From: Chao Du <duchao@eswincomputing.com>

The KVM_CAP_SET_GUEST_DEBUG is probed during kvm_init().
gdbserver will fail to start if the CAP is not supported.
So no need to make another probe here, like other targets.

Signed-off-by: Chao Du <duchao@eswincomputing.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20231025070726.22689-1-duchao@eswincomputing.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/kvm64.c | 28 +++++++---------------------
 1 file changed, 7 insertions(+), 21 deletions(-)

diff --git a/target/arm/kvm64.c b/target/arm/kvm64.c
index 3c175c93a7..b8bb25a1ea 100644
--- a/target/arm/kvm64.c
+++ b/target/arm/kvm64.c
@@ -32,13 +32,9 @@
 #include "hw/acpi/acpi.h"
 #include "hw/acpi/ghes.h"
 
-static bool have_guest_debug;
 
 void kvm_arm_init_debug(KVMState *s)
 {
-    have_guest_debug = kvm_check_extension(s,
-                                           KVM_CAP_SET_GUEST_DEBUG);
-
     max_hw_wps = kvm_check_extension(s, KVM_CAP_GUEST_DEBUG_HW_WPS);
     hw_watchpoints = g_array_sized_new(true, true,
                                        sizeof(HWWatchpoint), max_hw_wps);
@@ -1141,33 +1137,23 @@ static const uint32_t brk_insn = 0xd4200000;
 
 int kvm_arch_insert_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp)
 {
-    if (have_guest_debug) {
-        if (cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&bp->saved_insn, 4, 0) ||
-            cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&brk_insn, 4, 1)) {
-            return -EINVAL;
-        }
-        return 0;
-    } else {
-        error_report("guest debug not supported on this kernel");
+    if (cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&bp->saved_insn, 4, 0) ||
+        cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&brk_insn, 4, 1)) {
         return -EINVAL;
     }
+    return 0;
 }
 
 int kvm_arch_remove_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp)
 {
     static uint32_t brk;
 
-    if (have_guest_debug) {
-        if (cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&brk, 4, 0) ||
-            brk != brk_insn ||
-            cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&bp->saved_insn, 4, 1)) {
-            return -EINVAL;
-        }
-        return 0;
-    } else {
-        error_report("guest debug not supported on this kernel");
+    if (cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&brk, 4, 0) ||
+        brk != brk_insn ||
+        cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&bp->saved_insn, 4, 1)) {
         return -EINVAL;
     }
+    return 0;
 }
 
 /* See v8 ARM ARM D7.2.27 ESR_ELx, Exception Syndrome Register
-- 
2.34.1

On 11/23/23 15:42, Richard Henderson wrote:
> From: Chao Du <duchao@eswincomputing.com>
> 
> The KVM_CAP_SET_GUEST_DEBUG is probed during kvm_init().
> gdbserver will fail to start if the CAP is not supported.
> So no need to make another probe here, like other targets.
> 
> Signed-off-by: Chao Du <duchao@eswincomputing.com>
> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
> Message-Id: <20231025070726.22689-1-duchao@eswincomputing.com>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   target/arm/kvm64.c | 28 +++++++---------------------
>   1 file changed, 7 insertions(+), 21 deletions(-)
> 

Reviewed-by: Gavin Shan <gshan@redhat.com>

On 23/11/23 05:42, Richard Henderson wrote:
> From: Chao Du <duchao@eswincomputing.com>
> 
> The KVM_CAP_SET_GUEST_DEBUG is probed during kvm_init().
> gdbserver will fail to start if the CAP is not supported.
> So no need to make another probe here, like other targets.
> 
> Signed-off-by: Chao Du <duchao@eswincomputing.com>
> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
> Message-Id: <20231025070726.22689-1-duchao@eswincomputing.com>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   target/arm/kvm64.c | 28 +++++++---------------------
>   1 file changed, 7 insertions(+), 21 deletions(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>