From: David Hildenbrand <d...@linux.vnet.ibm.com>
We can avoid loads of syscalls when dropping to user space by storing the values
of more registers directly within kvm_run.
Support is added for:
- ARCH0: CPU timer, clock comparator, TOD programmable register,
guest breaking-event register, program parameter
- PFAULT: pfault parameters (token, select, compare)
Signed-off-by: David Hildenbrand <d...@linux.vnet.ibm.com>
Signed-off-by: Jens Freimann <jf...@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.h...@de.ibm.com>
Acked-by: Christian Borntraeger <borntrae...@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.h...@de.ibm.com>
---
target-s390x/kvm.c | 72 ++++++++++++++++++++++++++++++++++++----------------
1 file changed, 50 insertions(+), 22 deletions(-)
diff --git a/target-s390x/kvm.c b/target-s390x/kvm.c
index 1483082..d188c8b 100644
--- a/target-s390x/kvm.c
+++ b/target-s390x/kvm.c
@@ -252,18 +252,33 @@ int kvm_arch_put_registers(CPUState *cs, int level)
return 0;
}
- /*
- * These ONE_REGS are not protected by a capability. As they are only
- * necessary for migration we just trace a possible error, but don't
- * return with an error return code.
- */
- kvm_set_one_reg(cs, KVM_REG_S390_CPU_TIMER, &env->cputm);
- kvm_set_one_reg(cs, KVM_REG_S390_CLOCK_COMP, &env->ckc);
- kvm_set_one_reg(cs, KVM_REG_S390_TODPR, &env->todpr);
- kvm_set_one_reg(cs, KVM_REG_S390_GBEA, &env->gbea);
- kvm_set_one_reg(cs, KVM_REG_S390_PP, &env->pp);
+ if (can_sync_regs(cs, KVM_SYNC_ARCH0)) {
+ cs->kvm_run->s.regs.cputm = env->cputm;
+ cs->kvm_run->s.regs.ckc = env->ckc;
+ cs->kvm_run->s.regs.todpr = env->todpr;
+ cs->kvm_run->s.regs.gbea = env->gbea;
+ cs->kvm_run->s.regs.pp = env->pp;
+ cs->kvm_run->kvm_dirty_regs |= KVM_SYNC_ARCH0;
+ } else {
+ /*
+ * These ONE_REGS are not protected by a capability. As they are only
+ * necessary for migration we just trace a possible error, but don't
+ * return with an error return code.
+ */
+ kvm_set_one_reg(cs, KVM_REG_S390_CPU_TIMER, &env->cputm);
+ kvm_set_one_reg(cs, KVM_REG_S390_CLOCK_COMP, &env->ckc);
+ kvm_set_one_reg(cs, KVM_REG_S390_TODPR, &env->todpr);
+ kvm_set_one_reg(cs, KVM_REG_S390_GBEA, &env->gbea);
+ kvm_set_one_reg(cs, KVM_REG_S390_PP, &env->pp);
+ }
- if (cap_async_pf) {
+ /* pfault parameters */
+ if (can_sync_regs(cs, KVM_SYNC_PFAULT)) {
+ cs->kvm_run->s.regs.pft = env->pfault_token;
+ cs->kvm_run->s.regs.pfs = env->pfault_select;
+ cs->kvm_run->s.regs.pfc = env->pfault_compare;
+ cs->kvm_run->kvm_dirty_regs |= KVM_SYNC_PFAULT;
+ } else if (cap_async_pf) {
r = kvm_set_one_reg(cs, KVM_REG_S390_PFTOKEN, &env->pfault_token);
if (r < 0) {
return r;
@@ -367,18 +382,31 @@ int kvm_arch_get_registers(CPUState *cs)
env->psa = cs->kvm_run->s.regs.prefix;
}
- /*
- * These ONE_REGS are not protected by a capability. As they are only
- * necessary for migration we just trace a possible error, but don't
- * return with an error return code.
- */
- kvm_get_one_reg(cs, KVM_REG_S390_CPU_TIMER, &env->cputm);
- kvm_get_one_reg(cs, KVM_REG_S390_CLOCK_COMP, &env->ckc);
- kvm_get_one_reg(cs, KVM_REG_S390_TODPR, &env->todpr);
- kvm_get_one_reg(cs, KVM_REG_S390_GBEA, &env->gbea);
- kvm_get_one_reg(cs, KVM_REG_S390_PP, &env->pp);
+ if (can_sync_regs(cs, KVM_SYNC_ARCH0)) {
+ env->cputm = cs->kvm_run->s.regs.cputm;
+ env->ckc = cs->kvm_run->s.regs.ckc;
+ env->todpr = cs->kvm_run->s.regs.todpr;
+ env->gbea = cs->kvm_run->s.regs.gbea;
+ env->pp = cs->kvm_run->s.regs.pp;
+ } else {
+ /*
+ * These ONE_REGS are not protected by a capability. As they are only
+ * necessary for migration we just trace a possible error, but don't
+ * return with an error return code.
+ */
+ kvm_get_one_reg(cs, KVM_REG_S390_CPU_TIMER, &env->cputm);
+ kvm_get_one_reg(cs, KVM_REG_S390_CLOCK_COMP, &env->ckc);
+ kvm_get_one_reg(cs, KVM_REG_S390_TODPR, &env->todpr);
+ kvm_get_one_reg(cs, KVM_REG_S390_GBEA, &env->gbea);
+ kvm_get_one_reg(cs, KVM_REG_S390_PP, &env->pp);
+ }
- if (cap_async_pf) {
+ /* pfault parameters */
+ if (can_sync_regs(cs, KVM_SYNC_PFAULT)) {
+ env->pfault_token = cs->kvm_run->s.regs.pft;
+ env->pfault_select = cs->kvm_run->s.regs.pfs;
+ env->pfault_compare = cs->kvm_run->s.regs.pfc;
+ } else if (cap_async_pf) {
r = kvm_get_one_reg(cs, KVM_REG_S390_PFTOKEN, &env->pfault_token);
if (r < 0) {
return r;
--
1.7.9.5
