[Xen-devel] [PATCH v14 16/23] x86: L2 CAT: implement CPU init flow.

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

This patch implements the CPU init flow for L2 CAT.

Signed-off-by: Yi Sun <yi.y.sun@xxxxxxxxxxxxxxx>
---
v14:
    - remove the 'Notes' in commit message because a stub function is
      implemented to avoid the potential issue.
      (suggested by Jan Beulich)
    - put address of 'feat_l2_cat' back to it if 'cat_init_feature()' fails
      to avoid leakage.
      (suggested by Jan Beulich)
    - change 'feat_name' to 'cat_feat_name' and move it into
      'cat_init_feature()' which is the only caller.
      (suggested by Jan Beulich)
    - register the callback functions into 'l2_cat_props' to avoid crash if
      user does not apply later patches.
      (suggested by Jan Beulich)
v13:
    - add commit message.
      (suggested by Jan Beulich)
    - set 'alt_type' for L2 CAT.
      (suggested by Jan Beulich)
    - define a static string array to show which feature's info is printing.
      (suggested by Jan Beulich)
v12:
    - move 'type[]' assignment into l2_cat_props declaration to make it be
      'const'.
      (suggested by Jan Beulich)
    - add "L2 CAT" indicator in printk.
      (suggested by Jan Beulich)
    - restore mask(0) MSR to default value.
      (suggested by Jan Beulich)
v11:
    - move l2 cat 'type[]' assignement into 'psr_cpu_init'.
    - remove COS MSR restore action in 'cpu_init_feature'.
    - set 'feat_init' to true after CPU init.
    - modify commit message.
v10:
    - implement L2 CAT case in 'cat_init_feature'.
      (suggested by Jan Beulich)
    - changes about 'props'.
      (suggested by Jan Beulich)
    - introduce 'PSR_CBM_TYPE_L2'.
v9:
    - modify error handling process in 'psr_cpu_prepare' to reduce redundant
      codes.
    - reuse 'cat_init_feature' and 'cat_get_cos_max' for L2 CAT to reduce
      redundant codes.
      (suggested by Roger Pau)
    - remove unnecessary comment.
      (suggested by Jan Beulich)
    - move L2 CAT related codes from 'cpu_init_work' into 'psr_cpu_init'.
      (suggested by Jan Beulich)
    - do not free resource when allocation fails in 'psr_cpu_prepare'.
      (suggested by Jan Beulich)
v7:
    - initialize 'l2_cat'.
      (suggested by Konrad Rzeszutek Wilk)
v6:
    - use 'struct cpuid_leaf'.
      (suggested by Konrad Rzeszutek Wilk and Jan Beulich)
v5:
    - remove 'feat_l2_cat' free in 'free_feature'.
      (suggested by Jan Beulich)
    - encapsulate cpuid registers into 'struct cpuid_leaf_regs'.
      (suggested by Jan Beulich)
    - print socket info when 'opt_cpu_info' is true.
      (suggested by Jan Beulich)
    - rename 'l2_cat_get_max_cos_max' to 'l2_cat_get_cos_max'.
      (suggested by Jan Beulich)
    - rename 'dat[]' to 'data[]'
      (suggested by Jan Beulich)
    - move 'cpu_prepare_work' contents into 'psr_cpu_prepare'.
      (suggested by Jan Beulich)
v4:
    - create this patch because of codes architecture change.
      (suggested by Jan Beulich)
---
 xen/arch/x86/psr.c              | 48 ++++++++++++++++++++++++++++++++++++++---
 xen/include/asm-x86/msr-index.h |  1 +
 xen/include/asm-x86/psr.h       |  2 ++
 3 files changed, 48 insertions(+), 3 deletions(-)

diff --git a/xen/arch/x86/psr.c b/xen/arch/x86/psr.c
index c211c77..320c2c7 100644
--- a/xen/arch/x86/psr.c
+++ b/xen/arch/x86/psr.c
@@ -63,6 +63,7 @@
 enum psr_feat_type {
     FEAT_TYPE_L3_CAT,
     FEAT_TYPE_L3_CDP,
+    FEAT_TYPE_L2_CAT,
     FEAT_TYPE_NUM,
     FEAT_TYPE_UNKNOWN,
 };
@@ -159,6 +160,7 @@ static DEFINE_PER_CPU(struct psr_assoc, psr_assoc);
  * array creation. It is used to transiently store a spare node.
  */
 static struct feat_node *feat_l3;
+static struct feat_node *feat_l2_cat;
 
 /* Common functions */
 #define cat_default_val(len) (0xffffffff >> (32 - (len)))
@@ -273,6 +275,12 @@ static int cat_init_feature(const struct cpuid_leaf *regs,
                             struct psr_socket_info *info,
                             enum psr_feat_type type)
 {
+    const char * const cat_feat_name[FEAT_TYPE_NUM] = {
+        "L3 CAT",
+        "CDP",
+        "L2 CAT",
+    };
+
     /* No valid value so do not enable feature. */
     if ( !regs->a || !regs->d )
         return -ENOENT;
@@ -283,13 +291,17 @@ static int cat_init_feature(const struct cpuid_leaf *regs,
     switch ( type )
     {
     case FEAT_TYPE_L3_CAT:
+    case FEAT_TYPE_L2_CAT:
         if ( feat->cos_max < 1 )
             return -ENOENT;
 
         /* We reserve cos=0 as default cbm (all bits within cbm_len are 1). */
         feat->cos_reg_val[0] = cat_default_val(feat->cbm_len);
 
-        wrmsrl(MSR_IA32_PSR_L3_MASK(0), cat_default_val(feat->cbm_len));
+        wrmsrl((type == FEAT_TYPE_L3_CAT ?
+                MSR_IA32_PSR_L3_MASK(0) :
+                MSR_IA32_PSR_L2_MASK(0)),
+               cat_default_val(feat->cbm_len));
 
         break;
 
@@ -327,8 +339,8 @@ static int cat_init_feature(const struct cpuid_leaf *regs,
         return 0;
 
     printk(XENLOG_INFO "%s: enabled on socket %u, cos_max:%u, cbm_len:%u\n",
-           ((type == FEAT_TYPE_L3_CDP) ? "CDP" : "L3 CAT"),
-           cpu_to_socket(smp_processor_id()), feat->cos_max, feat->cbm_len);
+           cat_feat_name[type], cpu_to_socket(smp_processor_id()),
+           feat->cos_max, feat->cbm_len);
 
     return 0;
 }
@@ -389,6 +401,19 @@ static const struct feat_props l3_cdp_props = {
     .write_msr = l3_cdp_write_msr,
 };
 
+/* L2 CAT props */
+static void l2_cat_write_msr(unsigned int cos, uint32_t val, enum cbm_type 
type)
+{
+}
+
+static const struct feat_props l2_cat_props = {
+    .cos_num = 1,
+    .type[0] = PSR_CBM_TYPE_L2,
+    .alt_type = PSR_CBM_TYPE_UNKNOWN,
+    .get_feat_info = cat_get_feat_info,
+    .write_msr = l2_cat_write_msr,
+};
+
 static void __init parse_psr_bool(char *s, char *value, char *feature,
                                   unsigned int mask)
 {
@@ -1343,6 +1368,10 @@ static int psr_cpu_prepare(void)
          (feat_l3 = xzalloc(struct feat_node)) == NULL )
         return -ENOMEM;
 
+    if ( feat_l2_cat == NULL &&
+         (feat_l2_cat = xzalloc(struct feat_node)) == NULL )
+        return -ENOMEM;
+
     return 0;
 }
 
@@ -1395,6 +1424,19 @@ static void psr_cpu_init(void)
         }
     }
 
+    cpuid_count_leaf(PSR_CPUID_LEVEL_CAT, 0, &regs);
+    if ( regs.b & PSR_RESOURCE_TYPE_L2 )
+    {
+        cpuid_count_leaf(PSR_CPUID_LEVEL_CAT, 2, &regs);
+
+        feat = feat_l2_cat;
+        feat_l2_cat = NULL;
+        if ( !cat_init_feature(&regs, feat, info, FEAT_TYPE_L2_CAT) )
+            feat_props[FEAT_TYPE_L2_CAT] = &l2_cat_props;
+        else
+            feat_l2_cat = feat;
+    }
+
     info->feat_init = true;
 
  assoc_init:
diff --git a/xen/include/asm-x86/msr-index.h b/xen/include/asm-x86/msr-index.h
index 756b23d..4e08de6 100644
--- a/xen/include/asm-x86/msr-index.h
+++ b/xen/include/asm-x86/msr-index.h
@@ -347,6 +347,7 @@
 #define MSR_IA32_PSR_L3_MASK(n)        (0x00000c90 + (n))
 #define MSR_IA32_PSR_L3_MASK_CODE(n)   (0x00000c90 + (n) * 2 + 1)
 #define MSR_IA32_PSR_L3_MASK_DATA(n)   (0x00000c90 + (n) * 2)
+#define MSR_IA32_PSR_L2_MASK(n)                (0x00000d10 + (n))
 
 /* Intel Model 6 */
 #define MSR_P6_PERFCTR(n)              (0x000000c1 + (n))
diff --git a/xen/include/asm-x86/psr.h b/xen/include/asm-x86/psr.h
index 50b8757..18a42f3 100644
--- a/xen/include/asm-x86/psr.h
+++ b/xen/include/asm-x86/psr.h
@@ -23,6 +23,7 @@
 
 /* Resource Type Enumeration */
 #define PSR_RESOURCE_TYPE_L3            0x2
+#define PSR_RESOURCE_TYPE_L2            0x4
 
 /* L3 Monitoring Features */
 #define PSR_CMT_L3_OCCUPANCY            0x1
@@ -56,6 +57,7 @@ enum cbm_type {
     PSR_CBM_TYPE_L3,
     PSR_CBM_TYPE_L3_CODE,
     PSR_CBM_TYPE_L3_DATA,
+    PSR_CBM_TYPE_L2,
     PSR_CBM_TYPE_UNKNOWN,
 };
 
-- 
1.9.1


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel