diff mbox

[v5,4/6] target-arm: kvm - support for single step

Message ID 1432912764-7073-5-git-send-email-alex.bennee@linaro.org
State New
Headers show

Commit Message

Alex Bennée May 29, 2015, 3:19 p.m. UTC 
This adds support for single-step. There isn't much to do on the QEMU
side as after we set-up the request for single step via the debug ioctl
it is all handled within the kernel.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

---
v2
  - convert to using HSR_EC
v3
  - use internals.h definitions
---
 target-arm/kvm.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

Comments

Peter Maydell June 4, 2015, 10:59 a.m. UTC | #1 
On 29 May 2015 at 16:19, Alex Bennée <alex.bennee@linaro.org> wrote:
> This adds support for single-step. There isn't much to do on the QEMU
> side as after we set-up the request for single step via the debug ioctl
> it is all handled within the kernel.
>
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
>
> ---
> v2
>   - convert to using HSR_EC
> v3
>   - use internals.h definitions
> ---
>  target-arm/kvm.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
>
> diff --git a/target-arm/kvm.c b/target-arm/kvm.c
> index c3bad6f..de2865a 100644
> --- a/target-arm/kvm.c
> +++ b/target-arm/kvm.c
> @@ -528,6 +528,13 @@ static int kvm_handle_debug(CPUState *cs, struct kvm_run *run)
>      kvm_cpu_synchronize_state(cs);
>
>      switch (hsr_ec) {
> +    case EC_SOFTWARESTEP:
> +        if (cs->singlestep_enabled) {
> +            return true;
> +        } else {
> +            error_report("Came out of SINGLE STEP when not enabled");

All-caps there is a bit odd.

> +        }
> +        break;
>      case EC_AA64_BKPT:
>          if (kvm_find_sw_breakpoint(cs, env->pc)) {
>              return true;
> @@ -588,6 +595,9 @@ int kvm_arch_on_sigbus(int code, void *addr)
>
>  void kvm_arch_update_guest_debug(CPUState *cs, struct kvm_guest_debug *dbg)
>  {
> +    if (cs->singlestep_enabled) {
> +        dbg->control |= KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_SINGLESTEP;
> +    }
>      if (kvm_sw_breakpoints_active(cs)) {
>          dbg->control |= KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP;
>      }

Again, is there a guard somewhere to prevent us trying to enable
singlestep if the kernel doesn't support it?

-- PMM
diff mbox

Patch

diff --git a/target-arm/kvm.c b/target-arm/kvm.c
index c3bad6f..de2865a 100644
--- a/target-arm/kvm.c
+++ b/target-arm/kvm.c
@@ -528,6 +528,13 @@  static int kvm_handle_debug(CPUState *cs, struct kvm_run *run)
     kvm_cpu_synchronize_state(cs);
 
     switch (hsr_ec) {
+    case EC_SOFTWARESTEP:
+        if (cs->singlestep_enabled) {
+            return true;
+        } else {
+            error_report("Came out of SINGLE STEP when not enabled");
+        }
+        break;
     case EC_AA64_BKPT:
         if (kvm_find_sw_breakpoint(cs, env->pc)) {
             return true;
@@ -588,6 +595,9 @@  int kvm_arch_on_sigbus(int code, void *addr)
 
 void kvm_arch_update_guest_debug(CPUState *cs, struct kvm_guest_debug *dbg)
 {
+    if (cs->singlestep_enabled) {
+        dbg->control |= KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_SINGLESTEP;
+    }
     if (kvm_sw_breakpoints_active(cs)) {
         dbg->control |= KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP;
     }