From 71cde5879f10b639506bc0b9f29a89f58b42a17e Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Wed, 21 May 2008 13:37:34 +0200 Subject: KVM: s390: handle machine checks when guest is running The low-level interrupt handler on s390 checks for _TIF_WORK_INT and exits the guest context, if work is pending. TIF_WORK_INT is defined as_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_MCCK_PENDING. Currently the sie loop checks for signals and reschedule, but it does not check for machine checks. That means that we exit the guest context if a machine check is pending, but we do not handle the machine check. Signed-off-by: Christian Borntraeger CC: Heiko Carstens Signed-off-by: Carsten Otte Signed-off-by: Avi Kivity --- arch/s390/kvm/kvm-s390.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'arch/s390/kvm/kvm-s390.c') diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 0ac36a6..40e4f2d 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -423,6 +423,8 @@ int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu, return -EINVAL; /* not implemented yet */ } +extern void s390_handle_mcck(void); + static void __vcpu_run(struct kvm_vcpu *vcpu) { memcpy(&vcpu->arch.sie_block->gg14, &vcpu->arch.guest_gprs[14], 16); @@ -430,6 +432,9 @@ static void __vcpu_run(struct kvm_vcpu *vcpu) if (need_resched()) schedule(); + if (test_thread_flag(TIF_MCCK_PENDING)) + s390_handle_mcck(); + vcpu->arch.sie_block->icptcode = 0; local_irq_disable(); kvm_guest_enter(); -- cgit v1.1 From 0ff318674503ce3787ef62d84f4d948db204b268 Mon Sep 17 00:00:00 2001 From: Carsten Otte Date: Wed, 21 May 2008 13:37:37 +0200 Subject: KVM: s390: fix interrupt delivery The current code delivers pending interrupts before it checks for need_resched. On a busy host, this can lead to a longer interrupt latency if the interrupt is injected while the process is scheduled away. This patch moves delivering the interrupt _after_ schedule(), which makes more sense. Signed-off-by: Carsten Otte Signed-off-by: Avi Kivity --- arch/s390/kvm/kvm-s390.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'arch/s390/kvm/kvm-s390.c') diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 40e4f2d..ded27c7 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -435,6 +435,8 @@ static void __vcpu_run(struct kvm_vcpu *vcpu) if (test_thread_flag(TIF_MCCK_PENDING)) s390_handle_mcck(); + kvm_s390_deliver_pending_interrupts(vcpu); + vcpu->arch.sie_block->icptcode = 0; local_irq_disable(); kvm_guest_enter(); @@ -480,7 +482,6 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) might_sleep(); do { - kvm_s390_deliver_pending_interrupts(vcpu); __vcpu_run(vcpu); rc = kvm_handle_sie_intercept(vcpu); } while (!signal_pending(current) && !rc); -- cgit v1.1 From 1f0d0f094df9a570dfc26d5eb825986b7e165e1d Mon Sep 17 00:00:00 2001 From: Carsten Otte Date: Wed, 21 May 2008 13:37:40 +0200 Subject: KVM: s390: Send program check on access error If the guest accesses non-existing memory, the sie64a function returns -EFAULT. We must check the return value and send a program check to the guest if the sie instruction faulted, otherwise the guest will loop at the faulting code. Signed-off-by: Christian Borntraeger Signed-off-by: Carsten Otte Signed-off-by: Avi Kivity --- arch/s390/kvm/kvm-s390.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'arch/s390/kvm/kvm-s390.c') diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index ded27c7..6558b09 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -443,7 +443,10 @@ static void __vcpu_run(struct kvm_vcpu *vcpu) local_irq_enable(); VCPU_EVENT(vcpu, 6, "entering sie flags %x", atomic_read(&vcpu->arch.sie_block->cpuflags)); - sie64a(vcpu->arch.sie_block, vcpu->arch.guest_gprs); + if (sie64a(vcpu->arch.sie_block, vcpu->arch.guest_gprs)) { + VCPU_EVENT(vcpu, 3, "%s", "fault in sie instruction"); + kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING); + } VCPU_EVENT(vcpu, 6, "exit sie icptcode %d", vcpu->arch.sie_block->icptcode); local_irq_disable(); -- cgit v1.1