[Xen-devel] [PATCH v9 04/13] x86: add COS information for each domain

[Chao Peng <chao.p.peng@xxxxxxxxxxxxxxx>]

In Xen's implementation, the CAT enforcement granularity is per domain.
Due to the length of CBM and the number of COS may be socket-different,
each domain has COS ID for each socket. The domain get COS=0 by default
and at runtime its COS is then allocated dynamically when user specifies
a CBM for the domain.

Signed-off-by: Chao Peng <chao.p.peng@xxxxxxxxxxxxxxx>
Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
Changes in v6:
* Add spinlock for cos_to_cbm.
---
 xen/arch/x86/domain.c        |  6 +++++-
 xen/arch/x86/psr.c           | 49 ++++++++++++++++++++++++++++++++++++++++++++
 xen/include/asm-x86/domain.h |  5 ++++-
 xen/include/asm-x86/psr.h    |  3 +++
 4 files changed, 61 insertions(+), 2 deletions(-)

diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index db073a6..0c4c43b 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -616,6 +616,9 @@ int arch_domain_create(struct domain *d, unsigned int 
domcr_flags,
         /* 64-bit PV guest by default. */
         d->arch.is_32bit_pv = d->arch.has_32bit_shinfo = 0;
 
+    if ( (rc = psr_domain_init(d)) != 0 )
+        goto fail;
+
     /* initialize default tsc behavior in case tools don't */
     tsc_set_info(d, TSC_MODE_DEFAULT, 0UL, 0, 0);
     spin_lock_init(&d->arch.vtsc_lock);
@@ -634,6 +637,7 @@ int arch_domain_create(struct domain *d, unsigned int 
domcr_flags,
     free_perdomain_mappings(d);
     if ( is_pv_domain(d) )
         free_xenheap_page(d->arch.pv_domain.gdt_ldt_l1tab);
+    psr_domain_free(d);
     return rc;
 }
 
@@ -657,7 +661,7 @@ void arch_domain_destroy(struct domain *d)
     free_xenheap_page(d->shared_info);
     cleanup_domain_irq_mapping(d);
 
-    psr_free_rmid(d);
+    psr_domain_free(d);
 }
 
 void arch_domain_shutdown(struct domain *d)
diff --git a/xen/arch/x86/psr.c b/xen/arch/x86/psr.c
index 2388121..bbb2485 100644
--- a/xen/arch/x86/psr.c
+++ b/xen/arch/x86/psr.c
@@ -30,6 +30,7 @@ struct psr_cat_socket_info {
     unsigned int cbm_len;
     unsigned int cos_max;
     struct psr_cat_cbm *cos_to_cbm;
+    spinlock_t cbm_lock;
 };
 
 struct psr_assoc {
@@ -215,6 +216,52 @@ void psr_ctxt_switch_to(struct domain *d)
     }
 }
 
+/* Called with domain lock held, no extra lock needed for 'psr_cos_ids' */
+static void psr_free_cos(struct domain *d)
+{
+    unsigned int socket;
+    unsigned int cos;
+    struct psr_cat_socket_info *info;
+
+    if( !d->arch.psr_cos_ids )
+        return;
+
+    for ( socket = 0; socket < nr_sockets; socket++ )
+    {
+        if ( !test_bit(socket, cat_socket_enable) )
+            continue;
+
+        if ( (cos = d->arch.psr_cos_ids[socket]) == 0 )
+            continue;
+
+        info = cat_socket_info + socket;
+        spin_lock(&info->cbm_lock);
+        info->cos_to_cbm[cos].ref--;
+        spin_unlock(&info->cbm_lock);
+    }
+
+    xfree(d->arch.psr_cos_ids);
+    d->arch.psr_cos_ids = NULL;
+}
+
+int psr_domain_init(struct domain *d)
+{
+    if ( cat_socket_info )
+    {
+        d->arch.psr_cos_ids = xzalloc_array(unsigned int, nr_sockets);
+        if ( !d->arch.psr_cos_ids )
+            return -ENOMEM;
+    }
+
+    return 0;
+}
+
+void psr_domain_free(struct domain *d)
+{
+    psr_free_rmid(d);
+    psr_free_cos(d);
+}
+
 static int cat_cpu_prepare(unsigned int cpu)
 {
     struct psr_cat_socket_info *info;
@@ -258,6 +305,8 @@ static void cat_cpu_init(void)
         /* cos=0 is reserved as default cbm(all ones). */
         info->cos_to_cbm[0].cbm = (1ull << info->cbm_len) - 1;
 
+        spin_lock_init(&info->cbm_lock);
+
         set_bit(socket, cat_socket_enable);
         printk(XENLOG_INFO "CAT: enabled on socket %u, cos_max:%u, 
cbm_len:%u\n",
                socket, info->cos_max, info->cbm_len);
diff --git a/xen/include/asm-x86/domain.h b/xen/include/asm-x86/domain.h
index 45b5283..fee50a1 100644
--- a/xen/include/asm-x86/domain.h
+++ b/xen/include/asm-x86/domain.h
@@ -333,7 +333,10 @@ struct arch_domain
     struct e820entry *e820;
     unsigned int nr_e820;
 
-    unsigned int psr_rmid; /* RMID assigned to the domain for CMT */
+    /* RMID assigned to the domain for CMT */
+    unsigned int psr_rmid;
+    /* COS assigned to the domain for each socket */
+    unsigned int *psr_cos_ids;
 
     /* Shared page for notifying that explicit PIRQ EOI is required. */
     unsigned long *pirq_eoi_map;
diff --git a/xen/include/asm-x86/psr.h b/xen/include/asm-x86/psr.h
index bdda111..1023d5f 100644
--- a/xen/include/asm-x86/psr.h
+++ b/xen/include/asm-x86/psr.h
@@ -51,6 +51,9 @@ int psr_alloc_rmid(struct domain *d);
 void psr_free_rmid(struct domain *d);
 void psr_ctxt_switch_to(struct domain *d);
 
+int psr_domain_init(struct domain *d);
+void psr_domain_free(struct domain *d);
+
 #endif /* __ASM_PSR_H__ */
 
 /*
-- 
1.9.1


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