[PATCH -V2 2/4] powerpc: Contiguous memory allocator based hash page allocation
Aneesh Kumar K.V
aneesh.kumar at linux.vnet.ibm.com
Fri Jun 28 19:11:00 EST 2013
From: "Aneesh Kumar K.V" <aneesh.kumar at linux.vnet.ibm.com>
Use CMA for allocation of guest hash page.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.vnet.ibm.com>
---
arch/powerpc/include/asm/kvm_book3s_64.h | 1 -
arch/powerpc/include/asm/kvm_host.h | 2 +-
arch/powerpc/include/asm/kvm_ppc.h | 8 +-
arch/powerpc/kernel/setup_64.c | 2 +
arch/powerpc/kvm/Kconfig | 1 +
arch/powerpc/kvm/Makefile | 1 +
arch/powerpc/kvm/book3s_64_mmu_hv.c | 36 +++--
arch/powerpc/kvm/book3s_hv_builtin.c | 83 ++++++++----
arch/powerpc/kvm/book3s_hv_cma.c | 220 +++++++++++++++++++++++++++++++
arch/powerpc/kvm/book3s_hv_cma.h | 21 +++
10 files changed, 324 insertions(+), 51 deletions(-)
create mode 100644 arch/powerpc/kvm/book3s_hv_cma.c
create mode 100644 arch/powerpc/kvm/book3s_hv_cma.h
diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
index 9c1ff33..f8355a9 100644
--- a/arch/powerpc/include/asm/kvm_book3s_64.h
+++ b/arch/powerpc/include/asm/kvm_book3s_64.h
@@ -37,7 +37,6 @@ static inline void svcpu_put(struct kvmppc_book3s_shadow_vcpu *svcpu)
#ifdef CONFIG_KVM_BOOK3S_64_HV
#define KVM_DEFAULT_HPT_ORDER 24 /* 16MB HPT by default */
-extern int kvm_hpt_order; /* order of preallocated HPTs */
#endif
#define VRMA_VSID 0x1ffffffUL /* 1TB VSID reserved for VRMA */
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index af326cd..0097dab 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -259,7 +259,7 @@ struct kvm_arch {
spinlock_t slot_phys_lock;
cpumask_t need_tlb_flush;
struct kvmppc_vcore *vcores[KVM_MAX_VCORES];
- struct kvmppc_linear_info *hpt_li;
+ int hpt_cma_alloc;
#endif /* CONFIG_KVM_BOOK3S_64_HV */
#ifdef CONFIG_PPC_BOOK3S_64
struct list_head spapr_tce_tables;
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index a5287fe..058ac93 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -139,8 +139,8 @@ extern long kvm_vm_ioctl_allocate_rma(struct kvm *kvm,
struct kvm_allocate_rma *rma);
extern struct kvmppc_linear_info *kvm_alloc_rma(void);
extern void kvm_release_rma(struct kvmppc_linear_info *ri);
-extern struct kvmppc_linear_info *kvm_alloc_hpt(void);
-extern void kvm_release_hpt(struct kvmppc_linear_info *li);
+extern struct page *kvm_alloc_hpt(int nr_pages);
+extern void kvm_release_hpt(struct page *page, int nr_pages);
extern int kvmppc_core_init_vm(struct kvm *kvm);
extern void kvmppc_core_destroy_vm(struct kvm *kvm);
extern void kvmppc_core_free_memslot(struct kvm_memory_slot *free,
@@ -261,6 +261,7 @@ void kvmppc_set_pid(struct kvm_vcpu *vcpu, u32 pid);
struct openpic;
#ifdef CONFIG_KVM_BOOK3S_64_HV
+extern void kvm_cma_reserve(void) __init;
static inline void kvmppc_set_xics_phys(int cpu, unsigned long addr)
{
paca[cpu].kvm_hstate.xics_phys = addr;
@@ -284,6 +285,9 @@ extern void kvmppc_fast_vcpu_kick(struct kvm_vcpu *vcpu);
extern void kvm_linear_init(void);
#else
+static inline void __init kvm_cma_reserve(void)
+{}
+
static inline void kvmppc_set_xics_phys(int cpu, unsigned long addr)
{}
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index e379d3f..ee28d1f 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -229,6 +229,8 @@ void __init early_setup(unsigned long dt_ptr)
/* Initialize the hash table or TLB handling */
early_init_mmu();
+ kvm_cma_reserve();
+
/*
* Reserve any gigantic pages requested on the command line.
* memblock needs to have been initialized by the time this is
diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig
index eb643f8..ffaef2c 100644
--- a/arch/powerpc/kvm/Kconfig
+++ b/arch/powerpc/kvm/Kconfig
@@ -72,6 +72,7 @@ config KVM_BOOK3S_64_HV
bool "KVM support for POWER7 and PPC970 using hypervisor mode in host"
depends on KVM_BOOK3S_64
select MMU_NOTIFIER
+ select CMA
---help---
Support running unmodified book3s_64 guest kernels in
virtual machines on POWER7 and PPC970 processors that have
diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile
index 422de3f..6640393 100644
--- a/arch/powerpc/kvm/Makefile
+++ b/arch/powerpc/kvm/Makefile
@@ -80,6 +80,7 @@ kvm-book3s_64-builtin-objs-$(CONFIG_KVM_BOOK3S_64_HV) := \
book3s_64_vio_hv.o \
book3s_hv_ras.o \
book3s_hv_builtin.o \
+ book3s_hv_cma.o \
$(kvm-book3s_64-builtin-xics-objs-y)
kvm-book3s_64-objs-$(CONFIG_KVM_XICS) += \
diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index 5880dfb..e96470d 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -52,8 +52,8 @@ long kvmppc_alloc_hpt(struct kvm *kvm, u32 *htab_orderp)
{
unsigned long hpt;
struct revmap_entry *rev;
- struct kvmppc_linear_info *li;
- long order = kvm_hpt_order;
+ struct page *page = NULL;
+ long order = KVM_DEFAULT_HPT_ORDER;
if (htab_orderp) {
order = *htab_orderp;
@@ -62,25 +62,20 @@ long kvmppc_alloc_hpt(struct kvm *kvm, u32 *htab_orderp)
}
/*
- * If the user wants a different size from default,
* try first to allocate it from the kernel page allocator.
+ * We keep the CMA reserved for failed allocation.
*/
- hpt = 0;
- if (order != kvm_hpt_order) {
- hpt = __get_free_pages(GFP_KERNEL|__GFP_ZERO|__GFP_REPEAT|
- __GFP_NOWARN, order - PAGE_SHIFT);
- if (!hpt)
- --order;
- }
+ hpt = __get_free_pages(GFP_KERNEL | __GFP_ZERO | __GFP_REPEAT |
+ __GFP_NOWARN, order - PAGE_SHIFT);
/* Next try to allocate from the preallocated pool */
if (!hpt) {
- li = kvm_alloc_hpt();
- if (li) {
- hpt = (ulong)li->base_virt;
- kvm->arch.hpt_li = li;
- order = kvm_hpt_order;
- }
+ page = kvm_alloc_hpt(1 << (order - PAGE_SHIFT));
+ if (page) {
+ hpt = (unsigned long)pfn_to_kaddr(page_to_pfn(page));
+ kvm->arch.hpt_cma_alloc = 1;
+ } else
+ --order;
}
/* Lastly try successively smaller sizes from the page allocator */
@@ -118,8 +113,8 @@ long kvmppc_alloc_hpt(struct kvm *kvm, u32 *htab_orderp)
return 0;
out_freehpt:
- if (kvm->arch.hpt_li)
- kvm_release_hpt(kvm->arch.hpt_li);
+ if (kvm->arch.hpt_cma_alloc)
+ kvm_release_hpt(page, 1 << (order - PAGE_SHIFT));
else
free_pages(hpt, order - PAGE_SHIFT);
return -ENOMEM;
@@ -165,8 +160,9 @@ void kvmppc_free_hpt(struct kvm *kvm)
{
kvmppc_free_lpid(kvm->arch.lpid);
vfree(kvm->arch.revmap);
- if (kvm->arch.hpt_li)
- kvm_release_hpt(kvm->arch.hpt_li);
+ if (kvm->arch.hpt_cma_alloc)
+ kvm_release_hpt(virt_to_page(kvm->arch.hpt_virt),
+ 1 << (kvm->arch.hpt_order - PAGE_SHIFT));
else
free_pages(kvm->arch.hpt_virt,
kvm->arch.hpt_order - PAGE_SHIFT);
diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c
index ec0a9e5..ee27a02 100644
--- a/arch/powerpc/kvm/book3s_hv_builtin.c
+++ b/arch/powerpc/kvm/book3s_hv_builtin.c
@@ -13,20 +13,29 @@
#include <linux/spinlock.h>
#include <linux/bootmem.h>
#include <linux/init.h>
+#include <linux/memblock.h>
+#include <linux/sizes.h>
#include <asm/cputable.h>
#include <asm/kvm_ppc.h>
#include <asm/kvm_book3s.h>
+#include "book3s_hv_cma.h"
+
#define KVM_LINEAR_RMA 0
#define KVM_LINEAR_HPT 1
static void __init kvm_linear_init_one(ulong size, int count, int type);
static struct kvmppc_linear_info *kvm_alloc_linear(int type);
static void kvm_release_linear(struct kvmppc_linear_info *ri);
-
-int kvm_hpt_order = KVM_DEFAULT_HPT_ORDER;
-EXPORT_SYMBOL_GPL(kvm_hpt_order);
+/*
+ * should be power of 2
+ */
+static unsigned long hpt_align_pages = (1 << 18) >> PAGE_SHIFT; /* 256k */
+/*
+ * By default we reserve 5% of memory for hash pagetable allocation.
+ */
+static unsigned long kvm_cma_resv_ratio = 5;
/*************** RMA *************/
@@ -101,36 +110,29 @@ void kvm_release_rma(struct kvmppc_linear_info *ri)
}
EXPORT_SYMBOL_GPL(kvm_release_rma);
-/*************** HPT *************/
-
-/*
- * This maintains a list of big linear HPT tables that contain the GVA->HPA
- * memory mappings. If we don't reserve those early on, we might not be able
- * to get a big (usually 16MB) linear memory region from the kernel anymore.
- */
-
-static unsigned long kvm_hpt_count;
-
-static int __init early_parse_hpt_count(char *p)
+static int __init early_parse_kvm_cma_resv(char *p)
{
+ pr_debug("%s(%s)\n", __func__, p);
if (!p)
- return 1;
-
- kvm_hpt_count = simple_strtoul(p, NULL, 0);
-
- return 0;
+ return -EINVAL;
+ return kstrtoul(p, 0, &kvm_cma_resv_ratio);
}
-early_param("kvm_hpt_count", early_parse_hpt_count);
+early_param("kvm_cma_resv_ratio", early_parse_kvm_cma_resv);
-struct kvmppc_linear_info *kvm_alloc_hpt(void)
+struct page *kvm_alloc_hpt(int nr_pages)
{
- return kvm_alloc_linear(KVM_LINEAR_HPT);
+ unsigned long align_pages = hpt_align_pages;
+
+ /* Old CPUs require HPT aligned on a multiple of its size */
+ if (!cpu_has_feature(CPU_FTR_ARCH_206))
+ align_pages = nr_pages;
+ return kvm_alloc_cma(nr_pages, align_pages);
}
EXPORT_SYMBOL_GPL(kvm_alloc_hpt);
-void kvm_release_hpt(struct kvmppc_linear_info *li)
+void kvm_release_hpt(struct page *page, int nr_pages)
{
- kvm_release_linear(li);
+ kvm_release_cma(page, nr_pages);
}
EXPORT_SYMBOL_GPL(kvm_release_hpt);
@@ -211,9 +213,6 @@ static void kvm_release_linear(struct kvmppc_linear_info *ri)
*/
void __init kvm_linear_init(void)
{
- /* HPT */
- kvm_linear_init_one(1 << kvm_hpt_order, kvm_hpt_count, KVM_LINEAR_HPT);
-
/* RMA */
/* Only do this on PPC970 in HV mode */
if (!cpu_has_feature(CPU_FTR_HVMODE) ||
@@ -231,3 +230,33 @@ void __init kvm_linear_init(void)
kvm_linear_init_one(kvm_rma_size, kvm_rma_count, KVM_LINEAR_RMA);
}
+
+/**
+ * kvm_cma_reserve() - reserve area for kvm hash pagetable
+ *
+ * This function reserves memory from early allocator. It should be
+ * called by arch specific code once the early allocator (memblock or bootmem)
+ * has been activated and all other subsystems have already allocated/reserved
+ * memory.
+ */
+void __init kvm_cma_reserve(void)
+{
+ int align_size;
+ struct memblock_region *reg;
+ phys_addr_t selected_size = 0;
+ /*
+ * We cannot use memblock_phys_mem_size() here, because
+ * memblock_analyze() has not been called yet.
+ */
+ for_each_memblock(memory, reg)
+ selected_size += memblock_region_memory_end_pfn(reg) -
+ memblock_region_memory_base_pfn(reg);
+
+ selected_size = (selected_size * kvm_cma_resv_ratio / 100) << PAGE_SHIFT;
+ if (selected_size) {
+ pr_debug("%s: reserving %ld MiB for global area\n", __func__,
+ (unsigned long)selected_size / SZ_1M);
+ align_size = hpt_align_pages << PAGE_SHIFT;
+ kvm_cma_declare_contiguous(selected_size, align_size);
+ }
+}
diff --git a/arch/powerpc/kvm/book3s_hv_cma.c b/arch/powerpc/kvm/book3s_hv_cma.c
new file mode 100644
index 0000000..fdd0b88
--- /dev/null
+++ b/arch/powerpc/kvm/book3s_hv_cma.c
@@ -0,0 +1,220 @@
+/*
+ * Contiguous Memory Allocator for ppc KVM hash pagetable based on CMA
+ * for DMA mapping framework
+ *
+ * Copyright IBM Corporation, 2013
+ * Author Aneesh Kumar K.V <aneesh.kumar at linux.vnet.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License or (at your optional) any later version of the license.
+ *
+ */
+#define pr_fmt(fmt) "kvm_cma: " fmt
+
+#ifdef CONFIG_CMA_DEBUG
+#ifndef DEBUG
+# define DEBUG
+#endif
+#endif
+
+#include <linux/memblock.h>
+#include <linux/mutex.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+
+struct kvm_cma {
+ unsigned long base_pfn;
+ unsigned long count;
+ unsigned long *bitmap;
+};
+
+static DEFINE_MUTEX(kvm_cma_mutex);
+static struct kvm_cma kvm_cma_area;
+
+/**
+ * kvm_cma_declare_contiguous() - reserve area for contiguous memory handling
+ * for kvm hash pagetable
+ * @size: Size of the reserved memory.
+ * @alignment: Alignment for the contiguous memory area
+ *
+ * This function reserves memory for kvm cma area. It should be
+ * called by arch code when early allocator (memblock or bootmem)
+ * is still activate.
+ */
+long __init kvm_cma_declare_contiguous(phys_addr_t size, phys_addr_t alignment)
+{
+ long base_pfn;
+ phys_addr_t addr;
+ struct kvm_cma *cma = &kvm_cma_area;
+
+ pr_debug("%s(size %lx)\n", __func__, (unsigned long)size);
+
+ if (!size)
+ return -EINVAL;
+ /*
+ * Sanitise input arguments.
+ * We should be pageblock aligned for CMA.
+ */
+ alignment = max(alignment, (phys_addr_t)(PAGE_SIZE << pageblock_order));
+ size = ALIGN(size, alignment);
+ /*
+ * Reserve memory
+ * Use __memblock_alloc_base() since
+ * memblock_alloc_base() panic()s.
+ */
+ addr = __memblock_alloc_base(size, alignment, 0);
+ if (!addr) {
+ base_pfn = -ENOMEM;
+ goto err;
+ } else
+ base_pfn = PFN_DOWN(addr);
+
+ /*
+ * Each reserved area must be initialised later, when more kernel
+ * subsystems (like slab allocator) are available.
+ */
+ cma->base_pfn = base_pfn;
+ cma->count = size >> PAGE_SHIFT;
+ pr_info("CMA: reserved %ld MiB\n", (unsigned long)size / SZ_1M);
+ return 0;
+err:
+ pr_err("CMA: failed to reserve %ld MiB\n", (unsigned long)size / SZ_1M);
+ return base_pfn;
+}
+
+/**
+ * kvm_alloc_cma() - allocate pages from contiguous area
+ * @nr_pages: Requested number of pages.
+ * @align_pages: Requested alignment in number of pages
+ *
+ * This function allocates memory buffer for hash pagetable.
+ */
+struct page *kvm_alloc_cma(int nr_pages, unsigned long align_pages)
+{
+ int ret;
+ struct page *page = NULL;
+ struct kvm_cma *cma = &kvm_cma_area;
+ unsigned long mask, pfn, pageno, start = 0;
+
+
+ if (!cma || !cma->count)
+ return NULL;
+
+ pr_debug("%s(cma %p, count %d, align pages %lu)\n", __func__,
+ (void *)cma, nr_pages, align_pages);
+
+ if (!nr_pages)
+ return NULL;
+
+ mask = align_pages - 1;
+
+ mutex_lock(&kvm_cma_mutex);
+ for (;;) {
+ pageno = bitmap_find_next_zero_area(cma->bitmap, cma->count,
+ start, nr_pages, mask);
+ if (pageno >= cma->count)
+ break;
+
+ pfn = cma->base_pfn + pageno;
+ ret = alloc_contig_range(pfn, pfn + nr_pages, MIGRATE_CMA);
+ if (ret == 0) {
+ bitmap_set(cma->bitmap, pageno, nr_pages);
+ page = pfn_to_page(pfn);
+ memset(pfn_to_kaddr(pfn), 0, nr_pages << PAGE_SHIFT);
+ break;
+ } else if (ret != -EBUSY) {
+ break;
+ }
+ pr_debug("%s(): memory range at %p is busy, retrying\n",
+ __func__, pfn_to_page(pfn));
+ /* try again with a bit different memory target */
+ start = pageno + mask + 1;
+ }
+ mutex_unlock(&kvm_cma_mutex);
+ pr_debug("%s(): returned %p\n", __func__, page);
+ return page;
+}
+
+/**
+ * kvm_release_cma() - release allocated pages for hash pagetable
+ * @pages: Allocated pages.
+ * @nr_pages: Number of allocated pages.
+ *
+ * This function releases memory allocated by kvm_alloc_cma().
+ * It returns false when provided pages do not belong to contiguous area and
+ * true otherwise.
+ */
+bool kvm_release_cma(struct page *pages, int nr_pages)
+{
+ unsigned long pfn;
+ struct kvm_cma *cma = &kvm_cma_area;
+
+
+ if (!cma || !pages)
+ return false;
+
+ pr_debug("%s(page %p count %d)\n", __func__, (void *)pages, nr_pages);
+
+ pfn = page_to_pfn(pages);
+
+ if (pfn < cma->base_pfn || pfn >= cma->base_pfn + cma->count)
+ return false;
+
+ VM_BUG_ON(pfn + nr_pages > cma->base_pfn + cma->count);
+
+ mutex_lock(&kvm_cma_mutex);
+ bitmap_clear(cma->bitmap, pfn - cma->base_pfn, nr_pages);
+ free_contig_range(pfn, nr_pages);
+ mutex_unlock(&kvm_cma_mutex);
+
+ return true;
+}
+
+static int __init kvm_cma_activate_area(unsigned long base_pfn,
+ unsigned long count)
+{
+ unsigned long pfn = base_pfn;
+ unsigned i = count >> pageblock_order;
+ struct zone *zone;
+
+ WARN_ON_ONCE(!pfn_valid(pfn));
+ zone = page_zone(pfn_to_page(pfn));
+ do {
+ unsigned j;
+ base_pfn = pfn;
+ for (j = pageblock_nr_pages; j; --j, pfn++) {
+ WARN_ON_ONCE(!pfn_valid(pfn));
+ if (page_zone(pfn_to_page(pfn)) != zone)
+ return -EINVAL;
+ }
+ init_cma_reserved_pageblock(pfn_to_page(base_pfn));
+ } while (--i);
+ return 0;
+}
+
+static int __init kvm_cma_init_reserved_areas(void)
+{
+ int bitmap_size, ret;
+ struct kvm_cma *cma = &kvm_cma_area;
+
+ pr_debug("%s()\n", __func__);
+ if (!cma->count)
+ return 0;
+
+ bitmap_size = BITS_TO_LONGS(cma->count) * sizeof(long);
+ cma->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
+ if (!cma->bitmap)
+ return -ENOMEM;
+
+ ret = kvm_cma_activate_area(cma->base_pfn, cma->count);
+ if (ret)
+ goto error;
+ return 0;
+
+error:
+ kfree(cma->bitmap);
+ return ret;
+}
+core_initcall(kvm_cma_init_reserved_areas);
diff --git a/arch/powerpc/kvm/book3s_hv_cma.h b/arch/powerpc/kvm/book3s_hv_cma.h
new file mode 100644
index 0000000..13ecb1d
--- /dev/null
+++ b/arch/powerpc/kvm/book3s_hv_cma.h
@@ -0,0 +1,21 @@
+/*
+ * Contiguous Memory Allocator for ppc KVM hash pagetable based on CMA
+ * for DMA mapping framework
+ *
+ * Copyright IBM Corporation, 2013
+ * Author Aneesh Kumar K.V <aneesh.kumar at linux.vnet.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License or (at your optional) any later version of the license.
+ *
+ */
+
+#ifndef __POWERPC_KVM_CMA_ALLOC_H__
+#define __POWERPC_KVM_CMA_ALLOC_H__
+extern struct page *kvm_alloc_cma(int nr_pages, unsigned long align_pages);
+extern bool kvm_release_cma(struct page *pages, int nr_pages);
+extern long kvm_cma_declare_contiguous(phys_addr_t size,
+ phys_addr_t alignment) __init;
+#endif
--
1.8.1.2
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