[PATCH 07/11] kvm: introduce debug memory encryption API

[Ashish Kalra <Ashish.Kalra@xxxxxxx>]

From: Brijesh Singh <brijesh.singh@xxxxxxx>

In order to support debugging with Secure Encrypted Virtualization (SEV),
add a high-level memory encryption API.

Also add a new API interface to override any CPU class specific callbacks
for supporting debugging with SEV, for example, overriding the guest MMU/
page-table walker callback.

Signed-off-by: Brijesh Singh <brijesh.singh@xxxxxxx>
Signed-off-by: Ashish Kalra <ashish.kalra@xxxxxxx>
---
 accel/kvm/kvm-all.c    | 19 +++++++++++++++++++
 accel/stubs/kvm-stub.c |  8 ++++++++
 include/sysemu/kvm.h   | 15 +++++++++++++++
 3 files changed, 42 insertions(+)

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 9ef5daf4c5..ae85f53e7d 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -123,6 +123,8 @@ struct KVMState
     /* memory encryption */
     void *memcrypt_handle;
     int (*memcrypt_encrypt_data)(void *handle, uint8_t *ptr, uint64_t len);
+    void (*memcrypt_debug_ops_memory_region)(void *handle, MemoryRegion *mr);
+    void (*memcrypt_debug_ops_cpu_state)(void *handle, CPUState *cpu);
 
     /* For "info mtree -f" to tell if an MR is registered in KVM */
     int nr_as;
@@ -222,6 +224,23 @@ int kvm_get_max_memslots(void)
     return s->nr_slots;
 }
 
+void kvm_memcrypt_set_debug_ops_memory_region(MemoryRegion *mr)
+{
+    if (kvm_state->memcrypt_handle &&
+        kvm_state->memcrypt_debug_ops_memory_region) {
+        kvm_state->memcrypt_debug_ops_memory_region(kvm_state->memcrypt_handle,
+                                                    mr);
+    }
+}
+
+void kvm_memcrypt_set_debug_ops_cpu_state(CPUState *cs)
+{
+    if (kvm_state->memcrypt_handle &&
+        kvm_state->memcrypt_debug_ops_cpu_state) {
+        kvm_state->memcrypt_debug_ops_cpu_state(kvm_state->memcrypt_handle, cs);
+    }
+}
+
 bool kvm_memcrypt_enabled(void)
 {
     if (kvm_state && kvm_state->memcrypt_handle) {
diff --git a/accel/stubs/kvm-stub.c b/accel/stubs/kvm-stub.c
index 680e099463..bf93431e46 100644
--- a/accel/stubs/kvm-stub.c
+++ b/accel/stubs/kvm-stub.c
@@ -91,6 +91,14 @@ int kvm_memcrypt_encrypt_data(uint8_t *ptr, uint64_t len)
   return 1;
 }
 
+void kvm_memcrypt_set_debug_ops_memory_region(MemoryRegion *mr)
+{
+}
+
+void kvm_memcrypt_set_debug_ops_cpu_state(CPUState *cs)
+{
+}
+
 #ifndef CONFIG_USER_ONLY
 int kvm_irqchip_add_msi_route(KVMState *s, int vector, PCIDevice *dev)
 {
diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
index bb5d5cf497..1bde2e3d71 100644
--- a/include/sysemu/kvm.h
+++ b/include/sysemu/kvm.h
@@ -470,6 +470,21 @@ uint32_t kvm_arch_get_supported_cpuid(KVMState *env, uint32_t function,
                                       uint32_t index, int reg);
 uint64_t kvm_arch_get_supported_msr_feature(KVMState *s, uint32_t index);
 
+/**
+ * kvm_memcrypt_set_debug_ram_ops: set debug_ram_ops callback
+ *
+ * When debug_ram_ops is set, debug access to this memory region will use
+ * memory encryption APIs.
+ */
+void kvm_memcrypt_set_debug_ops_memory_region(MemoryRegion *mr);
+
+/**
+ * kvm_memcrypt_set_debug_ops_cpu_state: override cpu_class callbacks
+ *
+ * This interface allows vendor specific debug ops to override any
+ * cpu_class callbacks.
+ */
+void kvm_memcrypt_set_debug_ops_cpu_state(CPUState *cs);
 
 void kvm_set_sigmask_len(KVMState *s, unsigned int sigmask_len);
 
-- 
2.17.1