[Xen-devel] [PATCH v4 2/6] microcode: save all microcodes which pass sanity check

[Chao Gao <chao.gao@xxxxxxxxx>]

... and search caches to find a suitable one when loading.

With this cache, the existing 'uci->mc' structure is redundent.
I deliberately avoid touching 'uci->mc' as I am going to remove
it completely in the next patch.

Signed-off-by: Chao Gao <chao.gao@xxxxxxxxx>
---
 xen/arch/x86/microcode.c        |  2 +
 xen/arch/x86/microcode_amd.c    | 93 +++++++++++++++++++++++++++++++++++---
 xen/arch/x86/microcode_intel.c  | 99 ++++++++++++++++++++++++++++++++++++++---
 xen/include/asm-x86/microcode.h | 11 +++++
 4 files changed, 193 insertions(+), 12 deletions(-)

diff --git a/xen/arch/x86/microcode.c b/xen/arch/x86/microcode.c
index 4163f50..4f2db88 100644
--- a/xen/arch/x86/microcode.c
+++ b/xen/arch/x86/microcode.c
@@ -61,6 +61,8 @@ static struct ucode_mod_blob __initdata ucode_blob;
  */
 static bool_t __initdata ucode_scan;
 
+LIST_HEAD(microcode_cache);
+
 void __init microcode_set_module(unsigned int idx)
 {
     ucode_mod_idx = idx;
diff --git a/xen/arch/x86/microcode_amd.c b/xen/arch/x86/microcode_amd.c
index fba44cc..a686a87 100644
--- a/xen/arch/x86/microcode_amd.c
+++ b/xen/arch/x86/microcode_amd.c
@@ -190,22 +190,90 @@ static bool_t microcode_fits(const struct microcode_amd 
*mc_amd,
     return 1;
 }
 
+static struct ucode_patch *alloc_ucode_patch(struct microcode_amd *mc_amd)
+{
+    struct ucode_patch *ucode_patch = xmalloc(struct ucode_patch);
+    struct microcode_amd *cache = xmalloc(struct microcode_amd);
+    void *mpb = xmalloc_bytes(mc_amd->mpb_size);
+    struct equiv_cpu_entry *equiv_cpu_table =
+                                xmalloc_bytes(mc_amd->equiv_cpu_table_size);
+
+    if ( !ucode_patch || !cache || !mpb || !equiv_cpu_table )
+        return ERR_PTR(-ENOMEM);
+
+    memcpy(cache->equiv_cpu_table, mc_amd->equiv_cpu_table,
+           mc_amd->equiv_cpu_table_size);
+    memcpy(cache->mpb, mc_amd->mpb, mc_amd->mpb_size);
+    cache->equiv_cpu_table_size = mc_amd->equiv_cpu_table_size;
+    cache->mpb_size = mc_amd->mpb_size;
+    ucode_patch->data = cache;
+    return ucode_patch;
+}
+
+static void free_ucode_patch(struct ucode_patch *ucode_patch)
+{
+    struct microcode_amd *mc_amd = ucode_patch->data;
+
+    xfree(mc_amd->equiv_cpu_table);
+    xfree(mc_amd->mpb);
+    xfree(mc_amd);
+    xfree(ucode_patch);
+}
+
+/*
+ * save a micrcode to the cache list
+ * return 1: added successfully
+ *        0: replaced an existing entry
+ *       -1: failed as a newer microcode was already cached
+ */
+static int save_patch(struct ucode_patch *new_patch)
+{
+    struct ucode_patch *ucode_patch;
+    struct microcode_amd *new_mc = new_patch->data;
+    struct microcode_header_amd *new_header = new_mc->mpb;
+
+    list_for_each_entry(ucode_patch, &microcode_cache, list)
+    {
+        struct microcode_amd *old_mc = ucode_patch->data;
+        struct microcode_header_amd *old_header = old_mc->mpb;
+
+        if ( new_header->processor_rev_id == old_header->processor_rev_id )
+        {
+            if ( new_header->patch_id <= old_header->patch_id )
+                return -1;
+            list_replace(&ucode_patch->list, &new_patch->list);
+            free_ucode_patch(ucode_patch);
+            return 0;
+        }
+    }
+    list_add_tail(&new_patch->list, &microcode_cache);
+    return 1;
+}
+
+static struct microcode_header_amd *find_patch(unsigned int cpu)
+{
+    struct ucode_patch *ucode_patch;
+
+    list_for_each_entry(ucode_patch, &microcode_cache, list)
+    {
+        if ( microcode_fits(ucode_patch->data, cpu) )
+            return ((struct microcode_amd *)ucode_patch->data)->mpb;
+    }
+    return NULL;
+}
+
 static int apply_microcode(unsigned int cpu)
 {
     unsigned long flags;
     struct ucode_cpu_info *uci = &per_cpu(ucode_cpu_info, cpu);
     uint32_t rev;
-    struct microcode_amd *mc_amd = uci->mc.mc_amd;
     struct microcode_header_amd *hdr;
     int hw_err;
 
     /* We should bind the task to the CPU */
     BUG_ON(raw_smp_processor_id() != cpu);
 
-    if ( mc_amd == NULL )
-        return -EINVAL;
-
-    hdr = mc_amd->mpb;
+    hdr = find_patch(cpu);
     if ( hdr == NULL )
         return -EINVAL;
 
@@ -491,6 +559,21 @@ static int cpu_request_microcode(unsigned int cpu, const 
void *buf,
     while ( (error = get_ucode_from_buffer_amd(mc_amd, buf, bufsize,
                                                &offset)) == 0 )
     {
+        struct ucode_patch *ucode_patch;
+
+        /*
+         * Save this microcode before checking the signature. It is to
+         * optimize microcode update on a mixed family system. Parsing
+         * microcode file is only done once on one of the CPUs, and
+         * during this process microcode cache is created. Other CPUs
+         * needn't parse the same micrcode file again and again.
+         * Instead, they just load the matched and latest microcode in
+         * the caches.
+         */
+        ucode_patch = alloc_ucode_patch(mc_amd);
+        if ( !IS_ERR_OR_NULL(ucode_patch) && (save_patch(ucode_patch) < 0) )
+            free_ucode_patch(ucode_patch);
+
         if ( microcode_fits(mc_amd, cpu) )
         {
             error = apply_microcode(cpu);
diff --git a/xen/arch/x86/microcode_intel.c b/xen/arch/x86/microcode_intel.c
index 8d9a3b2..c4f812f 100644
--- a/xen/arch/x86/microcode_intel.c
+++ b/xen/arch/x86/microcode_intel.c
@@ -251,6 +251,42 @@ static int microcode_sanity_check(void *mc)
 }
 
 /*
+ * save a micrcode to the cache list
+ * return 1: added successfully
+ *        0: replaced an existing entry
+ *       -1: failed as a newer microcode was already cached
+ */
+static int save_patch(struct ucode_patch *new_patch)
+{
+    void *mc;
+    struct ucode_patch *ucode_patch;
+
+    ASSERT(new_patch);
+
+    mc = new_patch->data;
+    list_for_each_entry(ucode_patch, &microcode_cache, list)
+    {
+        struct microcode_header_intel *saved_header = ucode_patch->data;
+        int ret;
+
+        ret = microcode_update_match(mc, saved_header->sig, saved_header->pf,
+                                     saved_header->rev);
+        if ( ret == OLD_UCODE )
+            return -1;
+        if ( ret == MIS_UCODE )
+            continue;
+
+        list_replace(&ucode_patch->list, &new_patch->list);
+        xfree(ucode_patch->data);
+        xfree(ucode_patch);
+        return 0;
+    }
+
+    list_add_tail(&new_patch->list, &microcode_cache);
+    return 1;
+}
+
+/*
  * return 0 - no update found
  * return 1 - found update
  * return < 0 - error
@@ -261,6 +297,30 @@ static int get_matching_microcode(const void *mc, unsigned 
int cpu)
     const struct microcode_header_intel *mc_header = mc;
     unsigned long total_size = get_totalsize(mc_header);
     void *new_mc;
+    struct ucode_patch *ucode_patch = xmalloc(struct ucode_patch);
+    void *new_mc2 = xmalloc_bytes(total_size);
+
+    /*
+     * Save this microcode before checking the signature. It is to
+     * optimize microcode update on a mixed family system. Parsing
+     * microcode file is only done once on one of the CPUs, and
+     * during this process microcode cache is created. Other CPUs
+     * needn't parse the same micrcode file again and again.
+     * Instead, they just load the matched and latest microcode in
+     * the caches.
+     */
+    if ( !ucode_patch || !new_mc2 )
+    {
+        printk(KERN_ERR "microcode: error! Can not allocate memory\n");
+        return -ENOMEM;
+    }
+    memcpy(new_mc2, mc, total_size);
+    ucode_patch->data = new_mc2;
+    if ( save_patch(ucode_patch) < 0 )
+    {
+        xfree(new_mc2);
+        xfree(ucode_patch);
+    }
 
     if ( microcode_update_match(mc, uci->cpu_sig.sig, uci->cpu_sig.pf,
                                 uci->cpu_sig.rev) != NEW_UCODE )
@@ -282,6 +342,29 @@ static int get_matching_microcode(const void *mc, unsigned 
int cpu)
     return 1;
 }
 
+static struct microcode_intel *find_patch(unsigned int cpu)
+{
+    int err;
+    struct ucode_cpu_info *uci = &per_cpu(ucode_cpu_info, cpu);
+    struct ucode_patch *ucode_patch;
+
+    err = collect_cpu_info(cpu, &uci->cpu_sig);
+    if ( unlikely(err) )
+    {
+        memset(uci, 0, sizeof(*uci));
+        return ERR_PTR(err);
+    }
+
+    list_for_each_entry(ucode_patch, &microcode_cache, list)
+    {
+        int ret = microcode_update_match(ucode_patch->data, uci->cpu_sig.sig,
+                                         uci->cpu_sig.pf, uci->cpu_sig.rev);
+        if (ret == NEW_UCODE)
+            return ucode_patch->data;
+    }
+    return NULL;
+}
+
 static int apply_microcode(unsigned int cpu)
 {
     unsigned long flags;
@@ -289,18 +372,20 @@ static int apply_microcode(unsigned int cpu)
     unsigned int val[2];
     unsigned int cpu_num = raw_smp_processor_id();
     struct ucode_cpu_info *uci = &per_cpu(ucode_cpu_info, cpu_num);
+    struct microcode_intel *mc_intel;
 
     /* We should bind the task to the CPU */
     BUG_ON(cpu_num != cpu);
 
-    if ( uci->mc.mc_intel == NULL )
+    mc_intel = find_patch(cpu);
+    if ( mc_intel == NULL )
         return -EINVAL;
 
     /* serialize access to the physical write to MSR 0x79 */
     spin_lock_irqsave(&microcode_update_lock, flags);
 
     /* write microcode via MSR 0x79 */
-    wrmsrl(MSR_IA32_UCODE_WRITE, (unsigned long)uci->mc.mc_intel->bits);
+    wrmsrl(MSR_IA32_UCODE_WRITE, (unsigned long)mc_intel->bits);
     wrmsrl(MSR_IA32_UCODE_REV, 0x0ULL);
 
     /* As documented in the SDM: Do a CPUID 1 here */
@@ -311,19 +396,19 @@ static int apply_microcode(unsigned int cpu)
     val[1] = (uint32_t)(msr_content >> 32);
 
     spin_unlock_irqrestore(&microcode_update_lock, flags);
-    if ( val[1] != uci->mc.mc_intel->hdr.rev )
+    if ( val[1] != mc_intel->hdr.rev )
     {
         printk(KERN_ERR "microcode: CPU%d update from revision "
                "%#x to %#x failed. Resulting revision is %#x.\n", cpu_num,
-               uci->cpu_sig.rev, uci->mc.mc_intel->hdr.rev, val[1]);
+               uci->cpu_sig.rev, mc_intel->hdr.rev, val[1]);
         return -EIO;
     }
     printk(KERN_INFO "microcode: CPU%d updated from revision "
            "%#x to %#x, date = %04x-%02x-%02x \n",
            cpu_num, uci->cpu_sig.rev, val[1],
-           uci->mc.mc_intel->hdr.date & 0xffff,
-           uci->mc.mc_intel->hdr.date >> 24,
-           (uci->mc.mc_intel->hdr.date >> 16) & 0xff);
+           mc_intel->hdr.date & 0xffff,
+           mc_intel->hdr.date >> 24,
+           (mc_intel->hdr.date >> 16) & 0xff);
     uci->cpu_sig.rev = val[1];
 
     return 0;
diff --git a/xen/include/asm-x86/microcode.h b/xen/include/asm-x86/microcode.h
index 23ea954..0236425 100644
--- a/xen/include/asm-x86/microcode.h
+++ b/xen/include/asm-x86/microcode.h
@@ -1,6 +1,7 @@
 #ifndef ASM_X86__MICROCODE_H
 #define ASM_X86__MICROCODE_H
 
+#include <xen/list.h>
 #include <xen/percpu.h>
 
 struct cpu_signature;
@@ -30,7 +31,17 @@ struct ucode_cpu_info {
     } mc;
 };
 
+struct ucode_patch {
+    struct list_head list;
+    void *data;
+    uint32_t patch_id;
+    uint16_t equiv_cpu;
+    void * equiv_cpu_table;
+    size_t equiv_cpu_table_size;
+};
+
 DECLARE_PER_CPU(struct ucode_cpu_info, ucode_cpu_info);
 extern const struct microcode_ops *microcode_ops;
+extern struct list_head microcode_cache;
 
 #endif /* ASM_X86__MICROCODE_H */
-- 
1.8.3.1


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