diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/s390/include/asm/pgtable.h | 2 | ||||
| -rw-r--r-- | arch/s390/include/asm/processor.h | 1 | ||||
| -rw-r--r-- | arch/s390/kvm/kvm-s390.c | 23 | ||||
| -rw-r--r-- | arch/s390/mm/fault.c | 26 |
4 files changed, 46 insertions, 6 deletions
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h index 2204400d0bd5..66101f6c6d81 100644 --- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -767,6 +767,7 @@ static inline void pgste_set_pte(pte_t *ptep, pte_t entry) * @table: pointer to the page directory * @asce: address space control element for gmap page table * @crst_list: list of all crst tables used in the guest address space + * @pfault_enabled: defines if pfaults are applicable for the guest */ struct gmap { struct list_head list; @@ -775,6 +776,7 @@ struct gmap { unsigned long asce; void *private; struct list_head crst_list; + bool pfault_enabled; }; /** diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h index 0a876bc543d3..dc5fc4f90e52 100644 --- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -79,6 +79,7 @@ struct thread_struct { unsigned long ksp; /* kernel stack pointer */ mm_segment_t mm_segment; unsigned long gmap_addr; /* address of last gmap fault. */ + unsigned int gmap_pfault; /* signal of a pending guest pfault */ struct per_regs per_user; /* User specified PER registers */ struct per_event per_event; /* Cause of the last PER trap */ unsigned long per_flags; /* Flags to control debug behavior */ diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 782420f3c4d5..9eec794caa7f 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -255,6 +255,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) if (!kvm->arch.gmap) goto out_nogmap; kvm->arch.gmap->private = kvm; + kvm->arch.gmap->pfault_enabled = 0; } kvm->arch.css_support = 0; @@ -701,6 +702,17 @@ static int kvm_s390_handle_requests(struct kvm_vcpu *vcpu) return 0; } +static long kvm_arch_fault_in_sync(struct kvm_vcpu *vcpu) +{ + long rc; + hva_t fault = gmap_fault(current->thread.gmap_addr, vcpu->arch.gmap); + struct mm_struct *mm = current->mm; + down_read(&mm->mmap_sem); + rc = get_user_pages(current, mm, fault, 1, 1, 0, NULL, NULL); + up_read(&mm->mmap_sem); + return rc; +} + static int vcpu_pre_run(struct kvm_vcpu *vcpu) { int rc, cpuflags; @@ -730,7 +742,7 @@ static int vcpu_pre_run(struct kvm_vcpu *vcpu) static int vcpu_post_run(struct kvm_vcpu *vcpu, int exit_reason) { - int rc; + int rc = -1; VCPU_EVENT(vcpu, 6, "exit sie icptcode %d", vcpu->arch.sie_block->icptcode); @@ -744,7 +756,14 @@ static int vcpu_post_run(struct kvm_vcpu *vcpu, int exit_reason) current->thread.gmap_addr; vcpu->run->s390_ucontrol.pgm_code = 0x10; rc = -EREMOTE; - } else { + + } else if (current->thread.gmap_pfault) { + current->thread.gmap_pfault = 0; + if (kvm_arch_fault_in_sync(vcpu) >= 0) + rc = 0; + } + + if (rc == -1) { VCPU_EVENT(vcpu, 3, "%s", "fault in sie instruction"); trace_kvm_s390_sie_fault(vcpu); rc = kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING); diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c index d95265b2719f..88cef505453b 100644 --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c @@ -50,6 +50,7 @@ #define VM_FAULT_BADMAP 0x020000 #define VM_FAULT_BADACCESS 0x040000 #define VM_FAULT_SIGNAL 0x080000 +#define VM_FAULT_PFAULT 0x100000 static unsigned long store_indication __read_mostly; @@ -227,6 +228,7 @@ static noinline void do_fault_error(struct pt_regs *regs, int fault) return; } case VM_FAULT_BADCONTEXT: + case VM_FAULT_PFAULT: do_no_context(regs); break; case VM_FAULT_SIGNAL: @@ -264,6 +266,9 @@ static noinline void do_fault_error(struct pt_regs *regs, int fault) */ static inline int do_exception(struct pt_regs *regs, int access) { +#ifdef CONFIG_PGSTE + struct gmap *gmap; +#endif struct task_struct *tsk; struct mm_struct *mm; struct vm_area_struct *vma; @@ -304,9 +309,10 @@ static inline int do_exception(struct pt_regs *regs, int access) down_read(&mm->mmap_sem); #ifdef CONFIG_PGSTE - if ((current->flags & PF_VCPU) && S390_lowcore.gmap) { - address = __gmap_fault(address, - (struct gmap *) S390_lowcore.gmap); + gmap = (struct gmap *) + ((current->flags & PF_VCPU) ? S390_lowcore.gmap : 0); + if (gmap) { + address = __gmap_fault(address, gmap); if (address == -EFAULT) { fault = VM_FAULT_BADMAP; goto out_up; @@ -315,6 +321,8 @@ static inline int do_exception(struct pt_regs *regs, int access) fault = VM_FAULT_OOM; goto out_up; } + if (gmap->pfault_enabled) + flags |= FAULT_FLAG_RETRY_NOWAIT; } #endif @@ -371,9 +379,19 @@ retry: regs, address); } if (fault & VM_FAULT_RETRY) { +#ifdef CONFIG_PGSTE + if (gmap && (flags & FAULT_FLAG_RETRY_NOWAIT)) { + /* FAULT_FLAG_RETRY_NOWAIT has been set, + * mmap_sem has not been released */ + current->thread.gmap_pfault = 1; + fault = VM_FAULT_PFAULT; + goto out_up; + } +#endif /* Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk * of starvation. */ - flags &= ~FAULT_FLAG_ALLOW_RETRY; + flags &= ~(FAULT_FLAG_ALLOW_RETRY | + FAULT_FLAG_RETRY_NOWAIT); flags |= FAULT_FLAG_TRIED; down_read(&mm->mmap_sem); goto retry; |
