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Commit fa61a4e3 authored by Aneesh Kumar K.V's avatar Aneesh Kumar K.V Committed by Alexander Graf
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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: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: default avatarPaul Mackerras <paulus@samba.org>
Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
parent f3532028

arch/powerpc/include/asm/kvm_book3s_64.h

+0 −1
Original line number Diff line number Diff line
@@ -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 */

arch/powerpc/include/asm/kvm_host.h

+1 −1
Original line number Diff line number Diff line
@@ -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;

arch/powerpc/include/asm/kvm_ppc.h

+6 −2
Original line number Diff line number Diff line
@@ -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)

{}

arch/powerpc/kernel/setup_64.c

+2 −0
Original line number Diff line number Diff line
@@ -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

arch/powerpc/kvm/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -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