[Xen-devel] [PATCH v10 04/16] microcode: clean up microcode_resume_cpu

[Chao Gao <chao.gao@xxxxxxxxx>]

Previously, a per-cpu ucode cache is maintained. Then each CPU had one
per-cpu update cache and there might be multiple versions of microcode.
Thus microcode_resume_cpu tried best to update microcode by loading
every update cache until a successful load.

But now the cache struct is simplified a lot and only a single ucode is
cached. a single invocation of ->apply_microcode() would load the cache
and make microcode updated.

Signed-off-by: Chao Gao <chao.gao@xxxxxxxxx>
Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
---
changes in v8:
 - new
 - separated from the following patch
---
 xen/arch/x86/microcode.c        | 40 ++---------------------------------
 xen/arch/x86/microcode_amd.c    | 47 -----------------------------------------
 xen/arch/x86/microcode_intel.c  |  6 ------
 xen/include/asm-x86/microcode.h |  1 -
 4 files changed, 2 insertions(+), 92 deletions(-)

diff --git a/xen/arch/x86/microcode.c b/xen/arch/x86/microcode.c
index e218a9d..922b94f 100644
--- a/xen/arch/x86/microcode.c
+++ b/xen/arch/x86/microcode.c
@@ -215,8 +215,6 @@ int microcode_resume_cpu(unsigned int cpu)
 {
     int err;
     struct ucode_cpu_info *uci = &per_cpu(ucode_cpu_info, cpu);
-    struct cpu_signature nsig;
-    unsigned int cpu2;
 
     if ( !microcode_ops )
         return 0;
@@ -224,42 +222,8 @@ int microcode_resume_cpu(unsigned int cpu)
     spin_lock(&microcode_mutex);
 
     err = microcode_ops->collect_cpu_info(cpu, &uci->cpu_sig);
-    if ( err )
-    {
-        __microcode_fini_cpu(cpu);
-        spin_unlock(&microcode_mutex);
-        return err;
-    }
-
-    if ( uci->mc.mc_valid )
-    {
-        err = microcode_ops->microcode_resume_match(cpu, uci->mc.mc_valid);
-        if ( err >= 0 )
-        {
-            if ( err )
-                err = microcode_ops->apply_microcode(cpu);
-            spin_unlock(&microcode_mutex);
-            return err;
-        }
-    }
-
-    nsig = uci->cpu_sig;
-    __microcode_fini_cpu(cpu);
-    uci->cpu_sig = nsig;
-
-    err = -EIO;
-    for_each_online_cpu ( cpu2 )
-    {
-        uci = &per_cpu(ucode_cpu_info, cpu2);
-        if ( uci->mc.mc_valid &&
-             microcode_ops->microcode_resume_match(cpu, uci->mc.mc_valid) > 0 )
-        {
-            err = microcode_ops->apply_microcode(cpu);
-            break;
-        }
-    }
-
-    __microcode_fini_cpu(cpu);
+    if ( likely(!err) )
+        err = microcode_ops->apply_microcode(cpu);
     spin_unlock(&microcode_mutex);
 
     return err;
diff --git a/xen/arch/x86/microcode_amd.c b/xen/arch/x86/microcode_amd.c
index 2dca1df..04b00aa 100644
--- a/xen/arch/x86/microcode_amd.c
+++ b/xen/arch/x86/microcode_amd.c
@@ -654,52 +654,6 @@ static int cpu_request_microcode(unsigned int cpu, const 
void *buf,
     return error;
 }
 
-static int microcode_resume_match(unsigned int cpu, const void *mc)
-{
-    struct ucode_cpu_info *uci = &per_cpu(ucode_cpu_info, cpu);
-    struct microcode_amd *mc_amd = uci->mc.mc_amd;
-    const struct microcode_amd *src = mc;
-
-    if ( microcode_fits(src, cpu) != NEW_UCODE )
-        return 0;
-
-    if ( src != mc_amd )
-    {
-        if ( mc_amd )
-        {
-            xfree(mc_amd->equiv_cpu_table);
-            xfree(mc_amd->mpb);
-            xfree(mc_amd);
-        }
-
-        mc_amd = xmalloc(struct microcode_amd);
-        uci->mc.mc_amd = mc_amd;
-        if ( !mc_amd )
-            return -ENOMEM;
-        mc_amd->equiv_cpu_table = xmalloc_bytes(src->equiv_cpu_table_size);
-        if ( !mc_amd->equiv_cpu_table )
-            goto err1;
-        mc_amd->mpb = xmalloc_bytes(src->mpb_size);
-        if ( !mc_amd->mpb )
-            goto err2;
-
-        mc_amd->equiv_cpu_table_size = src->equiv_cpu_table_size;
-        mc_amd->mpb_size = src->mpb_size;
-        memcpy(mc_amd->mpb, src->mpb, src->mpb_size);
-        memcpy(mc_amd->equiv_cpu_table, src->equiv_cpu_table,
-               src->equiv_cpu_table_size);
-    }
-
-    return 1;
-
-err2:
-    xfree(mc_amd->equiv_cpu_table);
-err1:
-    xfree(mc_amd);
-    uci->mc.mc_amd = NULL;
-    return -ENOMEM;
-}
-
 static int start_update(void)
 {
 #if CONFIG_HVM
@@ -719,7 +673,6 @@ static int start_update(void)
 }
 
 static const struct microcode_ops microcode_amd_ops = {
-    .microcode_resume_match           = microcode_resume_match,
     .cpu_request_microcode            = cpu_request_microcode,
     .collect_cpu_info                 = collect_cpu_info,
     .apply_microcode                  = apply_microcode,
diff --git a/xen/arch/x86/microcode_intel.c b/xen/arch/x86/microcode_intel.c
index eefc2d2..97f759e 100644
--- a/xen/arch/x86/microcode_intel.c
+++ b/xen/arch/x86/microcode_intel.c
@@ -455,13 +455,7 @@ static int cpu_request_microcode(unsigned int cpu, const 
void *buf,
     return error;
 }
 
-static int microcode_resume_match(unsigned int cpu, const void *mc)
-{
-    return get_matching_microcode(mc, cpu);
-}
-
 static const struct microcode_ops microcode_intel_ops = {
-    .microcode_resume_match           = microcode_resume_match,
     .cpu_request_microcode            = cpu_request_microcode,
     .collect_cpu_info                 = collect_cpu_info,
     .apply_microcode                  = apply_microcode,
diff --git a/xen/include/asm-x86/microcode.h b/xen/include/asm-x86/microcode.h
index 4d45401..da0b156 100644
--- a/xen/include/asm-x86/microcode.h
+++ b/xen/include/asm-x86/microcode.h
@@ -21,7 +21,6 @@ struct microcode_patch {
 };
 
 struct microcode_ops {
-    int (*microcode_resume_match)(unsigned int cpu, const void *mc);
     int (*cpu_request_microcode)(unsigned int cpu, const void *buf,
                                  size_t size);
     int (*collect_cpu_info)(unsigned int cpu, struct cpu_signature *csig);
-- 
1.8.3.1


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