[Xen-devel] [PATCH v9 11/15] microcode: unify loading update during CPU resuming and AP wakeup

[Chao Gao <chao.gao@xxxxxxxxx>]

Both are loading the cached patch. Since APs call the unified function,
microcode_update_one(), during wakeup, the 'start_update' parameter
which originally used to distinguish BSP and APs is redundant. So remove
this parameter.

Signed-off-by: Chao Gao <chao.gao@xxxxxxxxx>
---
Note that here is a functional change: resuming a CPU would call
->end_update() now while previously it wasn't. Not quite sure
whether it is correct.

Changes in v9:
 - return -EOPNOTSUPP rather than 0 if microcode_ops is NULL in
   microcode_update_one()
 - rebase and fix conflicts.

Changes in v8:
 - split out from the previous patch
---
 xen/arch/x86/acpi/power.c       |  2 +-
 xen/arch/x86/microcode.c        | 90 ++++++++++++++++++-----------------------
 xen/arch/x86/smpboot.c          |  5 +--
 xen/include/asm-x86/processor.h |  4 +-
 4 files changed, 44 insertions(+), 57 deletions(-)

diff --git a/xen/arch/x86/acpi/power.c b/xen/arch/x86/acpi/power.c
index 4f21903..24798d5 100644
--- a/xen/arch/x86/acpi/power.c
+++ b/xen/arch/x86/acpi/power.c
@@ -253,7 +253,7 @@ static int enter_state(u32 state)
 
     console_end_sync();
 
-    microcode_resume_cpu();
+    microcode_update_one();
 
     if ( !recheck_cpu_features(0) )
         panic("Missing previously available feature(s)\n");
diff --git a/xen/arch/x86/microcode.c b/xen/arch/x86/microcode.c
index a2febc7..bdd9c9f 100644
--- a/xen/arch/x86/microcode.c
+++ b/xen/arch/x86/microcode.c
@@ -203,24 +203,6 @@ static struct microcode_patch *parse_blob(const char *buf, 
uint32_t len)
     return NULL;
 }
 
-int microcode_resume_cpu(void)
-{
-    int err;
-    struct cpu_signature *sig = &this_cpu(cpu_sig);
-
-    if ( !microcode_ops )
-        return 0;
-
-    spin_lock(&microcode_mutex);
-
-    err = microcode_ops->collect_cpu_info(sig);
-    if ( likely(!err) )
-        err = microcode_ops->apply_microcode(microcode_cache);
-    spin_unlock(&microcode_mutex);
-
-    return err;
-}
-
 void microcode_free_patch(struct microcode_patch *microcode_patch)
 {
     microcode_ops->free_patch(microcode_patch->mc);
@@ -384,11 +366,29 @@ static int __init microcode_init(void)
 }
 __initcall(microcode_init);
 
-int __init early_microcode_update_cpu(bool start_update)
+/* Load a cached update to current cpu */
+int microcode_update_one(void)
+{
+    int rc;
+
+    if ( !microcode_ops )
+        return -EOPNOTSUPP;
+
+    rc = microcode_update_cpu(NULL);
+
+    if ( microcode_ops->end_update )
+        microcode_ops->end_update();
+
+    return rc;
+}
+
+/* BSP calls this function to parse ucode blob and then apply an update. */
+int __init early_microcode_update_cpu(void)
 {
     int rc = 0;
     void *data = NULL;
     size_t len;
+    struct microcode_patch *patch;
 
     if ( !microcode_ops )
         return -ENOSYS;
@@ -409,43 +409,33 @@ int __init early_microcode_update_cpu(bool start_update)
     if ( !data )
         return -ENOMEM;
 
-    if ( start_update )
-    {
-        struct microcode_patch *patch;
-
-        if ( microcode_ops->start_update )
-            rc = microcode_ops->start_update();
-
-        if ( rc )
-            return rc;
-
-        patch = parse_blob(data, len);
-        if ( IS_ERR(patch) )
-        {
-            printk(XENLOG_INFO "Parsing microcode blob error %ld\n",
-                   PTR_ERR(patch));
-            return PTR_ERR(patch);
-        }
+    if ( microcode_ops->start_update )
+        rc = microcode_ops->start_update();
 
-        if ( !patch )
-        {
-            printk(XENLOG_INFO "No ucode found. Update aborted!\n");
-            return -EINVAL;
-        }
+    if ( rc )
+        return rc;
 
-        spin_lock(&microcode_mutex);
-        rc = microcode_update_cache(patch);
-        spin_unlock(&microcode_mutex);
+    patch = parse_blob(data, len);
+    if ( IS_ERR(patch) )
+    {
+        printk(XENLOG_INFO "Parsing microcode blob error %ld\n",
+               PTR_ERR(patch));
+        return PTR_ERR(patch);
+    }
 
-        ASSERT(rc);
+    if ( !patch )
+    {
+        printk(XENLOG_INFO "No ucode found. Update aborted!\n");
+        return -EINVAL;
     }
 
-    rc = microcode_update_cpu(NULL);
+    spin_lock(&microcode_mutex);
+    rc = microcode_update_cache(patch);
+    spin_unlock(&microcode_mutex);
 
-    if ( microcode_ops->end_update )
-        microcode_ops->end_update();
+    ASSERT(rc);
 
-    return rc;
+    return microcode_update_one();
 }
 
 int __init early_microcode_init(void)
@@ -465,7 +455,7 @@ int __init early_microcode_init(void)
         microcode_ops->collect_cpu_info(&this_cpu(cpu_sig));
 
         if ( ucode_mod.mod_end || ucode_blob.size )
-            rc = early_microcode_update_cpu(true);
+            rc = early_microcode_update_cpu();
     }
 
     return rc;
diff --git a/xen/arch/x86/smpboot.c b/xen/arch/x86/smpboot.c
index c818cfc..e62a1ca 100644
--- a/xen/arch/x86/smpboot.c
+++ b/xen/arch/x86/smpboot.c
@@ -361,10 +361,7 @@ void start_secondary(void *unused)
 
     initialize_cpu_data(cpu);
 
-    if ( system_state <= SYS_STATE_smp_boot )
-        early_microcode_update_cpu(false);
-    else
-        microcode_resume_cpu();
+    microcode_update_one();
 
     /*
      * If MSR_SPEC_CTRL is available, apply Xen's default setting and discard
diff --git a/xen/include/asm-x86/processor.h b/xen/include/asm-x86/processor.h
index 104faa9..2a76d90 100644
--- a/xen/include/asm-x86/processor.h
+++ b/xen/include/asm-x86/processor.h
@@ -568,9 +568,9 @@ int guest_wrmsr_xen(struct vcpu *v, uint32_t idx, uint64_t 
val);
 
 void microcode_set_module(unsigned int);
 int microcode_update(XEN_GUEST_HANDLE_PARAM(const_void), unsigned long len);
-int microcode_resume_cpu(void);
-int early_microcode_update_cpu(bool start_update);
+int early_microcode_update_cpu(void);
 int early_microcode_init(void);
+int microcode_update_one(void);
 int microcode_init_intel(void);
 int microcode_init_amd(void);
 
-- 
1.8.3.1


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