[PATCH v4 19/24] xen/domctl: wrap hvm_save{,load} with CONFIG_MGMT_HYPERCALLS

[Penny Zheng <Penny.Zheng@xxxxxxx>]

The following functions have been referenced in places which is either guarded
with CONFIG_MGMT_HYPERCALLS or CONFIG_MEM_SHARING:
- arch_hvm_save
- arch_hvm_check
- arch_hvm_load
- hvm_save_size
- hvm_save
- hvm_load
While CONFIG_MEM_SHARING is also dependent on CONFIG_MGMT_HYPERCALLS.
So they shall be wrapped under MGMT_HYPERCALLS, otherwise they will become
unreachable codes when MGMT_HYPERCALLS=n, and hence violating Misra rule 2.1.
We move arch_hvm_save(), arch_hvm_check(), arch_hvm_load() and hvm_save_size()
nearer to the left functions, to avoid scattered #ifdef-wrapping.

Signed-off-by: Penny Zheng <Penny.Zheng@xxxxxxx>
---
v3 -> v4
- new commit
---
 xen/arch/x86/hvm/save.c | 154 ++++++++++++++++++++--------------------
 1 file changed, 78 insertions(+), 76 deletions(-)

diff --git a/xen/arch/x86/hvm/save.c b/xen/arch/x86/hvm/save.c
index 8ab6405706..5e99dd5998 100644
--- a/xen/arch/x86/hvm/save.c
+++ b/xen/arch/x86/hvm/save.c
@@ -15,62 +15,6 @@
 
 #include <public/hvm/save.h>
 
-static void arch_hvm_save(struct domain *d, struct hvm_save_header *hdr)
-{
-    uint32_t eax, ebx, ecx, edx;
-
-    /* Save some CPUID bits */
-    cpuid(1, &eax, &ebx, &ecx, &edx);
-    hdr->cpuid = eax;
-
-    /* Save guest's preferred TSC. */
-    hdr->gtsc_khz = d->arch.tsc_khz;
-
-    /* Time when saving started */
-    d->arch.hvm.sync_tsc = rdtsc();
-}
-
-static int arch_hvm_check(const struct domain *d,
-                          const struct hvm_save_header *hdr)
-{
-    uint32_t eax, ebx, ecx, edx;
-
-    if ( hdr->magic != HVM_FILE_MAGIC )
-    {
-        printk(XENLOG_G_ERR "HVM%d restore: bad magic number %#"PRIx32"\n",
-               d->domain_id, hdr->magic);
-        return -EINVAL;
-    }
-
-    if ( hdr->version != HVM_FILE_VERSION )
-    {
-        printk(XENLOG_G_ERR "HVM%d restore: unsupported version %u\n",
-               d->domain_id, hdr->version);
-        return -EINVAL;
-    }
-
-    cpuid(1, &eax, &ebx, &ecx, &edx);
-    /* CPUs ought to match but with feature-masking they might not */
-    if ( (hdr->cpuid & ~0x0fUL) != (eax & ~0x0fUL) )
-        printk(XENLOG_G_INFO "HVM%d restore: VM saved on one CPU "
-               "(%#"PRIx32") and restored on another (%#"PRIx32").\n",
-               d->domain_id, hdr->cpuid, eax);
-
-    return 0;
-}
-
-static void arch_hvm_load(struct domain *d, const struct hvm_save_header *hdr)
-{
-    /* Restore guest's preferred TSC frequency. */
-    if ( hdr->gtsc_khz )
-        d->arch.tsc_khz = hdr->gtsc_khz;
-    if ( d->arch.vtsc )
-        hvm_set_rdtsc_exiting(d, 1);
-
-    /* Time when restore started  */
-    d->arch.hvm.sync_tsc = rdtsc();
-}
-
 /* List of handlers for various HVM save and restore types */
 static struct {
     hvm_save_handler save;
@@ -101,26 +45,6 @@ void __init hvm_register_savevm(uint16_t typecode,
     hvm_sr_handlers[typecode].kind = kind;
 }
 
-size_t hvm_save_size(struct domain *d)
-{
-    struct vcpu *v;
-    size_t sz;
-    int i;
-
-    /* Basic overhead for header and footer */
-    sz = (2 * sizeof (struct hvm_save_descriptor)) + HVM_SAVE_LENGTH(HEADER);
-
-    /* Plus space for each thing we will be saving */
-    for ( i = 0; i <= HVM_SAVE_CODE_MAX; i++ )
-        if ( hvm_sr_handlers[i].kind == HVMSR_PER_VCPU )
-            for_each_vcpu(d, v)
-                sz += hvm_sr_handlers[i].size;
-        else
-            sz += hvm_sr_handlers[i].size;
-
-    return sz;
-}
-
 /*
  * Extract a single instance of a save record, by marshalling all records of
  * that type and copying out the one we need.
@@ -196,6 +120,83 @@ int hvm_save_one(struct domain *d, unsigned int typecode, 
unsigned int instance,
     return rv;
 }
 
+#ifdef CONFIG_MGMT_HYPERCALLS
+static void arch_hvm_save(struct domain *d, struct hvm_save_header *hdr)
+{
+    uint32_t eax, ebx, ecx, edx;
+
+    /* Save some CPUID bits */
+    cpuid(1, &eax, &ebx, &ecx, &edx);
+    hdr->cpuid = eax;
+
+    /* Save guest's preferred TSC. */
+    hdr->gtsc_khz = d->arch.tsc_khz;
+
+    /* Time when saving started */
+    d->arch.hvm.sync_tsc = rdtsc();
+}
+
+static int arch_hvm_check(const struct domain *d,
+                          const struct hvm_save_header *hdr)
+{
+    uint32_t eax, ebx, ecx, edx;
+
+    if ( hdr->magic != HVM_FILE_MAGIC )
+    {
+        printk(XENLOG_G_ERR "HVM%d restore: bad magic number %#"PRIx32"\n",
+               d->domain_id, hdr->magic);
+        return -EINVAL;
+    }
+
+    if ( hdr->version != HVM_FILE_VERSION )
+    {
+        printk(XENLOG_G_ERR "HVM%d restore: unsupported version %u\n",
+               d->domain_id, hdr->version);
+        return -EINVAL;
+    }
+
+    cpuid(1, &eax, &ebx, &ecx, &edx);
+    /* CPUs ought to match but with feature-masking they might not */
+    if ( (hdr->cpuid & ~0x0fUL) != (eax & ~0x0fUL) )
+        printk(XENLOG_G_INFO "HVM%d restore: VM saved on one CPU "
+               "(%#"PRIx32") and restored on another (%#"PRIx32").\n",
+               d->domain_id, hdr->cpuid, eax);
+
+    return 0;
+}
+
+static void arch_hvm_load(struct domain *d, const struct hvm_save_header *hdr)
+{
+    /* Restore guest's preferred TSC frequency. */
+    if ( hdr->gtsc_khz )
+        d->arch.tsc_khz = hdr->gtsc_khz;
+    if ( d->arch.vtsc )
+        hvm_set_rdtsc_exiting(d, 1);
+
+    /* Time when restore started  */
+    d->arch.hvm.sync_tsc = rdtsc();
+}
+
+size_t hvm_save_size(struct domain *d)
+{
+    struct vcpu *v;
+    size_t sz;
+    unsigned int i;
+
+    /* Basic overhead for header and footer */
+    sz = (2 * sizeof (struct hvm_save_descriptor)) + HVM_SAVE_LENGTH(HEADER);
+
+    /* Plus space for each thing we will be saving */
+    for ( i = 0; i <= HVM_SAVE_CODE_MAX; i++ )
+        if ( hvm_sr_handlers[i].kind == HVMSR_PER_VCPU )
+            for_each_vcpu(d, v)
+                sz += hvm_sr_handlers[i].size;
+        else
+            sz += hvm_sr_handlers[i].size;
+
+    return sz;
+}
+
 int hvm_save(struct domain *d, hvm_domain_context_t *h)
 {
     char *c;
@@ -390,6 +391,7 @@ int hvm_load(struct domain *d, bool real, 
hvm_domain_context_t *h)
 
     /* Not reached */
 }
+#endif /* CONFIG_MGMT_HYPERCALLS */
 
 int _hvm_init_entry(struct hvm_domain_context *h, uint16_t tc, uint16_t inst,
                     uint32_t len)
-- 
2.34.1