From 71f116bfedfdd6763f2caf842bf40a6506759029 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Mon, 19 Oct 2015 16:24:28 +0200 Subject: [PATCH] KVM: s390: rewrite vcpu_post_run and drop out early Let's rewrite this function to better reflect how we actually handle exit_code. By dropping out early we can save a few cycles. This especially speeds up sie exits caused by host irqs. Also, let's move the special -EOPNOTSUPP for intercepts to the place where it belongs and convert it to -EREMOTE. Reviewed-by: Dominik Dingel Reviewed-by: Cornelia Huck Signed-off-by: David Hildenbrand Signed-off-by: Christian Borntraeger --- arch/s390/kvm/intercept.c | 7 ++--- arch/s390/kvm/kvm-s390.c | 59 ++++++++++++++------------------------- 2 files changed, 24 insertions(+), 42 deletions(-) diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c index b4a5aa110cec..d53c10753c46 100644 --- a/arch/s390/kvm/intercept.c +++ b/arch/s390/kvm/intercept.c @@ -54,9 +54,6 @@ void kvm_s390_rewind_psw(struct kvm_vcpu *vcpu, int ilc) static int handle_noop(struct kvm_vcpu *vcpu) { switch (vcpu->arch.sie_block->icptcode) { - case 0x0: - vcpu->stat.exit_null++; - break; case 0x10: vcpu->stat.exit_external_request++; break; @@ -338,8 +335,10 @@ static int handle_partial_execution(struct kvm_vcpu *vcpu) int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu) { + if (kvm_is_ucontrol(vcpu->kvm)) + return -EOPNOTSUPP; + switch (vcpu->arch.sie_block->icptcode) { - case 0x00: case 0x10: case 0x18: return handle_noop(vcpu); diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 846589281b04..5c36c8e7e937 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -2071,8 +2071,6 @@ static int vcpu_post_run_fault_in_sie(struct kvm_vcpu *vcpu) static int vcpu_post_run(struct kvm_vcpu *vcpu, int exit_reason) { - int rc = -1; - VCPU_EVENT(vcpu, 6, "exit sie icptcode %d", vcpu->arch.sie_block->icptcode); trace_kvm_s390_sie_exit(vcpu, vcpu->arch.sie_block->icptcode); @@ -2080,40 +2078,35 @@ static int vcpu_post_run(struct kvm_vcpu *vcpu, int exit_reason) if (guestdbg_enabled(vcpu)) kvm_s390_restore_guest_per_regs(vcpu); - if (exit_reason >= 0) { - rc = 0; + memcpy(&vcpu->run->s.regs.gprs[14], &vcpu->arch.sie_block->gg14, 16); + + if (vcpu->arch.sie_block->icptcode > 0) { + int rc = kvm_handle_sie_intercept(vcpu); + + if (rc != -EOPNOTSUPP) + return rc; + vcpu->run->exit_reason = KVM_EXIT_S390_SIEIC; + vcpu->run->s390_sieic.icptcode = vcpu->arch.sie_block->icptcode; + vcpu->run->s390_sieic.ipa = vcpu->arch.sie_block->ipa; + vcpu->run->s390_sieic.ipb = vcpu->arch.sie_block->ipb; + return -EREMOTE; + } else if (exit_reason != -EFAULT) { + vcpu->stat.exit_null++; + return 0; } else if (kvm_is_ucontrol(vcpu->kvm)) { vcpu->run->exit_reason = KVM_EXIT_S390_UCONTROL; vcpu->run->s390_ucontrol.trans_exc_code = current->thread.gmap_addr; vcpu->run->s390_ucontrol.pgm_code = 0x10; - rc = -EREMOTE; - + return -EREMOTE; } else if (current->thread.gmap_pfault) { trace_kvm_s390_major_guest_pfault(vcpu); current->thread.gmap_pfault = 0; - if (kvm_arch_setup_async_pf(vcpu)) { - rc = 0; - } else { - gpa_t gpa = current->thread.gmap_addr; - rc = kvm_arch_fault_in_page(vcpu, gpa, 1); - } + if (kvm_arch_setup_async_pf(vcpu)) + return 0; + return kvm_arch_fault_in_page(vcpu, current->thread.gmap_addr, 1); } - - if (rc == -1) - rc = vcpu_post_run_fault_in_sie(vcpu); - - memcpy(&vcpu->run->s.regs.gprs[14], &vcpu->arch.sie_block->gg14, 16); - - if (rc == 0) { - if (kvm_is_ucontrol(vcpu->kvm)) - /* Don't exit for host interrupts. */ - rc = vcpu->arch.sie_block->icptcode ? -EOPNOTSUPP : 0; - else - rc = kvm_handle_sie_intercept(vcpu); - } - - return rc; + return vcpu_post_run_fault_in_sie(vcpu); } static int __vcpu_run(struct kvm_vcpu *vcpu) @@ -2233,18 +2226,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) rc = 0; } - if (rc == -EOPNOTSUPP) { - /* intercept cannot be handled in-kernel, prepare kvm-run */ - kvm_run->exit_reason = KVM_EXIT_S390_SIEIC; - kvm_run->s390_sieic.icptcode = vcpu->arch.sie_block->icptcode; - kvm_run->s390_sieic.ipa = vcpu->arch.sie_block->ipa; - kvm_run->s390_sieic.ipb = vcpu->arch.sie_block->ipb; - rc = 0; - } - if (rc == -EREMOTE) { - /* intercept was handled, but userspace support is needed - * kvm_run has been prepared by the handler */ + /* userspace support is needed, kvm_run has been prepared */ rc = 0; }