Commit c12fb43c authored by Alexander Graf's avatar Alexander Graf
Browse files

KVM: PPC: Handle magic page in kvmppc_ld/st 



We use kvmppc_ld and kvmppc_st to emulate load/store instructions that may as
well access the magic page. Special case it out so that we can properly access
it.

Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
parent c45c5514

arch/powerpc/include/asm/kvm_book3s.h

+7 −0
Original line number Diff line number Diff line
@@ -286,6 +286,13 @@ static inline bool is_kvmppc_resume_guest(int r) 
	return (r == RESUME_GUEST || r == RESUME_GUEST_NV);

}



static inline bool is_kvmppc_hv_enabled(struct kvm *kvm);

static inline bool kvmppc_supports_magic_page(struct kvm_vcpu *vcpu)

{

	/* Only PR KVM supports the magic page */

	return !is_kvmppc_hv_enabled(vcpu->kvm);

}



/* Magic register values loaded into r3 and r4 before the 'sc' assembly

 * instruction for the OSI hypercalls */

#define OSI_SC_MAGIC_R3			0x113724FA

arch/powerpc/include/asm/kvm_booke.h

+10 −0
Original line number Diff line number Diff line
@@ -103,4 +103,14 @@ static inline ulong kvmppc_get_fault_dar(struct kvm_vcpu *vcpu) 
{

	return vcpu->arch.fault_dear;

}



static inline bool kvmppc_supports_magic_page(struct kvm_vcpu *vcpu)

{

	/* Magic page is only supported on e500v2 */

#ifdef CONFIG_KVM_E500V2

	return true;

#else

	return false;

#endif

}

#endif /* __ASM_KVM_BOOKE_H__ */

arch/powerpc/kvm/powerpc.c

+22 −0
Original line number Diff line number Diff line
@@ -312,6 +312,7 @@ EXPORT_SYMBOL_GPL(kvmppc_emulate_mmio); 
int kvmppc_st(struct kvm_vcpu *vcpu, ulong *eaddr, int size, void *ptr,

	      bool data)

{

	ulong mp_pa = vcpu->arch.magic_page_pa & KVM_PAM & PAGE_MASK;

	struct kvmppc_pte pte;

	int r;
@@ -327,6 +328,16 @@ int kvmppc_st(struct kvm_vcpu *vcpu, ulong *eaddr, int size, void *ptr, 
	if (!pte.may_write)

		return -EPERM;



	/* Magic page override */

	if (kvmppc_supports_magic_page(vcpu) && mp_pa &&

	    ((pte.raddr & KVM_PAM & PAGE_MASK) == mp_pa) &&

	    !(kvmppc_get_msr(vcpu) & MSR_PR)) {

		void *magic = vcpu->arch.shared;

		magic += pte.eaddr & 0xfff;

		memcpy(magic, ptr, size);

		return EMULATE_DONE;

	}



	if (kvm_write_guest(vcpu->kvm, pte.raddr, ptr, size))

		return EMULATE_DO_MMIO;
@@ -337,6 +348,7 @@ EXPORT_SYMBOL_GPL(kvmppc_st); 
int kvmppc_ld(struct kvm_vcpu *vcpu, ulong *eaddr, int size, void *ptr,

		      bool data)

{

	ulong mp_pa = vcpu->arch.magic_page_pa & KVM_PAM & PAGE_MASK;

	struct kvmppc_pte pte;

	int rc;
@@ -355,6 +367,16 @@ int kvmppc_ld(struct kvm_vcpu *vcpu, ulong *eaddr, int size, void *ptr, 
	if (!data && !pte.may_execute)

		return -ENOEXEC;



	/* Magic page override */

	if (kvmppc_supports_magic_page(vcpu) && mp_pa &&

	    ((pte.raddr & KVM_PAM & PAGE_MASK) == mp_pa) &&

	    !(kvmppc_get_msr(vcpu) & MSR_PR)) {

		void *magic = vcpu->arch.shared;

		magic += pte.eaddr & 0xfff;

		memcpy(ptr, magic, size);

		return EMULATE_DONE;

	}



	if (kvm_read_guest(vcpu->kvm, pte.raddr, ptr, size))

		return EMULATE_DO_MMIO;