[PATCH v2 08/15] x86: Drop struct old_cpu_policy

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

With all the complicated callers of x86_cpu_policies_are_compatible() updated
to use a single cpu_policy object, we can drop the final user of struct
old_cpu_policy.

Update x86_cpu_policies_are_compatible() to take (new) cpu_policy pointers,
reducing the amount of internal pointer chasing, and update all callers to
pass their cpu_policy objects directly.

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
---
CC: Jan Beulich <JBeulich@xxxxxxxx>
CC: Roger Pau Monné <roger.pau@xxxxxxxxxx>
CC: Wei Liu <wl@xxxxxxx>

v2:
 * Fix host/guest typo in xc_cpu_policy_is_compatible()
---
 tools/libs/guest/xg_cpuid_x86.c          |  4 +-
 tools/tests/cpu-policy/test-cpu-policy.c | 50 +++++++-----------------
 xen/arch/x86/domctl.c                    |  7 +---
 xen/include/xen/lib/x86/cpu-policy.h     | 12 ++----
 xen/lib/x86/policy.c                     | 12 +++---
 5 files changed, 27 insertions(+), 58 deletions(-)

diff --git a/tools/libs/guest/xg_cpuid_x86.c b/tools/libs/guest/xg_cpuid_x86.c
index 5061fe357767..259029be8b36 100644
--- a/tools/libs/guest/xg_cpuid_x86.c
+++ b/tools/libs/guest/xg_cpuid_x86.c
@@ -868,9 +868,7 @@ bool xc_cpu_policy_is_compatible(xc_interface *xch, 
xc_cpu_policy_t *host,
                                  xc_cpu_policy_t *guest)
 {
     struct cpu_policy_errors err = INIT_CPU_POLICY_ERRORS;
-    struct old_cpu_policy h = { &host->policy, &host->policy };
-    struct old_cpu_policy g = { &guest->policy, &guest->policy };
-    int rc = x86_cpu_policies_are_compatible(&h, &g, &err);
+    int rc = x86_cpu_policies_are_compatible(&host->policy, &guest->policy, 
&err);
 
     if ( !rc )
         return true;
diff --git a/tools/tests/cpu-policy/test-cpu-policy.c 
b/tools/tests/cpu-policy/test-cpu-policy.c
index 909d6272f875..a4ca07f33973 100644
--- a/tools/tests/cpu-policy/test-cpu-policy.c
+++ b/tools/tests/cpu-policy/test-cpu-policy.c
@@ -98,7 +98,7 @@ static bool msrs_are_sorted(const xen_msr_entry_t *entries, 
unsigned int nr)
 
 static void test_cpuid_current(void)
 {
-    struct cpuid_policy p;
+    struct cpu_policy p;
     xen_cpuid_leaf_t leaves[CPUID_MAX_SERIALISED_LEAVES];
     unsigned int nr = ARRAY_SIZE(leaves);
     int rc;
@@ -118,7 +118,7 @@ static void test_cpuid_current(void)
 static void test_cpuid_serialise_success(void)
 {
     static const struct test {
-        struct cpuid_policy p;
+        struct cpu_policy p;
         const char *name;
         unsigned int nr_leaves;
     } tests[] = {
@@ -242,7 +242,7 @@ static void test_cpuid_serialise_success(void)
 static void test_msr_serialise_success(void)
 {
     static const struct test {
-        struct msr_policy p;
+        struct cpu_policy p;
         const char *name;
         unsigned int nr_msrs;
     } tests[] = {
@@ -430,7 +430,7 @@ static void test_cpuid_out_of_range_clearing(void)
     static const struct test {
         const char *name;
         unsigned int nr_markers;
-        struct cpuid_policy p;
+        struct cpu_policy p;
     } tests[] = {
         {
             .name = "basic",
@@ -550,7 +550,7 @@ static void test_cpuid_out_of_range_clearing(void)
     for ( size_t i = 0; i < ARRAY_SIZE(tests); ++i )
     {
         const struct test *t = &tests[i];
-        struct cpuid_policy *p = memdup(&t->p);
+        struct cpu_policy *p = memdup(&t->p);
         void *ptr;
         unsigned int nr_markers;
 
@@ -574,23 +574,20 @@ static void test_is_compatible_success(void)
 {
     static struct test {
         const char *name;
-        struct cpuid_policy host_cpuid;
-        struct cpuid_policy guest_cpuid;
-        struct msr_policy host_msr;
-        struct msr_policy guest_msr;
+        struct cpu_policy host, guest;
     } tests[] = {
         {
             .name = "Host CPUID faulting, Guest not",
-            .host_msr = {
+            .host = {
                 .platform_info.cpuid_faulting = true,
             },
         },
         {
             .name = "Host CPUID faulting, Guest wanted",
-            .host_msr = {
+            .host = {
                 .platform_info.cpuid_faulting = true,
             },
-            .guest_msr = {
+            .guest = {
                 .platform_info.cpuid_faulting = true,
             },
         },
@@ -602,15 +599,8 @@ static void test_is_compatible_success(void)
     for ( size_t i = 0; i < ARRAY_SIZE(tests); ++i )
     {
         struct test *t = &tests[i];
-        struct old_cpu_policy sys = {
-            &t->host_cpuid,
-            &t->host_msr,
-        }, new = {
-            &t->guest_cpuid,
-            &t->guest_msr,
-        };
         struct cpu_policy_errors e;
-        int res = x86_cpu_policies_are_compatible(&sys, &new, &e);
+        int res = x86_cpu_policies_are_compatible(&t->host, &t->guest, &e);
 
         /* Check the expected error output. */
         if ( res != 0 || memcmp(&no_errors, &e, sizeof(no_errors)) )
@@ -624,25 +614,22 @@ static void test_is_compatible_failure(void)
 {
     static struct test {
         const char *name;
-        struct cpuid_policy host_cpuid;
-        struct cpuid_policy guest_cpuid;
-        struct msr_policy host_msr;
-        struct msr_policy guest_msr;
+        struct cpu_policy host, guest;
         struct cpu_policy_errors e;
     } tests[] = {
         {
             .name = "Host basic.max_leaf out of range",
-            .guest_cpuid.basic.max_leaf = 1,
+            .guest.basic.max_leaf = 1,
             .e = { 0, -1, -1 },
         },
         {
             .name = "Host extd.max_leaf out of range",
-            .guest_cpuid.extd.max_leaf = 1,
+            .guest.extd.max_leaf = 1,
             .e = { 0x80000000, -1, -1 },
         },
         {
             .name = "Host no CPUID faulting, Guest wanted",
-            .guest_msr = {
+            .guest = {
                 .platform_info.cpuid_faulting = true,
             },
             .e = { -1, -1, 0xce },
@@ -654,15 +641,8 @@ static void test_is_compatible_failure(void)
     for ( size_t i = 0; i < ARRAY_SIZE(tests); ++i )
     {
         struct test *t = &tests[i];
-        struct old_cpu_policy sys = {
-            &t->host_cpuid,
-            &t->host_msr,
-        }, new = {
-            &t->guest_cpuid,
-            &t->guest_msr,
-        };
         struct cpu_policy_errors e;
-        int res = x86_cpu_policies_are_compatible(&sys, &new, &e);
+        int res = x86_cpu_policies_are_compatible(&t->host, &t->guest, &e);
 
         /* Check the expected error output. */
         if ( res == 0 || memcmp(&t->e, &e, sizeof(t->e)) )
diff --git a/xen/arch/x86/domctl.c b/xen/arch/x86/domctl.c
index 81be25c67731..c02528594102 100644
--- a/xen/arch/x86/domctl.c
+++ b/xen/arch/x86/domctl.c
@@ -41,10 +41,9 @@ static int update_domain_cpu_policy(struct domain *d,
                                     xen_domctl_cpu_policy_t *xdpc)
 {
     struct cpu_policy *new;
-    struct cpu_policy *sys = is_pv_domain(d)
+    const struct cpu_policy *sys = is_pv_domain(d)
         ? (IS_ENABLED(CONFIG_PV)  ?  &pv_max_cpu_policy : NULL)
         : (IS_ENABLED(CONFIG_HVM) ? &hvm_max_cpu_policy : NULL);
-    struct old_cpu_policy old_sys = { sys, sys }, old_new;
     struct cpu_policy_errors err = INIT_CPU_POLICY_ERRORS;
     int ret = -ENOMEM;
 
@@ -58,8 +57,6 @@ static int update_domain_cpu_policy(struct domain *d,
     if ( !(new = xmemdup(d->arch.cpu_policy)) )
         goto out;
 
-    old_new = (struct old_cpu_policy){ new, new };
-
     /* Merge the toolstack provided data. */
     if ( (ret = x86_cpuid_copy_from_buffer(
               new, xdpc->leaves, xdpc->nr_leaves,
@@ -72,7 +69,7 @@ static int update_domain_cpu_policy(struct domain *d,
     x86_cpuid_policy_clear_out_of_range_leaves(new);
 
     /* Audit the combined dataset. */
-    ret = x86_cpu_policies_are_compatible(&old_sys, &old_new, &err);
+    ret = x86_cpu_policies_are_compatible(sys, new, &err);
     if ( ret )
         goto out;
 
diff --git a/xen/include/xen/lib/x86/cpu-policy.h 
b/xen/include/xen/lib/x86/cpu-policy.h
index 53fffca55211..8b27a0725b8e 100644
--- a/xen/include/xen/lib/x86/cpu-policy.h
+++ b/xen/include/xen/lib/x86/cpu-policy.h
@@ -379,12 +379,6 @@ struct cpu_policy
 #define cpuid_policy cpu_policy
 #define msr_policy cpu_policy
 
-struct old_cpu_policy
-{
-    struct cpuid_policy *cpuid;
-    struct msr_policy *msr;
-};
-
 struct cpu_policy_errors
 {
     uint32_t leaf, subleaf;
@@ -559,7 +553,7 @@ int x86_msr_copy_from_buffer(struct msr_policy *policy,
                              const msr_entry_buffer_t msrs, uint32_t 
nr_entries,
                              uint32_t *err_msr);
 
-/*
+/**
  * Calculate whether two policies are compatible.
  *
  * i.e. Can a VM configured with @guest run on a CPU supporting @host.
@@ -573,8 +567,8 @@ int x86_msr_copy_from_buffer(struct msr_policy *policy,
  * incompatibility is detected, the optional err pointer may identify the
  * problematic leaf/subleaf and/or MSR.
  */
-int x86_cpu_policies_are_compatible(const struct old_cpu_policy *host,
-                                    const struct old_cpu_policy *guest,
+int x86_cpu_policies_are_compatible(const struct cpu_policy *host,
+                                    const struct cpu_policy *guest,
                                     struct cpu_policy_errors *err);
 
 #endif /* !XEN_LIB_X86_POLICIES_H */
diff --git a/xen/lib/x86/policy.c b/xen/lib/x86/policy.c
index 2975711d7c6c..a9c60000af9d 100644
--- a/xen/lib/x86/policy.c
+++ b/xen/lib/x86/policy.c
@@ -2,8 +2,8 @@
 
 #include <xen/lib/x86/cpu-policy.h>
 
-int x86_cpu_policies_are_compatible(const struct old_cpu_policy *host,
-                                    const struct old_cpu_policy *guest,
+int x86_cpu_policies_are_compatible(const struct cpu_policy *host,
+                                    const struct cpu_policy *guest,
                                     struct cpu_policy_errors *err)
 {
     struct cpu_policy_errors e = INIT_CPU_POLICY_ERRORS;
@@ -15,18 +15,18 @@ int x86_cpu_policies_are_compatible(const struct 
old_cpu_policy *host,
 #define FAIL_MSR(m) \
     do { e.msr = (m); goto out; } while ( 0 )
 
-    if ( guest->cpuid->basic.max_leaf > host->cpuid->basic.max_leaf )
+    if ( guest->basic.max_leaf > host->basic.max_leaf )
         FAIL_CPUID(0, NA);
 
-    if ( guest->cpuid->feat.max_subleaf > host->cpuid->feat.max_subleaf )
+    if ( guest->feat.max_subleaf > host->feat.max_subleaf )
         FAIL_CPUID(7, 0);
 
-    if ( guest->cpuid->extd.max_leaf > host->cpuid->extd.max_leaf )
+    if ( guest->extd.max_leaf > host->extd.max_leaf )
         FAIL_CPUID(0x80000000, NA);
 
     /* TODO: Audit more CPUID data. */
 
-    if ( ~host->msr->platform_info.raw & guest->msr->platform_info.raw )
+    if ( ~host->platform_info.raw & guest->platform_info.raw )
         FAIL_MSR(MSR_INTEL_PLATFORM_INFO);
 
 #undef FAIL_MSR
-- 
2.30.2