[PULL 36/51] KVM: PPC: E500: exit to user space on "ehpriv 1" instruction

Alexander Graf
2013-10-31T21:18:49Z

From: Bharat Bhushan <r65777@freescale.com>

"ehpriv 1" instruction is used for setting software breakpoints
by user space. This patch adds support to exit to user space
with "run->debug" have relevant information.

As this is the first point we are using run->debug, also defined
the run->debug structure.

Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
---
arch/powerpc/include/asm/disassemble.h | 4 ++++
arch/powerpc/include/asm/kvm_booke.h | 7 ++++++-
arch/powerpc/include/uapi/asm/kvm.h | 21 +++++++++++++++++----
arch/powerpc/kvm/booke.c | 2 +-
arch/powerpc/kvm/e500_emulate.c | 26 ++++++++++++++++++++++++++
5 files changed, 54 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/include/asm/disassemble.h b/arch/powerpc/include/asm/disassemble.h
index 9b198d1..856f8de 100644
--- a/arch/powerpc/include/asm/disassemble.h
+++ b/arch/powerpc/include/asm/disassemble.h
@@ -77,4 +77,8 @@ static inline unsigned int get_d(u32 inst)
return inst & 0xffff;
}

+static inline unsigned int get_oc(u32 inst)
+{
+ return (inst >> 11) & 0x7fff;
+}
#endif /* __ASM_PPC_DISASSEMBLE_H__ */
diff --git a/arch/powerpc/include/asm/kvm_booke.h b/arch/powerpc/include/asm/kvm_booke.h
index d3c1eb3..dd8f615 100644
--- a/arch/powerpc/include/asm/kvm_booke.h
+++ b/arch/powerpc/include/asm/kvm_booke.h
@@ -26,7 +26,12 @@
/* LPIDs we support with this build -- runtime limit may be lower */
#define KVMPPC_NR_LPIDS 64

-#define KVMPPC_INST_EHPRIV 0x7c00021c
+#define KVMPPC_INST_EHPRIV 0x7c00021c
+#define EHPRIV_OC_SHIFT 11
+/* "ehpriv 1" : ehpriv with OC = 1 is used for debug emulation */
+#define EHPRIV_OC_DEBUG 1
+#define KVMPPC_INST_EHPRIV_DEBUG (KVMPPC_INST_EHPRIV | \
+ (EHPRIV_OC_DEBUG << EHPRIV_OC_SHIFT))

static inline void kvmppc_set_gpr(struct kvm_vcpu *vcpu, int num, ulong val)
{
diff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/include/uapi/asm/kvm.h
index e420d46..482bba5 100644
--- a/arch/powerpc/include/uapi/asm/kvm.h
+++ b/arch/powerpc/include/uapi/asm/kvm.h
@@ -269,7 +269,24 @@ struct kvm_fpu {
__u64 fpr[32];
};

+/*
+ * Defines for h/w breakpoint, watchpoint (read, write or both) and
+ * software breakpoint.
+ * These are used as "type" in KVM_SET_GUEST_DEBUG ioctl and "status"
+ * for KVM_DEBUG_EXIT.
+ */
+#define KVMPPC_DEBUG_NONE 0x0
+#define KVMPPC_DEBUG_BREAKPOINT (1UL << 1)
+#define KVMPPC_DEBUG_WATCH_WRITE (1UL << 2)
+#define KVMPPC_DEBUG_WATCH_READ (1UL << 3)
struct kvm_debug_exit_arch {
+ __u64 address;
+ /*
+ * exiting to userspace because of h/w breakpoint, watchpoint
+ * (read, write or both) and software breakpoint.
+ */
+ __u32 status;
+ __u32 reserved;
};

/* for KVM_SET_GUEST_DEBUG */
@@ -281,10 +298,6 @@ struct kvm_guest_debug_arch {
* Type denotes h/w breakpoint, read watchpoint, write
* watchpoint or watchpoint (both read and write).
*/
-#define KVMPPC_DEBUG_NONE 0x0
-#define KVMPPC_DEBUG_BREAKPOINT (1UL << 1)
-#define KVMPPC_DEBUG_WATCH_WRITE (1UL << 2)
-#define KVMPPC_DEBUG_WATCH_READ (1UL << 3)
__u32 type;
__u32 reserved;
} bp[16];
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 65fa775..1d6edf0 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -1477,7 +1477,7 @@ int kvm_vcpu_ioctl_get_one_reg(struct kvm_vcpu *vcpu, struct kvm_one_reg *reg)
val = get_reg_val(reg->id, vcpu->arch.tsr);
break;
case KVM_REG_PPC_DEBUG_INST:
- val = get_reg_val(reg->id, KVMPPC_INST_EHPRIV);
+ val = get_reg_val(reg->id, KVMPPC_INST_EHPRIV_DEBUG);
break;
case KVM_REG_PPC_VRSAVE:
val = get_reg_val(reg->id, vcpu->arch.vrsave);
diff --git a/arch/powerpc/kvm/e500_emulate.c b/arch/powerpc/kvm/e500_emulate.c
index b10a012..6163a03 100644
--- a/arch/powerpc/kvm/e500_emulate.c
+++ b/arch/powerpc/kvm/e500_emulate.c
@@ -26,6 +26,7 @@
#define XOP_TLBRE 946
#define XOP_TLBWE 978
#define XOP_TLBILX 18
+#define XOP_EHPRIV 270

#ifdef CONFIG_KVM_E500MC
static int dbell2prio(ulong param)
@@ -82,6 +83,26 @@ static int kvmppc_e500_emul_msgsnd(struct kvm_vcpu *vcpu, int rb)
}
#endif

+static int kvmppc_e500_emul_ehpriv(struct kvm_run *run, struct kvm_vcpu *vcpu,
+ unsigned int inst, int *advance)
+{
+ int emulated = EMULATE_DONE;
+
+ switch (get_oc(inst)) {
+ case EHPRIV_OC_DEBUG:
+ run->exit_reason = KVM_EXIT_DEBUG;
+ run->debug.arch.address = vcpu->arch.pc;
+ run->debug.arch.status = 0;
+ kvmppc_account_exit(vcpu, DEBUG_EXITS);
+ emulated = EMULATE_EXIT_USER;
+ *advance = 0;
+ break;
+ default:
+ emulated = EMULATE_FAIL;
+ }
+ return emulated;
+}
+
int kvmppc_core_emulate_op(struct kvm_run *run, struct kvm_vcpu *vcpu,
unsigned int inst, int *advance)
{
@@ -130,6 +151,11 @@ int kvmppc_core_emulate_op(struct kvm_run *run, struct kvm_vcpu *vcpu,
emulated = kvmppc_e500_emul_tlbivax(vcpu, ea);
break;

+ case XOP_EHPRIV:
+ emulated = kvmppc_e500_emul_ehpriv(run, vcpu, inst,
+ advance);
+ break;
+
default:
emulated = EMULATE_FAIL;
}
--
1.8.1.4