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| author | Christian Borntraeger <borntraeger@de.ibm.com> | 2020-01-31 13:02:00 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-02-15 00:32:20 +0300 |
| commit | 9a473fc4c82c35d2c54095c09dde1dd7e1dc298f (patch) | |
| tree | 5f99fef59d3adc42715efa76e674116c2e48c3a9 /arch/s390 | |
| parent | 0941ce401d489cb4d53b852fbff7cfce3982beb0 (diff) | |
| download | linux-9a473fc4c82c35d2c54095c09dde1dd7e1dc298f.tar.xz | |
KVM: s390: do not clobber registers during guest reset/store status
[ Upstream commit 55680890ea78be0df5e1384989f1be835043c084 ]
The initial CPU reset clobbers the userspace fpc and the store status
ioctl clobbers the guest acrs + fpr. As these calls are only done via
ioctl (and not via vcpu_run), no CPU context is loaded, so we can (and
must) act directly on the sync regs, not on the thread context.
Cc: stable@kernel.org
Fixes: e1788bb995be ("KVM: s390: handle floating point registers in the run ioctl not in vcpu_put/load")
Fixes: 31d8b8d41a7e ("KVM: s390: handle access registers in the run ioctl not in vcpu_put/load")
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Link: https://lore.kernel.org/r/20200131100205.74720-2-frankja@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/kvm/kvm-s390.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 91c24e87fe10..46fee3f4dedd 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -2384,9 +2384,7 @@ static void kvm_s390_vcpu_initial_reset(struct kvm_vcpu *vcpu) memset(vcpu->arch.sie_block->gcr, 0, 16 * sizeof(__u64)); vcpu->arch.sie_block->gcr[0] = 0xE0UL; vcpu->arch.sie_block->gcr[14] = 0xC2000000UL; - /* make sure the new fpc will be lazily loaded */ - save_fpu_regs(); - current->thread.fpu.fpc = 0; + vcpu->run->s.regs.fpc = 0; vcpu->arch.sie_block->gbea = 1; vcpu->arch.sie_block->pp = 0; vcpu->arch.sie_block->fpf &= ~FPF_BPBC; @@ -3753,7 +3751,7 @@ long kvm_arch_vcpu_ioctl(struct file *filp, } case KVM_S390_STORE_STATUS: idx = srcu_read_lock(&vcpu->kvm->srcu); - r = kvm_s390_vcpu_store_status(vcpu, arg); + r = kvm_s390_store_status_unloaded(vcpu, arg); srcu_read_unlock(&vcpu->kvm->srcu, idx); break; case KVM_S390_SET_INITIAL_PSW: { |