* [Qemu-devel] [PATCH 1/4 v8] ppc: debug stub: Get trap instruction opcode from KVM
2014-07-14 9:15 [Qemu-devel] [PATCH 0/4 v8] ppc: Add debug stub support Bharat Bhushan
@ 2014-07-14 9:15 ` Bharat Bhushan
2014-07-14 11:52 ` Madhavan Srinivasan
2014-07-14 9:15 ` [Qemu-devel] [PATCH 2/4 v8] ppc: synchronize excp_vectors for injecting exception Bharat Bhushan
` (3 subsequent siblings)
4 siblings, 1 reply; 8+ messages in thread
From: Bharat Bhushan @ 2014-07-14 9:15 UTC (permalink / raw)
To: agraf; +Cc: Bharat Bhushan, maddy, qemu-ppc, qemu-devel
Get trap instruction opcode from KVM and this opcode will
be used for setting software breakpoint in following patch
Signed-off-by: Bharat Bhushan <Bharat.Bhushan@freescale.com>
---
v7->v8
- No change
target-ppc/kvm.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
index 2d87108..4df23dd 100644
--- a/target-ppc/kvm.c
+++ b/target-ppc/kvm.c
@@ -72,6 +72,8 @@ static int cap_papr;
static int cap_htab_fd;
static int cap_fixup_hcalls;
+static uint32_t debug_inst_opcode;
+
/* XXX We have a race condition where we actually have a level triggered
* interrupt, but the infrastructure can't expose that yet, so the guest
* takes but ignores it, goes to sleep and never gets notified that there's
@@ -436,6 +438,8 @@ int kvm_arch_init_vcpu(CPUState *cs)
break;
}
+ kvm_get_one_reg(cs, KVM_REG_PPC_DEBUG_INST, &debug_inst_opcode);
+
return ret;
}
--
1.9.3
^ permalink raw reply related [flat|nested] 8+ messages in thread* Re: [Qemu-devel] [PATCH 1/4 v8] ppc: debug stub: Get trap instruction opcode from KVM
2014-07-14 9:15 ` [Qemu-devel] [PATCH 1/4 v8] ppc: debug stub: Get trap instruction opcode from KVM Bharat Bhushan
@ 2014-07-14 11:52 ` Madhavan Srinivasan
0 siblings, 0 replies; 8+ messages in thread
From: Madhavan Srinivasan @ 2014-07-14 11:52 UTC (permalink / raw)
To: Bharat Bhushan, agraf; +Cc: qemu-ppc, qemu-devel
On Monday 14 July 2014 02:45 PM, Bharat Bhushan wrote:
> Get trap instruction opcode from KVM and this opcode will
> be used for setting software breakpoint in following patch
>
> Signed-off-by: Bharat Bhushan <Bharat.Bhushan@freescale.com>
> ---
> v7->v8
> - No change
>
Reviewed By: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
> target-ppc/kvm.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
> index 2d87108..4df23dd 100644
> --- a/target-ppc/kvm.c
> +++ b/target-ppc/kvm.c
> @@ -72,6 +72,8 @@ static int cap_papr;
> static int cap_htab_fd;
> static int cap_fixup_hcalls;
>
> +static uint32_t debug_inst_opcode;
> +
> /* XXX We have a race condition where we actually have a level triggered
> * interrupt, but the infrastructure can't expose that yet, so the guest
> * takes but ignores it, goes to sleep and never gets notified that there's
> @@ -436,6 +438,8 @@ int kvm_arch_init_vcpu(CPUState *cs)
> break;
> }
>
> + kvm_get_one_reg(cs, KVM_REG_PPC_DEBUG_INST, &debug_inst_opcode);
> +
> return ret;
> }
>
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Qemu-devel] [PATCH 2/4 v8] ppc: synchronize excp_vectors for injecting exception
2014-07-14 9:15 [Qemu-devel] [PATCH 0/4 v8] ppc: Add debug stub support Bharat Bhushan
2014-07-14 9:15 ` [Qemu-devel] [PATCH 1/4 v8] ppc: debug stub: Get trap instruction opcode from KVM Bharat Bhushan
@ 2014-07-14 9:15 ` Bharat Bhushan
2014-07-14 9:15 ` [Qemu-devel] [PATCH 4/4 v8] ppc: Add hw breakpoint watchpoint support Bharat Bhushan
` (2 subsequent siblings)
4 siblings, 0 replies; 8+ messages in thread
From: Bharat Bhushan @ 2014-07-14 9:15 UTC (permalink / raw)
To: agraf; +Cc: Bharat Bhushan, maddy, qemu-ppc, qemu-devel
This patch synchronizes env->excp_vectors[] with env->iovr[].
This is required for using the existing interrupt injection mechanism
for kvm.
Signed-off-by: Bharat Bhushan <Bharat.Bhushan@freescale.com>
---
v7->v8
- No change
target-ppc/kvm.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)
diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
index 4df23dd..e00a20f 100644
--- a/target-ppc/kvm.c
+++ b/target-ppc/kvm.c
@@ -903,6 +903,11 @@ int kvm_arch_put_registers(CPUState *cs, int level)
return ret;
}
+static void kvm_sync_excp(CPUPPCState *env, int vector, int ivor)
+{
+ env->excp_vectors[vector] = env->spr[ivor] + env->spr[SPR_BOOKE_IVPR];
+}
+
int kvm_arch_get_registers(CPUState *cs)
{
PowerPCCPU *cpu = POWERPC_CPU(cs);
@@ -985,35 +990,57 @@ int kvm_arch_get_registers(CPUState *cs)
if (sregs.u.e.features & KVM_SREGS_E_IVOR) {
env->spr[SPR_BOOKE_IVOR0] = sregs.u.e.ivor_low[0];
+ kvm_sync_excp(env, POWERPC_EXCP_CRITICAL, SPR_BOOKE_IVOR0);
env->spr[SPR_BOOKE_IVOR1] = sregs.u.e.ivor_low[1];
+ kvm_sync_excp(env, POWERPC_EXCP_MCHECK, SPR_BOOKE_IVOR1);
env->spr[SPR_BOOKE_IVOR2] = sregs.u.e.ivor_low[2];
+ kvm_sync_excp(env, POWERPC_EXCP_DSI, SPR_BOOKE_IVOR2);
env->spr[SPR_BOOKE_IVOR3] = sregs.u.e.ivor_low[3];
+ kvm_sync_excp(env, POWERPC_EXCP_ISI, SPR_BOOKE_IVOR3);
env->spr[SPR_BOOKE_IVOR4] = sregs.u.e.ivor_low[4];
+ kvm_sync_excp(env, POWERPC_EXCP_EXTERNAL, SPR_BOOKE_IVOR4);
env->spr[SPR_BOOKE_IVOR5] = sregs.u.e.ivor_low[5];
+ kvm_sync_excp(env, POWERPC_EXCP_ALIGN, SPR_BOOKE_IVOR5);
env->spr[SPR_BOOKE_IVOR6] = sregs.u.e.ivor_low[6];
+ kvm_sync_excp(env, POWERPC_EXCP_PROGRAM, SPR_BOOKE_IVOR6);
env->spr[SPR_BOOKE_IVOR7] = sregs.u.e.ivor_low[7];
+ kvm_sync_excp(env, POWERPC_EXCP_FPU, SPR_BOOKE_IVOR7);
env->spr[SPR_BOOKE_IVOR8] = sregs.u.e.ivor_low[8];
+ kvm_sync_excp(env, POWERPC_EXCP_SYSCALL, SPR_BOOKE_IVOR8);
env->spr[SPR_BOOKE_IVOR9] = sregs.u.e.ivor_low[9];
+ kvm_sync_excp(env, POWERPC_EXCP_APU, SPR_BOOKE_IVOR9);
env->spr[SPR_BOOKE_IVOR10] = sregs.u.e.ivor_low[10];
+ kvm_sync_excp(env, POWERPC_EXCP_DECR, SPR_BOOKE_IVOR10);
env->spr[SPR_BOOKE_IVOR11] = sregs.u.e.ivor_low[11];
+ kvm_sync_excp(env, POWERPC_EXCP_FIT, SPR_BOOKE_IVOR11);
env->spr[SPR_BOOKE_IVOR12] = sregs.u.e.ivor_low[12];
+ kvm_sync_excp(env, POWERPC_EXCP_WDT, SPR_BOOKE_IVOR12);
env->spr[SPR_BOOKE_IVOR13] = sregs.u.e.ivor_low[13];
+ kvm_sync_excp(env, POWERPC_EXCP_DTLB, SPR_BOOKE_IVOR13);
env->spr[SPR_BOOKE_IVOR14] = sregs.u.e.ivor_low[14];
+ kvm_sync_excp(env, POWERPC_EXCP_ITLB, SPR_BOOKE_IVOR14);
env->spr[SPR_BOOKE_IVOR15] = sregs.u.e.ivor_low[15];
+ kvm_sync_excp(env, POWERPC_EXCP_DEBUG, SPR_BOOKE_IVOR15);
if (sregs.u.e.features & KVM_SREGS_E_SPE) {
env->spr[SPR_BOOKE_IVOR32] = sregs.u.e.ivor_high[0];
+ kvm_sync_excp(env, POWERPC_EXCP_SPEU, SPR_BOOKE_IVOR32);
env->spr[SPR_BOOKE_IVOR33] = sregs.u.e.ivor_high[1];
+ kvm_sync_excp(env, POWERPC_EXCP_EFPDI, SPR_BOOKE_IVOR33);
env->spr[SPR_BOOKE_IVOR34] = sregs.u.e.ivor_high[2];
+ kvm_sync_excp(env, POWERPC_EXCP_EFPRI, SPR_BOOKE_IVOR34);
}
if (sregs.u.e.features & KVM_SREGS_E_PM) {
env->spr[SPR_BOOKE_IVOR35] = sregs.u.e.ivor_high[3];
+ kvm_sync_excp(env, POWERPC_EXCP_EPERFM, SPR_BOOKE_IVOR35);
}
if (sregs.u.e.features & KVM_SREGS_E_PC) {
env->spr[SPR_BOOKE_IVOR36] = sregs.u.e.ivor_high[4];
+ kvm_sync_excp(env, POWERPC_EXCP_DOORI, SPR_BOOKE_IVOR36);
env->spr[SPR_BOOKE_IVOR37] = sregs.u.e.ivor_high[5];
+ kvm_sync_excp(env, POWERPC_EXCP_DOORCI, SPR_BOOKE_IVOR37);
}
}
--
1.9.3
^ permalink raw reply related [flat|nested] 8+ messages in thread* [Qemu-devel] [PATCH 4/4 v8] ppc: Add hw breakpoint watchpoint support
2014-07-14 9:15 [Qemu-devel] [PATCH 0/4 v8] ppc: Add debug stub support Bharat Bhushan
2014-07-14 9:15 ` [Qemu-devel] [PATCH 1/4 v8] ppc: debug stub: Get trap instruction opcode from KVM Bharat Bhushan
2014-07-14 9:15 ` [Qemu-devel] [PATCH 2/4 v8] ppc: synchronize excp_vectors for injecting exception Bharat Bhushan
@ 2014-07-14 9:15 ` Bharat Bhushan
2014-07-14 9:15 ` [Qemu-devel] [PATCH 3/4 v8] ppc: Add software breakpoint support Bharat Bhushan
2014-07-28 13:36 ` [Qemu-devel] [PATCH 0/4 v8] ppc: Add debug stub support Alexander Graf
4 siblings, 0 replies; 8+ messages in thread
From: Bharat Bhushan @ 2014-07-14 9:15 UTC (permalink / raw)
To: agraf; +Cc: Bharat Bhushan, maddy, qemu-ppc, qemu-devel
This patch adds hardware breakpoint and hardware watchpoint support
for ppc.
On BOOKE architecture we cannot share debug resources between QEMU
and guest because:
When QEMU is using debug resources then debug exception must
be always enabled. To achieve this we set MSR_DE and also set
MSRP_DEP so guest cannot change MSR_DE.
When emulating debug resource for guest we want guest
to control MSR_DE (enable/disable debug interrupt on need).
So above mentioned two configuration cannot be supported
at the same time. So the result is that we cannot share
debug resources between QEMU and Guest on BOOKE architecture.
In the current design QEMU gets priority over guest,
this means that if QEMU is using debug resources then guest
cannot use them and if guest is using debug resource then
qemu can overwrite them.
When QEMU is not able to handle debug exception then we inject program
exception to guest. Yes program exception NOT debug exception and the
reason is:
1) QEMU and guest not sharing debug resources
2) For software breakpoint QEMU uses a ehpriv-1 instruction;
So there cannot be any reason that we are in qemu with exit reason
KVM_EXIT_DEBUG for guest set debug exception, only possibility is
guest executed ehpriv-1 privilege instruction and that's why we are
injecting program exception.
Signed-off-by: Bharat Bhushan <Bharat.Bhushan@freescale.com>
---
v7->v8
- No change
target-ppc/kvm.c | 234 +++++++++++++++++++++++++++++++++++++++++++++++++++----
1 file changed, 219 insertions(+), 15 deletions(-)
diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
index 0f2e8e4..a0948ae 100644
--- a/target-ppc/kvm.c
+++ b/target-ppc/kvm.c
@@ -38,6 +38,7 @@
#include "hw/ppc/ppc.h"
#include "sysemu/watchdog.h"
#include "trace.h"
+#include "exec/gdbstub.h"
//#define DEBUG_KVM
@@ -412,6 +413,38 @@ unsigned long kvm_arch_vcpu_id(CPUState *cpu)
return ppc_get_vcpu_dt_id(POWERPC_CPU(cpu));
}
+/* e500 supports 2 h/w breakpoint and 2 watchpoint.
+ * book3s supports only 1 watchpoint, so array size
+ * of 4 is sufficient for now.
+ */
+#define MAX_HW_BKPTS 4
+
+static struct HWBreakpoint {
+ target_ulong addr;
+ int type;
+} hw_debug_points[MAX_HW_BKPTS];
+
+static CPUWatchpoint hw_watchpoint;
+
+/* Default there is no breakpoint and watchpoint supported */
+static int max_hw_breakpoint;
+static int max_hw_watchpoint;
+static int nb_hw_breakpoint;
+static int nb_hw_watchpoint;
+
+static void kvmppc_hw_debug_points_init(CPUPPCState *cenv)
+{
+ if (cenv->excp_model == POWERPC_EXCP_BOOKE) {
+ max_hw_breakpoint = 2;
+ max_hw_watchpoint = 2;
+ }
+
+ if ((max_hw_breakpoint + max_hw_watchpoint) > MAX_HW_BKPTS) {
+ fprintf(stderr, "Error initializing h/w breakpoints\n");
+ return;
+ }
+}
+
int kvm_arch_init_vcpu(CPUState *cs)
{
PowerPCCPU *cpu = POWERPC_CPU(cs);
@@ -439,6 +472,7 @@ int kvm_arch_init_vcpu(CPUState *cs)
}
kvm_get_one_reg(cs, KVM_REG_PPC_DEBUG_INST, &debug_inst_opcode);
+ kvmppc_hw_debug_points_init(cenv);
return ret;
}
@@ -1303,12 +1337,163 @@ int kvm_arch_remove_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp)
return 0;
}
+static int find_hw_breakpoint(target_ulong addr, int type)
+{
+ int n;
+
+ assert((nb_hw_breakpoint + nb_hw_watchpoint)
+ <= ARRAY_SIZE(hw_debug_points));
+
+ for (n = 0; n < nb_hw_breakpoint + nb_hw_watchpoint; n++) {
+ if (hw_debug_points[n].addr == addr &&
+ hw_debug_points[n].type == type) {
+ return n;
+ }
+ }
+
+ return -1;
+}
+
+static int find_hw_watchpoint(target_ulong addr, int *flag)
+{
+ int n;
+
+ n = find_hw_breakpoint(addr, GDB_WATCHPOINT_ACCESS);
+ if (n >= 0) {
+ *flag = BP_MEM_ACCESS;
+ return n;
+ }
+
+ n = find_hw_breakpoint(addr, GDB_WATCHPOINT_WRITE);
+ if (n >= 0) {
+ *flag = BP_MEM_WRITE;
+ return n;
+ }
+
+ n = find_hw_breakpoint(addr, GDB_WATCHPOINT_READ);
+ if (n >= 0) {
+ *flag = BP_MEM_READ;
+ return n;
+ }
+
+ return -1;
+}
+
+int kvm_arch_insert_hw_breakpoint(target_ulong addr,
+ target_ulong len, int type)
+{
+ if ((nb_hw_breakpoint + nb_hw_watchpoint) >= ARRAY_SIZE(hw_debug_points)) {
+ return -ENOBUFS;
+ }
+
+ hw_debug_points[nb_hw_breakpoint + nb_hw_watchpoint].addr = addr;
+ hw_debug_points[nb_hw_breakpoint + nb_hw_watchpoint].type = type;
+
+ switch (type) {
+ case GDB_BREAKPOINT_HW:
+ if (nb_hw_breakpoint >= max_hw_breakpoint) {
+ return -ENOBUFS;
+ }
+
+ if (find_hw_breakpoint(addr, type) >= 0) {
+ return -EEXIST;
+ }
+
+ nb_hw_breakpoint++;
+ break;
+
+ case GDB_WATCHPOINT_WRITE:
+ case GDB_WATCHPOINT_READ:
+ case GDB_WATCHPOINT_ACCESS:
+ if (nb_hw_watchpoint >= max_hw_watchpoint) {
+ return -ENOBUFS;
+ }
+
+ if (find_hw_breakpoint(addr, type) >= 0) {
+ return -EEXIST;
+ }
+
+ nb_hw_watchpoint++;
+ break;
+
+ default:
+ return -ENOSYS;
+ }
+
+ return 0;
+}
+
+int kvm_arch_remove_hw_breakpoint(target_ulong addr,
+ target_ulong len, int type)
+{
+ int n;
+
+ n = find_hw_breakpoint(addr, type);
+ if (n < 0) {
+ return -ENOENT;
+ }
+
+ switch (type) {
+ case GDB_BREAKPOINT_HW:
+ nb_hw_breakpoint--;
+ break;
+
+ case GDB_WATCHPOINT_WRITE:
+ case GDB_WATCHPOINT_READ:
+ case GDB_WATCHPOINT_ACCESS:
+ nb_hw_watchpoint--;
+ break;
+
+ default:
+ return -ENOSYS;
+ }
+ hw_debug_points[n] = hw_debug_points[nb_hw_breakpoint + nb_hw_watchpoint];
+
+ return 0;
+}
+
+void kvm_arch_remove_all_hw_breakpoints(void)
+{
+ nb_hw_breakpoint = nb_hw_watchpoint = 0;
+}
+
void kvm_arch_update_guest_debug(CPUState *cs, struct kvm_guest_debug *dbg)
{
+ int n;
+
/* Software Breakpoint updates */
if (kvm_sw_breakpoints_active(cs)) {
dbg->control |= KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP;
}
+
+ assert((nb_hw_breakpoint + nb_hw_watchpoint)
+ <= ARRAY_SIZE(hw_debug_points));
+ assert((nb_hw_breakpoint + nb_hw_watchpoint) <= ARRAY_SIZE(dbg->arch.bp));
+
+ if (nb_hw_breakpoint + nb_hw_watchpoint > 0) {
+ dbg->control |= KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_HW_BP;
+ memset(dbg->arch.bp, 0, sizeof(dbg->arch.bp));
+ for (n = 0; n < nb_hw_breakpoint + nb_hw_watchpoint; n++) {
+ switch (hw_debug_points[n].type) {
+ case GDB_BREAKPOINT_HW:
+ dbg->arch.bp[n].type = KVMPPC_DEBUG_BREAKPOINT;
+ break;
+ case GDB_WATCHPOINT_WRITE:
+ dbg->arch.bp[n].type = KVMPPC_DEBUG_WATCH_WRITE;
+ break;
+ case GDB_WATCHPOINT_READ:
+ dbg->arch.bp[n].type = KVMPPC_DEBUG_WATCH_READ;
+ break;
+ case GDB_WATCHPOINT_ACCESS:
+ dbg->arch.bp[n].type = KVMPPC_DEBUG_WATCH_WRITE |
+ KVMPPC_DEBUG_WATCH_READ;
+ break;
+ default:
+ cpu_abort(cs, "Unsupported breakpoint type\n");
+ }
+ dbg->arch.bp[n].addr = hw_debug_points[n].addr;
+ }
+ }
}
static int kvm_handle_debug(PowerPCCPU *cpu, struct kvm_run *run)
@@ -1317,13 +1502,46 @@ static int kvm_handle_debug(PowerPCCPU *cpu, struct kvm_run *run)
CPUPPCState *env = &cpu->env;
struct kvm_debug_exit_arch *arch_info = &run->debug.arch;
int handle = 0;
+ int n;
+ int flag = 0;
- if (kvm_find_sw_breakpoint(cs, arch_info->address)) {
+ if (cs->singlestep_enabled) {
+ handle = 1;
+ } else if (arch_info->status) {
+ if (nb_hw_breakpoint + nb_hw_watchpoint > 0) {
+ if (arch_info->status & KVMPPC_DEBUG_BREAKPOINT) {
+ n = find_hw_breakpoint(arch_info->address, GDB_BREAKPOINT_HW);
+ if (n >= 0) {
+ handle = 1;
+ }
+ } else if (arch_info->status & (KVMPPC_DEBUG_WATCH_READ |
+ KVMPPC_DEBUG_WATCH_WRITE)) {
+ n = find_hw_watchpoint(arch_info->address, &flag);
+ if (n >= 0) {
+ handle = 1;
+ cs->watchpoint_hit = &hw_watchpoint;
+ hw_watchpoint.vaddr = hw_debug_points[n].addr;
+ hw_watchpoint.flags = flag;
+ }
+ }
+ }
+ } else if (kvm_find_sw_breakpoint(cs, arch_info->address)) {
handle = 1;
} else {
/* QEMU is not able to handle debug exception, so inject
* program exception to guest;
* Yes program exception NOT debug exception !!
+ * When QEMU is using debug resources then debug exception must
+ * be always set. To achieve this we set MSR_DE and also set
+ * MSRP_DEP so guest cannot change MSR_DE.
+ * When emulating debug resource for guest we want guest
+ * to control MSR_DE (enable/disable debug interrupt on need).
+ * Supporting both configurations are NOT possible.
+ * So the result is that we cannot share debug resources
+ * between QEMU and Guest on BOOKE architecture.
+ * In the current design QEMU gets the priority over guest,
+ * this means that if QEMU is using debug resources then guest
+ * cannot use them;
* For software breakpoint QEMU uses a ehpriv-1 instruction;
* So there cannot be any reason that we are here for guest
* set debug exception, only possibility is guest executed a
@@ -2082,20 +2300,6 @@ void kvm_arch_init_irq_routing(KVMState *s)
{
}
-int kvm_arch_insert_hw_breakpoint(target_ulong addr, target_ulong len, int type)
-{
- return -EINVAL;
-}
-
-int kvm_arch_remove_hw_breakpoint(target_ulong addr, target_ulong len, int type)
-{
- return -EINVAL;
-}
-
-void kvm_arch_remove_all_hw_breakpoints(void)
-{
-}
-
struct kvm_get_htab_buf {
struct kvm_get_htab_header header;
/*
--
1.9.3
^ permalink raw reply related [flat|nested] 8+ messages in thread* [Qemu-devel] [PATCH 3/4 v8] ppc: Add software breakpoint support
2014-07-14 9:15 [Qemu-devel] [PATCH 0/4 v8] ppc: Add debug stub support Bharat Bhushan
` (2 preceding siblings ...)
2014-07-14 9:15 ` [Qemu-devel] [PATCH 4/4 v8] ppc: Add hw breakpoint watchpoint support Bharat Bhushan
@ 2014-07-14 9:15 ` Bharat Bhushan
2014-07-14 11:51 ` Madhavan Srinivasan
2014-07-28 13:36 ` [Qemu-devel] [PATCH 0/4 v8] ppc: Add debug stub support Alexander Graf
4 siblings, 1 reply; 8+ messages in thread
From: Bharat Bhushan @ 2014-07-14 9:15 UTC (permalink / raw)
To: agraf; +Cc: Bharat Bhushan, maddy, qemu-ppc, qemu-devel
This patch allow insert/remove software breakpoint.
When QEMU is not able to handle debug exception then we inject
program exception to guest because for software breakpoint QEMU
uses a ehpriv-1 instruction;
So there cannot be any reason that we are in qemu with exit reason
KVM_EXIT_DEBUG for guest set debug exception, only possibility is
guest executed ehpriv-1 privilege instruction and that's why we are
injecting program exception.
Signed-off-by: Bharat Bhushan <Bharat.Bhushan@freescale.com>
---
v7->v8
- Decrement nip by 4 before calling ppc_cpu_do_interrupt()
as pointed by "Madhavan Srinivasan"
- Also added missing cpu_sync()
target-ppc/kvm.c | 93 +++++++++++++++++++++++++++++++++++++++++++++++---------
1 file changed, 79 insertions(+), 14 deletions(-)
diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
index e00a20f..0f2e8e4 100644
--- a/target-ppc/kvm.c
+++ b/target-ppc/kvm.c
@@ -1275,6 +1275,75 @@ static int kvmppc_handle_dcr_write(CPUPPCState *env, uint32_t dcrn, uint32_t dat
return 0;
}
+int kvm_arch_insert_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp)
+{
+ /* Mixed endian case is not handled */
+ uint32_t sc = debug_inst_opcode;
+
+ if (cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&bp->saved_insn,
+ sizeof(sc), 0) ||
+ cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&sc, sizeof(sc), 1)) {
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+int kvm_arch_remove_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp)
+{
+ uint32_t sc;
+
+ if (cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&sc, sizeof(sc), 0) ||
+ sc != debug_inst_opcode ||
+ cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&bp->saved_insn,
+ sizeof(sc), 1)) {
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+void kvm_arch_update_guest_debug(CPUState *cs, struct kvm_guest_debug *dbg)
+{
+ /* Software Breakpoint updates */
+ if (kvm_sw_breakpoints_active(cs)) {
+ dbg->control |= KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP;
+ }
+}
+
+static int kvm_handle_debug(PowerPCCPU *cpu, struct kvm_run *run)
+{
+ CPUState *cs = CPU(cpu);
+ CPUPPCState *env = &cpu->env;
+ struct kvm_debug_exit_arch *arch_info = &run->debug.arch;
+ int handle = 0;
+
+ if (kvm_find_sw_breakpoint(cs, arch_info->address)) {
+ handle = 1;
+ } else {
+ /* QEMU is not able to handle debug exception, so inject
+ * program exception to guest;
+ * Yes program exception NOT debug exception !!
+ * For software breakpoint QEMU uses a ehpriv-1 instruction;
+ * So there cannot be any reason that we are here for guest
+ * set debug exception, only possibility is guest executed a
+ * privilege instruction and that's why we are injecting
+ * program exception.
+ */
+
+ cpu_synchronize_state(cs);
+ /* env->nip is PC, so increment this by 4 to use
+ * ppc_cpu_do_interrupt(), which set srr0 = env->nip - 4.
+ */
+ env->nip += 4;
+ cs->exception_index = POWERPC_EXCP_PROGRAM;
+ env->error_code = POWERPC_EXCP_INVAL;
+ ppc_cpu_do_interrupt(cs);
+ }
+
+ return handle;
+}
+
int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run)
{
PowerPCCPU *cpu = POWERPC_CPU(cs);
@@ -1315,6 +1384,16 @@ int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run)
ret = 0;
break;
+ case KVM_EXIT_DEBUG:
+ DPRINTF("handle debug exception\n");
+ if (kvm_handle_debug(cpu, run)) {
+ ret = EXCP_DEBUG;
+ break;
+ }
+ /* re-enter, this exception was guest-internal */
+ ret = 0;
+ break;
+
default:
fprintf(stderr, "KVM: unknown exit reason %d\n", run->exit_reason);
ret = -1;
@@ -2003,16 +2082,6 @@ void kvm_arch_init_irq_routing(KVMState *s)
{
}
-int kvm_arch_insert_sw_breakpoint(CPUState *cpu, struct kvm_sw_breakpoint *bp)
-{
- return -EINVAL;
-}
-
-int kvm_arch_remove_sw_breakpoint(CPUState *cpu, struct kvm_sw_breakpoint *bp)
-{
- return -EINVAL;
-}
-
int kvm_arch_insert_hw_breakpoint(target_ulong addr, target_ulong len, int type)
{
return -EINVAL;
@@ -2027,10 +2096,6 @@ void kvm_arch_remove_all_hw_breakpoints(void)
{
}
-void kvm_arch_update_guest_debug(CPUState *cpu, struct kvm_guest_debug *dbg)
-{
-}
-
struct kvm_get_htab_buf {
struct kvm_get_htab_header header;
/*
--
1.9.3
^ permalink raw reply related [flat|nested] 8+ messages in thread* Re: [Qemu-devel] [PATCH 3/4 v8] ppc: Add software breakpoint support
2014-07-14 9:15 ` [Qemu-devel] [PATCH 3/4 v8] ppc: Add software breakpoint support Bharat Bhushan
@ 2014-07-14 11:51 ` Madhavan Srinivasan
0 siblings, 0 replies; 8+ messages in thread
From: Madhavan Srinivasan @ 2014-07-14 11:51 UTC (permalink / raw)
To: Bharat Bhushan, agraf; +Cc: qemu-ppc, qemu-devel
On Monday 14 July 2014 02:45 PM, Bharat Bhushan wrote:
> This patch allow insert/remove software breakpoint.
>
> When QEMU is not able to handle debug exception then we inject
> program exception to guest because for software breakpoint QEMU
> uses a ehpriv-1 instruction;
> So there cannot be any reason that we are in qemu with exit reason
> KVM_EXIT_DEBUG for guest set debug exception, only possibility is
> guest executed ehpriv-1 privilege instruction and that's why we are
> injecting program exception.
>
> Signed-off-by: Bharat Bhushan <Bharat.Bhushan@freescale.com>
> ---
> v7->v8
> - Decrement nip by 4 before calling ppc_cpu_do_interrupt()
> as pointed by "Madhavan Srinivasan"
Just a minor change. We increment the nip.
> - Also added missing cpu_sync()
>
> target-ppc/kvm.c | 93 +++++++++++++++++++++++++++++++++++++++++++++++---------
> 1 file changed, 79 insertions(+), 14 deletions(-)
>
> diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
> index e00a20f..0f2e8e4 100644
> --- a/target-ppc/kvm.c
> +++ b/target-ppc/kvm.c
> @@ -1275,6 +1275,75 @@ static int kvmppc_handle_dcr_write(CPUPPCState *env, uint32_t dcrn, uint32_t dat
> return 0;
> }
>
> +int kvm_arch_insert_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp)
> +{
> + /* Mixed endian case is not handled */
> + uint32_t sc = debug_inst_opcode;
> +
> + if (cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&bp->saved_insn,
> + sizeof(sc), 0) ||
> + cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&sc, sizeof(sc), 1)) {
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> +int kvm_arch_remove_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp)
> +{
> + uint32_t sc;
> +
> + if (cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&sc, sizeof(sc), 0) ||
> + sc != debug_inst_opcode ||
> + cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&bp->saved_insn,
> + sizeof(sc), 1)) {
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> +void kvm_arch_update_guest_debug(CPUState *cs, struct kvm_guest_debug *dbg)
> +{
> + /* Software Breakpoint updates */
> + if (kvm_sw_breakpoints_active(cs)) {
> + dbg->control |= KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP;
> + }
> +}
> +
> +static int kvm_handle_debug(PowerPCCPU *cpu, struct kvm_run *run)
> +{
> + CPUState *cs = CPU(cpu);
> + CPUPPCState *env = &cpu->env;
> + struct kvm_debug_exit_arch *arch_info = &run->debug.arch;
> + int handle = 0;
> +
> + if (kvm_find_sw_breakpoint(cs, arch_info->address)) {
> + handle = 1;
> + } else {
> + /* QEMU is not able to handle debug exception, so inject
> + * program exception to guest;
> + * Yes program exception NOT debug exception !!
> + * For software breakpoint QEMU uses a ehpriv-1 instruction;
Instead, can you say "QEMU uses a SW breakpoint instruction". In server
side, we use illegal instruction to trap to hypervisor ("0x00dddd00")
> + * So there cannot be any reason that we are here for guest
> + * set debug exception, only possibility is guest executed a
> + * privilege instruction and that's why we are injecting
^^^^privilege or illegal instruction
My Bad. I should have read just last time. But just minor and I am ok as is.
Reviewed By: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
> + * program exception.
> + */
> +
> + cpu_synchronize_state(cs);
> + /* env->nip is PC, so increment this by 4 to use
> + * ppc_cpu_do_interrupt(), which set srr0 = env->nip - 4.
> + */
> + env->nip += 4;
> + cs->exception_index = POWERPC_EXCP_PROGRAM;
> + env->error_code = POWERPC_EXCP_INVAL;
> + ppc_cpu_do_interrupt(cs);
> + }
> +
> + return handle;
> +}
> +
> int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run)
> {
> PowerPCCPU *cpu = POWERPC_CPU(cs);
> @@ -1315,6 +1384,16 @@ int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run)
> ret = 0;
> break;
>
> + case KVM_EXIT_DEBUG:
> + DPRINTF("handle debug exception\n");
> + if (kvm_handle_debug(cpu, run)) {
> + ret = EXCP_DEBUG;
> + break;
> + }
> + /* re-enter, this exception was guest-internal */
> + ret = 0;
> + break;
> +
> default:
> fprintf(stderr, "KVM: unknown exit reason %d\n", run->exit_reason);
> ret = -1;
> @@ -2003,16 +2082,6 @@ void kvm_arch_init_irq_routing(KVMState *s)
> {
> }
>
> -int kvm_arch_insert_sw_breakpoint(CPUState *cpu, struct kvm_sw_breakpoint *bp)
> -{
> - return -EINVAL;
> -}
> -
> -int kvm_arch_remove_sw_breakpoint(CPUState *cpu, struct kvm_sw_breakpoint *bp)
> -{
> - return -EINVAL;
> -}
> -
> int kvm_arch_insert_hw_breakpoint(target_ulong addr, target_ulong len, int type)
> {
> return -EINVAL;
> @@ -2027,10 +2096,6 @@ void kvm_arch_remove_all_hw_breakpoints(void)
> {
> }
>
> -void kvm_arch_update_guest_debug(CPUState *cpu, struct kvm_guest_debug *dbg)
> -{
> -}
> -
> struct kvm_get_htab_buf {
> struct kvm_get_htab_header header;
> /*
>
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [Qemu-devel] [PATCH 0/4 v8] ppc: Add debug stub support
2014-07-14 9:15 [Qemu-devel] [PATCH 0/4 v8] ppc: Add debug stub support Bharat Bhushan
` (3 preceding siblings ...)
2014-07-14 9:15 ` [Qemu-devel] [PATCH 3/4 v8] ppc: Add software breakpoint support Bharat Bhushan
@ 2014-07-28 13:36 ` Alexander Graf
4 siblings, 0 replies; 8+ messages in thread
From: Alexander Graf @ 2014-07-28 13:36 UTC (permalink / raw)
To: Bharat Bhushan; +Cc: maddy, qemu-ppc, qemu-devel
On 14.07.14 11:15, Bharat Bhushan wrote:
> This patchset add support for
> - software breakpoint
> - h/w breakpoint
> - h/w watchpoint
>
> Please find description in individual patch.
Thanks, applied (with minor edits in comments) to ppc-next-2.2.
Alex
^ permalink raw reply [flat|nested] 8+ messages in thread