[RFC PATCH 14/25] target/i386/mshv: Add CPU create and remove logic

[Magnus Kulke]

Implement MSHV-specific hooks for vCPU creation and teardown in the
i386 target. A list of locks per vCPU is maintained to lock CPU state in
MMIO operations.

Signed-off-by: Magnus Kulke <magnusku...@linux.microsoft.com>
---
 target/i386/mshv/mshv-cpu.c | 61 +++++++++++++++++++++++++++++++++----
 1 file changed, 55 insertions(+), 6 deletions(-)

diff --git a/target/i386/mshv/mshv-cpu.c b/target/i386/mshv/mshv-cpu.c
index c4b2c297e2..0ba1dacaed 100644
--- a/target/i386/mshv/mshv-cpu.c
+++ b/target/i386/mshv/mshv-cpu.c
@@ -14,6 +14,8 @@
  */
 
 #include "qemu/osdep.h"
+#include "qemu/atomic.h"
+#include "qemu/lockable.h"
 #include "qemu/error-report.h"
 #include "qemu/typedefs.h"
 
@@ -30,6 +32,36 @@
 #include "trace-accel_mshv.h"
 #include "trace.h"
 
+#include <sys/ioctl.h>
+
+static QemuMutex *cpu_guards_lock;
+static GHashTable *cpu_guards;
+
+static void add_cpu_guard(int cpu_fd)
+{
+    QemuMutex *guard;
+
+    WITH_QEMU_LOCK_GUARD(cpu_guards_lock) {
+        guard = g_new0(QemuMutex, 1);
+        qemu_mutex_init(guard);
+        g_hash_table_insert(cpu_guards, GUINT_TO_POINTER(cpu_fd), guard);
+    }
+}
+
+static void remove_cpu_guard(int cpu_fd)
+{
+    QemuMutex *guard;
+
+    WITH_QEMU_LOCK_GUARD(cpu_guards_lock) {
+        guard = g_hash_table_lookup(cpu_guards, GUINT_TO_POINTER(cpu_fd));
+        if (guard) {
+            qemu_mutex_destroy(guard);
+            g_free(guard);
+            g_hash_table_remove(cpu_guards, GUINT_TO_POINTER(cpu_fd));
+        }
+    }
+}
+
 int mshv_store_regs(CPUState *cpu)
 {
        error_report("unimplemented");
@@ -62,20 +94,37 @@ int mshv_run_vcpu(int vm_fd, CPUState *cpu, hv_message 
*msg, MshvVmExit *exit)
 
 void mshv_remove_vcpu(int vm_fd, int cpu_fd)
 {
-       error_report("unimplemented");
-       abort();
+    /*
+     * TODO: don't we have to perform an ioctl to remove the vcpu?
+     * there is WHvDeleteVirtualProcessor in the WHV api
+     */
+    remove_cpu_guard(cpu_fd);
 }
 
+
 int mshv_create_vcpu(int vm_fd, uint8_t vp_index, int *cpu_fd)
 {
-       error_report("unimplemented");
-       abort();
+    int ret;
+    struct mshv_create_vp vp_arg = {
+        .vp_index = vp_index,
+    };
+    ret = ioctl(vm_fd, MSHV_CREATE_VP, &vp_arg);
+    if (ret < 0) {
+        error_report("failed to create mshv vcpu: %s", strerror(errno));
+        return -1;
+    }
+
+    add_cpu_guard(ret);
+    *cpu_fd = ret;
+
+    return 0;
 }
 
 void mshv_init_cpu_logic(void)
 {
-       error_report("unimplemented");
-       abort();
+    cpu_guards_lock = g_new0(QemuMutex, 1);
+    qemu_mutex_init(cpu_guards_lock);
+    cpu_guards = g_hash_table_new(g_direct_hash, g_direct_equal);
 }
 
 void mshv_arch_init_vcpu(CPUState *cpu)
-- 
2.34.1