[PATCH v6 0/3] pseries NUMA distance rework

[PATCH v6 0/3] pseries NUMA distance rework

[Daniel Henrique Barboza]

changes from v5, all suggested by Greg:
- patch 2:
    * changed g_malloc() to g_new()
    * removed the unneeded g_assert()
- all patches: added Greg's R-b

v5 link: https://lists.gnu.org/archive/html/qemu-devel/2020-09/msg01978.html

Daniel Henrique Barboza (3):
  spapr: move h_home_node_associativity to spapr_numa.c
  spapr_numa: create a vcpu associativity helper
  spapr_numa: use spapr_numa_get_vcpu_assoc() in home_node hcall

 hw/ppc/spapr_hcall.c   |  40 ----------------
 hw/ppc/spapr_numa.c    | 101 +++++++++++++++++++++++++++++++++++------
 include/hw/ppc/spapr.h |   7 ++-
 3 files changed, 94 insertions(+), 54 deletions(-)

-- 
2.26.2

[PATCH v6 1/3] spapr: move h_home_node_associativity to spapr_numa.c

[Daniel Henrique Barboza]

The implementation of this hypercall will be modified to use
spapr->numa_assoc_arrays input. Moving it to spapr_numa.c makes
make more sense.

Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
---
 hw/ppc/spapr_hcall.c | 40 ---------------------------------------
 hw/ppc/spapr_numa.c  | 45 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 45 insertions(+), 40 deletions(-)

diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
index c1d01228c6..c2776b6a7d 100644
--- a/hw/ppc/spapr_hcall.c
+++ b/hw/ppc/spapr_hcall.c
@@ -1873,42 +1873,6 @@ static target_ulong h_client_architecture_support(PowerPCCPU *cpu,
     return ret;
 }
 
-static target_ulong h_home_node_associativity(PowerPCCPU *cpu,
-                                              SpaprMachineState *spapr,
-                                              target_ulong opcode,
-                                              target_ulong *args)
-{
-    target_ulong flags = args[0];
-    target_ulong procno = args[1];
-    PowerPCCPU *tcpu;
-    int idx;
-
-    /* only support procno from H_REGISTER_VPA */
-    if (flags != 0x1) {
-        return H_FUNCTION;
-    }
-
-    tcpu = spapr_find_cpu(procno);
-    if (tcpu == NULL) {
-        return H_P2;
-    }
-
-    /* sequence is the same as in the "ibm,associativity" property */
-
-    idx = 0;
-#define ASSOCIATIVITY(a, b) (((uint64_t)(a) << 32) | \
-                             ((uint64_t)(b) & 0xffffffff))
-    args[idx++] = ASSOCIATIVITY(0, 0);
-    args[idx++] = ASSOCIATIVITY(0, tcpu->node_id);
-    args[idx++] = ASSOCIATIVITY(procno, -1);
-    for ( ; idx < 6; idx++) {
-        args[idx] = -1;
-    }
-#undef ASSOCIATIVITY
-
-    return H_SUCCESS;
-}
-
 static target_ulong h_get_cpu_characteristics(PowerPCCPU *cpu,
                                               SpaprMachineState *spapr,
                                               target_ulong opcode,
@@ -2139,10 +2103,6 @@ static void hypercall_register_types(void)
     spapr_register_hypercall(KVMPPC_H_CAS, h_client_architecture_support);
 
     spapr_register_hypercall(KVMPPC_H_UPDATE_DT, h_update_dt);
-
-    /* Virtual Processor Home Node */
-    spapr_register_hypercall(H_HOME_NODE_ASSOCIATIVITY,
-                             h_home_node_associativity);
 }
 
 type_init(hypercall_register_types)
diff --git a/hw/ppc/spapr_numa.c b/hw/ppc/spapr_numa.c
index 93a000b729..368c1a494d 100644
--- a/hw/ppc/spapr_numa.c
+++ b/hw/ppc/spapr_numa.c
@@ -165,3 +165,48 @@ void spapr_numa_write_rtas_dt(SpaprMachineState *spapr, void *fdt, int rtas)
     _FDT(fdt_setprop(fdt, rtas, "ibm,max-associativity-domains",
                      maxdomains, sizeof(maxdomains)));
 }
+
+static target_ulong h_home_node_associativity(PowerPCCPU *cpu,
+                                              SpaprMachineState *spapr,
+                                              target_ulong opcode,
+                                              target_ulong *args)
+{
+    target_ulong flags = args[0];
+    target_ulong procno = args[1];
+    PowerPCCPU *tcpu;
+    int idx;
+
+    /* only support procno from H_REGISTER_VPA */
+    if (flags != 0x1) {
+        return H_FUNCTION;
+    }
+
+    tcpu = spapr_find_cpu(procno);
+    if (tcpu == NULL) {
+        return H_P2;
+    }
+
+    /* sequence is the same as in the "ibm,associativity" property */
+
+    idx = 0;
+#define ASSOCIATIVITY(a, b) (((uint64_t)(a) << 32) | \
+                             ((uint64_t)(b) & 0xffffffff))
+    args[idx++] = ASSOCIATIVITY(0, 0);
+    args[idx++] = ASSOCIATIVITY(0, tcpu->node_id);
+    args[idx++] = ASSOCIATIVITY(procno, -1);
+    for ( ; idx < 6; idx++) {
+        args[idx] = -1;
+    }
+#undef ASSOCIATIVITY
+
+    return H_SUCCESS;
+}
+
+static void spapr_numa_register_types(void)
+{
+    /* Virtual Processor Home Node */
+    spapr_register_hypercall(H_HOME_NODE_ASSOCIATIVITY,
+                             h_home_node_associativity);
+}
+
+type_init(spapr_numa_register_types)
-- 
2.26.2

[PATCH v6 2/3] spapr_numa: create a vcpu associativity helper

[Daniel Henrique Barboza]

The work to be done in h_home_node_associativity() intersects
with what is already done in spapr_numa_fixup_cpu_dt(). This
patch creates a new helper, spapr_numa_get_vcpu_assoc(), to
be used for both spapr_numa_fixup_cpu_dt() and
h_home_node_associativity().

While we're at it, use memcpy() instead of loop assignment
to created the returned array.

Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
---
 hw/ppc/spapr_numa.c    | 31 ++++++++++++++++++-------------
 include/hw/ppc/spapr.h |  7 ++++++-
 2 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/hw/ppc/spapr_numa.c b/hw/ppc/spapr_numa.c
index 368c1a494d..066ffc2a5f 100644
--- a/hw/ppc/spapr_numa.c
+++ b/hw/ppc/spapr_numa.c
@@ -71,31 +71,36 @@ void spapr_numa_write_associativity_dt(SpaprMachineState *spapr, void *fdt,
                       sizeof(spapr->numa_assoc_array[nodeid]))));
 }
 
-int spapr_numa_fixup_cpu_dt(SpaprMachineState *spapr, void *fdt,
-                            int offset, PowerPCCPU *cpu)
+static uint32_t *spapr_numa_get_vcpu_assoc(SpaprMachineState *spapr,
+                                           PowerPCCPU *cpu)
 {
-    uint vcpu_assoc_size = NUMA_ASSOC_SIZE + 1;
-    uint32_t vcpu_assoc[vcpu_assoc_size];
+    uint32_t *vcpu_assoc = g_new(uint32_t, VCPU_ASSOC_SIZE);
     int index = spapr_get_vcpu_id(cpu);
-    int i;
 
     /*
      * VCPUs have an extra 'cpu_id' value in ibm,associativity
      * compared to other resources. Increment the size at index
-     * 0, copy all associativity domains already set, then put
-     * cpu_id last.
+     * 0, put cpu_id last, then copy the remaining associativity
+     * domains.
      */
     vcpu_assoc[0] = cpu_to_be32(MAX_DISTANCE_REF_POINTS + 1);
+    vcpu_assoc[VCPU_ASSOC_SIZE - 1] = cpu_to_be32(index);
+    memcpy(vcpu_assoc + 1, spapr->numa_assoc_array[cpu->node_id] + 1,
+           (VCPU_ASSOC_SIZE - 2) * sizeof(uint32_t));
 
-    for (i = 1; i <= MAX_DISTANCE_REF_POINTS; i++) {
-        vcpu_assoc[i] = spapr->numa_assoc_array[cpu->node_id][i];
-    }
+    return vcpu_assoc;
+}
+
+int spapr_numa_fixup_cpu_dt(SpaprMachineState *spapr, void *fdt,
+                            int offset, PowerPCCPU *cpu)
+{
+    g_autofree uint32_t *vcpu_assoc = NULL;
 
-    vcpu_assoc[vcpu_assoc_size - 1] = cpu_to_be32(index);
+    vcpu_assoc = spapr_numa_get_vcpu_assoc(spapr, cpu);
 
     /* Advertise NUMA via ibm,associativity */
-    return fdt_setprop(fdt, offset, "ibm,associativity",
-                       vcpu_assoc, sizeof(vcpu_assoc));
+    return fdt_setprop(fdt, offset, "ibm,associativity", vcpu_assoc,
+                       VCPU_ASSOC_SIZE * sizeof(uint32_t));
 }
 
 
diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index 9a63380801..e50a2672e3 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -107,13 +107,18 @@ typedef enum {
 
 /*
  * NUMA related macros. MAX_DISTANCE_REF_POINTS was taken
- * from Taken from Linux kernel arch/powerpc/mm/numa.h.
+ * from Linux kernel arch/powerpc/mm/numa.h. It represents the
+ * amount of associativity domains for non-CPU resources.
  *
  * NUMA_ASSOC_SIZE is the base array size of an ibm,associativity
  * array for any non-CPU resource.
+ *
+ * VCPU_ASSOC_SIZE represents the size of ibm,associativity array
+ * for CPUs, which has an extra element (vcpu_id) in the end.
  */
 #define MAX_DISTANCE_REF_POINTS    4
 #define NUMA_ASSOC_SIZE            (MAX_DISTANCE_REF_POINTS + 1)
+#define VCPU_ASSOC_SIZE            (NUMA_ASSOC_SIZE + 1)
 
 typedef struct SpaprCapabilities SpaprCapabilities;
 struct SpaprCapabilities {
-- 
2.26.2

[PATCH v6 3/3] spapr_numa: use spapr_numa_get_vcpu_assoc() in home_node hcall

[Daniel Henrique Barboza]

The current implementation of h_home_node_associativity hard codes
the values of associativity domains of the vcpus. Let's make
it consider the values already initialized in spapr->numa_assoc_array,
via the spapr_numa_get_vcpu_assoc() helper.

We want to set it and forget it, and for that we also need to
assert that we don't overflow the registers of the hypercall.
From R4 to R9 we can squeeze in 12 associativity domains for
vcpus, so let's assert that VCPU_ASSOC_SIZE -1 isn't greater
than that.

Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
---
 hw/ppc/spapr_numa.c | 41 +++++++++++++++++++++++++++++++++--------
 1 file changed, 33 insertions(+), 8 deletions(-)

diff --git a/hw/ppc/spapr_numa.c b/hw/ppc/spapr_numa.c
index 066ffc2a5f..64fe567f5d 100644
--- a/hw/ppc/spapr_numa.c
+++ b/hw/ppc/spapr_numa.c
@@ -176,10 +176,11 @@ static target_ulong h_home_node_associativity(PowerPCCPU *cpu,
                                               target_ulong opcode,
                                               target_ulong *args)
 {
+    g_autofree uint32_t *vcpu_assoc = NULL;
     target_ulong flags = args[0];
     target_ulong procno = args[1];
     PowerPCCPU *tcpu;
-    int idx;
+    int idx, assoc_idx;
 
     /* only support procno from H_REGISTER_VPA */
     if (flags != 0x1) {
@@ -191,16 +192,40 @@ static target_ulong h_home_node_associativity(PowerPCCPU *cpu,
         return H_P2;
     }
 
-    /* sequence is the same as in the "ibm,associativity" property */
+    /*
+     * Given that we want to be flexible with the sizes and indexes,
+     * we must consider that there is a hard limit of how many
+     * associativities domain we can fit in R4 up to R9, which would be
+     * 12 associativity domains for vcpus. Assert and bail if that's
+     * not the case.
+     */
+    G_STATIC_ASSERT((VCPU_ASSOC_SIZE - 1) <= 12);
+
+    vcpu_assoc = spapr_numa_get_vcpu_assoc(spapr, tcpu);
+    /* assoc_idx starts at 1 to skip associativity size */
+    assoc_idx = 1;
 
-    idx = 0;
 #define ASSOCIATIVITY(a, b) (((uint64_t)(a) << 32) | \
                              ((uint64_t)(b) & 0xffffffff))
-    args[idx++] = ASSOCIATIVITY(0, 0);
-    args[idx++] = ASSOCIATIVITY(0, tcpu->node_id);
-    args[idx++] = ASSOCIATIVITY(procno, -1);
-    for ( ; idx < 6; idx++) {
-        args[idx] = -1;
+
+    for (idx = 0; idx < 6; idx++) {
+        int32_t a, b;
+
+        /*
+         * vcpu_assoc[] will contain the associativity domains for tcpu,
+         * including tcpu->node_id and procno, meaning that we don't
+         * need to use these variables here.
+         *
+         * We'll read 2 values at a time to fill up the ASSOCIATIVITY()
+         * macro. The ternary will fill the remaining registers with -1
+         * after we went through vcpu_assoc[].
+         */
+        a = assoc_idx < VCPU_ASSOC_SIZE ?
+            be32_to_cpu(vcpu_assoc[assoc_idx++]) : -1;
+        b = assoc_idx < VCPU_ASSOC_SIZE ?
+            be32_to_cpu(vcpu_assoc[assoc_idx++]) : -1;
+
+        args[idx] = ASSOCIATIVITY(a, b);
     }
 #undef ASSOCIATIVITY
 
-- 
2.26.2

Re: [PATCH v6 0/3] pseries NUMA distance rework

[David Gibson]

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On Fri, Sep 04, 2020 at 02:24:19PM -0300, Daniel Henrique Barboza wrote:

> changes from v5, all suggested by Greg:
> - patch 2:
>     * changed g_malloc() to g_new()
>     * removed the unneeded g_assert()
> - all patches: added Greg's R-b

Applied to ppc-for-5.2.

> 
> v5 link: https://lists.gnu.org/archive/html/qemu-devel/2020-09/msg01978.html
> 
> Daniel Henrique Barboza (3):
>   spapr: move h_home_node_associativity to spapr_numa.c
>   spapr_numa: create a vcpu associativity helper
>   spapr_numa: use spapr_numa_get_vcpu_assoc() in home_node hcall
> 
>  hw/ppc/spapr_hcall.c   |  40 ----------------
>  hw/ppc/spapr_numa.c    | 101 +++++++++++++++++++++++++++++++++++------
>  include/hw/ppc/spapr.h |   7 ++-
>  3 files changed, 94 insertions(+), 54 deletions(-)
> 

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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