From: David Hildenbrand <david@redhat.com>
To: Janosch Frank <frankja@linux.ibm.com>, kvm@vger.kernel.org
Cc: thuth@redhat.com, borntraeger@de.ibm.com, cohuck@redhat.com,
linux-s390@vger.kernel.org
Subject: Re: [PATCH v9 1/6] KVM: s390: do not clobber registers during guest reset/store status
Date: Thu, 30 Jan 2020 13:39:29 +0100 [thread overview]
Message-ID: <a8d55fbd-402d-6ee5-b0b4-a47b32b8f0cf@redhat.com> (raw)
In-Reply-To: <20200130123434.68129-2-frankja@linux.ibm.com>
On 30.01.20 13:34, Janosch Frank wrote:
> From: Christian Borntraeger <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>
> ---
> arch/s390/kvm/kvm-s390.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index c059b86aacd4..328dee666b24 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -2824,8 +2824,7 @@ 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();
> + vcpu->run->s.regs.fpc = 0;
> current->thread.fpu.fpc = 0;
> vcpu->arch.sie_block->gbea = 1;
> vcpu->arch.sie_block->pp = 0;
> @@ -4343,7 +4342,7 @@ 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: {
>
Reviewed-by: David Hildenbrand <david@redhat.com>
--
Thanks,
David / dhildenb
next prev parent reply other threads:[~2020-01-30 12:39 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-30 12:34 [PATCH v9 0/6] KVM: s390: Add new reset vcpu API Janosch Frank
2020-01-30 12:34 ` [PATCH v9 1/6] KVM: s390: do not clobber registers during guest reset/store status Janosch Frank
2020-01-30 12:39 ` David Hildenbrand [this message]
2020-01-30 13:00 ` Cornelia Huck
2020-01-30 13:02 ` Christian Borntraeger
2020-01-30 12:34 ` [PATCH v9 2/6] KVM: s390: Cleanup initial cpu reset Janosch Frank
2020-01-30 13:20 ` Thomas Huth
2020-01-30 12:34 ` [PATCH v9 3/6] KVM: s390: Add new reset vcpu API Janosch Frank
2020-01-30 12:49 ` Janosch Frank
2020-01-30 12:55 ` [PATCH v9] " Janosch Frank
2020-01-30 12:59 ` Christian Borntraeger
2020-01-30 13:02 ` Janosch Frank
2020-01-30 13:01 ` Cornelia Huck
2020-01-30 12:53 ` [PATCH v9 3/6] " Christian Borntraeger
2020-01-30 12:34 ` [PATCH v9 4/6] selftests: KVM: Add fpu and one reg set/get library functions Janosch Frank
2020-01-30 13:03 ` Cornelia Huck
2020-01-30 12:34 ` [PATCH v9 5/6] selftests: KVM: s390x: Add reset tests Janosch Frank
2020-01-30 13:25 ` Thomas Huth
2020-01-30 16:22 ` Cornelia Huck
2020-01-30 12:34 ` [PATCH v9 6/6] selftests: KVM: testing the local IRQs resets Janosch Frank
2020-01-30 16:27 ` Cornelia Huck
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