This is a note to let you know that I've just added the patch titled
KVM: s390: provide only a single function for setting the tod (fix SCK)
to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: kvm-s390-provide-only-a-single-function-for-setting-the-tod-fix-sck.patch and it can be found in the queue-4.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From 0e7def5fb0dc53ddbb9f62a497d15f1e11ccdc36 Mon Sep 17 00:00:00 2001
From: David Hildenbrand david@redhat.com Date: Wed, 7 Feb 2018 12:46:43 +0100 Subject: KVM: s390: provide only a single function for setting the tod (fix SCK)
From: David Hildenbrand david@redhat.com
commit 0e7def5fb0dc53ddbb9f62a497d15f1e11ccdc36 upstream.
Right now, SET CLOCK called in the guest does not properly take care of the epoch index, as the call goes via the old kvm_s390_set_tod_clock() interface. So the epoch index is neither reset to 0, if required, nor properly set to e.g. 0xff on negative values.
Fix this by providing a single kvm_s390_set_tod_clock() function. Move Multiple-epoch facility handling into it.
Signed-off-by: David Hildenbrand david@redhat.com Message-Id: 20180207114647.6220-3-david@redhat.com Reviewed-by: Christian Borntraeger borntraeger@de.ibm.com Fixes: 8fa1696ea781 ("KVM: s390: Multiple Epoch Facility support") Cc: stable@vger.kernel.org Signed-off-by: Christian Borntraeger borntraeger@de.ibm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/s390/kvm/kvm-s390.c | 46 +++++++++++++++------------------------------- arch/s390/kvm/kvm-s390.h | 5 ++--- arch/s390/kvm/priv.c | 9 +++++---- 3 files changed, 22 insertions(+), 38 deletions(-)
--- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -889,12 +889,9 @@ static int kvm_s390_set_tod_ext(struct k if (copy_from_user(>od, (void __user *)attr->addr, sizeof(gtod))) return -EFAULT;
- if (test_kvm_facility(kvm, 139)) - kvm_s390_set_tod_clock_ext(kvm, >od); - else if (gtod.epoch_idx == 0) - kvm_s390_set_tod_clock(kvm, gtod.tod); - else + if (!test_kvm_facility(kvm, 139) && gtod.epoch_idx) return -EINVAL; + kvm_s390_set_tod_clock(kvm, >od);
VM_EVENT(kvm, 3, "SET: TOD extension: 0x%x, TOD base: 0x%llx", gtod.epoch_idx, gtod.tod); @@ -919,13 +916,14 @@ static int kvm_s390_set_tod_high(struct
static int kvm_s390_set_tod_low(struct kvm *kvm, struct kvm_device_attr *attr) { - u64 gtod; + struct kvm_s390_vm_tod_clock gtod = { 0 };
- if (copy_from_user(>od, (void __user *)attr->addr, sizeof(gtod))) + if (copy_from_user(>od.tod, (void __user *)attr->addr, + sizeof(gtod.tod))) return -EFAULT;
- kvm_s390_set_tod_clock(kvm, gtod); - VM_EVENT(kvm, 3, "SET: TOD base: 0x%llx", gtod); + kvm_s390_set_tod_clock(kvm, >od); + VM_EVENT(kvm, 3, "SET: TOD base: 0x%llx", gtod.tod); return 0; }
@@ -2947,8 +2945,8 @@ retry: return 0; }
-void kvm_s390_set_tod_clock_ext(struct kvm *kvm, - const struct kvm_s390_vm_tod_clock *gtod) +void kvm_s390_set_tod_clock(struct kvm *kvm, + const struct kvm_s390_vm_tod_clock *gtod) { struct kvm_vcpu *vcpu; struct kvm_s390_tod_clock_ext htod; @@ -2960,10 +2958,12 @@ void kvm_s390_set_tod_clock_ext(struct k get_tod_clock_ext((char *)&htod);
kvm->arch.epoch = gtod->tod - htod.tod; - kvm->arch.epdx = gtod->epoch_idx - htod.epoch_idx; - - if (kvm->arch.epoch > gtod->tod) - kvm->arch.epdx -= 1; + kvm->arch.epdx = 0; + if (test_kvm_facility(kvm, 139)) { + kvm->arch.epdx = gtod->epoch_idx - htod.epoch_idx; + if (kvm->arch.epoch > gtod->tod) + kvm->arch.epdx -= 1; + }
kvm_s390_vcpu_block_all(kvm); kvm_for_each_vcpu(i, vcpu, kvm) { @@ -2974,22 +2974,6 @@ void kvm_s390_set_tod_clock_ext(struct k kvm_s390_vcpu_unblock_all(kvm); preempt_enable(); mutex_unlock(&kvm->lock); -} - -void kvm_s390_set_tod_clock(struct kvm *kvm, u64 tod) -{ - struct kvm_vcpu *vcpu; - int i; - - mutex_lock(&kvm->lock); - preempt_disable(); - kvm->arch.epoch = tod - get_tod_clock(); - kvm_s390_vcpu_block_all(kvm); - kvm_for_each_vcpu(i, vcpu, kvm) - vcpu->arch.sie_block->epoch = kvm->arch.epoch; - kvm_s390_vcpu_unblock_all(kvm); - preempt_enable(); - mutex_unlock(&kvm->lock); }
/** --- a/arch/s390/kvm/kvm-s390.h +++ b/arch/s390/kvm/kvm-s390.h @@ -268,9 +268,8 @@ int kvm_s390_handle_sigp(struct kvm_vcpu int kvm_s390_handle_sigp_pei(struct kvm_vcpu *vcpu);
/* implemented in kvm-s390.c */ -void kvm_s390_set_tod_clock_ext(struct kvm *kvm, - const struct kvm_s390_vm_tod_clock *gtod); -void kvm_s390_set_tod_clock(struct kvm *kvm, u64 tod); +void kvm_s390_set_tod_clock(struct kvm *kvm, + const struct kvm_s390_vm_tod_clock *gtod); long kvm_arch_fault_in_page(struct kvm_vcpu *vcpu, gpa_t gpa, int writable); int kvm_s390_store_status_unloaded(struct kvm_vcpu *vcpu, unsigned long addr); int kvm_s390_vcpu_store_status(struct kvm_vcpu *vcpu, unsigned long addr); --- a/arch/s390/kvm/priv.c +++ b/arch/s390/kvm/priv.c @@ -81,9 +81,10 @@ int kvm_s390_handle_e3(struct kvm_vcpu * /* Handle SCK (SET CLOCK) interception */ static int handle_set_clock(struct kvm_vcpu *vcpu) { + struct kvm_s390_vm_tod_clock gtod = { 0 }; int rc; u8 ar; - u64 op2, val; + u64 op2;
if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE) return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP); @@ -91,12 +92,12 @@ static int handle_set_clock(struct kvm_v op2 = kvm_s390_get_base_disp_s(vcpu, &ar); if (op2 & 7) /* Operand must be on a doubleword boundary */ return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); - rc = read_guest(vcpu, op2, ar, &val, sizeof(val)); + rc = read_guest(vcpu, op2, ar, >od.tod, sizeof(gtod.tod)); if (rc) return kvm_s390_inject_prog_cond(vcpu, rc);
- VCPU_EVENT(vcpu, 3, "SCK: setting guest TOD to 0x%llx", val); - kvm_s390_set_tod_clock(vcpu->kvm, val); + VCPU_EVENT(vcpu, 3, "SCK: setting guest TOD to 0x%llx", gtod.tod); + kvm_s390_set_tod_clock(vcpu->kvm, >od);
kvm_s390_set_psw_cc(vcpu, 0); return 0;
Patches currently in stable-queue which might be from david@redhat.com are
queue-4.15/kvm-s390-take-care-of-clock-comparator-sign-control.patch queue-4.15/kvm-s390-provide-only-a-single-function-for-setting-the-tod-fix-sck.patch queue-4.15/kvm-s390-consider-epoch-index-on-tod-clock-syncs.patch queue-4.15/kvm-s390-consider-epoch-index-on-hotplugged-cpus.patch