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| author | David Hildenbrand <dahi@linux.vnet.ibm.com> | 2014-10-09 16:10:13 +0400 |
|---|---|---|
| committer | Christian Borntraeger <borntraeger@de.ibm.com> | 2015-01-23 15:25:37 +0300 |
| commit | 2444b352c3acf54897b0e2803a7c4e66699f9f43 (patch) | |
| tree | 42490c1860791c4d674fe8c40aaf77c4d0407ab7 /arch/s390/kvm/sigp.c | |
| parent | 9fbd80828cef1b1bba5a293609a021047bb86a7e (diff) | |
| download | linux-2444b352c3acf54897b0e2803a7c4e66699f9f43.tar.xz | |
KVM: s390: forward most SIGP orders to user space
Most SIGP orders are handled partially in kernel and partially in
user space. In order to:
- Get a correct SIGP SET PREFIX handler that informs user space
- Avoid race conditions between concurrently executed SIGP orders
- Serialize SIGP orders per VCPU
We need to handle all "slow" SIGP orders in user space. The remaining
ones to be handled completely in kernel are:
- SENSE
- SENSE RUNNING
- EXTERNAL CALL
- EMERGENCY SIGNAL
- CONDITIONAL EMERGENCY SIGNAL
According to the PoP, they have to be fast. They can be executed
without conflicting to the actions of other pending/concurrently
executing orders (e.g. STOP vs. START).
This patch introduces a new capability that will - when enabled -
forward all but the mentioned SIGP orders to user space. The
instruction counters in the kernel are still updated.
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Diffstat (limited to 'arch/s390/kvm/sigp.c')
| -rw-r--r-- | arch/s390/kvm/sigp.c | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/arch/s390/kvm/sigp.c b/arch/s390/kvm/sigp.c index 1524be9120ad..23b1e86b2122 100644 --- a/arch/s390/kvm/sigp.c +++ b/arch/s390/kvm/sigp.c @@ -371,6 +371,53 @@ static int handle_sigp_dst(struct kvm_vcpu *vcpu, u8 order_code, return rc; } +static int handle_sigp_order_in_user_space(struct kvm_vcpu *vcpu, u8 order_code) +{ + if (!vcpu->kvm->arch.user_sigp) + return 0; + + switch (order_code) { + case SIGP_SENSE: + case SIGP_EXTERNAL_CALL: + case SIGP_EMERGENCY_SIGNAL: + case SIGP_COND_EMERGENCY_SIGNAL: + case SIGP_SENSE_RUNNING: + return 0; + /* update counters as we're directly dropping to user space */ + case SIGP_STOP: + vcpu->stat.instruction_sigp_stop++; + break; + case SIGP_STOP_AND_STORE_STATUS: + vcpu->stat.instruction_sigp_stop_store_status++; + break; + case SIGP_STORE_STATUS_AT_ADDRESS: + vcpu->stat.instruction_sigp_store_status++; + break; + case SIGP_SET_PREFIX: + vcpu->stat.instruction_sigp_prefix++; + break; + case SIGP_START: + vcpu->stat.instruction_sigp_start++; + break; + case SIGP_RESTART: + vcpu->stat.instruction_sigp_restart++; + break; + case SIGP_INITIAL_CPU_RESET: + vcpu->stat.instruction_sigp_init_cpu_reset++; + break; + case SIGP_CPU_RESET: + vcpu->stat.instruction_sigp_cpu_reset++; + break; + default: + vcpu->stat.instruction_sigp_unknown++; + } + + VCPU_EVENT(vcpu, 4, "sigp order %u: completely handled in user space", + order_code); + + return 1; +} + int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu) { int r1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4; @@ -385,6 +432,8 @@ int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu) return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP); order_code = kvm_s390_get_base_disp_rs(vcpu); + if (handle_sigp_order_in_user_space(vcpu, order_code)) + return -EOPNOTSUPP; if (r1 % 2) parameter = vcpu->run->s.regs.gprs[r1]; |