[v7,23/52] i386/tdx: Add TDVF memory via KVM_TDX_INIT_MEM_REGION

Commit Message

Xiaoyao Li Jan. 24, 2025, 1:20 p.m. UTC

From: Isaku Yamahata <[e-mail]>

TDVF firmware (CODE and VARS) needs to be copied to TD's private
memory via KVM_TDX_INIT_MEM_REGION, as well as TD HOB and TEMP memory.

If the TDVF section has TDVF_SECTION_ATTRIBUTES_MR_EXTEND set in the
flag, calling KVM_TDX_EXTEND_MEMORY to extend the measurement.

After populating the TDVF memory, the original image located in shared
ramblock can be discarded.

Signed-off-by: Isaku Yamahata <[e-mail]>
Signed-off-by: Xiaoyao Li <[e-mail]>
Acked-by: Gerd Hoffmann <[e-mail]>
---
Changes in v6:
 - switch back to use KVM_TDX_INIT_MEM_REGION according to KVM's change;
---
 target/i386/kvm/tdx.c | 42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

Patch

diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c
index cac073a6d291..08320b59b62a 100644
--- a/target/i386/kvm/tdx.c
+++ b/target/i386/kvm/tdx.c
@@ -17,6 +17,7 @@ 
 #include "qom/object_interfaces.h"
 #include "crypto/hash.h"
 #include "system/system.h"
+#include "exec/ramblock.h"
 
 #include "hw/i386/e820_memory_layout.h"
 #include "hw/i386/x86.h"
@@ -270,6 +271,9 @@  static void tdx_finalize_vm(Notifier *notifier, void *unused)
 {
     TdxFirmware *tdvf = &tdx_guest->tdvf;
     TdxFirmwareEntry *entry;
+    RAMBlock *ram_block;
+    Error *local_err = NULL;
+    int r;
 
     tdx_init_ram_entries();
 
@@ -295,6 +299,44 @@  static void tdx_finalize_vm(Notifier *notifier, void *unused)
           sizeof(TdxRamEntry), &tdx_ram_entry_compare);
 
     tdvf_hob_create(tdx_guest, tdx_get_hob_entry(tdx_guest));
+
+    for_each_tdx_fw_entry(tdvf, entry) {
+        struct kvm_tdx_init_mem_region region;
+        uint32_t flags;
+
+        region = (struct kvm_tdx_init_mem_region) {
+            .source_addr = (uint64_t)entry->mem_ptr,
+            .gpa = entry->address,
+            .nr_pages = entry->size >> 12,
+        };
+
+        flags = entry->attributes & TDVF_SECTION_ATTRIBUTES_MR_EXTEND ?
+                KVM_TDX_MEASURE_MEMORY_REGION : 0;
+
+        do {
+            error_free(local_err);
+            local_err = NULL;
+            r = tdx_vcpu_ioctl(first_cpu, KVM_TDX_INIT_MEM_REGION, flags,
+                               &region, &local_err);
+        } while (r == -EAGAIN || r == -EINTR);
+        if (r < 0) {
+            error_report_err(local_err);
+            exit(1);
+        }
+
+        if (entry->type == TDVF_SECTION_TYPE_TD_HOB ||
+            entry->type == TDVF_SECTION_TYPE_TEMP_MEM) {
+            qemu_ram_munmap(-1, entry->mem_ptr, entry->size);
+            entry->mem_ptr = NULL;
+        }
+    }
+
+    /*
+     * TDVF image has been copied into private region above via
+     * KVM_MEMORY_MAPPING. It becomes useless.
+     */
+    ram_block = tdx_guest->tdvf_mr->ram_block;
+    ram_block_discard_range(ram_block, 0, ram_block->max_length);
 }
 
 static Notifier tdx_machine_done_notify = {