[Qemu-devel] [PATCH v7 20/26] hw: i386: set ram_debug_ops when memory encryption is enabled

[Brijesh Singh <brijesh.singh@amd.com>]

When memory encryption is enabled, the guest RAM and boot flash ROM will
contain the encrypted data. By setting the debug ops allow us to invoke
encryption APIs when accessing the memory for the debug purposes.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
---
 hw/i386/pc.c       | 9 +++++++++
 hw/i386/pc_sysfw.c | 6 ++++++
 2 files changed, 15 insertions(+)

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index ccc50baa85e0..ba451c0dc520 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1357,6 +1357,15 @@ void pc_memory_init(PCMachineState *pcms,
         e820_add_entry(0x100000000ULL, pcms->above_4g_mem_size, E820_RAM);
     }
 
+    /*
+     * When memory encryption is enabled, the guest RAM will be encrypted with
+     * a guest unique key. Set the debug ops so that any debug access to the
+     * guest RAM will go through the memory encryption APIs.
+     */
+    if (kvm_memcrypt_enabled()) {
+        kvm_memcrypt_set_debug_ops(ram);
+    }
+
     if (!pcmc->has_reserved_memory &&
         (machine->ram_slots ||
          (machine->maxram_size > machine->ram_size))) {
diff --git a/hw/i386/pc_sysfw.c b/hw/i386/pc_sysfw.c
index 8ddbbf74d330..3d149b1c9f3c 100644
--- a/hw/i386/pc_sysfw.c
+++ b/hw/i386/pc_sysfw.c
@@ -180,6 +180,12 @@ static void pc_system_flash_init(MemoryRegion *rom_memory)
                     error_report("failed to encrypt pflash rom");
                     exit(1);
                 }
+
+                /*
+                 * The pflash ROM is encrypted, set the debug ops so that any
+                 * debug accesses will use memory encryption APIs.
+                 */
+                kvm_memcrypt_set_debug_ops(flash_mem);
             }
         }
     }
-- 
2.14.3