[Xen-devel] [PATCH v13 15/23] x86: refactor psr: CDP: implement set value callback function.

[Yi Sun <yi.y.sun@xxxxxxxxxxxxxxx>]

This patch implements L3 CDP set value related callback function.

With this patch, 'psr-cat-cbm-set' command can work for L3 CDP.

Signed-off-by: Yi Sun <yi.y.sun@xxxxxxxxxxxxxxx>
---
v13:
    - remove 'strict' from 'psr_cbm_type_to_feat_type' because we use 'alt_type'
      to check if we need set both DATA and CODE now.
      (suggested by Jan Beulich)
    - adjust the implementation in circle in 'insert_val_into_array' to make
      codes clearer to show how to decide the return value.
      (suggested by Jan Beulich)
v12:
    - add comment to explain how to deal with the case that user set new val
      for both DATA and CODE at same time.
    - add parameter for 'psr_cbm_type_to_feat_type' to return the feature type
      according to it.
    - use the feature type returned by 'psr_cbm_type_to_feat_type' to check
      if we need insert the new value into all items of the feature value array.
    - use conditional expression for wrmsrl.
      (suggested by Jan Beulich)
v11:
    - move 'feat->cos_reg_val' assignment and value comparison in 'write_msr'
      callback function out as generic codes.
      (suggested by Jan Beulich)
    - changes about setting both CDP DATA and CODE at same time.
    - move 'type[]' declaration into previous patch which introduced 'cos_num'.
      (suggested by Jan Beulich)
    - changes about 'type[]'.
      (suggested by Jan Beulich)
    - move 'compare_val' to previous patch.
      (suggested by Jan Beulich)
    - changes about 'get_val' which has been replace by generic codes.
      (suggested by Jan Beulich)
    - remove 'restore_default_val' which is unnecessary now.
      (suggested by Jan Beulich)
v10:
    - remove 'l3_cdp_get_old_val' and use 'l3_cdp_get_val' to replace it.
      (suggested by Jan Beulich)
    - remove 'l3_cdp_set_new_val'.
    - modify 'insert_val_to_array' flow to handle multiple COSs case.
      (suggested by Jan Beulich)
    - remove 'l3_cdp_compare_val' and implement a generic function
      'comapre_val'.
      (suggested by Jan Beulich)
    - remove 'l3_cdp_fits_cos_max'.
      (suggested by Jan Beulich)
    - introduce macro 'PSR_MAX_COS_NUM'.
    - introduce a new member in 'feat_props', 'type[PSR_MAX_COS_NUM]' to record
      all 'cbm_type' the feature has.
      (suggested by Jan Beulich)
    - modify 'gather_val_array' flow to handle multiple COSs case.
      (suggested by Jan Beulich)
    - modify 'find_cos' flow and implement 'compare_val' to handle multiple
      COSs case.
      (suggested by Jan Beulich)
    - modify 'fits_cos_max' flow to handle multiple COSs case.
      (suggested by Jan Beulich)
    - changes about 'props'.
      (suggested by Jan Beulich)
    - remove cast in 'l3_cdp_write_msr'.
      (suggested by Jan Beulich)
    - implement 'compare_val' function to compare if feature values are what
      we expect in finding flow.
    - implement 'restore_default_val' function to restore feature's COS values
      to default if the feature has multiple COSs. It is called when the COS
      ID is reduced to 0.
v9:
    - add comment to explain why CDP uses 2 COSs.
      (suggested by Wei Liu)
    - use 'cat_default_val'.
      (suggested by Wei Liu)
    - remove 'l3_cdp_get_cos_num' because we can directly get cos_num from
      feat_node now.
      (suggested by Jan Beulich)
    - remove cos checking because it has been moved to common function.
      (suggested by Jan Beulich)
    - l3_cdp_set_new_val parameter 'm' is changed to 'new_val'.
      (suggested by Jan Beulich)
    - directly use get_cdp_data(feat, 0) and get_cdp_code(feat, 0) to get
      default value.
      (suggested by Jan Beulich)
    - modify 'l3_cdp_write_msr' flow to write value into register according
      to input type.
    - changes about 'uint64_t' to 'uint32_t'.
      (suggested by Jan Beulich)
v8:
    - modify 'l3_cdp_write_msr' type to 'void'.
v5:
    - remove type check in callback function.
      (suggested by Jan Beulich)
    - modify return value of callback functions because we do not need them
      to return number of entries the feature uses. In caller, we call
      'get_cos_num' to get the number of entries the feature uses.
      (suggested by Jan Beulich)
    - remove 'l3_cdp_get_cos_max_from_type'.
    - rename 'l3_cdp_exceeds_cos_max' to 'l3_cdp_fits_cos_max'.
      (suggested by Jan Beulich)
v4:
    - create this patch to make codes easier to understand.
      (suggested by Jan Beulich)
---
 xen/arch/x86/psr.c | 27 +++++++++++++++++++++++----
 1 file changed, 23 insertions(+), 4 deletions(-)

diff --git a/xen/arch/x86/psr.c b/xen/arch/x86/psr.c
index 46b8d32..e831165 100644
--- a/xen/arch/x86/psr.c
+++ b/xen/arch/x86/psr.c
@@ -373,12 +373,21 @@ static bool l3_cdp_get_feat_info(const struct feat_node 
*feat,
     return true;
 }
 
+static void l3_cdp_write_msr(unsigned int cos, uint32_t val, enum cbm_type 
type)
+{
+    wrmsrl(((type == PSR_CBM_TYPE_L3_DATA) ?
+            MSR_IA32_PSR_L3_MASK_DATA(cos) :
+            MSR_IA32_PSR_L3_MASK_CODE(cos)),
+           val);
+}
+
 static const struct feat_props l3_cdp_props = {
     .cos_num = 2,
     .type[0] = PSR_CBM_TYPE_L3_DATA,
     .type[1] = PSR_CBM_TYPE_L3_CODE,
-    .alt_type = FEAT_TYPE_L3_CAT,
+    .alt_type = PSR_CBM_TYPE_L3,
     .get_feat_info = l3_cdp_get_feat_info,
+    .write_msr = l3_cdp_write_msr,
 };
 
 static void __init parse_psr_bool(char *s, char *value, char *feature,
@@ -824,17 +833,27 @@ static int insert_val_into_array(uint32_t val[],
     if ( !psr_check_cbm(feat->cbm_len, new_val) )
         return -EINVAL;
 
-    /* Value setting position is same as feature array. */
+    /*
+     * Value setting position is same as feature array.
+     * For CDP, user may set both DATA and CODE to same value. For such case,
+     * user input 'PSR_CBM_TYPE_L3' as type. The alternative type of CDP is 
same
+     * as it. So we should set new_val to both of DATA and CODE under such 
case.
+     */
     for ( i = 0; i < props->cos_num; i++ )
     {
         if ( type == props->type[i] )
         {
             val[i] = new_val;
-            return 0;
+            ret = 0;
+            break;
         }
+        else if ( type == props->alt_type )
+            val[i] = new_val;
+        else
+            ret = -EINVAL;
     }
 
-    return -EINVAL;
+    return ret;
 }
 
 static int compare_val(const uint32_t val[],
-- 
1.9.1


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