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authorJanosch Frank <frankja@linux.ibm.com>2020-01-31 13:02:02 +0300
committerChristian Borntraeger <borntraeger@de.ibm.com>2020-01-31 14:50:04 +0300
commit7de3f1423ff9431f3bd5023bb78d1e062314e7f0 (patch)
tree580e4d6a6b9388f187a01578f53c8b2e8ebde8ed /Documentation/virt
parentcca00ebb8ad3b3a5eb6e60b1ac7e9211f66af477 (diff)
downloadlinux-7de3f1423ff9431f3bd5023bb78d1e062314e7f0.tar.xz
KVM: s390: Add new reset vcpu API
The architecture states that we need to reset local IRQs for all CPU resets. Because the old reset interface did not support the normal CPU reset we never did that on a normal reset. Let's implement an interface for the missing normal and clear resets and reset all local IRQs, registers and control structures as stated in the architecture. Userspace might already reset the registers via the vcpu run struct, but as we need the interface for the interrupt clearing part anyway, we implement the resets fully and don't rely on userspace to reset the rest. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Link: https://lore.kernel.org/r/20200131100205.74720-4-frankja@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Diffstat (limited to 'Documentation/virt')
-rw-r--r--Documentation/virt/kvm/api.txt43
1 files changed, 43 insertions, 0 deletions
diff --git a/Documentation/virt/kvm/api.txt b/Documentation/virt/kvm/api.txt
index ebb37b34dcfc..73448764f544 100644
--- a/Documentation/virt/kvm/api.txt
+++ b/Documentation/virt/kvm/api.txt
@@ -4168,6 +4168,42 @@ This ioctl issues an ultravisor call to terminate the secure guest,
unpins the VPA pages and releases all the device pages that are used to
track the secure pages by hypervisor.
+4.122 KVM_S390_NORMAL_RESET
+
+Capability: KVM_CAP_S390_VCPU_RESETS
+Architectures: s390
+Type: vcpu ioctl
+Parameters: none
+Returns: 0
+
+This ioctl resets VCPU registers and control structures according to
+the cpu reset definition in the POP (Principles Of Operation).
+
+4.123 KVM_S390_INITIAL_RESET
+
+Capability: none
+Architectures: s390
+Type: vcpu ioctl
+Parameters: none
+Returns: 0
+
+This ioctl resets VCPU registers and control structures according to
+the initial cpu reset definition in the POP. However, the cpu is not
+put into ESA mode. This reset is a superset of the normal reset.
+
+4.124 KVM_S390_CLEAR_RESET
+
+Capability: KVM_CAP_S390_VCPU_RESETS
+Architectures: s390
+Type: vcpu ioctl
+Parameters: none
+Returns: 0
+
+This ioctl resets VCPU registers and control structures according to
+the clear cpu reset definition in the POP. However, the cpu is not put
+into ESA mode. This reset is a superset of the initial reset.
+
+
5. The kvm_run structure
------------------------
@@ -5396,3 +5432,10 @@ handling by KVM (as some KVM hypercall may be mistakenly treated as TLB
flush hypercalls by Hyper-V) so userspace should disable KVM identification
in CPUID and only exposes Hyper-V identification. In this case, guest
thinks it's running on Hyper-V and only use Hyper-V hypercalls.
+
+8.22 KVM_CAP_S390_VCPU_RESETS
+
+Architectures: s390
+
+This capability indicates that the KVM_S390_NORMAL_RESET and
+KVM_S390_CLEAR_RESET ioctls are available.