From 190df4a212a708fdd18f6cabfdd82594c91fdf25 Mon Sep 17 00:00:00 2001 From: Claudio Imbrenda Date: Thu, 4 Aug 2016 17:54:42 +0200 Subject: KVM: s390: CMMA tracking, ESSA emulation, migration mode * Add a migration state bitmap to keep track of which pages have dirty CMMA information. * Disable CMMA by default, so we can track if it's used or not. Enable it on first use like we do for storage keys (unless we are doing a migration). * Creates a VM attribute to enter and leave migration mode. * In migration mode, CMMA is disabled in the SIE block, so ESSA is always interpreted and emulated in software. * Free the migration state on VM destroy. Signed-off-by: Claudio Imbrenda Acked-by: Cornelia Huck Reviewed-by: Christian Borntraeger Signed-off-by: Christian Borntraeger --- Documentation/virtual/kvm/devices/vm.txt | 33 ++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) (limited to 'Documentation/virtual') diff --git a/Documentation/virtual/kvm/devices/vm.txt b/Documentation/virtual/kvm/devices/vm.txt index 575ccb022aac..903fc926860b 100644 --- a/Documentation/virtual/kvm/devices/vm.txt +++ b/Documentation/virtual/kvm/devices/vm.txt @@ -222,3 +222,36 @@ Allows user space to disable dea key wrapping, clearing the wrapping key. Parameters: none Returns: 0 + +5. GROUP: KVM_S390_VM_MIGRATION +Architectures: s390 + +5.1. ATTRIBUTE: KVM_S390_VM_MIGRATION_STOP (w/o) + +Allows userspace to stop migration mode, needed for PGSTE migration. +Setting this attribute when migration mode is not active will have no +effects. + +Parameters: none +Returns: 0 + +5.2. ATTRIBUTE: KVM_S390_VM_MIGRATION_START (w/o) + +Allows userspace to start migration mode, needed for PGSTE migration. +Setting this attribute when migration mode is already active will have +no effects. + +Parameters: none +Returns: -ENOMEM if there is not enough free memory to start migration mode + -EINVAL if the state of the VM is invalid (e.g. no memory defined) + 0 in case of success. + +5.3. ATTRIBUTE: KVM_S390_VM_MIGRATION_STATUS (r/o) + +Allows userspace to query the status of migration mode. + +Parameters: address of a buffer in user space to store the data (u64) to; + the data itself is either 0 if migration mode is disabled or 1 + if it is enabled +Returns: -EFAULT if the given address is not accessible from kernel space + 0 in case of success. -- cgit v1.2.3