KVM: s390: lazy enable RI

Only enable runtime instrumentation if the guest issues an RI related
instruction or if userspace changes the riccb to a valid state.
This makes entry/exit a tiny bit faster.

Initial patch by Christian Borntraeger
Signed-off-by: Fan Zhang <zhangfan@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This commit is contained in:
Fan Zhang 2016-08-15 04:53:22 +02:00 committed by Christian Borntraeger
parent c14b88d766
commit 80cd876338
4 changed files with 36 additions and 2 deletions

View File

@ -29,6 +29,7 @@ static const intercept_handler_t instruction_handlers[256] = {
[0x01] = kvm_s390_handle_01,
[0x82] = kvm_s390_handle_lpsw,
[0x83] = kvm_s390_handle_diag,
[0xaa] = kvm_s390_handle_aa,
[0xae] = kvm_s390_handle_sigp,
[0xb2] = kvm_s390_handle_b2,
[0xb6] = kvm_s390_handle_stctl,

View File

@ -1938,8 +1938,6 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
vcpu->arch.sie_block->eca |= 1;
if (sclp.has_sigpif)
vcpu->arch.sie_block->eca |= 0x10000000U;
if (test_kvm_facility(vcpu->kvm, 64))
vcpu->arch.sie_block->ecb3 |= 0x01;
if (test_kvm_facility(vcpu->kvm, 129)) {
vcpu->arch.sie_block->eca |= 0x00020000;
vcpu->arch.sie_block->ecd |= 0x20000000;
@ -2694,6 +2692,19 @@ static void sync_regs(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
if (vcpu->arch.pfault_token == KVM_S390_PFAULT_TOKEN_INVALID)
kvm_clear_async_pf_completion_queue(vcpu);
}
/*
* If userspace sets the riccb (e.g. after migration) to a valid state,
* we should enable RI here instead of doing the lazy enablement.
*/
if ((kvm_run->kvm_dirty_regs & KVM_SYNC_RICCB) &&
test_kvm_facility(vcpu->kvm, 64)) {
struct runtime_instr_cb *riccb =
(struct runtime_instr_cb *) &kvm_run->s.regs.riccb;
if (riccb->valid)
vcpu->arch.sie_block->ecb3 |= 0x01;
}
kvm_run->kvm_dirty_regs = 0;
}

View File

@ -245,6 +245,7 @@ static inline void kvm_s390_retry_instr(struct kvm_vcpu *vcpu)
/* implemented in priv.c */
int is_valid_psw(psw_t *psw);
int kvm_s390_handle_aa(struct kvm_vcpu *vcpu);
int kvm_s390_handle_b2(struct kvm_vcpu *vcpu);
int kvm_s390_handle_e5(struct kvm_vcpu *vcpu);
int kvm_s390_handle_01(struct kvm_vcpu *vcpu);

View File

@ -32,6 +32,24 @@
#include "kvm-s390.h"
#include "trace.h"
static int handle_ri(struct kvm_vcpu *vcpu)
{
if (test_kvm_facility(vcpu->kvm, 64)) {
vcpu->arch.sie_block->ecb3 |= 0x01;
kvm_s390_retry_instr(vcpu);
return 0;
} else
return kvm_s390_inject_program_int(vcpu, PGM_OPERATION);
}
int kvm_s390_handle_aa(struct kvm_vcpu *vcpu)
{
if ((vcpu->arch.sie_block->ipa & 0xf) <= 4)
return handle_ri(vcpu);
else
return -EOPNOTSUPP;
}
/* Handle SCK (SET CLOCK) interception */
static int handle_set_clock(struct kvm_vcpu *vcpu)
{
@ -1093,6 +1111,9 @@ static int handle_stctg(struct kvm_vcpu *vcpu)
static const intercept_handler_t eb_handlers[256] = {
[0x2f] = handle_lctlg,
[0x25] = handle_stctg,
[0x60] = handle_ri,
[0x61] = handle_ri,
[0x62] = handle_ri,
};
int kvm_s390_handle_eb(struct kvm_vcpu *vcpu)