Commit 96bc451a authored by Alexander Graf's avatar Alexander Graf Committed by Avi Kivity
Browse files

KVM: PPC: Introduce shared page 



For transparent variable sharing between the hypervisor and guest, I introduce
a shared page. This shared page will contain all the registers the guest can
read and write safely without exiting guest context.

This patch only implements the stubs required for the basic structure of the
shared page. The actual register moving follows.

Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 34698d8c

arch/powerpc/include/asm/kvm_host.h

+2 −0
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ 
#include <linux/interrupt.h>

#include <linux/types.h>

#include <linux/kvm_types.h>

#include <linux/kvm_para.h>

#include <asm/kvm_asm.h>



#define KVM_MAX_VCPUS 1
@@ -290,6 +291,7 @@ struct kvm_vcpu_arch { 
	struct tasklet_struct tasklet;

	u64 dec_jiffies;

	unsigned long pending_exceptions;

	struct kvm_vcpu_arch_shared *shared;



#ifdef CONFIG_PPC_BOOK3S

	struct hlist_head hpte_hash_pte[HPTEG_HASH_NUM_PTE];

arch/powerpc/include/asm/kvm_para.h

+5 −0
Original line number Diff line number Diff line
@@ -20,6 +20,11 @@ 
#ifndef __POWERPC_KVM_PARA_H__

#define __POWERPC_KVM_PARA_H__



#include <linux/types.h>



struct kvm_vcpu_arch_shared {

};



#ifdef __KERNEL__



static inline int kvm_para_available(void)

arch/powerpc/kernel/asm-offsets.c

+1 −0
Original line number Diff line number Diff line
@@ -400,6 +400,7 @@ int main(void) 
	DEFINE(VCPU_SPRG6, offsetof(struct kvm_vcpu, arch.sprg6));

	DEFINE(VCPU_SPRG7, offsetof(struct kvm_vcpu, arch.sprg7));

	DEFINE(VCPU_SHADOW_PID, offsetof(struct kvm_vcpu, arch.shadow_pid));

	DEFINE(VCPU_SHARED, offsetof(struct kvm_vcpu, arch.shared));



	/* book3s */

#ifdef CONFIG_PPC_BOOK3S

arch/powerpc/kvm/44x.c

+7 −0
Original line number Diff line number Diff line
@@ -123,8 +123,14 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id) 
	if (err)

		goto free_vcpu;



	vcpu->arch.shared = (void*)__get_free_page(GFP_KERNEL|__GFP_ZERO);

	if (!vcpu->arch.shared)

		goto uninit_vcpu;



	return vcpu;



uninit_vcpu:

	kvm_vcpu_uninit(vcpu);

free_vcpu:

	kmem_cache_free(kvm_vcpu_cache, vcpu_44x);

out:
@@ -135,6 +141,7 @@ void kvmppc_core_vcpu_free(struct kvm_vcpu *vcpu) 
{

	struct kvmppc_vcpu_44x *vcpu_44x = to_44x(vcpu);



	free_page((unsigned long)vcpu->arch.shared);

	kvm_vcpu_uninit(vcpu);

	kmem_cache_free(kvm_vcpu_cache, vcpu_44x);

}

arch/powerpc/kvm/book3s.c

+8 −1
Original line number Diff line number Diff line
@@ -1242,6 +1242,10 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id) 
	if (err)

		goto free_shadow_vcpu;



	vcpu->arch.shared = (void*)__get_free_page(GFP_KERNEL|__GFP_ZERO);

	if (!vcpu->arch.shared)

		goto uninit_vcpu;



	vcpu->arch.host_retip = kvm_return_point;

	vcpu->arch.host_msr = mfmsr();

#ifdef CONFIG_PPC_BOOK3S_64
@@ -1268,10 +1272,12 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id) 


	err = kvmppc_mmu_init(vcpu);

	if (err < 0)

		goto free_shadow_vcpu;

		goto uninit_vcpu;



	return vcpu;



uninit_vcpu:

	kvm_vcpu_uninit(vcpu);

free_shadow_vcpu:

	kfree(vcpu_book3s->shadow_vcpu);

free_vcpu:
@@ -1284,6 +1290,7 @@ void kvmppc_core_vcpu_free(struct kvm_vcpu *vcpu) 
{

	struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);



	free_page((unsigned long)vcpu->arch.shared);

	kvm_vcpu_uninit(vcpu);

	kfree(vcpu_book3s->shadow_vcpu);

	vfree(vcpu_book3s);

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