KVM: PPC: Convert RMA allocation into generic code

We have code to allocate big chunks of linear memory on bootup for later use.
This code is currently used for RMA allocation, but can be useful beyond that
extent.

Make it generic so we can reuse it for other stuff later.

Signed-off-by: Alexander Graf <agraf@suse.de>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Avi Kivity <avi@redhat.com>

arch/powerpc/include/asm/kvm_host.h

@@ -173,12 +173,13 @@ struct kvmppc_spapr_tce_table {
 	struct page *pages[0];
 };
 
-struct kvmppc_rma_info {
+struct kvmppc_linear_info {
 	void		*base_virt;
 	unsigned long	 base_pfn;
 	unsigned long	 npages;
 	struct list_head list;
-	atomic_t 	 use_count;
+	atomic_t	 use_count;
+	int		 type;
 };
 
 /*
@@ -224,7 +225,7 @@ struct kvm_arch {
 	int tlbie_lock;
 	unsigned long lpcr;
 	unsigned long rmor;
-	struct kvmppc_rma_info *rma;
+	struct kvmppc_linear_info *rma;
 	unsigned long vrma_slb_v;
 	int rma_setup_done;
 	int using_mmu_notifiers;

arch/powerpc/include/asm/kvm_ppc.h

@@ -128,8 +128,8 @@ extern long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
 				struct kvm_create_spapr_tce *args);
 extern long kvm_vm_ioctl_allocate_rma(struct kvm *kvm,
 				struct kvm_allocate_rma *rma);
-extern struct kvmppc_rma_info *kvm_alloc_rma(void);
-extern void kvm_release_rma(struct kvmppc_rma_info *ri);
+extern struct kvmppc_linear_info *kvm_alloc_rma(void);
+extern void kvm_release_rma(struct kvmppc_linear_info *ri);
 extern int kvmppc_core_init_vm(struct kvm *kvm);
 extern void kvmppc_core_destroy_vm(struct kvm *kvm);
 extern int kvmppc_core_prepare_memory_region(struct kvm *kvm,
@@ -187,13 +187,13 @@ static inline void kvmppc_set_xics_phys(int cpu, unsigned long addr)
 	paca[cpu].kvm_hstate.xics_phys = addr;
 }
 
-extern void kvm_rma_init(void);
+extern void kvm_linear_init(void);
 
 #else
 static inline void kvmppc_set_xics_phys(int cpu, unsigned long addr)
 {}
 
-static inline void kvm_rma_init(void)
+static inline void kvm_linear_init(void)
 {}
 #endif
 

arch/powerpc/kernel/setup_64.c

@@ -598,7 +598,7 @@ void __init setup_arch(char **cmdline_p)
 	/* Initialize the MMU context management stuff */
 	mmu_context_init();
 
-	kvm_rma_init();
+	kvm_linear_init();
 
 	ppc64_boot_msg(0x15, "Setup Done");
 }

arch/powerpc/kvm/book3s_hv.c

@@ -1055,7 +1055,7 @@ static inline int lpcr_rmls(unsigned long rma_size)
 
 static int kvm_rma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
-	struct kvmppc_rma_info *ri = vma->vm_file->private_data;
+	struct kvmppc_linear_info *ri = vma->vm_file->private_data;
 	struct page *page;
 
 	if (vmf->pgoff >= ri->npages)
@@ -1080,7 +1080,7 @@ static int kvm_rma_mmap(struct file *file, struct vm_area_struct *vma)
 
 static int kvm_rma_release(struct inode *inode, struct file *filp)
 {
-	struct kvmppc_rma_info *ri = filp->private_data;
+	struct kvmppc_linear_info *ri = filp->private_data;
 
 	kvm_release_rma(ri);
 	return 0;
@@ -1093,7 +1093,7 @@ static struct file_operations kvm_rma_fops = {
 
 long kvm_vm_ioctl_allocate_rma(struct kvm *kvm, struct kvm_allocate_rma *ret)
 {
-	struct kvmppc_rma_info *ri;
+	struct kvmppc_linear_info *ri;
 	long fd;
 
 	ri = kvm_alloc_rma();
@@ -1212,7 +1212,7 @@ static int kvmppc_hv_setup_rma(struct kvm_vcpu *vcpu)
 {
 	int err = 0;
 	struct kvm *kvm = vcpu->kvm;
-	struct kvmppc_rma_info *ri = NULL;
+	struct kvmppc_linear_info *ri = NULL;
 	unsigned long hva;
 	struct kvm_memory_slot *memslot;
 	struct vm_area_struct *vma;

arch/powerpc/kvm/book3s_hv_builtin.c

@@ -18,6 +18,14 @@
 #include <asm/kvm_ppc.h>
 #include <asm/kvm_book3s.h>
 
+#define KVM_LINEAR_RMA		0
+
+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);
+
+/*************** RMA *************/
+
 /*
  * This maintains a list of RMAs (real mode areas) for KVM guests to use.
  * Each RMA has to be physically contiguous and of a size that the
@@ -29,32 +37,6 @@
 static unsigned long kvm_rma_size = 64 << 20;	/* 64MB */
 static unsigned long kvm_rma_count;
 
-static int __init early_parse_rma_size(char *p)
-{
-	if (!p)
-		return 1;
-
-	kvm_rma_size = memparse(p, &p);
-
-	return 0;
-}
-early_param("kvm_rma_size", early_parse_rma_size);
-
-static int __init early_parse_rma_count(char *p)
-{
-	if (!p)
-		return 1;
-
-	kvm_rma_count = simple_strtoul(p, NULL, 0);
-
-	return 0;
-}
-early_param("kvm_rma_count", early_parse_rma_count);
-
-static struct kvmppc_rma_info *rma_info;
-static LIST_HEAD(free_rmas);
-static DEFINE_SPINLOCK(rma_lock);
-
 /* Work out RMLS (real mode limit selector) field value for a given RMA size.
    Assumes POWER7 or PPC970. */
 static inline int lpcr_rmls(unsigned long rma_size)
@@ -81,45 +63,73 @@ static inline int lpcr_rmls(unsigned long rma_size)
 	}
 }
 
-/*
- * Called at boot time while the bootmem allocator is active,
- * to allocate contiguous physical memory for the real memory
- * areas for guests.
- */
-void __init kvm_rma_init(void)
+static int __init early_parse_rma_size(char *p)
+{
+	if (!p)
+		return 1;
+
+	kvm_rma_size = memparse(p, &p);
+
+	return 0;
+}
+early_param("kvm_rma_size", early_parse_rma_size);
+
+static int __init early_parse_rma_count(char *p)
+{
+	if (!p)
+		return 1;
+
+	kvm_rma_count = simple_strtoul(p, NULL, 0);
+
+	return 0;
+}
+early_param("kvm_rma_count", early_parse_rma_count);
+
+struct kvmppc_linear_info *kvm_alloc_rma(void)
+{
+	return kvm_alloc_linear(KVM_LINEAR_RMA);
+}
+EXPORT_SYMBOL_GPL(kvm_alloc_rma);
+
+void kvm_release_rma(struct kvmppc_linear_info *ri)
+{
+	kvm_release_linear(ri);
+}
+EXPORT_SYMBOL_GPL(kvm_release_rma);
+
+/*************** generic *************/
+
+static LIST_HEAD(free_linears);
+static DEFINE_SPINLOCK(linear_lock);
+
+static void __init kvm_linear_init_one(ulong size, int count, int type)
 {
 	unsigned long i;
 	unsigned long j, npages;
-	void *rma;
+	void *linear;
 	struct page *pg;
+	const char *typestr;
+	struct kvmppc_linear_info *linear_info;
 
-	/* Only do this on PPC970 in HV mode */
-	if (!cpu_has_feature(CPU_FTR_HVMODE) ||
-	    !cpu_has_feature(CPU_FTR_ARCH_201))
-		return;
-
-	if (!kvm_rma_size || !kvm_rma_count)
+	if (!count)
 		return;
 
-	/* Check that the requested size is one supported in hardware */
-	if (lpcr_rmls(kvm_rma_size) < 0) {
-		pr_err("RMA size of 0x%lx not supported\n", kvm_rma_size);
-		return;
-	}
-
-	npages = kvm_rma_size >> PAGE_SHIFT;
-	rma_info = alloc_bootmem(kvm_rma_count * sizeof(struct kvmppc_rma_info));
-	for (i = 0; i < kvm_rma_count; ++i) {
-		rma = alloc_bootmem_align(kvm_rma_size, kvm_rma_size);
-		pr_info("Allocated KVM RMA at %p (%ld MB)\n", rma,
-			kvm_rma_size >> 20);
-		rma_info[i].base_virt = rma;
-		rma_info[i].base_pfn = __pa(rma) >> PAGE_SHIFT;
-		rma_info[i].npages = npages;
-		list_add_tail(&rma_info[i].list, &free_rmas);
-		atomic_set(&rma_info[i].use_count, 0);
-
-		pg = pfn_to_page(rma_info[i].base_pfn);
+	typestr = (type == KVM_LINEAR_RMA) ? "RMA" : "";
+
+	npages = size >> PAGE_SHIFT;
+	linear_info = alloc_bootmem(count * sizeof(struct kvmppc_linear_info));
+	for (i = 0; i < count; ++i) {
+		linear = alloc_bootmem_align(size, size);
+		pr_info("Allocated KVM %s at %p (%ld MB)\n", typestr, linear,
+			size >> 20);
+		linear_info[i].base_virt = linear;
+		linear_info[i].base_pfn = __pa(linear) >> PAGE_SHIFT;
+		linear_info[i].npages = npages;
+		linear_info[i].type = type;
+		list_add_tail(&linear_info[i].list, &free_linears);
+		atomic_set(&linear_info[i].use_count, 0);
+
+		pg = pfn_to_page(linear_info[i].base_pfn);
 		for (j = 0; j < npages; ++j) {
 			atomic_inc(&pg->_count);
 			++pg;
@@ -127,30 +137,55 @@ void __init kvm_rma_init(void)
 	}
 }
 
-struct kvmppc_rma_info *kvm_alloc_rma(void)
+static struct kvmppc_linear_info *kvm_alloc_linear(int type)
 {
-	struct kvmppc_rma_info *ri;
+	struct kvmppc_linear_info *ri;
 
 	ri = NULL;
-	spin_lock(&rma_lock);
-	if (!list_empty(&free_rmas)) {
-		ri = list_first_entry(&free_rmas, struct kvmppc_rma_info, list);
+	spin_lock(&linear_lock);
+	list_for_each_entry(ri, &free_linears, list) {
+		if (ri->type != type)
+			continue;
+
 		list_del(&ri->list);
 		atomic_inc(&ri->use_count);
+		break;
 	}
-	spin_unlock(&rma_lock);
+	spin_unlock(&linear_lock);
 	return ri;
 }
-EXPORT_SYMBOL_GPL(kvm_alloc_rma);
 
-void kvm_release_rma(struct kvmppc_rma_info *ri)
+static void kvm_release_linear(struct kvmppc_linear_info *ri)
 {
 	if (atomic_dec_and_test(&ri->use_count)) {
-		spin_lock(&rma_lock);
-		list_add_tail(&ri->list, &free_rmas);
-		spin_unlock(&rma_lock);
+		spin_lock(&linear_lock);
+		list_add_tail(&ri->list, &free_linears);
+		spin_unlock(&linear_lock);
 
 	}
 }
-EXPORT_SYMBOL_GPL(kvm_release_rma);
 
+/*
+ * Called at boot time while the bootmem allocator is active,
+ * to allocate contiguous physical memory for the hash page
+ * tables for guests.
+ */
+void __init kvm_linear_init(void)
+{
+	/* RMA */
+	/* Only do this on PPC970 in HV mode */
+	if (!cpu_has_feature(CPU_FTR_HVMODE) ||
+	    !cpu_has_feature(CPU_FTR_ARCH_201))
+		return;
+
+	if (!kvm_rma_size || !kvm_rma_count)
+		return;
+
+	/* Check that the requested size is one supported in hardware */
+	if (lpcr_rmls(kvm_rma_size) < 0) {
+		pr_err("RMA size of 0x%lx not supported\n", kvm_rma_size);
+		return;
+	}
+
+	kvm_linear_init_one(kvm_rma_size, kvm_rma_count, KVM_LINEAR_RMA);
+}