From: Christian Borntraeger <borntraeger@de.ibm.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: KVM <kvm@vger.kernel.org>, Cornelia Huck <cohuck@redhat.com>,
Christian Borntraeger <borntraeger@de.ibm.com>,
linux-s390 <linux-s390@vger.kernel.org>,
Janosch Frank <frankja@linux.vnet.ibm.com>,
David Hildenbrand <david@redhat.com>,
Thomas Huth <thuth@redhat.com>
Subject: [GIT PULL 2/7] KVM: s390: do not clobber registers during guest reset/store status
Date: Fri, 31 Jan 2020 16:03:43 +0100 [thread overview]
Message-ID: <20200131150348.73360-3-borntraeger@de.ibm.com> (raw)
In-Reply-To: <20200131150348.73360-1-borntraeger@de.ibm.com>
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>
---
arch/s390/kvm/kvm-s390.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index d9e6bf3d54f0..876802894b35 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -2860,9 +2860,7 @@ static void kvm_s390_vcpu_initial_reset(struct kvm_vcpu *vcpu)
vcpu->arch.sie_block->gcr[14] = CR14_UNUSED_32 |
CR14_UNUSED_33 |
CR14_EXTERNAL_DAMAGE_SUBMASK;
- /* 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;
@@ -4351,7 +4349,7 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
switch (ioctl) {
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: {
--
2.21.0
next prev parent reply other threads:[~2020-01-31 15:04 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-31 15:03 [GIT PULL 0/7] KVM: s390: Fixes and cleanups for 5.6 Christian Borntraeger
2020-01-31 15:03 ` [GIT PULL 1/7] KVM: s390: ENOTSUPP -> EOPNOTSUPP fixups Christian Borntraeger
2020-01-31 15:03 ` Christian Borntraeger [this message]
2020-01-31 15:03 ` [GIT PULL 3/7] KVM: s390: Cleanup initial cpu reset Christian Borntraeger
2020-01-31 15:03 ` [GIT PULL 4/7] KVM: s390: Add new reset vcpu API Christian Borntraeger
2020-01-31 15:03 ` [GIT PULL 5/7] selftests: KVM: Add fpu and one reg set/get library functions Christian Borntraeger
2020-01-31 15:03 ` [GIT PULL 6/7] selftests: KVM: s390x: Add reset tests Christian Borntraeger
2020-01-31 15:03 ` [GIT PULL 7/7] selftests: KVM: testing the local IRQs resets Christian Borntraeger
2020-02-05 15:15 ` [GIT PULL 0/7] KVM: s390: Fixes and cleanups for 5.6 Paolo Bonzini
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