[Xen-devel] [PATCH v9 06/25] x86: refactor psr: L3 CAT: implement Domain init/free and schedule flows.

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

This patch implements the Domain init/free and schedule flows.
- When domain init, its psr resource should be allocated.
- When domain free, its psr resource should be freed too.
- When domain is scheduled, its COS ID on the socket should be
  set into ASSOC register to make corresponding COS MSR value
  work.

Signed-off-by: Yi Sun <yi.y.sun@xxxxxxxxxxxxxxx>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
---
v9:
    - rename 'l3_cat_get_cos_max' to 'cat_get_cos_max' to cover all CAT/CDP
      features.
      (suggested by Roger Pau)
    - replace feature list handling to feature array handling.
      (suggested by Roger Pau)
    - implement 'psr_alloc_cos' to match 'psr_free_cos'.
      (suggested by Wei Liu)
    - use 'psr_alloc_feat_enabled'.
      (suggested by Wei Liu)
    - fix coding style issue.
      (suggested by Wei Liu)
    - remove 'inline'.
      (suggested by Jan Beulich)
    - modify patch title to indicate 'L3 CAT'.
      (suggested by Jan Beulich)
    - remove 'psr_cos_ids' check in 'psr_free_cos'.
      (suggested by Jan Beulich)
v6:
    - change 'PSR_ASSOC_REG_POS' to 'PSR_ASSOC_REG_SHIFT'.
      (suggested by Konrad Rzeszutek Wilk)
v5:
    - rename 'feat_tmp' to 'feat'.
      (suggested by Jan Beulich)
    - define 'PSR_ASSOC_REG_POS'.
      (suggested by Jan Beulich)
v4:
    - create this patch to make codes easier to understand.
      (suggested by Jan Beulich)
---
 xen/arch/x86/psr.c | 77 +++++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 74 insertions(+), 3 deletions(-)

diff --git a/xen/arch/x86/psr.c b/xen/arch/x86/psr.c
index 66a9ce8..a6a8081 100644
--- a/xen/arch/x86/psr.c
+++ b/xen/arch/x86/psr.c
@@ -50,6 +50,8 @@
  */
 #define MAX_COS_REG_CNT  128
 
+#define PSR_ASSOC_REG_SHIFT 32
+
 /* CAT features use 1 COS register in one access. */
 #define CAT_COS_NUM      1
 
@@ -233,8 +235,14 @@ static void cat_init_feature(struct cpuid_leaf regs,
     return;
 }
 
+static unsigned int cat_get_cos_max(const struct feat_node *feat)
+{
+    return feat->info.cat_info.cos_max;
+}
+
 /* L3 CAT ops */
 static const struct feat_ops l3_cat_ops = {
+    .get_cos_max = cat_get_cos_max,
 };
 
 static void __init parse_psr_bool(char *s, char *value, char *feature,
@@ -378,11 +386,39 @@ void psr_free_rmid(struct domain *d)
     d->arch.psr_rmid = 0;
 }
 
-static inline void psr_assoc_init(void)
+static unsigned int get_max_cos_max(const struct psr_socket_info *info)
+{
+    const struct feat_node *feat;
+    unsigned int cos_max = 0, i;
+
+    for ( i = 0; i < PSR_SOCKET_MAX_FEAT; i++ )
+    {
+        feat = info->features[i];
+        if ( !feat )
+            continue;
+
+        cos_max = max(feat->ops.get_cos_max(feat), cos_max);
+    }
+
+    return cos_max;
+}
+
+static void psr_assoc_init(void)
 {
     struct psr_assoc *psra = &this_cpu(psr_assoc);
 
-    if ( psr_cmt_enabled() )
+    if ( psr_alloc_feat_enabled() )
+    {
+        unsigned int socket = cpu_to_socket(smp_processor_id());
+        const struct psr_socket_info *info = socket_info + socket;
+        unsigned int cos_max = get_max_cos_max(info);
+
+        if ( info->feat_mask )
+            psra->cos_mask = ((1ull << get_count_order(cos_max)) - 1) <<
+                             PSR_ASSOC_REG_SHIFT;
+    }
+
+    if ( psr_cmt_enabled() || psra->cos_mask )
         rdmsrl(MSR_IA32_PSR_ASSOC, psra->val);
 }
 
@@ -391,6 +427,13 @@ static inline void psr_assoc_rmid(uint64_t *reg, unsigned 
int rmid)
     *reg = (*reg & ~rmid_mask) | (rmid & rmid_mask);
 }
 
+static void psr_assoc_cos(uint64_t *reg, unsigned int cos,
+                          uint64_t cos_mask)
+{
+    *reg = (*reg & ~cos_mask) |
+            (((uint64_t)cos << PSR_ASSOC_REG_SHIFT) & cos_mask);
+}
+
 void psr_ctxt_switch_to(struct domain *d)
 {
     struct psr_assoc *psra = &this_cpu(psr_assoc);
@@ -399,6 +442,11 @@ void psr_ctxt_switch_to(struct domain *d)
     if ( psr_cmt_enabled() )
         psr_assoc_rmid(&reg, d->arch.psr_rmid);
 
+    if ( psra->cos_mask )
+        psr_assoc_cos(&reg, d->arch.psr_cos_ids ?
+                      d->arch.psr_cos_ids[cpu_to_socket(smp_processor_id())] :
+                      0, psra->cos_mask);
+
     if ( reg != psra->val )
     {
         wrmsrl(MSR_IA32_PSR_ASSOC, reg);
@@ -424,14 +472,37 @@ int psr_set_l3_cbm(struct domain *d, unsigned int socket,
     return 0;
 }
 
-int psr_domain_init(struct domain *d)
+/* Called with domain lock held, no extra lock needed for 'psr_cos_ids' */
+static void psr_free_cos(struct domain *d)
+{
+    xfree(d->arch.psr_cos_ids);
+    d->arch.psr_cos_ids = NULL;
+}
+
+static int psr_alloc_cos(struct domain *d)
 {
+    d->arch.psr_cos_ids = xzalloc_array(unsigned int, nr_sockets);
+    if ( !d->arch.psr_cos_ids )
+        return -ENOMEM;
+
     return 0;
 }
 
+int psr_domain_init(struct domain *d)
+{
+    /* Init to success value */
+    int ret = 0;
+
+    if ( psr_alloc_feat_enabled() )
+        ret = psr_alloc_cos(d);
+
+    return ret;
+}
+
 void psr_domain_free(struct domain *d)
 {
     psr_free_rmid(d);
+    psr_free_cos(d);
 }
 
 static void __init init_psr(void)
-- 
1.9.1


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