From: David Hildenbrand <dahi@xxxxxxxxxxxxxxxxxx>
In order to reduce the number of syscalls when dropping to user space, this
patch enables the synchronization of the following "registers" with kvm_run:
- ARCH0: CPU timer, clock comparator, TOD programmable register,
guest breaking-event register, program parameter
- PFAULT: pfault parameters (token, select, compare)
The registers are grouped to reduce the overhead when syncing.
As this grows the number of sync registers quite a bit, let's move the code
synchronizing registers with kvm_run from kvm_arch_vcpu_ioctl_run() into
separate helper routines.
Signed-off-by: David Hildenbrand <dahi@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Cornelia Huck <cornelia.huck@xxxxxxxxxx>
Reviewed-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
---
arch/s390/include/uapi/asm/kvm.h | 10 +++++++
arch/s390/kvm/kvm-s390.c | 60 ++++++++++++++++++++++++++++++----------
2 files changed, 56 insertions(+), 14 deletions(-)
diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h
index 0fc2643..48eda3a 100644
--- a/arch/s390/include/uapi/asm/kvm.h
+++ b/arch/s390/include/uapi/asm/kvm.h
@@ -111,12 +111,22 @@ struct kvm_guest_debug_arch {
#define KVM_SYNC_GPRS (1UL << 1)
#define KVM_SYNC_ACRS (1UL << 2)
#define KVM_SYNC_CRS (1UL << 3)
+#define KVM_SYNC_ARCH0 (1UL << 4)
+#define KVM_SYNC_PFAULT (1UL << 5)
/* definition of registers in kvm_run */
struct kvm_sync_regs {
__u64 prefix; /* prefix register */
__u64 gprs[16]; /* general purpose registers */
__u32 acrs[16]; /* access registers */
__u64 crs[16]; /* control registers */
+ __u64 todpr; /* tod programmable register [ARCH0] */
+ __u64 cputm; /* cpu timer [ARCH0] */
+ __u64 ckc; /* clock comparator [ARCH0] */
+ __u64 pp; /* program parameter [ARCH0] */
+ __u64 gbea; /* guest breaking-event address [ARCH0] */
+ __u64 pft; /* pfault token [PFAULT] */
+ __u64 pfs; /* pfault select [PFAULT] */
+ __u64 pfc; /* pfault compare [PFAULT] */
};
#define KVM_REG_S390_TODPR (KVM_REG_S390 | KVM_REG_SIZE_U32 | 0x1)
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index f00d0b0..ab7cd64 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -546,7 +546,9 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
vcpu->run->kvm_valid_regs = KVM_SYNC_PREFIX |
KVM_SYNC_GPRS |
KVM_SYNC_ACRS |
- KVM_SYNC_CRS;
+ KVM_SYNC_CRS |
+ KVM_SYNC_ARCH0 |
+ KVM_SYNC_PFAULT;
return 0;
}
@@ -1296,6 +1298,47 @@ static int __vcpu_run(struct kvm_vcpu *vcpu)
return rc;
}
+static void sync_regs(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
+{
+ vcpu->arch.sie_block->gpsw.mask = kvm_run->psw_mask;
+ vcpu->arch.sie_block->gpsw.addr = kvm_run->psw_addr;
+ if (kvm_run->kvm_dirty_regs & KVM_SYNC_PREFIX)
+ kvm_s390_set_prefix(vcpu, kvm_run->s.regs.prefix);
+ if (kvm_run->kvm_dirty_regs & KVM_SYNC_CRS) {
+ memcpy(&vcpu->arch.sie_block->gcr, &kvm_run->s.regs.crs, 128);
+ kvm_s390_set_prefix(vcpu, kvm_run->s.regs.prefix);
+ }
+ if (kvm_run->kvm_dirty_regs & KVM_SYNC_ARCH0) {
+ vcpu->arch.sie_block->cputm = kvm_run->s.regs.cputm;
+ vcpu->arch.sie_block->ckc = kvm_run->s.regs.ckc;
+ vcpu->arch.sie_block->todpr = kvm_run->s.regs.todpr;
+ vcpu->arch.sie_block->pp = kvm_run->s.regs.pp;
+ vcpu->arch.sie_block->gbea = kvm_run->s.regs.gbea;
+ }
+ if (kvm_run->kvm_dirty_regs & KVM_SYNC_PFAULT) {
+ vcpu->arch.pfault_token = kvm_run->s.regs.pft;
+ vcpu->arch.pfault_select = kvm_run->s.regs.pfs;
+ vcpu->arch.pfault_compare = kvm_run->s.regs.pfc;
+ }
+ kvm_run->kvm_dirty_regs = 0;
+}
+
+static void store_regs(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
+{
+ kvm_run->psw_mask = vcpu->arch.sie_block->gpsw.mask;
+ kvm_run->psw_addr = vcpu->arch.sie_block->gpsw.addr;
+ kvm_run->s.regs.prefix = kvm_s390_get_prefix(vcpu);
+ memcpy(&kvm_run->s.regs.crs, &vcpu->arch.sie_block->gcr, 128);
+ kvm_run->s.regs.cputm = vcpu->arch.sie_block->cputm;
+ kvm_run->s.regs.ckc = vcpu->arch.sie_block->ckc;
+ kvm_run->s.regs.todpr = vcpu->arch.sie_block->todpr;
+ kvm_run->s.regs.pp = vcpu->arch.sie_block->pp;
+ kvm_run->s.regs.gbea = vcpu->arch.sie_block->gbea;
+ kvm_run->s.regs.pft = vcpu->arch.pfault_token;
+ kvm_run->s.regs.pfs = vcpu->arch.pfault_select;
+ kvm_run->s.regs.pfc = vcpu->arch.pfault_compare;
+}
+
int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
int rc;
@@ -1317,15 +1360,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
return -EINVAL;
}
- vcpu->arch.sie_block->gpsw.mask = kvm_run->psw_mask;
- vcpu->arch.sie_block->gpsw.addr = kvm_run->psw_addr;
- if (kvm_run->kvm_dirty_regs & KVM_SYNC_PREFIX)
- kvm_s390_set_prefix(vcpu, kvm_run->s.regs.prefix);
- if (kvm_run->kvm_dirty_regs & KVM_SYNC_CRS) {
- memcpy(&vcpu->arch.sie_block->gcr, &kvm_run->s.regs.crs, 128);
- kvm_s390_set_prefix(vcpu, kvm_run->s.regs.prefix);
- }
- kvm_run->kvm_dirty_regs = 0;
+ sync_regs(vcpu, kvm_run);
might_fault();
rc = __vcpu_run(vcpu);
@@ -1355,10 +1390,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
rc = 0;
}
- kvm_run->psw_mask = vcpu->arch.sie_block->gpsw.mask;
- kvm_run->psw_addr = vcpu->arch.sie_block->gpsw.addr;
- kvm_run->s.regs.prefix = kvm_s390_get_prefix(vcpu);
- memcpy(&kvm_run->s.regs.crs, &vcpu->arch.sie_block->gcr, 128);
+ store_regs(vcpu, kvm_run);
if (vcpu->sigset_active)
sigprocmask(SIG_SETMASK, &sigsaved, NULL);
--
1.8.4.2
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