diff options
| author | Ilya Leoshkevich <iii@linux.ibm.com> | 2023-07-25 16:37:18 +0200 |
|---|---|---|
| committer | Janosch Frank <frankja@linux.ibm.com> | 2023-08-28 11:24:19 +0200 |
| commit | ba853a4e1c7addc631df55535bf0b04c62dc79d8 (patch) | |
| tree | 6b85fcc2e0a89e26a7fbd17cad63331aeda501a4 /arch/s390 | |
| parent | KVM: s390: interrupt: Fix single-stepping into program interrupt handlers (diff) | |
| download | linux-ba853a4e1c7addc631df55535bf0b04c62dc79d8.tar.xz linux-ba853a4e1c7addc631df55535bf0b04c62dc79d8.zip | |
KVM: s390: interrupt: Fix single-stepping kernel-emulated instructions
Single-stepping a kernel-emulated instruction that generates an
interrupt causes GDB to land on the instruction following it instead of
the respective interrupt handler.
The reason is that kvm_handle_sie_intercept(), after injecting the
interrupt, also processes the PER event and arranges a KVM_SINGLESTEP
exit. The interrupt is not yet delivered, however, so the userspace
sees the next instruction.
Fix by avoiding the KVM_SINGLESTEP exit when there is a pending
interrupt. The next __vcpu_run() loop iteration will arrange a
KVM_SINGLESTEP exit after delivering the interrupt.
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-ID: <20230725143857.228626-4-iii@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/kvm/intercept.c | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c index e54496740859..db222c749e5e 100644 --- a/arch/s390/kvm/intercept.c +++ b/arch/s390/kvm/intercept.c @@ -583,6 +583,19 @@ static int handle_pv_notification(struct kvm_vcpu *vcpu) return handle_instruction(vcpu); } +static bool should_handle_per_ifetch(const struct kvm_vcpu *vcpu, int rc) +{ + /* Process PER, also if the instruction is processed in user space. */ + if (!(vcpu->arch.sie_block->icptstatus & 0x02)) + return false; + if (rc != 0 && rc != -EOPNOTSUPP) + return false; + if (guestdbg_sstep_enabled(vcpu) && vcpu->arch.local_int.pending_irqs) + /* __vcpu_run() will exit after delivering the interrupt. */ + return false; + return true; +} + int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu) { int rc, per_rc = 0; @@ -645,9 +658,7 @@ int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu) return -EOPNOTSUPP; } - /* process PER, also if the instruction is processed in user space */ - if (vcpu->arch.sie_block->icptstatus & 0x02 && - (!rc || rc == -EOPNOTSUPP)) + if (should_handle_per_ifetch(vcpu, rc)) per_rc = kvm_s390_handle_per_ifetch_icpt(vcpu); return per_rc ? per_rc : rc; } |