[Xen-devel] [PATCH v14 05/23] 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: Jan Beulich <jbeulich@xxxxxxxx>
---
v13:
    - modify macro name to be consistent.
      (suggested by Jan Beulich)
    - fix indenting issue.
      (suggested by Jan Beulich)
v12:
    - fix coding style issue.
      (suggested by Jan Beulich)
    - in 'get_max_cos_max', invert the condition and dropping 'continue'.
      (suggested by Jan Beulich)
    - modify 'psr_assoc_cos' to directly return 'reg' value.
      (suggested by Jan Beulich)
    - modify code style.
      (suggested by Jan Beulich)
    - do not break domain creation if 'psr_cos_ids' allocation fails.
      (suggested by Jan Beulich)
v11:
    - replace 'feat_init_done()' to 'feat_init' flag.
      (suggested by Jan Beulich)
    - adjust parameters positions when calling 'psr_assoc_cos'.
      (suggested by Jan Beulich)
    - add comment to explain why to check 'psr_cos_ids'.
v10:
    - remove 'cat_get_cos_max' as 'cos_max' is a feature property now which
      can be directly used.
      (suggested by Jan Beulich)
    - replace 'info->feat_mask' check to 'feat_init_done'.
      (suggested by Jan Beulich)
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/domain.c     |  3 +--
 xen/arch/x86/psr.c        | 67 ++++++++++++++++++++++++++++++++++++++++++++---
 xen/include/asm-x86/psr.h |  2 +-
 3 files changed, 65 insertions(+), 7 deletions(-)

diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index dd8bf13..b88ee75 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -495,8 +495,7 @@ int arch_domain_create(struct domain *d, unsigned int 
domcr_flags,
     }
     spin_lock_init(&d->arch.e820_lock);
 
-    if ( (rc = psr_domain_init(d)) != 0 )
-        goto fail;
+    psr_domain_init(d);
 
     if ( is_hvm_domain(d) )
     {
diff --git a/xen/arch/x86/psr.c b/xen/arch/x86/psr.c
index 39d8581..91bb1f0 100644
--- a/xen/arch/x86/psr.c
+++ b/xen/arch/x86/psr.c
@@ -50,6 +50,8 @@
  */
 #define MAX_COS_REG_CNT  128
 
+#define ASSOC_REG_SHIFT 32
+
 /*
  * Every PSR feature uses some COS registers for each COS ID, e.g. CDP uses 2
  * COS registers (DATA and CODE) for one COS ID, but CAT uses 1 COS register.
@@ -372,11 +374,37 @@ 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)
+{
+    unsigned int cos_max = 0, i;
+
+    for ( i = 0; i < ARRAY_SIZE(info->features); i++ )
+    {
+        const struct feat_node *feat = info->features[i];
+
+        if ( feat )
+            cos_max = max(feat->cos_max, 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_init )
+            psra->cos_mask = ((1ull << get_count_order(cos_max)) - 1) <<
+                             ASSOC_REG_SHIFT;
+    }
+
+    if ( psr_cmt_enabled() || psra->cos_mask )
         rdmsrl(MSR_IA32_PSR_ASSOC, psra->val);
 }
 
@@ -385,6 +413,13 @@ static inline void psr_assoc_rmid(uint64_t *reg, unsigned 
int rmid)
     *reg = (*reg & ~rmid_mask) | (rmid & rmid_mask);
 }
 
+static uint64_t psr_assoc_cos(uint64_t reg, unsigned int cos,
+                              uint64_t cos_mask)
+{
+    return (reg & ~cos_mask) |
+            (((uint64_t)cos << ASSOC_REG_SHIFT) & cos_mask);
+}
+
 void psr_ctxt_switch_to(struct domain *d)
 {
     struct psr_assoc *psra = &this_cpu(psr_assoc);
@@ -393,6 +428,14 @@ void psr_ctxt_switch_to(struct domain *d)
     if ( psr_cmt_enabled() )
         psr_assoc_rmid(&reg, d->arch.psr_rmid);
 
+    /* If domain's 'psr_cos_ids' is NULL, we set default value for it. */
+    if ( psra->cos_mask )
+        reg = 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);
@@ -418,14 +461,30 @@ 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)
 {
-    return 0;
+    xfree(d->arch.psr_cos_ids);
+    d->arch.psr_cos_ids = NULL;
+}
+
+static void psr_alloc_cos(struct domain *d)
+{
+    d->arch.psr_cos_ids = xzalloc_array(unsigned int, nr_sockets);
+    if ( !d->arch.psr_cos_ids )
+        printk(XENLOG_WARNING "Failed to alloc psr_cos_ids!\n");
+}
+
+void psr_domain_init(struct domain *d)
+{
+    if ( psr_alloc_feat_enabled() )
+        psr_alloc_cos(d);
 }
 
 void psr_domain_free(struct domain *d)
 {
     psr_free_rmid(d);
+    psr_free_cos(d);
 }
 
 static void __init init_psr(void)
diff --git a/xen/include/asm-x86/psr.h b/xen/include/asm-x86/psr.h
index 8141336..a17e31a 100644
--- a/xen/include/asm-x86/psr.h
+++ b/xen/include/asm-x86/psr.h
@@ -71,7 +71,7 @@ int psr_get_l3_cbm(struct domain *d, unsigned int socket,
 int psr_set_l3_cbm(struct domain *d, unsigned int socket,
                    uint64_t cbm, enum cbm_type type);
 
-int psr_domain_init(struct domain *d);
+void psr_domain_init(struct domain *d);
 void psr_domain_free(struct domain *d);
 
 #endif /* __ASM_PSR_H__ */
-- 
1.9.1


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