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authorChristian Borntraeger <borntraeger@de.ibm.com>2008-03-25 18:47:23 +0100
committerAvi Kivity <avi@qumranet.com>2008-04-27 12:00:43 +0300
commit8f2abe6a1e525e878bdf58f68ccd146d543fde84 (patch)
tree5f52959474a16847c740fb8668ebd9d6cbc75d07 /arch/s390
parentb0c632db637d68ad39d9f97f452ce176253f5f4e (diff)
KVM: s390: sie intercept handling
This path introduces handling of sie intercepts in three flavors: Intercepts are either handled completely in-kernel by kvm_handle_sie_intercept(), or passed to userspace with corresponding data in struct kvm_run in case kvm_handle_sie_intercept() returns -ENOTSUPP. In case of partial execution in kernel with the need of userspace support, kvm_handle_sie_intercept() may choose to set up struct kvm_run and return -EREMOTE. The trivial intercept reasons are handled in this patch: handle_noop() just does nothing for intercepts that don't require our support at all handle_stop() is called when a cpu enters stopped state, and it drops out to userland after updating our vcpu state handle_validity() faults in the cpu lowcore if needed, or passes the request to userland Acked-by: Martin Schwidefsky <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')
-rw-r--r--arch/s390/kvm/Makefile2
-rw-r--r--arch/s390/kvm/intercept.c80
-rw-r--r--arch/s390/kvm/kvm-s390.c46
-rw-r--r--arch/s390/kvm/kvm-s390.h7
4 files changed, 133 insertions, 2 deletions
diff --git a/arch/s390/kvm/Makefile b/arch/s390/kvm/Makefile
index 0d8d1135a27..27882b35ef0 100644
--- a/arch/s390/kvm/Makefile
+++ b/arch/s390/kvm/Makefile
@@ -10,5 +10,5 @@ common-objs = $(addprefix ../../../virt/kvm/, kvm_main.o)
EXTRA_CFLAGS += -Ivirt/kvm -Iarch/s390/kvm
-kvm-objs := $(common-objs) kvm-s390.o sie64a.o
+kvm-objs := $(common-objs) kvm-s390.o sie64a.o intercept.o
obj-$(CONFIG_KVM) += kvm.o
diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c
new file mode 100644
index 00000000000..e757230b982
--- /dev/null
+++ b/arch/s390/kvm/intercept.c
@@ -0,0 +1,80 @@
+/*
+ * intercept.c - in-kernel handling for sie intercepts
+ *
+ * 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_host.h>
+#include <linux/errno.h>
+#include <linux/pagemap.h>
+
+#include <asm/kvm_host.h>
+
+#include "kvm-s390.h"
+
+static int handle_noop(struct kvm_vcpu *vcpu)
+{
+ switch (vcpu->arch.sie_block->icptcode) {
+ case 0x10:
+ vcpu->stat.exit_external_request++;
+ break;
+ case 0x14:
+ vcpu->stat.exit_external_interrupt++;
+ break;
+ default:
+ break; /* nothing */
+ }
+ return 0;
+}
+
+static int handle_stop(struct kvm_vcpu *vcpu)
+{
+ vcpu->stat.exit_stop_request++;
+ VCPU_EVENT(vcpu, 3, "%s", "cpu stopped");
+ atomic_clear_mask(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);
+ return -ENOTSUPP;
+}
+
+static int handle_validity(struct kvm_vcpu *vcpu)
+{
+ int viwhy = vcpu->arch.sie_block->ipb >> 16;
+ vcpu->stat.exit_validity++;
+ if (viwhy == 0x37) {
+ fault_in_pages_writeable((char __user *)
+ vcpu->kvm->arch.guest_origin +
+ vcpu->arch.sie_block->prefix,
+ PAGE_SIZE);
+ return 0;
+ }
+ VCPU_EVENT(vcpu, 2, "unhandled validity intercept code %d",
+ viwhy);
+ return -ENOTSUPP;
+}
+
+static const intercept_handler_t intercept_funcs[0x48 >> 2] = {
+ [0x00 >> 2] = handle_noop,
+ [0x10 >> 2] = handle_noop,
+ [0x14 >> 2] = handle_noop,
+ [0x20 >> 2] = handle_validity,
+ [0x28 >> 2] = handle_stop,
+};
+
+int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
+{
+ intercept_handler_t func;
+ u8 code = vcpu->arch.sie_block->icptcode;
+
+ if (code & 3 || code > 0x48)
+ return -ENOTSUPP;
+ func = intercept_funcs[code >> 2];
+ if (func)
+ return func(vcpu);
+ return -ENOTSUPP;
+}
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 6e1e1d39ae1..a906499214b 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -23,12 +23,17 @@
#include <asm/lowcore.h>
#include <asm/pgtable.h>
+#include "kvm-s390.h"
#include "gaccess.h"
#define VCPU_STAT(x) offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU
struct kvm_stats_debugfs_item debugfs_entries[] = {
{ "userspace_handled", VCPU_STAT(exit_userspace) },
+ { "exit_validity", VCPU_STAT(exit_validity) },
+ { "exit_stop_request", VCPU_STAT(exit_stop_request) },
+ { "exit_external_request", VCPU_STAT(exit_external_request) },
+ { "exit_external_interrupt", VCPU_STAT(exit_external_interrupt) },
{ NULL }
};
@@ -380,6 +385,7 @@ static void __vcpu_run(struct kvm_vcpu *vcpu)
int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
+ int rc;
sigset_t sigsaved;
vcpu_load(vcpu);
@@ -389,7 +395,45 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
atomic_set_mask(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);
- __vcpu_run(vcpu);
+ switch (kvm_run->exit_reason) {
+ case KVM_EXIT_S390_SIEIC:
+ vcpu->arch.sie_block->gpsw.mask = kvm_run->s390_sieic.mask;
+ vcpu->arch.sie_block->gpsw.addr = kvm_run->s390_sieic.addr;
+ break;
+ case KVM_EXIT_UNKNOWN:
+ case KVM_EXIT_S390_RESET:
+ break;
+ default:
+ BUG();
+ }
+
+ might_sleep();
+
+ do {
+ __vcpu_run(vcpu);
+
+ rc = kvm_handle_sie_intercept(vcpu);
+ } while (!signal_pending(current) && !rc);
+
+ if (signal_pending(current) && !rc)
+ rc = -EINTR;
+
+ if (rc == -ENOTSUPP) {
+ /* intercept cannot be handled in-kernel, prepare kvm-run */
+ kvm_run->exit_reason = KVM_EXIT_S390_SIEIC;
+ kvm_run->s390_sieic.icptcode = vcpu->arch.sie_block->icptcode;
+ kvm_run->s390_sieic.mask = vcpu->arch.sie_block->gpsw.mask;
+ kvm_run->s390_sieic.addr = vcpu->arch.sie_block->gpsw.addr;
+ kvm_run->s390_sieic.ipa = vcpu->arch.sie_block->ipa;
+ kvm_run->s390_sieic.ipb = vcpu->arch.sie_block->ipb;
+ rc = 0;
+ }
+
+ if (rc == -EREMOTE) {
+ /* intercept was handled, but userspace support is needed
+ * kvm_run has been prepared by the handler */
+ rc = 0;
+ }
if (vcpu->sigset_active)
sigprocmask(SIG_SETMASK, &sigsaved, NULL);
diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h
index ed64a22ca86..5b82527b7f8 100644
--- a/arch/s390/kvm/kvm-s390.h
+++ b/arch/s390/kvm/kvm-s390.h
@@ -13,6 +13,13 @@
#ifndef ARCH_S390_KVM_S390_H
#define ARCH_S390_KVM_S390_H
+
+#include <linux/kvm_host.h>
+
+typedef int (*intercept_handler_t)(struct kvm_vcpu *vcpu);
+
+int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu);
+
#define VM_EVENT(d_kvm, d_loglevel, d_string, d_args...)\
do { \
debug_sprintf_event(d_kvm->arch.dbf, d_loglevel, d_string "\n", \