diff options
| author | Ilya Leoshkevich <iii@linux.ibm.com> | 2023-07-25 17:37:17 +0300 |
|---|---|---|
| committer | Janosch Frank <frankja@linux.ibm.com> | 2023-08-28 12:24:19 +0300 |
| commit | 74a439ef7b67d89d29ec7485c3aeca20a64449c5 (patch) | |
| tree | aaade94674733cd89121d0fc19e05d22123b3b73 /arch/s390/kvm/intercept.c | |
| parent | 16631c42e6ff4f5acf30998fda6c2ea09d1adbfe (diff) | |
| download | linux-74a439ef7b67d89d29ec7485c3aeca20a64449c5.tar.xz | |
KVM: s390: interrupt: Fix single-stepping into program interrupt handlers
Currently, after single-stepping an instruction that generates a
specification exception, GDB ends up on the instruction immediately
following it.
The reason is that vcpu_post_run() injects the interrupt and sets
KVM_GUESTDBG_EXIT_PENDING, causing a KVM_SINGLESTEP exit. The
interrupt is not delivered, however, therefore userspace sees the
address of the next instruction.
Fix by letting the __vcpu_run() loop go into the next iteration,
where vcpu_pre_run() delivers the interrupt and sets
KVM_GUESTDBG_EXIT_PENDING.
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Message-ID: <20230725143857.228626-3-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/kvm/intercept.c')
| -rw-r--r-- | arch/s390/kvm/intercept.c | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c index 954d39adf85c..e54496740859 100644 --- a/arch/s390/kvm/intercept.c +++ b/arch/s390/kvm/intercept.c @@ -228,6 +228,21 @@ static int handle_itdb(struct kvm_vcpu *vcpu) #define per_event(vcpu) (vcpu->arch.sie_block->iprcc & PGM_PER) +static bool should_handle_per_event(const struct kvm_vcpu *vcpu) +{ + if (!guestdbg_enabled(vcpu) || !per_event(vcpu)) + return false; + if (guestdbg_sstep_enabled(vcpu) && + vcpu->arch.sie_block->iprcc != PGM_PER) { + /* + * __vcpu_run() will exit after delivering the concurrently + * indicated condition. + */ + return false; + } + return true; +} + static int handle_prog(struct kvm_vcpu *vcpu) { psw_t psw; @@ -242,7 +257,7 @@ static int handle_prog(struct kvm_vcpu *vcpu) if (kvm_s390_pv_cpu_is_protected(vcpu)) return -EOPNOTSUPP; - if (guestdbg_enabled(vcpu) && per_event(vcpu)) { + if (should_handle_per_event(vcpu)) { rc = kvm_s390_handle_per_event(vcpu); if (rc) return rc; |