Add an option to the vm_event response to toggle singlestepping on the vCPU.
This is only supported on Intel CPUs which have Monitor Trap Flag capability.
Singed-off-by: Tamas K Lengyel <tleng...@novetta.com>
Acked-by: Razvan Cojocaru <rcojoc...@bitdefender.com>
---
v2: Include sched.h in headers and sanity check that vcpu is paused.
---
MAINTAINERS | 1 +
xen/arch/x86/Makefile | 1 +
xen/arch/x86/hvm/hvm.c | 11 +++++++++++
xen/arch/x86/vm_event.c | 41 +++++++++++++++++++++++++++++++++++++++++
xen/common/vm_event.c | 7 ++++++-
xen/include/asm-arm/vm_event.h | 31 +++++++++++++++++++++++++++++++
xen/include/asm-x86/hvm/hvm.h | 3 +++
xen/include/asm-x86/vm_event.h | 27 +++++++++++++++++++++++++++
xen/include/public/vm_event.h | 12 +++++++++---
9 files changed, 130 insertions(+), 4 deletions(-)
create mode 100644 xen/arch/x86/vm_event.c
create mode 100644 xen/include/asm-arm/vm_event.h
create mode 100644 xen/include/asm-x86/vm_event.h
diff --git a/MAINTAINERS b/MAINTAINERS
index 6b1068e..59c0822 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -383,6 +383,7 @@ F: xen/common/vm_event.c
F: xen/common/mem_access.c
F: xen/arch/x86/hvm/event.c
F: xen/arch/x86/monitor.c
+F: xen/arch/x86/vm_event.c
XENTRACE
M: George Dunlap <george.dun...@eu.citrix.com>
diff --git a/xen/arch/x86/Makefile b/xen/arch/x86/Makefile
index 37e547c..5f24951 100644
--- a/xen/arch/x86/Makefile
+++ b/xen/arch/x86/Makefile
@@ -60,6 +60,7 @@ obj-y += machine_kexec.o
obj-y += crash.o
obj-y += tboot.o
obj-y += hpet.o
+obj-y += vm_event.o
obj-y += xstate.o
obj-$(crash_debug) += gdbstub.o
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 535d622..e951020 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -6431,6 +6431,17 @@ int hvm_debug_op(struct vcpu *v, int32_t op)
return rc;
}
+void hvm_toggle_singlestep(struct vcpu *v)
+{
+ ASSERT(atomic_read(&v->pause_count));
+
+ /* This feature is only available on Intel CPUs. */
+ if ( !cpu_has_monitor_trap_flag )
+ return;
+
+ v->arch.hvm_vcpu.single_step = !v->arch.hvm_vcpu.single_step;
+}
+
int nhvm_vcpu_hostrestore(struct vcpu *v, struct cpu_user_regs *regs)
{
if (hvm_funcs.nhvm_vcpu_hostrestore)
diff --git a/xen/arch/x86/vm_event.c b/xen/arch/x86/vm_event.c
new file mode 100644
index 0000000..c390225
--- /dev/null
+++ b/xen/arch/x86/vm_event.c
@@ -0,0 +1,41 @@
+/*
+ * arch/x86/vm_event.c
+ *
+ * Architecture-specific vm_event handling routines
+ *
+ * Copyright (c) 2015 Tamas K Lengyel (ta...@tklengyel.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <xen/sched.h>
+#include <asm/hvm/hvm.h>
+
+void vm_event_toggle_singlestep(struct domain *d, struct vcpu *v)
+{
+ if ( !is_hvm_domain(d) || !atomic_read(&v->vm_event_pause_count) )
+ return;
+
+ hvm_toggle_singlestep(v);
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/common/vm_event.c b/xen/common/vm_event.c
index 120a78a..a4b9c36 100644
--- a/xen/common/vm_event.c
+++ b/xen/common/vm_event.c
@@ -27,6 +27,7 @@
#include <xen/vm_event.h>
#include <xen/mem_access.h>
#include <asm/p2m.h>
+#include <asm/vm_event.h>
#include <xsm/xsm.h>
/* for public/io/ring.h macros */
@@ -399,9 +400,13 @@ void vm_event_resume(struct domain *d, struct
vm_event_domain *ved)
};
- /* Unpause domain. */
if ( rsp.flags & VM_EVENT_FLAG_VCPU_PAUSED )
+ {
+ if ( rsp.flags & VM_EVENT_FLAG_TOGGLE_SINGLESTEP )
+ vm_event_toggle_singlestep(d, v);
+
vm_event_vcpu_unpause(v);
+ }
}
}
diff --git a/xen/include/asm-arm/vm_event.h b/xen/include/asm-arm/vm_event.h
new file mode 100644
index 0000000..a517495
--- /dev/null
+++ b/xen/include/asm-arm/vm_event.h
@@ -0,0 +1,31 @@
+/*
+ * vm_event.h: architecture specific vm_event handling routines
+ *
+ * Copyright (c) 2015 Tamas K Lengyel (ta...@tklengyel.com)
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place - Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#ifndef __ASM_ARM_VM_EVENT_H__
+#define __ASM_ARM_VM_EVENT_H__
+
+#include <xen/sched.h>
+
+static inline
+void vm_event_toggle_singlestep(struct domain *d, struct vcpu *v)
+{
+ /* Not supported on ARM. */
+}
+
+#endif /* __ASM_ARM_VM_EVENT_H__ */
diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h
index 57f9605..073b758 100644
--- a/xen/include/asm-x86/hvm/hvm.h
+++ b/xen/include/asm-x86/hvm/hvm.h
@@ -448,6 +448,9 @@ static inline void hvm_set_info_guest(struct vcpu *v)
int hvm_debug_op(struct vcpu *v, int32_t op);
+/* Caller should pause vcpu before calling this function */
+void hvm_toggle_singlestep(struct vcpu *v);
+
static inline void hvm_invalidate_regs_fields(struct cpu_user_regs *regs)
{
#ifndef NDEBUG
diff --git a/xen/include/asm-x86/vm_event.h b/xen/include/asm-x86/vm_event.h
new file mode 100644
index 0000000..7cc3a3d
--- /dev/null
+++ b/xen/include/asm-x86/vm_event.h
@@ -0,0 +1,27 @@
+/*
+ * vm_event.h: architecture specific vm_event handling routines
+ *
+ * Copyright (c) 2015 Tamas K Lengyel (ta...@tklengyel.com)
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place - Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#ifndef __ASM_X86_VM_EVENT_H__
+#define __ASM_X86_VM_EVENT_H__
+
+#include <xen/sched.h>
+
+void vm_event_toggle_singlestep(struct domain *d, struct vcpu *v);
+
+#endif /* __ASM_X86_VM_EVENT_H__ */
diff --git a/xen/include/public/vm_event.h b/xen/include/public/vm_event.h
index 577e971..b8c3dde 100644
--- a/xen/include/public/vm_event.h
+++ b/xen/include/public/vm_event.h
@@ -44,9 +44,15 @@
* paused
* VCPU_PAUSED in a response signals to unpause the vCPU
*/
-#define VM_EVENT_FLAG_VCPU_PAUSED (1 << 0)
-/* Flags to aid debugging mem_event */
-#define VM_EVENT_FLAG_FOREIGN (1 << 1)
+#define VM_EVENT_FLAG_VCPU_PAUSED (1 << 0)
+/* Flag to aid debugging mem_event */
+#define VM_EVENT_FLAG_FOREIGN (1 << 1)
+/*
+ * Toggle singlestepping on vm_event response.
+ * Requires the vCPU to be paused already (synchronous events only).
+ * Only supported on Intel CPUs with MTF capability.
+ */
+#define VM_EVENT_FLAG_TOGGLE_SINGLESTEP (1 << 2)
/*
* Reasons for the vm event request
--
2.1.4
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