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authorChristian Borntraeger <borntraeger@de.ibm.com>2008-03-25 18:47:34 +0100
committerAvi Kivity <avi@qumranet.com>2008-04-27 12:00:46 +0300
commite28acfea5dd9dbc67c2594cbefc140129dbd0e3f (patch)
tree2f66c3afcf18fd938bae1460f1c5d35ccbf75550 /arch/s390/kvm/diag.c
parent5288fbf0ef041ba0e8b4dcb2df4536b5e3a48b32 (diff)
downloadop-kernel-dev-e28acfea5dd9dbc67c2594cbefc140129dbd0e3f.zip
op-kernel-dev-e28acfea5dd9dbc67c2594cbefc140129dbd0e3f.tar.gz
KVM: s390: intercepts for diagnose instructions
This patch introduces interpretation of some diagnose instruction intercepts. Diagnose is our classic architected way of doing a hypercall. This patch features the following diagnose codes: - vm storage size, that tells the guest about its memory layout - time slice end, which is used by the guest to indicate that it waits for a lock and thus cannot use up its time slice in a useful way - ipl functions, which a guest can use to reset and reboot itself In order to implement ipl functions, we also introduce an exit reason that causes userspace to perform various resets on the virtual machine. All resets are described in the principles of operation book, except KVM_S390_RESET_IPL which causes a reboot of the machine. Acked-by: Martin Schwidefsky <martin.schwidefsky@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'arch/s390/kvm/diag.c')
-rw-r--r--arch/s390/kvm/diag.c67
1 files changed, 67 insertions, 0 deletions
diff --git a/arch/s390/kvm/diag.c b/arch/s390/kvm/diag.c
new file mode 100644
index 0000000..f639a15
--- /dev/null
+++ b/arch/s390/kvm/diag.c
@@ -0,0 +1,67 @@
+/*
+ * diag.c - handling diagnose instructions
+ *
+ * Copyright IBM Corp. 2008
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License (version 2 only)
+ * as published by the Free Software Foundation.
+ *
+ * Author(s): Carsten Otte <cotte@de.ibm.com>
+ * Christian Borntraeger <borntraeger@de.ibm.com>
+ */
+
+#include <linux/kvm.h>
+#include <linux/kvm_host.h>
+#include "kvm-s390.h"
+
+static int __diag_time_slice_end(struct kvm_vcpu *vcpu)
+{
+ VCPU_EVENT(vcpu, 5, "%s", "diag time slice end");
+ vcpu->stat.diagnose_44++;
+ vcpu_put(vcpu);
+ schedule();
+ vcpu_load(vcpu);
+ return 0;
+}
+
+static int __diag_ipl_functions(struct kvm_vcpu *vcpu)
+{
+ unsigned int reg = vcpu->arch.sie_block->ipa & 0xf;
+ unsigned long subcode = vcpu->arch.guest_gprs[reg] & 0xffff;
+
+ VCPU_EVENT(vcpu, 5, "diag ipl functions, subcode %lx", subcode);
+ switch (subcode) {
+ case 3:
+ vcpu->run->s390_reset_flags = KVM_S390_RESET_CLEAR;
+ break;
+ case 4:
+ vcpu->run->s390_reset_flags = 0;
+ break;
+ default:
+ return -ENOTSUPP;
+ }
+
+ atomic_clear_mask(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);
+ vcpu->run->s390_reset_flags |= KVM_S390_RESET_SUBSYSTEM;
+ vcpu->run->s390_reset_flags |= KVM_S390_RESET_IPL;
+ vcpu->run->s390_reset_flags |= KVM_S390_RESET_CPU_INIT;
+ vcpu->run->exit_reason = KVM_EXIT_S390_RESET;
+ VCPU_EVENT(vcpu, 3, "requesting userspace resets %lx",
+ vcpu->run->s390_reset_flags);
+ return -EREMOTE;
+}
+
+int kvm_s390_handle_diag(struct kvm_vcpu *vcpu)
+{
+ int code = (vcpu->arch.sie_block->ipb & 0xfff0000) >> 16;
+
+ switch (code) {
+ case 0x44:
+ return __diag_time_slice_end(vcpu);
+ case 0x308:
+ return __diag_ipl_functions(vcpu);
+ default:
+ return -ENOTSUPP;
+ }
+}
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