From e168bf8de33e16a909df2401af1f7d419c5780de Mon Sep 17 00:00:00 2001 From: Carsten Otte Date: Wed, 4 Jan 2012 10:25:22 +0100 Subject: KVM: s390: ucontrol: export page faults to user This patch introduces a new exit reason in the kvm_run structure named KVM_EXIT_S390_UCONTROL. This exit indicates, that a virtual cpu has regognized a fault on the host page table. The idea is that userspace can handle this fault by mapping memory at the fault location into the cpu's address space and then continue to run the virtual cpu. Signed-off-by: Carsten Otte Signed-off-by: Marcelo Tosatti Signed-off-by: Avi Kivity --- arch/s390/kvm/kvm-s390.c | 32 +++++++++++++++++++++++++++----- 1 file changed, 27 insertions(+), 5 deletions(-) (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 2d3248895def..af05328aca25 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -493,8 +493,10 @@ int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu, return -EINVAL; /* not implemented yet */ } -static void __vcpu_run(struct kvm_vcpu *vcpu) +static int __vcpu_run(struct kvm_vcpu *vcpu) { + int rc; + memcpy(&vcpu->arch.sie_block->gg14, &vcpu->arch.guest_gprs[14], 16); if (need_resched()) @@ -511,9 +513,15 @@ 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)); - 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); + rc = sie64a(vcpu->arch.sie_block, vcpu->arch.guest_gprs); + if (rc) { + if (kvm_is_ucontrol(vcpu->kvm)) { + rc = SIE_INTERCEPT_UCONTROL; + } else { + VCPU_EVENT(vcpu, 3, "%s", "fault in sie instruction"); + kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING); + rc = 0; + } } VCPU_EVENT(vcpu, 6, "exit sie icptcode %d", vcpu->arch.sie_block->icptcode); @@ -522,6 +530,7 @@ static void __vcpu_run(struct kvm_vcpu *vcpu) local_irq_enable(); memcpy(&vcpu->arch.guest_gprs[14], &vcpu->arch.sie_block->gg14, 16); + return rc; } int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) @@ -542,6 +551,7 @@ rerun_vcpu: case KVM_EXIT_UNKNOWN: case KVM_EXIT_INTR: case KVM_EXIT_S390_RESET: + case KVM_EXIT_S390_UCONTROL: break; default: BUG(); @@ -553,7 +563,9 @@ rerun_vcpu: might_fault(); do { - __vcpu_run(vcpu); + rc = __vcpu_run(vcpu); + if (rc) + break; rc = kvm_handle_sie_intercept(vcpu); } while (!signal_pending(current) && !rc); @@ -565,6 +577,16 @@ rerun_vcpu: rc = -EINTR; } +#ifdef CONFIG_KVM_S390_UCONTROL + if (rc == SIE_INTERCEPT_UCONTROL) { + kvm_run->exit_reason = KVM_EXIT_S390_UCONTROL; + kvm_run->s390_ucontrol.trans_exc_code = + current->thread.gmap_addr; + kvm_run->s390_ucontrol.pgm_code = 0x10; + rc = 0; + } +#endif + if (rc == -EOPNOTSUPP) { /* intercept cannot be handled in-kernel, prepare kvm-run */ kvm_run->exit_reason = KVM_EXIT_S390_SIEIC; -- cgit v1.2.3