[PATCH v3 1/2] xen: vnuma for pv guests

[Elena Ufimtseva]

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 |   10 ++++
 arch/x86/mm/numa.c               |    3 +
 arch/x86/xen/Makefile            |    1 +
 arch/x86/xen/setup.c             |    6 +-
 arch/x86/xen/vnuma.c             |  121 ++++++++++++++++++++++++++++++++++++++
 include/xen/interface/memory.h   |   50 ++++++++++++++++
 6 files changed, 190 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..8c8b098
--- /dev/null
+++ b/arch/x86/include/asm/xen/vnuma.h
@@ -0,0 +1,10 @@
+#ifndef _ASM_X86_VNUMA_H
+#define _ASM_X86_VNUMA_H
+
+#ifdef CONFIG_XEN
+int xen_numa_init(void);
+#else
+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 1d045f9..37a9c84 100644
--- a/arch/x86/mm/numa.c
+++ b/arch/x86/mm/numa.c
@@ -18,6 +18,7 @@
 #include <asm/acpi.h>
 #include <asm/amd_nb.h>
 
+#include "asm/xen/vnuma.h"
 #include "numa_internal.h"
 
 int __initdata numa_off;
@@ -687,6 +688,8 @@ 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_ACPI_NUMA
 		if (!numa_init(x86_acpi_numa_init))
 			return;
diff --git a/arch/x86/xen/Makefile b/arch/x86/xen/Makefile
index 96ab2c0..185ec9b 100644
--- a/arch/x86/xen/Makefile
+++ b/arch/x86/xen/Makefile
@@ -22,3 +22,4 @@ obj-$(CONFIG_PARAVIRT_SPINLOCKS)+= spinlock.o
 obj-$(CONFIG_XEN_DEBUG_FS)	+= debugfs.o
 obj-$(CONFIG_XEN_DOM0)		+= apic.o vga.o
 obj-$(CONFIG_SWIOTLB_XEN)	+= pci-swiotlb-xen.o
+obj-$(CONFIG_NUMA)		+= vnuma.o
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 0982233..0235f19 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -20,6 +20,7 @@
 #include <asm/numa.h>
 #include <asm/xen/hypervisor.h>
 #include <asm/xen/hypercall.h>
+#include <asm/xen/vnuma.h>
 
 #include <xen/xen.h>
 #include <xen/page.h>
@@ -622,6 +623,9 @@ void __init xen_arch_setup(void)
 	WARN_ON(xen_set_default_idle());
 	fiddle_vdso();
 #ifdef CONFIG_NUMA
-	numa_off = 1;
+	if (xen_initial_domain())
+		numa_off = 1;
+	else
+		numa_off = 0;
 #endif
 }
diff --git a/arch/x86/xen/vnuma.c b/arch/x86/xen/vnuma.c
new file mode 100644
index 0000000..a02f9c6
--- /dev/null
+++ b/arch/x86/xen/vnuma.c
@@ -0,0 +1,121 @@
+#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>
+
+/*
+ * Called from numa_init if numa_off = 0;
+ */
+int __init xen_numa_init(void)
+{
+	unsigned int i, j, idx;
+	unsigned int cpu, pcpus, nr_nodes, nr_cpus;
+	unsigned int *vdistance, *cpu_to_node;
+	unsigned long mem_size, dist_size, cpu_to_node_size;
+	struct vmemrange *vmem;
+	u64 physm, physd, physc;
+	int rc;
+
+	struct vnuma_topology_info numa_topo = {
+		.domid = DOMID_SELF
+	};
+
+	rc = -EINVAL;
+	physm = physd = physc = 0;
+
+	/* For now only PV guests are supported */
+	if (!xen_pv_domain())
+		return rc;
+
+	/* get the number of nodes for allocation of memblocks */
+	pcpus = num_possible_cpus();
+	nr_cpus = setup_max_cpus < pcpus ? setup_max_cpus : pcpus;
+
+	/* support for nodes with at least one cpu */
+	nr_nodes = nr_cpus;
+
+	/*
+	 * Allocate arrays for nr_cpus/nr_nodes sizes and let
+	 * hypervisor know that these are the boundaries. Partial
+	 * copy is not allowed and hypercall will fail.
+	 */
+
+	mem_size =  nr_nodes * sizeof(struct vmemrange);
+	dist_size = nr_nodes * nr_nodes * sizeof(*numa_topo.distance.h);
+	cpu_to_node_size = nr_cpus * sizeof(*numa_topo.cpu_to_node.h);
+
+	physm = memblock_alloc(mem_size, PAGE_SIZE);
+	physd = memblock_alloc(dist_size, PAGE_SIZE);
+	physc = memblock_alloc(cpu_to_node_size, PAGE_SIZE);
+
+	if (!physm || !physd || !physc)
+		goto out;
+
+	vmem = __va(physm);
+	vdistance  = __va(physd);
+	cpu_to_node  = __va(physc);
+
+	numa_topo.nr_nodes = nr_nodes;
+	numa_topo.nr_cpus = nr_cpus;
+
+	set_xen_guest_handle(numa_topo.memrange.h, vmem);
+	set_xen_guest_handle(numa_topo.distance.h, vdistance);
+	set_xen_guest_handle(numa_topo.cpu_to_node.h, cpu_to_node);
+
+	if (HYPERVISOR_memory_op(XENMEM_get_vnuma_info, &numa_topo) < 0)
+		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, vmem[i].start, vmem[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 < nr_nodes; j++) {
+			idx = (i * nr_nodes) + j;
+			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);
+		/* cpus up to max_cpus will be assigned to one node */
+		numa_add_memblk(0, 0, PFN_PHYS(max_pfn));
+		setup_nr_node_ids();
+	}
+	return 0;
+}
diff --git a/include/xen/interface/memory.h b/include/xen/interface/memory.h
index 2ecfe4f..96d6387 100644
--- a/include/xen/interface/memory.h
+++ b/include/xen/interface/memory.h
@@ -263,4 +263,54 @@ struct xen_remove_from_physmap {
 };
 DEFINE_GUEST_HANDLE_STRUCT(xen_remove_from_physmap);
 
+/* vNUMA structures */
+struct vmemrange {
+	uint64_t start, end;
+};
+DEFINE_GUEST_HANDLE_STRUCT(vmemrange);
+
+struct vnuma_topology_info {
+	/* OUT */
+	domid_t domid;
+	/*
+	 * nr_nodes and nr_cpus are used for retreival of sizes
+	 * of will be allocated arrays for vnuma topology.
+	 * We need to know vcpus numberfor domain as NR_CPUS
+	 * is less then domain max_vcpus, number of possible
+	 * cpus will equal to NR_CPUS and we have no way of
+	 * learning domain vcpus number.
+	 */
+	/* number of virtual numa nodes */
+	unsigned int nr_nodes;
+	unsigned int nr_cpus;
+	/* distance table */
+	union {
+		GUEST_HANDLE(uint) h;
+		uint64_t    _pad;
+	} distance;
+	/* cpu mapping to vnodes */
+	union {
+		GUEST_HANDLE(uint) h;
+		uint64_t    _pad;
+	} cpu_to_node;
+	/*
+	* 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) h;
+		uint64_t    _pad;
+	} memrange;
+};
+DEFINE_GUEST_HANDLE_STRUCT(vnuma_topology_info);
+
+/*
+ * Used to retreive vnuma topology info.
+ * Use XENMEM_get_vnuma_nodes to obtain number of
+ * nodes before allocating memory for topology.
+ */
+#define XENMEM_get_vnuma_info	26
+
 #endif /* __XEN_PUBLIC_MEMORY_H__ */
-- 
1.7.10.4

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