Age | Commit message (Collapse) | Author | |
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2016-06-10 | KVM: s390: Limit sthyi execution | Janosch Frank | |
Store hypervisor information is a valid instruction not only in supervisor state but also in problem state, i.e. the guest's userspace. Its execution is not only computational and memory intensive, but also has to get hold of the ipte lock to write to the guest's memory. This lock is not intended to be held often and long, especially not from the untrusted guest userspace. Therefore we apply rate limiting of sthyi executions per VM. Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com> Acked-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> | |||
2016-06-10 | KVM: s390: Add sthyi emulation | Janosch Frank | |
Store Hypervisor Information is an emulated z/VM instruction that provides a guest with basic information about the layers it is running on. This includes information about the cpu configuration of both the machine and the lpar, as well as their names, machine model and machine type. This information enables an application to determine the maximum capacity of CPs and IFLs available to software. The instruction is available whenever the facility bit 74 is set, otherwise executing it results in an operation exception. It is important to check the validity flags in the sections before using data from any structure member. It is not guaranteed that all members will be valid on all machines / machine configurations. Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> |