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[Qemu-devel] [PULL v3 4/7] s390x/kvm: avoid syscalls by syncing register
From: |
Cornelia Huck |
Subject: |
[Qemu-devel] [PULL v3 4/7] s390x/kvm: avoid syscalls by syncing registers with kvm_run |
Date: |
Mon, 12 Jan 2015 11:04:49 +0100 |
From: David Hildenbrand <address@hidden>
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 <address@hidden>
Signed-off-by: Jens Freimann <address@hidden>
Reviewed-by: Cornelia Huck <address@hidden>
Acked-by: Christian Borntraeger <address@hidden>
Signed-off-by: Cornelia Huck <address@hidden>
---
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
- [Qemu-devel] [PULL v3 0/7] s390x patches for 2.3, Cornelia Huck, 2015/01/12
- [Qemu-devel] [PULL v3 1/7] s390x/ccw: fix oddity in machine class init, Cornelia Huck, 2015/01/12
- [Qemu-devel] [PULL v3 3/7] s390x/kvm: sync register support helper function, Cornelia Huck, 2015/01/12
- [Qemu-devel] [PULL v3 2/7] s390x/css: Clean up unnecessary CONFIG_USER_ONLY wrappers, Cornelia Huck, 2015/01/12
- [Qemu-devel] [PULL v3 5/7] s390: Add PCI bus support, Cornelia Huck, 2015/01/12
- [Qemu-devel] [PULL v3 4/7] s390x/kvm: avoid syscalls by syncing registers with kvm_run,
Cornelia Huck <=
- [Qemu-devel] [PULL v3 6/7] s390: implement pci instructions, Cornelia Huck, 2015/01/12
- [Qemu-devel] [PULL v3 7/7] kvm: extend kvm_irqchip_add_msi_route to work on s390, Cornelia Huck, 2015/01/12
- Re: [Qemu-devel] [PULL v3 0/7] s390x patches for 2.3, Peter Maydell, 2015/01/12