From 1b0462e574f5238bb1ee811f014d629092c160cb Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Wed, 1 Jan 2014 16:31:49 +0100 Subject: [PATCH] KVM: s390: add 'pgm' member to kvm_vcpu_arch and helper function Add a 'struct kvm_s390_pgm_info pgm' member to kvm_vcpu_arch. This structure will be used if during instruction emulation in the context of a vcpu exception data needs to be stored somewhere. Also add a helper function kvm_s390_inject_prog_cond() which can inject vcpu's last exception if needed. Signed-off-by: Heiko Carstens Reviewed-by: Cornelia Huck Signed-off-by: Christian Borntraeger --- arch/s390/include/asm/kvm_host.h | 1 + arch/s390/kvm/kvm-s390.h | 33 ++++++++++++++++++++++++++++++++ 2 files changed, 34 insertions(+) diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h index 90905ca93725..c290d443d2c1 100644 --- a/arch/s390/include/asm/kvm_host.h +++ b/arch/s390/include/asm/kvm_host.h @@ -286,6 +286,7 @@ struct kvm_vcpu_arch { struct kvm_s390_local_interrupt local_int; struct hrtimer ckc_timer; struct tasklet_struct tasklet; + struct kvm_s390_pgm_info pgm; union { struct cpuid cpu_id; u64 stidp_data; diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h index f3ab9fcad496..11ed0a596b5a 100644 --- a/arch/s390/kvm/kvm-s390.h +++ b/arch/s390/kvm/kvm-s390.h @@ -170,6 +170,39 @@ int kvm_s390_handle_diag(struct kvm_vcpu *vcpu); int kvm_s390_inject_prog_irq(struct kvm_vcpu *vcpu, struct kvm_s390_pgm_info *pgm_info); +/** + * kvm_s390_inject_prog_cond - conditionally inject a program check + * @vcpu: virtual cpu + * @rc: original return/error code + * + * This function is supposed to be used after regular guest access functions + * failed, to conditionally inject a program check to a vcpu. The typical + * pattern would look like + * + * rc = write_guest(vcpu, addr, data, len); + * if (rc) + * return kvm_s390_inject_prog_cond(vcpu, rc); + * + * A negative return code from guest access functions implies an internal error + * like e.g. out of memory. In these cases no program check should be injected + * to the guest. + * A positive value implies that an exception happened while accessing a guest's + * memory. In this case all data belonging to the corresponding program check + * has been stored in vcpu->arch.pgm and can be injected with + * kvm_s390_inject_prog_irq(). + * + * Returns: - the original @rc value if @rc was negative (internal error) + * - zero if @rc was already zero + * - zero or error code from injecting if @rc was positive + * (program check injected to @vcpu) + */ +static inline int kvm_s390_inject_prog_cond(struct kvm_vcpu *vcpu, int rc) +{ + if (rc <= 0) + return rc; + return kvm_s390_inject_prog_irq(vcpu, &vcpu->arch.pgm); +} + /* implemented in interrupt.c */ int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu); int psw_extint_disabled(struct kvm_vcpu *vcpu); -- 2.20.1