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>
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 6e1e1d3..a906499 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 @@
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 @@
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);