[PATCH v2 1/2] xen: vnuma support for PV guests running as domU

From: Elena Ufimtseva
Date: Mon Nov 18 2013 - 15:32:13 EST


Issues Xen hypercall subop XENMEM_get_vnumainfo and sets the
NUMA topology, otherwise sets dummy NUMA node and prevents
numa_init from calling other numa initializators as they dont
work with pv guests.

Signed-off-by: Elena Ufimtseva <ufimtseva@xxxxxxxxx>
---
arch/x86/include/asm/xen/vnuma.h | 12 ++++
arch/x86/mm/numa.c | 3 +
arch/x86/xen/Makefile | 2 +-
arch/x86/xen/vnuma.c | 127 ++++++++++++++++++++++++++++++++++++++
include/xen/interface/memory.h | 44 +++++++++++++
5 files changed, 187 insertions(+), 1 deletion(-)
create mode 100644 arch/x86/include/asm/xen/vnuma.h
create mode 100644 arch/x86/xen/vnuma.c

diff --git a/arch/x86/include/asm/xen/vnuma.h b/arch/x86/include/asm/xen/vnuma.h
new file mode 100644
index 0000000..aee4e92
--- /dev/null
+++ b/arch/x86/include/asm/xen/vnuma.h
@@ -0,0 +1,12 @@
+#ifndef _ASM_X86_VNUMA_H
+#define _ASM_X86_VNUMA_H
+
+#ifdef CONFIG_XEN
+bool xen_vnuma_supported(void);
+int xen_numa_init(void);
+#else
+static inline bool xen_vnuma_supported(void) { return false; };
+static inline int xen_numa_init(void) { return -1; };
+#endif
+
+#endif /* _ASM_X86_VNUMA_H */
diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
index 24aec58..99efa1b 100644
--- a/arch/x86/mm/numa.c
+++ b/arch/x86/mm/numa.c
@@ -17,6 +17,7 @@
#include <asm/dma.h>
#include <asm/acpi.h>
#include <asm/amd_nb.h>
+#include "asm/xen/vnuma.h"

#include "numa_internal.h"

@@ -632,6 +633,8 @@ static int __init dummy_numa_init(void)
void __init x86_numa_init(void)
{
if (!numa_off) {
+ if (!numa_init(xen_numa_init))
+ return;
#ifdef CONFIG_X86_NUMAQ
if (!numa_init(numaq_numa_init))
return;
diff --git a/arch/x86/xen/Makefile b/arch/x86/xen/Makefile
index 96ab2c0..de9deab 100644
--- a/arch/x86/xen/Makefile
+++ b/arch/x86/xen/Makefile
@@ -13,7 +13,7 @@ CFLAGS_mmu.o := $(nostackp)
obj-y := enlighten.o setup.o multicalls.o mmu.o irq.o \
time.o xen-asm.o xen-asm_$(BITS).o \
grant-table.o suspend.o platform-pci-unplug.o \
- p2m.o
+ p2m.o vnuma.o

obj-$(CONFIG_EVENT_TRACING) += trace.o

diff --git a/arch/x86/xen/vnuma.c b/arch/x86/xen/vnuma.c
new file mode 100644
index 0000000..bce4523
--- /dev/null
+++ b/arch/x86/xen/vnuma.c
@@ -0,0 +1,127 @@
+#include <linux/err.h>
+#include <linux/memblock.h>
+#include <xen/interface/xen.h>
+#include <xen/interface/memory.h>
+#include <asm/xen/interface.h>
+#include <asm/xen/hypercall.h>
+#include <asm/xen/vnuma.h>
+
+#ifdef CONFIG_NUMA
+
+/* Checks if hypercall is supported */
+bool xen_vnuma_supported()
+{
+ return HYPERVISOR_memory_op(XENMEM_get_vnuma_info, NULL) == -ENOSYS ? false : true;
+}
+
+/*
+ * Called from numa_init if numa_off = 0;
+ * we set numa_off = 0 if xen_vnuma_supported()
+ * returns true and its a domU;
+ */
+int __init xen_numa_init(void)
+{
+ int rc;
+ unsigned int i, j, nr_nodes, cpu, idx, pcpus;
+ u64 physm, physd, physc;
+ unsigned int *vdistance, *cpu_to_node;
+ unsigned long mem_size, dist_size, cpu_to_node_size;
+ struct vmemrange *vblock;
+
+ struct vnuma_topology_info numa_topo = {
+ .domid = DOMID_SELF,
+ .__pad = 0
+ };
+ rc = -EINVAL;
+ physm = physd = physc = 0;
+
+ /* For now only PV guests are supported */
+ if (!xen_pv_domain())
+ return rc;
+
+ pcpus = num_possible_cpus();
+
+ mem_size = pcpus * sizeof(struct vmemrange);
+ dist_size = pcpus * pcpus * sizeof(*numa_topo.distance);
+ cpu_to_node_size = pcpus * sizeof(*numa_topo.cpu_to_node);
+
+ physm = memblock_alloc(mem_size, PAGE_SIZE);
+ vblock = __va(physm);
+
+ physd = memblock_alloc(dist_size, PAGE_SIZE);
+ vdistance = __va(physd);
+
+ physc = memblock_alloc(cpu_to_node_size, PAGE_SIZE);
+ cpu_to_node = __va(physc);
+
+ if (!physm || !physc || !physd)
+ goto out;
+
+ set_xen_guest_handle(numa_topo.nr_nodes, &nr_nodes);
+ set_xen_guest_handle(numa_topo.memrange, vblock);
+ set_xen_guest_handle(numa_topo.distance, vdistance);
+ set_xen_guest_handle(numa_topo.cpu_to_node, cpu_to_node);
+
+ rc = HYPERVISOR_memory_op(XENMEM_get_vnuma_info, &numa_topo);
+
+ if (rc < 0)
+ goto out;
+ nr_nodes = *numa_topo.nr_nodes;
+ if (nr_nodes == 0) {
+ goto out;
+ }
+ if (nr_nodes > num_possible_cpus()) {
+ pr_debug("vNUMA: Node without cpu is not supported in this version.\n");
+ goto out;
+ }
+
+ /*
+ * NUMA nodes memory ranges are in pfns, constructed and
+ * aligned based on e820 ram domain map.
+ */
+ for (i = 0; i < nr_nodes; i++) {
+ if (numa_add_memblk(i, vblock[i].start, vblock[i].end))
+ goto out;
+ node_set(i, numa_nodes_parsed);
+ }
+
+ setup_nr_node_ids();
+ /* Setting the cpu, apicid to node */
+ for_each_cpu(cpu, cpu_possible_mask) {
+ set_apicid_to_node(cpu, cpu_to_node[cpu]);
+ numa_set_node(cpu, cpu_to_node[cpu]);
+ cpumask_set_cpu(cpu, node_to_cpumask_map[cpu_to_node[cpu]]);
+ }
+
+ for (i = 0; i < nr_nodes; i++) {
+ for (j = 0; j < *numa_topo.nr_nodes; j++) {
+ idx = (j * nr_nodes) + i;
+ numa_set_distance(i, j, *(vdistance + idx));
+ }
+ }
+
+ rc = 0;
+out:
+ if (physm)
+ memblock_free(__pa(physm), mem_size);
+ if (physd)
+ memblock_free(__pa(physd), dist_size);
+ if (physc)
+ memblock_free(__pa(physc), cpu_to_node_size);
+ /*
+ * Set a dummy node and return success. This prevents calling any
+ * hardware-specific initializers which do not work in a PV guest.
+ * Taken from dummy_numa_init code.
+ */
+ if (rc != 0) {
+ for (i = 0; i < MAX_LOCAL_APIC; i++)
+ set_apicid_to_node(i, NUMA_NO_NODE);
+ nodes_clear(numa_nodes_parsed);
+ nodes_clear(node_possible_map);
+ nodes_clear(node_online_map);
+ node_set(0, numa_nodes_parsed);
+ numa_add_memblk(0, 0, PFN_PHYS(max_pfn));
+ }
+ return 0;
+}
+#endif
diff --git a/include/xen/interface/memory.h b/include/xen/interface/memory.h
index 2ecfe4f..b61482c 100644
--- a/include/xen/interface/memory.h
+++ b/include/xen/interface/memory.h
@@ -263,4 +263,48 @@ struct xen_remove_from_physmap {
};
DEFINE_GUEST_HANDLE_STRUCT(xen_remove_from_physmap);

+/* vNUMA structures */
+struct vmemrange {
+ uint64_t start, end;
+ /* reserved */
+ uint64_t _padm;
+};
+DEFINE_GUEST_HANDLE_STRUCT(vmemrange);
+
+struct vnuma_topology_info {
+ /* OUT */
+ domid_t domid;
+ uint32_t __pad;
+ /* IN */
+ /* number of virtual numa nodes */
+ union {
+ GUEST_HANDLE(uint) nr_nodes;
+ uint64_t _padn;
+ };
+ /* distance table */
+ union {
+ GUEST_HANDLE(uint) distance;
+ uint64_t _padd;
+ };
+ /* cpu mapping to vnodes */
+ union {
+ GUEST_HANDLE(uint) cpu_to_node;
+ uint64_t _padc;
+ };
+ /*
+ * memory areas constructed by Xen, start and end
+ * of the ranges are specific to domain e820 map.
+ * Xen toolstack constructs these ranges for domain
+ * when building it.
+ */
+ union {
+ GUEST_HANDLE(vmemrange) memrange;
+ uint64_t _padm;
+ };
+};
+typedef struct vnuma_topology_info vnuma_topology_info_t;
+DEFINE_GUEST_HANDLE_STRUCT(vnuma_topology_info);
+
+#define XENMEM_get_vnuma_info 25
+
#endif /* __XEN_PUBLIC_MEMORY_H__ */
--
1.7.10.4

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