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authorLaurent Vivier <lvivier@redhat.com>2016-04-08 18:05:00 +0200
committerPaul Mackerras <paulus@samba.org>2016-05-11 21:19:10 +1000
commit11dd6ac0254ed9a2b6994e22c903192edd0fa8fc (patch)
treeb2c1a13f033dc9b1dc54c510633c7333e7df8cfc /arch/powerpc/kvm/book3s_pr.c
parent05b1159e641fa45e885aec8bf8e515117c8977d9 (diff)
KVM: PPC: Book3S PR: Manage single-step mode
Until now, when we connect gdb to the QEMU gdb-server, the single-step mode is not managed. This patch adds this, only for kvm-pr: If KVM_GUESTDBG_SINGLESTEP is set, we enable single-step trace bit in the MSR (MSR_SE) just before the __kvmppc_vcpu_run(), and disable it just after. In kvmppc_handle_exit_pr, instead of routing the interrupt to the guest, we return to host, with KVM_EXIT_DEBUG reason. Signed-off-by: Laurent Vivier <lvivier@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Thomas Huth <thuth@redhat.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/powerpc/kvm/book3s_pr.c')
-rw-r--r--arch/powerpc/kvm/book3s_pr.c32
1 files changed, 31 insertions, 1 deletions
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index 95bceca8f40e..8129b0db131e 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -882,6 +882,24 @@ void kvmppc_set_fscr(struct kvm_vcpu *vcpu, u64 fscr)
}
#endif
+static void kvmppc_setup_debug(struct kvm_vcpu *vcpu)
+{
+ if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP) {
+ u64 msr = kvmppc_get_msr(vcpu);
+
+ kvmppc_set_msr(vcpu, msr | MSR_SE);
+ }
+}
+
+static void kvmppc_clear_debug(struct kvm_vcpu *vcpu)
+{
+ if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP) {
+ u64 msr = kvmppc_get_msr(vcpu);
+
+ kvmppc_set_msr(vcpu, msr & ~MSR_SE);
+ }
+}
+
int kvmppc_handle_exit_pr(struct kvm_run *run, struct kvm_vcpu *vcpu,
unsigned int exit_nr)
{
@@ -1207,10 +1225,18 @@ program_interrupt:
break;
#endif
case BOOK3S_INTERRUPT_MACHINE_CHECK:
- case BOOK3S_INTERRUPT_TRACE:
kvmppc_book3s_queue_irqprio(vcpu, exit_nr);
r = RESUME_GUEST;
break;
+ case BOOK3S_INTERRUPT_TRACE:
+ if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP) {
+ run->exit_reason = KVM_EXIT_DEBUG;
+ r = RESUME_HOST;
+ } else {
+ kvmppc_book3s_queue_irqprio(vcpu, exit_nr);
+ r = RESUME_GUEST;
+ }
+ break;
default:
{
ulong shadow_srr1 = vcpu->arch.shadow_srr1;
@@ -1479,6 +1505,8 @@ static int kvmppc_vcpu_run_pr(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
goto out;
}
+ kvmppc_setup_debug(vcpu);
+
/*
* Interrupts could be timers for the guest which we have to inject
* again, so let's postpone them until we're in the guest and if we
@@ -1501,6 +1529,8 @@ static int kvmppc_vcpu_run_pr(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
ret = __kvmppc_vcpu_run(kvm_run, vcpu);
+ kvmppc_clear_debug(vcpu);
+
/* No need for kvm_guest_exit. It's done in handle_exit.
We also get here with interrupts enabled. */