From: Laurent Vivier <lvivier@redhat.com>
To: kvm-ppc@vger.kernel.org, kvm@vger.kernel.org
Cc: Gleb Natapov <gleb@kernel.org>,
Paolo Bonzini <pbonzini@redhat.com>,
Alexander Graf <agraf@suse.com>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Michael Ellerman <mpe@ellerman.id.au>,
linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
dgibson@redhat.com, thuth@redhat.com,
Laurent Vivier <lvivier@redhat.com>
Subject: [PATCH v2] kvm-pr: manage single-step mode
Date: Fri, 8 Apr 2016 18:05:00 +0200 [thread overview]
Message-ID: <1460131500-19560-1-git-send-email-lvivier@redhat.com> (raw)
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>
---
v2: split BOOK3S_INTERRUPT_MACHINE_CHECK and BOOK3S_INTERRUPT_TRACE
arch/powerpc/kvm/book3s_pr.c | 32 +++++++++++++++++++++++++++++++-
1 file changed, 31 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index 95bceca..8129b0d 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. */
--
2.5.5
next reply other threads:[~2016-04-08 16:05 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-08 16:05 Laurent Vivier [this message]
2016-04-11 4:02 ` [PATCH v2] kvm-pr: manage single-step mode David Gibson
2016-04-11 9:45 ` Thomas Huth
2016-05-11 11:36 ` Paul Mackerras
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