[Qemu-devel] [PATCH v9 27/27] gdbstub: Add support to write a MSR for KVM target

[Jon Doron]

gdb> maint packet Qqemu.kvm.Wrmsr:MsrIndex,Value

Signed-off-by: Jon Doron <ari...@gmail.com>
---
 gdbstub.c | 29 ++++++++++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/gdbstub.c b/gdbstub.c
index f48c3a2b5f..a434a3749e 100644
--- a/gdbstub.c
+++ b/gdbstub.c
@@ -2145,7 +2145,8 @@ static void handle_query_qemu_supported(GdbCmdContext 
*gdb_ctx, void *user_ctx)
              "sstepbits;sstep;PhyMemMode");
 
     if (kvm_enabled()) {
-        pstrcat(gdb_ctx->str_buf, sizeof(gdb_ctx->str_buf), ";kvm.Rdmsr");
+        pstrcat(gdb_ctx->str_buf, sizeof(gdb_ctx->str_buf),
+                ";kvm.Rdmsr;kvm.Wrmsr");
     }
 
     put_packet(gdb_ctx->s, gdb_ctx->str_buf);
@@ -2196,6 +2197,26 @@ static void handle_query_kvm_read_msr(GdbCmdContext 
*gdb_ctx, void *user_ctx)
     put_packet(gdb_ctx->s, gdb_ctx->str_buf);
 }
 
+static void handle_set_kvm_write_msr(GdbCmdContext *gdb_ctx, void *user_ctx)
+{
+    if (!kvm_enabled()) {
+        return;
+    }
+
+    if (gdb_ctx->num_params < 2) {
+        put_packet(gdb_ctx->s, "E22");
+        return;
+    }
+
+    if (kvm_arch_write_msr(gdbserver_state->c_cpu, gdb_ctx->params[0].val_ul,
+                           gdb_ctx->params[1].val_ull)) {
+        put_packet(gdb_ctx->s, "E00");
+        return;
+    }
+
+    put_packet(gdb_ctx->s, "OK");
+}
+
 static GdbCmdParseEntry gdb_gen_query_set_common_table[] = {
     /* Order is important if has same prefix */
     {
@@ -2302,6 +2323,12 @@ static GdbCmdParseEntry gdb_gen_set_table[] = {
         .cmd_startswith = 1,
         .schema = "l0"
     },
+    {
+        .handler = handle_set_kvm_write_msr,
+        .cmd = "qemu.kvm.Wrmsr:",
+        .cmd_startswith = 1,
+        .schema = "l,L0"
+    },
 };
 
 static void handle_gen_query(GdbCmdContext *gdb_ctx, void *user_ctx)
-- 
2.20.1