i386/tdx: Track mem_ptr for each firmware entry of TDVF

For each TDVF sections, QEMU needs to copy the content to guest
private memory via KVM API (KVM_TDX_INIT_MEM_REGION).

Introduce a field @mem_ptr for TdxFirmwareEntry to track the memory
pointer of each TDVF sections. So that QEMU can add/copy them to guest
private memory later.

TDVF sections can be classified into two groups:
 - Firmware itself, e.g., TDVF BFV and CFV, that located separately from
   guest RAM. Its memory pointer is the bios pointer.

 - Sections located at guest RAM, e.g., TEMP_MEM and TD_HOB.
   mmap a new memory range for them.

Register a machine_init_done callback to do the stuff.

Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250508150002.689633-21-xiaoyao.li@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/hw/i386/tdvf.c b/hw/i386/tdvf.c
index e2d486946a0fea9803b3aed4e661b089695459cf..bd993ea2f07a4e0b8c29f08b63436921985a758d 100644 (file)
--- a/hw/i386/tdvf.c
+++ b/hw/i386/tdvf.c
@@ -179,6 +179,7 @@ int tdvf_parse_metadata(TdxFirmware *fw, void *flash_ptr, int size)
         }
     }
 
+    fw->mem_ptr = flash_ptr;
     return 0;
 
 err:

diff --git a/include/hw/i386/tdvf.h b/include/hw/i386/tdvf.h
index 7ebcac42a36ce986eee6430dd6155e6272093969..e75c8d1acc68abbf1e18edd428c20f6c8ad8d28a 100644 (file)
--- a/include/hw/i386/tdvf.h
+++ b/include/hw/i386/tdvf.h
@@ -26,13 +26,20 @@ typedef struct TdxFirmwareEntry {
     uint64_t size;
     uint32_t type;
     uint32_t attributes;
+
+    void *mem_ptr;
 } TdxFirmwareEntry;
 
 typedef struct TdxFirmware {
+    void *mem_ptr;
+
     uint32_t nr_entries;
     TdxFirmwareEntry *entries;
 } TdxFirmware;
 
+#define for_each_tdx_fw_entry(fw, e)    \
+    for (e = (fw)->entries; e != (fw)->entries + (fw)->nr_entries; e++)
+
 int tdvf_parse_metadata(TdxFirmware *fw, void *flash_ptr, int size);
 
 #endif /* HW_I386_TDVF_H */

diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c
index 18beba2f5c30527191395048ccd54fe7c85003f5..bfdae4f1c0cd1ed0bf5fa7b695b48868d71cfb72 100644 (file)
--- a/target/i386/kvm/tdx.c
+++ b/target/i386/kvm/tdx.c
@@ -12,10 +12,13 @@
 #include "qemu/osdep.h"
 #include "qemu/error-report.h"
 #include "qemu/base64.h"
+#include "qemu/mmap-alloc.h"
 #include "qapi/error.h"
 #include "qom/object_interfaces.h"
 #include "crypto/hash.h"
+#include "system/system.h"
 
+#include "hw/i386/tdvf.h"
 #include "hw/i386/x86.h"
 #include "kvm_i386.h"
 #include "tdx.h"
@@ -143,6 +146,38 @@ void tdx_set_tdvf_region(MemoryRegion *tdvf_mr)
     tdx_guest->tdvf_mr = tdvf_mr;
 }
 
+static void tdx_finalize_vm(Notifier *notifier, void *unused)
+{
+    TdxFirmware *tdvf = &tdx_guest->tdvf;
+    TdxFirmwareEntry *entry;
+
+    for_each_tdx_fw_entry(tdvf, entry) {
+        switch (entry->type) {
+        case TDVF_SECTION_TYPE_BFV:
+        case TDVF_SECTION_TYPE_CFV:
+            entry->mem_ptr = tdvf->mem_ptr + entry->data_offset;
+            break;
+        case TDVF_SECTION_TYPE_TD_HOB:
+        case TDVF_SECTION_TYPE_TEMP_MEM:
+            entry->mem_ptr = qemu_ram_mmap(-1, entry->size,
+                                           qemu_real_host_page_size(), 0, 0);
+            if (entry->mem_ptr == MAP_FAILED) {
+                error_report("Failed to mmap memory for TDVF section %d",
+                             entry->type);
+                exit(1);
+            }
+            break;
+        default:
+            error_report("Unsupported TDVF section %d", entry->type);
+            exit(1);
+        }
+    }
+}
+
+static Notifier tdx_machine_done_notify = {
+    .notify = tdx_finalize_vm,
+};
+
 static int tdx_kvm_init(ConfidentialGuestSupport *cgs, Error **errp)
 {
     TdxGuest *tdx = TDX_GUEST(cgs);
@@ -157,6 +192,8 @@ static int tdx_kvm_init(ConfidentialGuestSupport *cgs, Error **errp)
         }
     }
 
+    qemu_add_machine_init_done_notifier(&tdx_machine_done_notify);
+
     tdx_guest = tdx;
     return 0;
 }