powerpc/kvm: Contiguous memory allocator based hash page table allocation

Powerpc architecture uses a hash based page table mechanism for mapping virtual
addresses to physical address. The architecture require this hash page table to
be physically contiguous. With KVM on Powerpc currently we use early reservation
mechanism for allocating guest hash page table. This implies that we need to
reserve a big memory region to ensure we can create large number of guest
simultaneously with KVM on Power. Another disadvantage is that the reserved memory
is not available to rest of the subsystems and and that implies we limit the total
available memory in the host.

This patch series switch the guest hash page table allocation to use
contiguous memory allocator.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>

1 files changed, 6 insertions, 2 deletions

diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index a5287fe03d77..b5ef7a3c606b 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(unsigned long nr_pages);
+extern void kvm_release_hpt(struct page *page, unsigned long 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)
 {}