mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-09-05 18:39:59 +00:00
Code Issues Releases Wiki Activity

KVM: PPC: Handle magic page in kvmppc_ld/st

Browse source 
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: Alexander Graf <agraf@suse.de>
This commit is contained in:
Alexander Graf 2014-06-20 14:43:36 +02:00
parent c45c551403
commit c12fb43c2f
3 changed files with 39 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

7
arch/powerpc/include/asm/kvm_book3s.h
View file

@ -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

10
arch/powerpc/include/asm/kvm_booke.h
View file

@ -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__ */

22
arch/powerpc/kvm/powerpc.c
View file

@ -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;