[Xen-devel] [PATCH v8 05/16] microcode/amd: distinguish old and mismatched ucode in microcode_fits()

[Chao Gao <chao.gao@xxxxxxxxx>]

Sometimes, an ucode with a level lower than or equal to current CPU's
patch level is useful. For example, to work around a broken bios which
only loads ucode for BSP, when BSP parses an ucode blob during bootup,
it is better to save an ucode with lower or equal level for APs

No functional change is made in this patch. But following patch would
handle "old ucode" and "mismatched ucode" separately.

Signed-off-by: Chao Gao <chao.gao@xxxxxxxxx>
---
Changes in v8:
 - new
---
 xen/arch/x86/microcode_amd.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/xen/arch/x86/microcode_amd.c b/xen/arch/x86/microcode_amd.c
index afca51f..e9a567f 100644
--- a/xen/arch/x86/microcode_amd.c
+++ b/xen/arch/x86/microcode_amd.c
@@ -152,8 +152,8 @@ static bool_t find_equiv_cpu_id(const struct 
equiv_cpu_entry *equiv_cpu_table,
     return 0;
 }
 
-static bool_t microcode_fits(const struct microcode_amd *mc_amd,
-                             unsigned int cpu)
+static enum microcode_match_result microcode_fits(
+    const struct microcode_amd *mc_amd, unsigned int cpu)
 {
     struct ucode_cpu_info *uci = &per_cpu(ucode_cpu_info, cpu);
     const struct microcode_header_amd *mc_header = mc_amd->mpb;
@@ -167,27 +167,27 @@ static bool_t microcode_fits(const struct microcode_amd 
*mc_amd,
     current_cpu_id = cpuid_eax(0x00000001);
 
     if ( !find_equiv_cpu_id(equiv_cpu_table, current_cpu_id, &equiv_cpu_id) )
-        return 0;
+        return MIS_UCODE;
 
     if ( (mc_header->processor_rev_id) != equiv_cpu_id )
-        return 0;
+        return MIS_UCODE;
 
     if ( !verify_patch_size(mc_amd->mpb_size) )
     {
         pr_debug("microcode: patch size mismatch\n");
-        return 0;
+        return MIS_UCODE;
     }
 
     if ( mc_header->patch_id <= uci->cpu_sig.rev )
     {
         pr_debug("microcode: patch is already at required level or 
greater.\n");
-        return 0;
+        return OLD_UCODE;
     }
 
     pr_debug("microcode: CPU%d found a matching microcode update with version 
%#x (current=%#x)\n",
              cpu, mc_header->patch_id, uci->cpu_sig.rev);
 
-    return 1;
+    return NEW_UCODE;
 }
 
 static int apply_microcode(unsigned int cpu)
@@ -502,7 +502,7 @@ static int cpu_request_microcode(unsigned int cpu, const 
void *buf,
     while ( (error = get_ucode_from_buffer_amd(mc_amd, buf, bufsize,
                                                &offset)) == 0 )
     {
-        if ( microcode_fits(mc_amd, cpu) )
+        if ( microcode_fits(mc_amd, cpu) == NEW_UCODE )
         {
             error = apply_microcode(cpu);
             if ( error )
@@ -583,7 +583,7 @@ static int microcode_resume_match(unsigned int cpu, const 
void *mc)
     struct microcode_amd *mc_amd = uci->mc.mc_amd;
     const struct microcode_amd *src = mc;
 
-    if ( !microcode_fits(src, cpu) )
+    if ( microcode_fits(src, cpu) != NEW_UCODE )
         return 0;
 
     if ( src != mc_amd )
-- 
1.8.3.1


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