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| author | Dominik Dingel <dingel@linux.vnet.ibm.com> | 2013-07-26 15:04:00 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-08-29 09:47:28 -0700 |
| commit | 6904756d54d4f98a9f835ed9cbc3f149ef7ac678 (patch) | |
| tree | 9584fe646c735d09b666c62497a0cabe98561642 /arch/s390 | |
| parent | 0a4b6d4ff200a553951f77f765971cb3e4c91ec0 (diff) | |
| download | lwn-6904756d54d4f98a9f835ed9cbc3f149ef7ac678.tar.gz lwn-6904756d54d4f98a9f835ed9cbc3f149ef7ac678.zip | |
KVM: s390: move kvm_guest_enter,exit closer to sie
commit 2b29a9fdcb92bfc6b6f4c412d71505869de61a56 upstream.
Any uaccess between guest_enter and guest_exit could trigger a page fault,
the page fault handler would handle it as a guest fault and translate a
user address as guest address.
Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/kvm/kvm-s390.c | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index c1c7c683fa26..698fb826e149 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -622,14 +622,25 @@ static int __vcpu_run(struct kvm_vcpu *vcpu) kvm_s390_deliver_pending_interrupts(vcpu); vcpu->arch.sie_block->icptcode = 0; - preempt_disable(); - kvm_guest_enter(); - preempt_enable(); VCPU_EVENT(vcpu, 6, "entering sie flags %x", atomic_read(&vcpu->arch.sie_block->cpuflags)); trace_kvm_s390_sie_enter(vcpu, atomic_read(&vcpu->arch.sie_block->cpuflags)); + + /* + * As PF_VCPU will be used in fault handler, between guest_enter + * and guest_exit should be no uaccess. + */ + preempt_disable(); + kvm_guest_enter(); + preempt_enable(); rc = sie64a(vcpu->arch.sie_block, vcpu->run->s.regs.gprs); + kvm_guest_exit(); + + VCPU_EVENT(vcpu, 6, "exit sie icptcode %d", + vcpu->arch.sie_block->icptcode); + trace_kvm_s390_sie_exit(vcpu, vcpu->arch.sie_block->icptcode); + if (rc) { if (kvm_is_ucontrol(vcpu->kvm)) { rc = SIE_INTERCEPT_UCONTROL; @@ -639,10 +650,6 @@ static int __vcpu_run(struct kvm_vcpu *vcpu) rc = kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING); } } - VCPU_EVENT(vcpu, 6, "exit sie icptcode %d", - vcpu->arch.sie_block->icptcode); - trace_kvm_s390_sie_exit(vcpu, vcpu->arch.sie_block->icptcode); - kvm_guest_exit(); memcpy(&vcpu->run->s.regs.gprs[14], &vcpu->arch.sie_block->gg14, 16); return rc; |