct xc_xend_cpuid *xend)
+int xc_cpu_policy_apply_cpuid(xc_interface *xch, xc_cpu_policy_t *policy,
+                              const struct xc_xend_cpuid *cpuid, bool hvm)
 {
     int rc;
-    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_cpuid_leaf_t *host = NULL, *def = NULL, *cur = NULL;
-    unsigned int nr_host, nr_def, nr_cur;
+    xc_cpu_policy_t *host = NULL, *def = NULL;
 
-    if ( xc_domain_getinfo(xch, domid, 1, &di) != 1 ||
-         di.domid != domid )
-    {
-        ERROR("Failed to obtain d%d info", domid);
-        rc = -ESRCH;
-        goto fail;
-    }
-
-    rc = xc_cpu_policy_get_size(xch, &nr_leaves, &nr_msrs);
-    if ( rc )
-    {
-        PERROR("Failed to obtain policy info size");
-        rc = -errno;
-        goto fail;
-    }
-
-    rc = -ENOMEM;
-    if ( (host = calloc(nr_leaves, sizeof(*host))) == NULL ||
-         (def  = calloc(nr_leaves, sizeof(*def)))  == NULL ||
-         (cur  = calloc(nr_leaves, sizeof(*cur)))  == NULL )
-    {
-        ERROR("Unable to allocate memory for %u CPUID leaves", nr_leaves);
-        goto fail;
-    }
-
-    /* Get the domain's current policy. */
-    nr_msrs = 0;
-    nr_cur = nr_leaves;
-    rc = get_domain_cpu_policy(xch, domid, &nr_cur, cur, &nr_msrs, NULL);
-    if ( rc )
+    host = xc_cpu_policy_init();
+    def = xc_cpu_policy_init();
+    if ( !host || !def )
     {
-        PERROR("Failed to obtain d%d current policy", domid);
-        rc = -errno;
-        goto fail;
+        PERROR("Failed to init policies");
+        rc = -ENOMEM;
+        goto out;
     }
 
     /* Get the domain type's default policy. */
-    nr_msrs = 0;
-    nr_def = nr_leaves;
-    rc = get_system_cpu_policy(xch, di.hvm ? XEN_SYSCTL_cpu_policy_hvm_default
+    rc = xc_cpu_policy_get_system(xch, hvm ? XEN_SYSCTL_cpu_policy_hvm_default
                                            : XEN_SYSCTL_cpu_policy_pv_default,
-                               &nr_def, def, &nr_msrs, NULL);
+                                  def);
     if ( rc )
     {
-        PERROR("Failed to obtain %s def policy", di.hvm ? "hvm" : "pv");
-        rc = -errno;
-        goto fail;
+        PERROR("Failed to obtain %s def policy", hvm ? "hvm" : "pv");
+        goto out;
     }
 
     /* Get the host policy. */
-    nr_msrs = 0;
-    nr_host = nr_leaves;
-    rc = get_system_cpu_policy(xch, XEN_SYSCTL_cpu_policy_host,
-                               &nr_host, host, &nr_msrs, NULL);
+    rc = xc_cpu_policy_get_system(xch, XEN_SYSCTL_cpu_policy_host, host);
     if ( rc )
     {
         PERROR("Failed to obtain host policy");
-        rc = -errno;
-        goto fail;
+        goto out;
     }
 
     rc = -EINVAL;
-    for ( ; xend->leaf != XEN_CPUID_INPUT_UNUSED; ++xend )
+    for ( ; cpuid->leaf != XEN_CPUID_INPUT_UNUSED; ++cpuid )
     {
-        xen_cpuid_leaf_t *cur_leaf = find_leaf(cur, nr_cur, xend);
-        const xen_cpuid_leaf_t *def_leaf = find_leaf(def, nr_def, xend);
-        const xen_cpuid_leaf_t *host_leaf = find_leaf(host, nr_host, xend);
+        xen_cpuid_leaf_t cur_leaf;
+        xen_cpuid_leaf_t def_leaf;
+        xen_cpuid_leaf_t host_leaf;
 
-        if ( cur_leaf == NULL || def_leaf == NULL || host_leaf == NULL )
+        rc = xc_cpu_policy_get_cpuid(xch, policy, cpuid->leaf, cpuid->subleaf,
+                                     &cur_leaf);
+        if ( rc )
+        {
+            ERROR("Failed to get current policy leaf %#x subleaf %#x",
+                  cpuid->leaf, cpuid->subleaf);
+            goto out;
+        }
+        rc = xc_cpu_policy_get_cpuid(xch, def, cpuid->leaf, cpuid->subleaf,
+                                     &def_leaf);
+        if ( rc )
+        {
+            ERROR("Failed to get def policy leaf %#x subleaf %#x",
+                  cpuid->leaf, cpuid->subleaf);
+            goto out;
+        }
+        rc = xc_cpu_policy_get_cpuid(xch, host, cpuid->leaf, cpuid->subleaf,
+                                     &host_leaf);
+        if ( rc )
         {
-            ERROR("Missing leaf %#x, subleaf %#x", xend->leaf, xend->subleaf);
-            goto fail;
+            ERROR("Failed to get host policy leaf %#x subleaf %#x",
+                  cpuid->leaf, cpuid->subleaf);
+            goto out;
         }
 
-        for ( unsigned int i = 0; i < ARRAY_SIZE(xend->policy); i++ )
+        for ( unsigned int i = 0; i < ARRAY_SIZE(cpuid->policy); i++ )
         {
-            uint32_t *cur_reg = &cur_leaf->a + i;
-            const uint32_t *def_reg = &def_leaf->a + i;
-            const uint32_t *host_reg = &host_leaf->a + i;
+            uint32_t *cur_reg = &cur_leaf.a + i;
+            const uint32_t *def_reg = &def_leaf.a + i;
+            const uint32_t *host_reg = &host_leaf.a + i;
 
-            if ( xend->policy[i] == NULL )
+            if ( cpuid->policy[i] == NULL )
                 continue;
 
             for ( unsigned int j = 0; j < 32; j++ )
             {
                 bool val;
 
-                if ( xend->policy[i][j] == '1' )
+                switch ( cpuid->policy[i][j] )
+                {
+                case '1':
                     val = true;
-                else if ( xend->policy[i][j] == '0' )
+                    break;
+
+                case '0':
                     val = false;
-                else if ( xend->policy[i][j] == 'x' )
+                    break;
+
+                case 'x':
                     val = test_bit(31 - j, def_reg);
-                else if ( xend->policy[i][j] == 'k' ||
-                          xend->policy[i][j] == 's' )
+                    break;
+
+                case 'k':
+                case 's':
                     val = test_bit(31 - j, host_reg);
-                else
-                {
+                    break;
+
+                default:
                     ERROR("Bad character '%c' in policy[%d] string '%s'",
-                          xend->policy[i][j], i, xend->policy[i]);
-                    goto fail;
+                          cpuid->policy[i][j], i, cpuid->policy[i]);
+                    goto out;
                 }
 
                 clear_bit(31 - j, cur_reg);
@@ -408,25 +371,19 @@ static int xc_cpuid_xend_policy(
                     set_bit(31 - j, cur_reg);
             }
         }
-    }
 
-    /* Feed the transformed currrent policy back up to Xen. */
-    rc = xc_set_domain_cpu_policy(xch, domid, nr_cur, cur, 0, NULL,
-                                  &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 fail;
+        rc = xc_cpu_policy_update_cpuid(xch, policy, &cur_leaf, 1);
+        if ( rc )
+        {
+            PERROR("Failed to set policy leaf %#x subleaf %#x",
+                   cpuid->leaf, cpuid->subleaf);
+            goto out;
+        }
     }
 
-    /* Success! */
-
- fail:
-    free(cur);
-    free(def);
-    free(host);
+ out:
+    xc_cpu_policy_destroy(def);
+    xc_cpu_policy_destroy(host);
 
     return rc;
 }
@@ -434,7 +391,7 @@ static int xc_cpuid_xend_policy(
 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 *cpuid)
 {
     int rc;
     xc_dominfo_t di;
@@ -554,6 +511,10 @@ int xc_cpuid_apply_policy(xc_interface *xch, uint32_t domid, bool restore,
         goto out;
     *p = policy.cpuid;
 
+    rc = xc_cpu_policy_apply_cpuid(xch, &policy, cpuid, di.hvm);
+    if ( rc )
+        goto out;
+
     rc = x86_cpuid_copy_to_buffer(p, leaves, &nr_leaves);
     if ( rc )
     {
@@ -571,9 +532,6 @@ int xc_cpuid_apply_policy(xc_interface *xch, uint32_t domid, bool restore,
         goto out;
     }
 
-    if ( xend && (rc = xc_cpuid_xend_policy(xch, domid, xend)) )
-        goto out;
-
     rc = 0;
 
 out:
-- 
2.31.1



^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH v4 08/10] libs/guest: apply a featureset into a cpu policy
  2021-05-07 11:04 [PATCH v4 00/10] libs/guest: new CPUID/MSR interface Roger Pau Monne
                   ` (6 preceding siblings ...)
  2021-05-07 11:04 ` [PATCH v4 07/10] libs/guest: rework xc_cpuid_xend_policy Roger Pau Monne
@ 2021-05-07 11:04 ` Roger Pau Monne
  2021-05-07 11:04 ` [PATCH v4 09/10] libs/{light,guest}: implement xc_cpuid_apply_policy in libxl Roger Pau Monne
  2021-05-07 11:04 ` [PATCH v4 10/10] libs/guest: (re)move xc_cpu_policy_apply_cpuid Roger Pau Monne
  9 siblings, 0 replies; 15+ messages in thread
From: Roger Pau Monne @ 2021-05-07 11:04 UTC (permalink / raw)
  To: xen-devel; +Cc: Andrew Cooper, Roger Pau Monne, Ian Jackson, Wei Liu

Pull out the code from xc_cpuid_apply_policy that applies a featureset
to a cpu policy and place it on it's own standalone function that's
part of the public interface.

No functional change intended.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
---
 tools/include/xenguest.h        |  5 ++
 tools/libs/guest/xg_cpuid_x86.c | 95 ++++++++++++++++++++-------------
 2 files changed, 62 insertions(+), 38 deletions(-)

diff --git a/tools/include/xenguest.h b/tools/include/xenguest.h
index 3e2fe7f3654..134c00f29a0 100644
--- a/tools/include/xenguest.h
+++ b/tools/include/xenguest.h
@@ -766,6 +766,11 @@ int xc_cpu_policy_legacy_topology(xc_interface *xch, xc_cpu_policy_t *policy,
 int xc_cpu_policy_apply_cpuid(xc_interface *xch, xc_cpu_policy_t *policy,
                               const struct xc_xend_cpuid *cpuid, bool hvm);
 
+/* Apply a featureset to the policy. */
+int xc_cpu_policy_apply_featureset(xc_interface *xch, xc_cpu_policy_t *policy,
+                                   const uint32_t *featureset,
+                                   unsigned int nr_features);
+
 int xc_get_cpu_levelling_caps(xc_interface *xch, uint32_t *caps);
 int xc_get_cpu_featureset(xc_interface *xch, uint32_t index,
                           uint32_t *nr_features, uint32_t *featureset);
diff --git a/tools/libs/guest/xg_cpuid_x86.c b/tools/libs/guest/xg_cpuid_x86.c
index 65b49753d3e..778bc2130ea 100644
--- a/tools/libs/guest/xg_cpuid_x86.c
+++ b/tools/libs/guest/xg_cpuid_x86.c
@@ -452,46 +452,15 @@ int xc_cpuid_apply_policy(xc_interface *xch, uint32_t domid, bool restore,
 
     if ( featureset )
     {
-        uint32_t disabled_features[FEATURESET_NR_ENTRIES],
-            feat[FEATURESET_NR_ENTRIES] = {};
-        static const uint32_t deep_features[] = INIT_DEEP_FEATURES;
-        unsigned int i, b;
-
-        /*
-         * The user supplied featureset may be shorter or longer than
-         * FEATURESET_NR_ENTRIES.  Shorter is fine, and we will zero-extend.
-         * Longer is fine, so long as it only padded with zeros.
-         */
-        unsigned int user_len = min(FEATURESET_NR_ENTRIES + 0u, nr_features);
-
-        /* Check for truncated set bits. */
-        rc = -EOPNOTSUPP;
-        for ( i = user_len; i < nr_features; ++i )
-            if ( featureset[i] != 0 )
-                goto out;
-
-        memcpy(feat, featureset, sizeof(*featureset) * user_len);
-
-        /* Disable deep dependencies of disabled features. */
-        for ( i = 0; i < ARRAY_SIZE(disabled_features); ++i )
-            disabled_features[i] = ~feat[i] & deep_features[i];
-
-        for ( b = 0; b < sizeof(disabled_features) * CHAR_BIT; ++b )
+        policy.cpuid = *p;
+        rc = xc_cpu_policy_apply_featureset(xch, &policy, featureset,
+                                            nr_features);
+        if ( rc )
         {
-            const uint32_t *dfs;
-
-            if ( !test_bit(b, disabled_features) ||
-                 !(dfs = x86_cpuid_lookup_deep_deps(b)) )
-                continue;
-
-            for ( i = 0; i < ARRAY_SIZE(disabled_features); ++i )
-            {
-                feat[i] &= ~dfs[i];
-                disabled_features[i] &= ~dfs[i];
-            }
+            ERROR("Failed to apply featureset to policy");
+            goto out;
         }
-
-        cpuid_featureset_to_policy(feat, p);
+        *p = policy.cpuid;
     }
     else
     {
@@ -923,3 +892,53 @@ int xc_cpu_policy_legacy_topology(xc_interface *xch, xc_cpu_policy_t *policy,
 
     return 0;
 }
+
+int xc_cpu_policy_apply_featureset(xc_interface *xch, xc_cpu_policy_t *policy,
+                                   const uint32_t *featureset,
+                                   unsigned int nr_features)
+{
+    uint32_t disabled_features[FEATURESET_NR_ENTRIES],
+        feat[FEATURESET_NR_ENTRIES] = {};
+    static const uint32_t deep_features[] = INIT_DEEP_FEATURES;
+    unsigned int i, b;
+
+    /*
+     * The user supplied featureset may be shorter or longer than
+     * FEATURESET_NR_ENTRIES.  Shorter is fine, and we will zero-extend.
+     * Longer is fine, so long as it only padded with zeros.
+     */
+    unsigned int user_len = min(FEATURESET_NR_ENTRIES + 0u, nr_features);
+
+    /* Check for truncated set bits. */
+    for ( i = user_len; i < nr_features; ++i )
+        if ( featureset[i] != 0 )
+        {
+            errno = EOPNOTSUPP;
+            return -1;
+        }
+
+    memcpy(feat, featureset, sizeof(*featureset) * user_len);
+
+    /* Disable deep dependencies of disabled features. */
+    for ( i = 0; i < ARRAY_SIZE(disabled_features); ++i )
+        disabled_features[i] = ~feat[i] & deep_features[i];
+
+    for ( b = 0; b < sizeof(disabled_features) * CHAR_BIT; ++b )
+    {
+        const uint32_t *dfs;
+
+        if ( !test_bit(b, disabled_features) ||
+             !(dfs = x86_cpuid_lookup_deep_deps(b)) )
+            continue;
+
+        for ( i = 0; i < ARRAY_SIZE(disabled_features); ++i )
+        {
+            feat[i] &= ~dfs[i];
+            disabled_features[i] &= ~dfs[i];
+        }
+    }
+
+    cpuid_featureset_to_policy(feat, &policy->cpuid);
+
+    return 0;
+}
-- 
2.31.1



^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH v4 09/10] libs/{light,guest}: implement xc_cpuid_apply_policy in libxl
  2021-05-07 11:04 [PATCH v4 00/10] libs/guest: new CPUID/MSR interface Roger Pau Monne
                   ` (7 preceding siblings ...)
  2021-05-07 11:04 ` [PATCH v4 08/10] libs/guest: apply a featureset into a cpu policy Roger Pau Monne
@ 2021-05-07 11:04 ` Roger Pau Monne
  2021-05-14  9:36   ` Roger Pau Monné
  2021-05-07 11:04 ` [PATCH v4 10/10] libs/guest: (re)move xc_cpu_policy_apply_cpuid Roger Pau Monne
  9 siblings, 1 reply; 15+ messages in thread
From: Roger Pau Monne @ 2021-05-07 11:04 UTC (permalink / raw)
  To: xen-devel
  Cc: Andrew Cooper, Roger Pau Monne, Ian Jackson, Wei Liu, Anthony PERARD

With the addition of the xc_cpu_policy_* now libxl can have better
control over the cpu policy, this allows removing the
xc_cpuid_apply_policy function and instead coding the required bits by
libxl in libxl__cpuid_legacy directly.

Remove xc_cpuid_apply_policy.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
---
Changes since v2:
 - Use 'r' for libxc return values.
 - Fix comment about making a cpu policy compatible.
 - Use LOG*D macros.
---
 tools/include/xenctrl.h         |  18 -----
 tools/libs/guest/xg_cpuid_x86.c | 122 --------------------------------
 tools/libs/light/libxl_cpuid.c  |  94 ++++++++++++++++++++++--
 3 files changed, 87 insertions(+), 147 deletions(-)

diff --git a/tools/include/xenctrl.h b/tools/include/xenctrl.h
index e894c5c392d..17fa3734800 100644
--- a/tools/include/xenctrl.h
+++ b/tools/include/xenctrl.h
@@ -1890,24 +1890,6 @@ struct xc_xend_cpuid {
     char *policy[4];
 };
 
-/*
- * Make adjustments to the CPUID settings for a domain.
- *
- * This path is used in two cases.  First, for fresh boots of the domain, and
- * secondly for migrate-in/restore of pre-4.14 guests (where CPUID data was
- * missing from the stream).  The @restore parameter distinguishes these
- * cases, and the generated policy must be compatible with a 4.13.
- *
- * 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.
- */
-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);
 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 778bc2130ea..8c62c3ac360 100644
--- a/tools/libs/guest/xg_cpuid_x86.c
+++ b/tools/libs/guest/xg_cpuid_x86.c
@@ -388,128 +388,6 @@ int xc_cpu_policy_apply_cpuid(xc_interface *xch, xc_cpu_policy_t *policy,
     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 *cpuid)
-{
-    int rc;
-    xc_dominfo_t di;
-    unsigned int nr_leaves, nr_msrs;
-    xen_cpuid_leaf_t *leaves = NULL;
-    struct cpuid_policy *p = NULL;
-    struct xc_cpu_policy policy = { };
-    uint32_t err_leaf = -1, err_subleaf = -1, err_msr = -1;
-
-    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_cpu_policy_get_size(xch, &nr_leaves, &nr_msrs);
-    if ( rc )
-    {
-        PERROR("Failed to obtain policy info size");
-        rc = -errno;
-        goto out;
-    }
-
-    rc = -ENOMEM;
-    if ( (leaves = calloc(nr_leaves, sizeof(*leaves))) == NULL ||
-         (p = calloc(1, sizeof(*p))) == NULL )
-        goto out;
-
-    /* Get the domain's default policy. */
-    nr_msrs = 0;
-    rc = get_system_cpu_policy(xch, di.hvm ? XEN_SYSCTL_cpu_policy_hvm_default
-                                           : XEN_SYSCTL_cpu_policy_pv_default,
-                               &nr_leaves, leaves, &nr_msrs, NULL);
-    if ( rc )
-    {
-        PERROR("Failed to obtain %s default policy", di.hvm ? "hvm" : "pv");
-        rc = -errno;
-        goto out;
-    }
-
-    rc = x86_cpuid_copy_from_buffer(p, leaves, nr_leaves,
-                                    &err_leaf, &err_subleaf);
-    if ( rc )
-    {
-        ERROR("Failed to deserialise CPUID (err leaf %#x, subleaf %#x) (%d = %s)",
-              err_leaf, err_subleaf, -rc, strerror(-rc));
-        goto out;
-    }
-
-    if ( restore )
-    {
-        policy.cpuid = *p;
-        xc_cpu_policy_make_compat_4_12(xch, &policy, di.hvm);
-        *p = policy.cpuid;
-    }
-
-    if ( featureset )
-    {
-        policy.cpuid = *p;
-        rc = xc_cpu_policy_apply_featureset(xch, &policy, featureset,
-                                            nr_features);
-        if ( rc )
-        {
-            ERROR("Failed to apply featureset to policy");
-            goto out;
-        }
-        *p = policy.cpuid;
-    }
-    else
-    {
-        p->extd.itsc = itsc;
-
-        if ( di.hvm )
-        {
-            p->basic.pae = pae;
-            p->basic.vmx = nested_virt;
-            p->extd.svm = nested_virt;
-        }
-    }
-
-    policy.cpuid = *p;
-    rc = xc_cpu_policy_legacy_topology(xch, &policy, di.hvm);
-    if ( rc )
-        goto out;
-    *p = policy.cpuid;
-
-    rc = xc_cpu_policy_apply_cpuid(xch, &policy, cpuid, di.hvm);
-    if ( rc )
-        goto out;
-
-    rc = x86_cpuid_copy_to_buffer(p, leaves, &nr_leaves);
-    if ( rc )
-    {
-        ERROR("Failed to serialise CPUID (%d = %s)", -rc, strerror(-rc));
-        goto out;
-    }
-
-    rc = xc_set_domain_cpu_policy(xch, domid, nr_leaves, leaves, 0, NULL,
-                                  &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;
-    }
-
-    rc = 0;
-
-out:
-    free(p);
-    free(leaves);
-
-    return rc;
-}
-
 xc_cpu_policy_t *xc_cpu_policy_init(void)
 {
     return calloc(1, sizeof(struct xc_cpu_policy));
diff --git a/tools/libs/light/libxl_cpuid.c b/tools/libs/light/libxl_cpuid.c
index eb6feaa96d1..6d17e89191f 100644
--- a/tools/libs/light/libxl_cpuid.c
+++ b/tools/libs/light/libxl_cpuid.c
@@ -430,9 +430,11 @@ int libxl__cpuid_legacy(libxl_ctx *ctx, uint32_t domid, bool restore,
                         libxl_domain_build_info *info)
 {
     GC_INIT(ctx);
+    xc_cpu_policy_t *policy = NULL;
+    bool hvm = info->type == LIBXL_DOMAIN_TYPE_HVM;
     bool pae = true;
     bool itsc;
-    int r;
+    int r, rc = 0;
 
     /*
      * Gross hack.  Using libxl_defbool_val() here causes libvirt to crash in
@@ -443,6 +445,41 @@ int libxl__cpuid_legacy(libxl_ctx *ctx, uint32_t domid, bool restore,
      */
     bool nested_virt = info->nested_hvm.val > 0;
 
+    policy = xc_cpu_policy_init();
+    if (!policy) {
+        LOGED(ERROR, domid, "Failed to init CPU policy");
+        rc = ERROR_FAIL;
+        goto out;
+    }
+
+    r = xc_cpu_policy_get_domain(ctx->xch, domid, policy);
+    if (r) {
+        LOGED(ERROR, domid, "Failed to fetch domain CPU policy");
+        rc = ERROR_FAIL;
+        goto out;
+    }
+
+    if (restore) {
+        /*
+         * Make sure the policy is compatible with pre Xen 4.13. Note that
+         * newer Xen versions will pass policy data on the restore stream, so
+         * any adjustments done here will be superseded.
+         */
+        r = xc_cpu_policy_make_compat_4_12(ctx->xch, policy, hvm);
+        if (r) {
+            LOGED(ERROR, domid, "Failed to setup compatible CPU policy");
+            rc = ERROR_FAIL;
+            goto out;
+        }
+    }
+
+    r = xc_cpu_policy_legacy_topology(ctx->xch, policy, hvm);
+    if (r) {
+        LOGED(ERROR, domid, "Failed to setup CPU policy topology");
+        rc = ERROR_FAIL;
+        goto out;
+    }
+
     /*
      * For PV guests, PAE is Xen-controlled (it is the 'p' that differentiates
      * the xen-3.0-x86_32 and xen-3.0-x86_32p ABIs).  It is mandatory as Xen
@@ -453,8 +490,15 @@ int libxl__cpuid_legacy(libxl_ctx *ctx, uint32_t domid, bool restore,
      *
      * HVM guests get a top-level choice of whether PAE is available.
      */
-    if (info->type == LIBXL_DOMAIN_TYPE_HVM)
+    if (hvm)
         pae = libxl_defbool_val(info->u.hvm.pae);
+    rc = libxl_cpuid_parse_config(&info->cpuid, GCSPRINTF("pae=%d", pae));
+    if (rc) {
+        LOGD(ERROR, domid, "Failed to set PAE CPUID flag");
+        rc = ERROR_FAIL;
+        goto out;
+    }
+
 
     /*
      * Advertising Invariant TSC to a guest means that the TSC frequency won't
@@ -470,14 +514,50 @@ int libxl__cpuid_legacy(libxl_ctx *ctx, uint32_t domid, bool restore,
      */
     itsc = (libxl_defbool_val(info->disable_migrate) ||
             info->tsc_mode == LIBXL_TSC_MODE_ALWAYS_EMULATE);
+    rc = libxl_cpuid_parse_config(&info->cpuid, GCSPRINTF("invtsc=%d", itsc));
+    if (rc) {
+        LOGD(ERROR, domid, "Failed to set Invariant TSC CPUID flag");
+        rc = ERROR_FAIL;
+        goto out;
+    }
 
-    r = xc_cpuid_apply_policy(ctx->xch, domid, restore, NULL, 0,
-                              pae, itsc, nested_virt, info->cpuid);
-    if (r)
-        LOGEVD(ERROR, -r, domid, "Failed to apply CPUID policy");
+    /* Set Nested virt CPUID bits for HVM. */
+    if (hvm) {
+        rc = libxl_cpuid_parse_config(&info->cpuid, GCSPRINTF("vmx=%d",
+                                                              nested_virt));
+        if (rc) {
+            LOGD(ERROR, domid, "Failed to set VMX CPUID flag");
+            rc = ERROR_FAIL;
+            goto out;
+        }
+
+        rc = libxl_cpuid_parse_config(&info->cpuid, GCSPRINTF("svm=%d",
+                                                              nested_virt));
+        if (rc) {
+            LOGD(ERROR, domid, "Failed to set SVM CPUID flag");
+            rc = ERROR_FAIL;
+            goto out;
+        }
+    }
+
+    /* Apply the bits from info->cpuid if any. */
+    r = xc_cpu_policy_apply_cpuid(ctx->xch, policy, info->cpuid, hvm);
+    if (r) {
+        LOGEVD(ERROR, domid, -r, "Failed to apply CPUID changes");
+        rc = ERROR_FAIL;
+        goto out;
+    }
+
+    r = xc_cpu_policy_set_domain(ctx->xch, domid, policy);
+    if (r) {
+        LOGED(ERROR, domid, "Failed to set domain CPUID policy");
+        rc = ERROR_FAIL;
+    }
 
+ out:
+    xc_cpu_policy_destroy(policy);
     GC_FREE;
-    return r ? ERROR_FAIL : 0;
+    return rc;
 }
 
 static const char *input_names[2] = { "leaf", "subleaf" };
-- 
2.31.1



^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH v4 10/10] libs/guest: (re)move xc_cpu_policy_apply_cpuid
  2021-05-07 11:04 [PATCH v4 00/10] libs/guest: new CPUID/MSR interface Roger Pau Monne
                   ` (8 preceding siblings ...)
  2021-05-07 11:04 ` [PATCH v4 09/10] libs/{light,guest}: implement xc_cpuid_apply_policy in libxl Roger Pau Monne
@ 2021-05-07 11:04 ` Roger Pau Monne
  9 siblings, 0 replies; 15+ messages in thread
From: Roger Pau Monne @ 2021-05-07 11:04 UTC (permalink / raw)
  To: xen-devel
  Cc: Andrew Cooper, Roger Pau Monne, Ian Jackson, Wei Liu, Anthony PERARD

Move the logic from xc_cpu_policy_apply_cpuid into libxl, now that the
xc_cpu_policy_* helpers allow modifying a cpu policy. By moving such
parsing into libxl directly we can get rid of xc_xend_cpuid, as libxl
will now implement it's own private type for storing CPUID
information, which currently matches xc_xend_cpuid.

Note the function logic is moved as-is, but requires adapting to the
libxl coding style.

No functional change intended.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
---
Changes since v2:
 - Use LOG*D.
 - Pass a gc to apply_policy.
 - Use 'r' for libxc return values.
---
 tools/include/libxl.h             |   6 +-
 tools/include/xenctrl.h           |  26 ------
 tools/include/xenguest.h          |   4 -
 tools/libs/guest/xg_cpuid_x86.c   | 125 --------------------------
 tools/libs/light/libxl_cpuid.c    | 142 ++++++++++++++++++++++++++++--
 tools/libs/light/libxl_internal.h |  26 ++++++
 6 files changed, 165 insertions(+), 164 deletions(-)

diff --git a/tools/include/libxl.h b/tools/include/libxl.h
index ae7fe27c1f2..150b7ba85ac 100644
--- a/tools/include/libxl.h
+++ b/tools/include/libxl.h
@@ -1375,10 +1375,10 @@ void libxl_bitmap_init(libxl_bitmap *map);
 void libxl_bitmap_dispose(libxl_bitmap *map);
 
 /*
- * libxl_cpuid_policy is opaque in the libxl ABI.  Users of both libxl and
- * libxc may not make assumptions about xc_xend_cpuid.
+ * libxl_cpuid_policy is opaque in the libxl ABI. Users of libxl may not make
+ * assumptions about libxl__cpuid_policy.
  */
-typedef struct xc_xend_cpuid libxl_cpuid_policy;
+typedef struct libxl__cpuid_policy libxl_cpuid_policy;
 typedef libxl_cpuid_policy * libxl_cpuid_policy_list;
 void libxl_cpuid_dispose(libxl_cpuid_policy_list *cpuid_list);
 int libxl_cpuid_policy_list_length(const libxl_cpuid_policy_list *l);
diff --git a/tools/include/xenctrl.h b/tools/include/xenctrl.h
index 17fa3734800..30c2a5f5284 100644
--- a/tools/include/xenctrl.h
+++ b/tools/include/xenctrl.h
@@ -1864,32 +1864,6 @@ int xc_domain_debug_control(xc_interface *xch,
 
 #if defined(__i386__) || defined(__x86_64__)
 
-/*
- * CPUID policy data, expressed in the legacy XEND format.
- *
- * Policy is an array of strings, 32 chars long:
- *   policy[0] = eax
- *   policy[1] = ebx
- *   policy[2] = ecx
- *   policy[3] = edx
- *
- * The format of the string is the following:
- *   '1' -> force to 1
- *   '0' -> force to 0
- *   'x' -> we don't care (use default)
- *   'k' -> pass through host value
- *   's' -> legacy alias for 'k'
- */
-struct xc_xend_cpuid {
-    union {
-        struct {
-            uint32_t leaf, subleaf;
-        };
-        uint32_t input[2];
-    };
-    char *policy[4];
-};
-
 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/include/xenguest.h b/tools/include/xenguest.h
index 134c00f29a0..414baa30171 100644
--- a/tools/include/xenguest.h
+++ b/tools/include/xenguest.h
@@ -762,10 +762,6 @@ int xc_cpu_policy_make_compat_4_12(xc_interface *xch, xc_cpu_policy_t *policy,
 int xc_cpu_policy_legacy_topology(xc_interface *xch, xc_cpu_policy_t *policy,
                                   bool hvm);
 
-/* Apply an xc_xend_cpuid object to the policy. */
-int xc_cpu_policy_apply_cpuid(xc_interface *xch, xc_cpu_policy_t *policy,
-                              const struct xc_xend_cpuid *cpuid, bool hvm);
-
 /* Apply a featureset to the policy. */
 int xc_cpu_policy_apply_featureset(xc_interface *xch, xc_cpu_policy_t *policy,
                                    const uint32_t *featureset,
diff --git a/tools/libs/guest/xg_cpuid_x86.c b/tools/libs/guest/xg_cpuid_x86.c
index 8c62c3ac360..e0fff98fe77 100644
--- a/tools/libs/guest/xg_cpuid_x86.c
+++ b/tools/libs/guest/xg_cpuid_x86.c
@@ -263,131 +263,6 @@ int xc_set_domain_cpu_policy(xc_interface *xch, uint32_t domid,
     return ret;
 }
 
-int xc_cpu_policy_apply_cpuid(xc_interface *xch, xc_cpu_policy_t *policy,
-                              const struct xc_xend_cpuid *cpuid, bool hvm)
-{
-    int rc;
-    xc_cpu_policy_t *host = NULL, *def = NULL;
-
-    host = xc_cpu_policy_init();
-    def = xc_cpu_policy_init();
-    if ( !host || !def )
-    {
-        PERROR("Failed to init policies");
-        rc = -ENOMEM;
-        goto out;
-    }
-
-    /* Get the domain type's default policy. */
-    rc = xc_cpu_policy_get_system(xch, hvm ? XEN_SYSCTL_cpu_policy_hvm_default
-                                           : XEN_SYSCTL_cpu_policy_pv_default,
-                                  def);
-    if ( rc )
-    {
-        PERROR("Failed to obtain %s def policy", hvm ? "hvm" : "pv");
-        goto out;
-    }
-
-    /* Get the host policy. */
-    rc = xc_cpu_policy_get_system(xch, XEN_SYSCTL_cpu_policy_host, host);
-    if ( rc )
-    {
-        PERROR("Failed to obtain host policy");
-        goto out;
-    }
-
-    rc = -EINVAL;
-    for ( ; cpuid->leaf != XEN_CPUID_INPUT_UNUSED; ++cpuid )
-    {
-        xen_cpuid_leaf_t cur_leaf;
-        xen_cpuid_leaf_t def_leaf;
-        xen_cpuid_leaf_t host_leaf;
-
-        rc = xc_cpu_policy_get_cpuid(xch, policy, cpuid->leaf, cpuid->subleaf,
-                                     &cur_leaf);
-        if ( rc )
-        {
-            ERROR("Failed to get current policy leaf %#x subleaf %#x",
-                  cpuid->leaf, cpuid->subleaf);
-            goto out;
-        }
-        rc = xc_cpu_policy_get_cpuid(xch, def, cpuid->leaf, cpuid->subleaf,
-                                     &def_leaf);
-        if ( rc )
-        {
-            ERROR("Failed to get def policy leaf %#x subleaf %#x",
-                  cpuid->leaf, cpuid->subleaf);
-            goto out;
-        }
-        rc = xc_cpu_policy_get_cpuid(xch, host, cpuid->leaf, cpuid->subleaf,
-                                     &host_leaf);
-        if ( rc )
-        {
-            ERROR("Failed to get host policy leaf %#x subleaf %#x",
-                  cpuid->leaf, cpuid->subleaf);
-            goto out;
-        }
-
-        for ( unsigned int i = 0; i < ARRAY_SIZE(cpuid->policy); i++ )
-        {
-            uint32_t *cur_reg = &cur_leaf.a + i;
-            const uint32_t *def_reg = &def_leaf.a + i;
-            const uint32_t *host_reg = &host_leaf.a + i;
-
-            if ( cpuid->policy[i] == NULL )
-                continue;
-
-            for ( unsigned int j = 0; j < 32; j++ )
-            {
-                bool val;
-
-                switch ( cpuid->policy[i][j] )
-                {
-                case '1':
-                    val = true;
-                    break;
-
-                case '0':
-                    val = false;
-                    break;
-
-                case 'x':
-                    val = test_bit(31 - j, def_reg);
-                    break;
-
-                case 'k':
-                case 's':
-                    val = test_bit(31 - j, host_reg);
-                    break;
-
-                default:
-                    ERROR("Bad character '%c' in policy[%d] string '%s'",
-                          cpuid->policy[i][j], i, cpuid->policy[i]);
-                    goto out;
-                }
-
-                clear_bit(31 - j, cur_reg);
-                if ( val )
-                    set_bit(31 - j, cur_reg);
-            }
-        }
-
-        rc = xc_cpu_policy_update_cpuid(xch, policy, &cur_leaf, 1);
-        if ( rc )
-        {
-            PERROR("Failed to set policy leaf %#x subleaf %#x",
-                   cpuid->leaf, cpuid->subleaf);
-            goto out;
-        }
-    }
-
- out:
-    xc_cpu_policy_destroy(def);
-    xc_cpu_policy_destroy(host);
-
-    return rc;
-}
-
 xc_cpu_policy_t *xc_cpu_policy_init(void)
 {
     return calloc(1, sizeof(struct xc_cpu_policy));
diff --git a/tools/libs/light/libxl_cpuid.c b/tools/libs/light/libxl_cpuid.c
index 6d17e89191f..6c11b7a7c1f 100644
--- a/tools/libs/light/libxl_cpuid.c
+++ b/tools/libs/light/libxl_cpuid.c
@@ -298,7 +298,7 @@ int libxl_cpuid_parse_config(libxl_cpuid_policy_list *cpuid, const char* str)
     char *sep, *val, *endptr;
     int i;
     const struct cpuid_flags *flag;
-    struct xc_xend_cpuid *entry;
+    struct libxl__cpuid_policy *entry;
     unsigned long num;
     char flags[33], *resstr;
 
@@ -376,7 +376,7 @@ int libxl_cpuid_parse_config_xend(libxl_cpuid_policy_list *cpuid,
     char *endptr;
     unsigned long value;
     uint32_t leaf, subleaf = XEN_CPUID_INPUT_UNUSED;
-    struct xc_xend_cpuid *entry;
+    struct libxl__cpuid_policy *entry;
 
     /* parse the leaf number */
     value = strtoul(str, &endptr, 0);
@@ -426,6 +426,137 @@ int libxl_cpuid_parse_config_xend(libxl_cpuid_policy_list *cpuid,
     return 0;
 }
 
+static int apply_cpuid(libxl__gc *gc, xc_cpu_policy_t *policy,
+                       libxl_cpuid_policy_list cpuid, bool hvm, domid_t domid)
+{
+    int r, rc = 0;
+    xc_cpu_policy_t *host = NULL, *def = NULL;
+
+    host = xc_cpu_policy_init();
+    def = xc_cpu_policy_init();
+    if (!host || !def) {
+        LOGD(ERROR, domid, "Failed to init policies");
+        rc = ERROR_FAIL;
+        goto out;
+    }
+
+    /* Get the domain type's default policy. */
+    r = xc_cpu_policy_get_system(CTX->xch,
+                                 hvm ? XEN_SYSCTL_cpu_policy_hvm_default
+                                     : XEN_SYSCTL_cpu_policy_pv_default,
+                                 def);
+    if (r) {
+        LOGED(ERROR, domid, "Failed to obtain %s def policy",
+              hvm ? "hvm" : "pv");
+        rc = ERROR_FAIL;
+        goto out;
+    }
+
+    /* Get the host policy. */
+    r = xc_cpu_policy_get_system(CTX->xch, XEN_SYSCTL_cpu_policy_host, host);
+    if (r) {
+        LOGED(ERROR, domid, "Failed to obtain host policy");
+        rc = ERROR_FAIL;
+        goto out;
+    }
+
+    for (; cpuid->leaf != XEN_CPUID_INPUT_UNUSED; ++cpuid) {
+        xen_cpuid_leaf_t cur_leaf;
+        xen_cpuid_leaf_t def_leaf;
+        xen_cpuid_leaf_t host_leaf;
+
+        r = xc_cpu_policy_get_cpuid(CTX->xch, policy, cpuid->leaf,
+                                    cpuid->subleaf, &cur_leaf);
+        if (r) {
+            LOGED(ERROR, domid,
+                  "Failed to get current policy leaf %#x subleaf %#x",
+                  cpuid->leaf, cpuid->subleaf);
+            r = ERROR_FAIL;
+            goto out;
+        }
+        r = xc_cpu_policy_get_cpuid(CTX->xch, def, cpuid->leaf, cpuid->subleaf,
+                                    &def_leaf);
+        if (r) {
+            LOGED(ERROR, domid,
+                  "Failed to get def policy leaf %#x subleaf %#x",
+                  cpuid->leaf, cpuid->subleaf);
+            rc = ERROR_FAIL;
+            goto out;
+        }
+        r = xc_cpu_policy_get_cpuid(CTX->xch, host, cpuid->leaf,
+                                    cpuid->subleaf, &host_leaf);
+        if (r) {
+            LOGED(ERROR, domid,
+                  "Failed to get host policy leaf %#x subleaf %#x",
+                  cpuid->leaf, cpuid->subleaf);
+            rc = ERROR_FAIL;
+            goto out;
+        }
+
+        for (unsigned int i = 0; i < ARRAY_SIZE(cpuid->policy); i++) {
+            uint32_t *cur_reg = &cur_leaf.a + i;
+            const uint32_t *def_reg = &def_leaf.a + i;
+            const uint32_t *host_reg = &host_leaf.a + i;
+
+            if (cpuid->policy[i] == NULL)
+                continue;
+
+#define test_bit(i, r) !!(*(r) & (1u << (i)))
+#define set_bit(i, r) (*(r) |= (1u << (i)))
+#define clear_bit(i, r)  (*(r) &= ~(1u << (i)))
+            for (unsigned int j = 0; j < 32; j++) {
+                bool val;
+
+                switch (cpuid->policy[i][j]) {
+                case '1':
+                    val = true;
+                    break;
+
+                case '0':
+                    val = false;
+                    break;
+
+                case 'x':
+                    val = test_bit(31 - j, def_reg);
+                    break;
+
+                case 'k':
+                case 's':
+                    val = test_bit(31 - j, host_reg);
+                    break;
+
+                default:
+                    LOGD(ERROR, domid,
+                         "Bad character '%c' in policy[%d] string '%s'",
+                         cpuid->policy[i][j], i, cpuid->policy[i]);
+                    rc = ERROR_FAIL;
+                    goto out;
+                }
+
+                clear_bit(31 - j, cur_reg);
+                if (val)
+                    set_bit(31 - j, cur_reg);
+            }
+#undef clear_bit
+#undef set_bit
+#undef test_bit
+        }
+
+        r = xc_cpu_policy_update_cpuid(CTX->xch, policy, &cur_leaf, 1);
+        if (r) {
+            LOGED(ERROR, domid, "Failed to set policy leaf %#x subleaf %#x",
+                  cpuid->leaf, cpuid->subleaf);
+            rc = ERROR_FAIL;
+            goto out;
+        }
+    }
+
+ out:
+    xc_cpu_policy_destroy(def);
+    xc_cpu_policy_destroy(host);
+    return rc;
+}
+
 int libxl__cpuid_legacy(libxl_ctx *ctx, uint32_t domid, bool restore,
                         libxl_domain_build_info *info)
 {
@@ -541,10 +672,9 @@ int libxl__cpuid_legacy(libxl_ctx *ctx, uint32_t domid, bool restore,
     }
 
     /* Apply the bits from info->cpuid if any. */
-    r = xc_cpu_policy_apply_cpuid(ctx->xch, policy, info->cpuid, hvm);
-    if (r) {
-        LOGEVD(ERROR, domid, -r, "Failed to apply CPUID changes");
-        rc = ERROR_FAIL;
+    rc = apply_cpuid(gc, policy, info->cpuid, hvm, domid);
+    if (rc) {
+        LOGD(ERROR, domid, "Failed to apply CPUID changes");
         goto out;
     }
 
diff --git a/tools/libs/light/libxl_internal.h b/tools/libs/light/libxl_internal.h
index 44a2f3c8fe3..f271a729fa7 100644
--- a/tools/libs/light/libxl_internal.h
+++ b/tools/libs/light/libxl_internal.h
@@ -2052,6 +2052,32 @@ typedef yajl_gen_status (*libxl__gen_json_callback)(yajl_gen hand, void *);
 _hidden char *libxl__object_to_json(libxl_ctx *ctx, const char *type,
                                     libxl__gen_json_callback gen, void *p);
 
+/*
+ * CPUID policy data, expressed in the internal libxl format.
+ *
+ * Policy is an array of strings, 32 chars long:
+ *   policy[0] = eax
+ *   policy[1] = ebx
+ *   policy[2] = ecx
+ *   policy[3] = edx
+ *
+ * The format of the string is the following:
+ *   '1' -> force to 1
+ *   '0' -> force to 0
+ *   'x' -> we don't care (use default)
+ *   'k' -> pass through host value
+ *   's' -> legacy alias for 'k'
+ */
+struct libxl__cpuid_policy {
+    union {
+        struct {
+            uint32_t leaf, subleaf;
+        };
+        uint32_t input[2];
+    };
+    char *policy[4];
+};
+
 _hidden int libxl__cpuid_legacy(libxl_ctx *ctx, uint32_t domid, bool retore,
                                 libxl_domain_build_info *info);
 
-- 
2.31.1



^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH v4 09/10] libs/{light,guest}: implement xc_cpuid_apply_policy in libxl
  2021-05-07 11:04 ` [PATCH v4 09/10] libs/{light,guest}: implement xc_cpuid_apply_policy in libxl Roger Pau Monne
@ 2021-05-14  9:36   ` Roger Pau Monné
  0 siblings, 0 replies; 15+ messages in thread
From: Roger Pau Monné @ 2021-05-14  9:36 UTC (permalink / raw)
  To: xen-devel; +Cc: Andrew Cooper, Ian Jackson, Wei Liu, Anthony PERARD

On Fri, May 07, 2021 at 01:04:21PM +0200, Roger Pau Monne wrote:
> diff --git a/tools/libs/light/libxl_cpuid.c b/tools/libs/light/libxl_cpuid.c
> index eb6feaa96d1..6d17e89191f 100644
> --- a/tools/libs/light/libxl_cpuid.c
> +++ b/tools/libs/light/libxl_cpuid.c
> @@ -430,9 +430,11 @@ int libxl__cpuid_legacy(libxl_ctx *ctx, uint32_t domid, bool restore,
>                          libxl_domain_build_info *info)
>  {
>      GC_INIT(ctx);
> +    xc_cpu_policy_t *policy = NULL;
> +    bool hvm = info->type == LIBXL_DOMAIN_TYPE_HVM;

This is wrong and should instead be:

bool hvm = info->type != LIBXL_DOMAIN_TYPE_PV;

To account for libxl having a different domain type for PVH. I've
fixed it on my local copy of the patch.

Maybe the variable should also have a different name? I really cannot
think of any other name short of 'translated' or hvm_container. Let me
know if I should change the variable name.

Roger.


^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH v4 03/10] libx86: introduce helper to fetch msr entry
  2021-05-07 11:04 ` [PATCH v4 03/10] libx86: introduce helper to fetch msr entry Roger Pau Monne
@ 2021-05-17 15:43   ` Jan Beulich
  2021-05-18 10:50     ` Roger Pau Monné
  0 siblings, 1 reply; 15+ messages in thread
From: Jan Beulich @ 2021-05-17 15:43 UTC (permalink / raw)
  To: Roger Pau Monne; +Cc: Andrew Cooper, Wei Liu, Ian Jackson, xen-devel

On 07.05.2021 13:04, Roger Pau Monne wrote:
> @@ -91,6 +91,21 @@ int x86_msr_copy_from_buffer(struct msr_policy *policy,
>                               const msr_entry_buffer_t msrs, uint32_t nr_entries,
>                               uint32_t *err_msr);
>  
> +/**
> + * Get a MSR entry from a policy object.
> + *
> + * @param policy      The msr_policy object.
> + * @param idx         The index.
> + * @returns a pointer to the requested leaf or NULL in case of error.
> + *
> + * Do not call this function directly and instead use x86_msr_get_entry that
> + * will deal with both const and non-const policies returning a pointer with
> + * constness matching that of the input.
> + */
> +const uint64_t *_x86_msr_get_entry(const struct msr_policy *policy,
> +                                   uint32_t idx);
> +#define x86_msr_get_entry(p, i) \
> +    ((__typeof__(&(p)->platform_info.raw))_x86_msr_get_entry(p, i))
>  #endif /* !XEN_LIB_X86_MSR_H */

Just two nits: I think it would be nice to retain a blank line ahead of
the #endif. And here as well as in the CPUID counterpart you introduce,
strictly speaking, name space violations (via the leading underscore).
I realize I'm not really liked for pointing such out, but it may be
more relevant here than in pure hypervisor code, as this library code
is supposed to be usable also in userland.

Jan


^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH v4 03/10] libx86: introduce helper to fetch msr entry
  2021-05-17 15:43   ` Jan Beulich
@ 2021-05-18 10:50     ` Roger Pau Monné
  2021-05-18 11:29       ` Jan Beulich
  0 siblings, 1 reply; 15+ messages in thread
From: Roger Pau Monné @ 2021-05-18 10:50 UTC (permalink / raw)
  To: Jan Beulich; +Cc: Andrew Cooper, Wei Liu, Ian Jackson, xen-devel

On Mon, May 17, 2021 at 05:43:33PM +0200, Jan Beulich wrote:
> On 07.05.2021 13:04, Roger Pau Monne wrote:
> > @@ -91,6 +91,21 @@ int x86_msr_copy_from_buffer(struct msr_policy *policy,
> >                               const msr_entry_buffer_t msrs, uint32_t nr_entries,
> >                               uint32_t *err_msr);
> >  
> > +/**
> > + * Get a MSR entry from a policy object.
> > + *
> > + * @param policy      The msr_policy object.
> > + * @param idx         The index.
> > + * @returns a pointer to the requested leaf or NULL in case of error.
> > + *
> > + * Do not call this function directly and instead use x86_msr_get_entry that
> > + * will deal with both const and non-const policies returning a pointer with
> > + * constness matching that of the input.
> > + */
> > +const uint64_t *_x86_msr_get_entry(const struct msr_policy *policy,
> > +                                   uint32_t idx);
> > +#define x86_msr_get_entry(p, i) \
> > +    ((__typeof__(&(p)->platform_info.raw))_x86_msr_get_entry(p, i))
> >  #endif /* !XEN_LIB_X86_MSR_H */
> 
> Just two nits: I think it would be nice to retain a blank line ahead of
> the #endif. And here as well as in the CPUID counterpart you introduce,
> strictly speaking, name space violations (via the leading underscore).

I guess another option would be to name the function
x86_msr_get_entry_const, and keep the x86_msr_get_entry macro as-is.

Does that seem better?

Thanks, Roger.


^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH v4 03/10] libx86: introduce helper to fetch msr entry
  2021-05-18 10:50     ` Roger Pau Monné
@ 2021-05-18 11:29       ` Jan Beulich
  0 siblings, 0 replies; 15+ messages in thread
From: Jan Beulich @ 2021-05-18 11:29 UTC (permalink / raw)
  To: Roger Pau Monné; +Cc: Andrew Cooper, Wei Liu, Ian Jackson, xen-devel

On 18.05.2021 12:50, Roger Pau Monné wrote:
> On Mon, May 17, 2021 at 05:43:33PM +0200, Jan Beulich wrote:
>> On 07.05.2021 13:04, Roger Pau Monne wrote:
>>> @@ -91,6 +91,21 @@ int x86_msr_copy_from_buffer(struct msr_policy *policy,
>>>                               const msr_entry_buffer_t msrs, uint32_t nr_entries,
>>>                               uint32_t *err_msr);
>>>  
>>> +/**
>>> + * Get a MSR entry from a policy object.
>>> + *
>>> + * @param policy      The msr_policy object.
>>> + * @param idx         The index.
>>> + * @returns a pointer to the requested leaf or NULL in case of error.
>>> + *
>>> + * Do not call this function directly and instead use x86_msr_get_entry that
>>> + * will deal with both const and non-const policies returning a pointer with
>>> + * constness matching that of the input.
>>> + */
>>> +const uint64_t *_x86_msr_get_entry(const struct msr_policy *policy,
>>> +                                   uint32_t idx);
>>> +#define x86_msr_get_entry(p, i) \
>>> +    ((__typeof__(&(p)->platform_info.raw))_x86_msr_get_entry(p, i))
>>>  #endif /* !XEN_LIB_X86_MSR_H */
>>
>> Just two nits: I think it would be nice to retain a blank line ahead of
>> the #endif. And here as well as in the CPUID counterpart you introduce,
>> strictly speaking, name space violations (via the leading underscore).
> 
> I guess another option would be to name the function
> x86_msr_get_entry_const, and keep the x86_msr_get_entry macro as-is.
> 
> Does that seem better?

This would be fine with me, as would be a trailing underscore or a
double underscore after e.g. the first name component.

Jan


^ permalink raw reply	[flat|nested] 15+ messages in thread

end of thread, other threads:[~2021-05-18 11:29 UTC | newest]

Thread overview: 15+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-05-07 11:04 [PATCH v4 00/10] libs/guest: new CPUID/MSR interface Roger Pau Monne
2021-05-07 11:04 ` [PATCH v4 01/10] libx86: introduce helper to fetch cpuid leaf Roger Pau Monne
2021-05-07 11:04 ` [PATCH v4 02/10] libs/guest: allow fetching a specific CPUID leaf from a cpu policy Roger Pau Monne
2021-05-07 11:04 ` [PATCH v4 03/10] libx86: introduce helper to fetch msr entry Roger Pau Monne
2021-05-17 15:43   ` Jan Beulich
2021-05-18 10:50     ` Roger Pau Monné
2021-05-18 11:29       ` Jan Beulich
2021-05-07 11:04 ` [PATCH v4 04/10] libs/guest: allow fetching a specific MSR entry from a cpu policy Roger Pau Monne
2021-05-07 11:04 ` [PATCH v4 05/10] libs/guest: make a cpu policy compatible with older Xen versions Roger Pau Monne
2021-05-07 11:04 ` [PATCH v4 06/10] libs/guest: introduce helper set cpu topology in cpu policy Roger Pau Monne
2021-05-07 11:04 ` [PATCH v4 07/10] libs/guest: rework xc_cpuid_xend_policy Roger Pau Monne
2021-05-07 11:04 ` [PATCH v4 08/10] libs/guest: apply a featureset into a cpu policy Roger Pau Monne
2021-05-07 11:04 ` [PATCH v4 09/10] libs/{light,guest}: implement xc_cpuid_apply_policy in libxl Roger Pau Monne
2021-05-14  9:36   ` Roger Pau Monné
2021-05-07 11:04 ` [PATCH v4 10/10] libs/guest: (re)move xc_cpu_policy_apply_cpuid Roger Pau Monne

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