i386/tdx: Setup the TD HOB list

The TD HOB list is used to pass the information from VMM to TDVF. The TD
HOB must include PHIT HOB and Resource Descriptor HOB. More details can
be found in TDVF specification and PI specification.

Build the TD HOB in TDX's machine_init_done callback.

Co-developed-by: Isaku Yamahata <isaku.yamahata@intel.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
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/20250508150002.689633-24-xiaoyao.li@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

3 files changed, 157 insertions, 1 deletions

diff --git a/hw/i386/meson.build b/hw/i386/meson.build
index 3bc1da2..7896f34 100644
--- a/hw/i386/meson.build
+++ b/hw/i386/meson.build
@@ -32,7 +32,7 @@ i386_ss.add(when: 'CONFIG_PC', if_true: files(
   'port92.c'))
 i386_ss.add(when: 'CONFIG_X86_FW_OVMF', if_true: files('pc_sysfw_ovmf.c'),
                                         if_false: files('pc_sysfw_ovmf-stubs.c'))
-i386_ss.add(when: 'CONFIG_TDX', if_true: files('tdvf.c'))
+i386_ss.add(when: 'CONFIG_TDX', if_true: files('tdvf.c', 'tdvf-hob.c'))
 
 subdir('kvm')
 subdir('xen')
diff --git a/hw/i386/tdvf-hob.c b/hw/i386/tdvf-hob.c
new file mode 100644
index 0000000..782b3d1
--- /dev/null
+++ b/hw/i386/tdvf-hob.c
@@ -0,0 +1,130 @@
+/*
+ * Copyright (c) 2025 Intel Corporation
+ * Author: Isaku Yamahata <isaku.yamahata at gmail.com>
+ *                        <isaku.yamahata at intel.com>
+ *         Xiaoyao Li <xiaoyao.li@intel.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/error-report.h"
+#include "standard-headers/uefi/uefi.h"
+#include "hw/pci/pcie_host.h"
+#include "tdvf-hob.h"
+
+typedef struct TdvfHob {
+    hwaddr hob_addr;
+    void *ptr;
+    int size;
+
+    /* working area */
+    void *current;
+    void *end;
+} TdvfHob;
+
+static uint64_t tdvf_current_guest_addr(const TdvfHob *hob)
+{
+    return hob->hob_addr + (hob->current - hob->ptr);
+}
+
+static void tdvf_align(TdvfHob *hob, size_t align)
+{
+    hob->current = QEMU_ALIGN_PTR_UP(hob->current, align);
+}
+
+static void *tdvf_get_area(TdvfHob *hob, uint64_t size)
+{
+    void *ret;
+
+    if (hob->current + size > hob->end) {
+        error_report("TD_HOB overrun, size = 0x%" PRIx64, size);
+        exit(1);
+    }
+
+    ret = hob->current;
+    hob->current += size;
+    tdvf_align(hob, 8);
+    return ret;
+}
+
+static void tdvf_hob_add_memory_resources(TdxGuest *tdx, TdvfHob *hob)
+{
+    EFI_HOB_RESOURCE_DESCRIPTOR *region;
+    EFI_RESOURCE_ATTRIBUTE_TYPE attr;
+    EFI_RESOURCE_TYPE resource_type;
+
+    TdxRamEntry *e;
+    int i;
+
+    for (i = 0; i < tdx->nr_ram_entries; i++) {
+        e = &tdx->ram_entries[i];
+
+        if (e->type == TDX_RAM_UNACCEPTED) {
+            resource_type = EFI_RESOURCE_MEMORY_UNACCEPTED;
+            attr = EFI_RESOURCE_ATTRIBUTE_TDVF_UNACCEPTED;
+        } else if (e->type == TDX_RAM_ADDED) {
+            resource_type = EFI_RESOURCE_SYSTEM_MEMORY;
+            attr = EFI_RESOURCE_ATTRIBUTE_TDVF_PRIVATE;
+        } else {
+            error_report("unknown TDX_RAM_ENTRY type %d", e->type);
+            exit(1);
+        }
+
+        region = tdvf_get_area(hob, sizeof(*region));
+        *region = (EFI_HOB_RESOURCE_DESCRIPTOR) {
+            .Header = {
+                .HobType = EFI_HOB_TYPE_RESOURCE_DESCRIPTOR,
+                .HobLength = cpu_to_le16(sizeof(*region)),
+                .Reserved = cpu_to_le32(0),
+            },
+            .Owner = EFI_HOB_OWNER_ZERO,
+            .ResourceType = cpu_to_le32(resource_type),
+            .ResourceAttribute = cpu_to_le32(attr),
+            .PhysicalStart = cpu_to_le64(e->address),
+            .ResourceLength = cpu_to_le64(e->length),
+        };
+    }
+}
+
+void tdvf_hob_create(TdxGuest *tdx, TdxFirmwareEntry *td_hob)
+{
+    TdvfHob hob = {
+        .hob_addr = td_hob->address,
+        .size = td_hob->size,
+        .ptr = td_hob->mem_ptr,
+
+        .current = td_hob->mem_ptr,
+        .end = td_hob->mem_ptr + td_hob->size,
+    };
+
+    EFI_HOB_GENERIC_HEADER *last_hob;
+    EFI_HOB_HANDOFF_INFO_TABLE *hit;
+
+    /* Note, Efi{Free}Memory{Bottom,Top} are ignored, leave 'em zeroed. */
+    hit = tdvf_get_area(&hob, sizeof(*hit));
+    *hit = (EFI_HOB_HANDOFF_INFO_TABLE) {
+        .Header = {
+            .HobType = EFI_HOB_TYPE_HANDOFF,
+            .HobLength = cpu_to_le16(sizeof(*hit)),
+            .Reserved = cpu_to_le32(0),
+        },
+        .Version = cpu_to_le32(EFI_HOB_HANDOFF_TABLE_VERSION),
+        .BootMode = cpu_to_le32(0),
+        .EfiMemoryTop = cpu_to_le64(0),
+        .EfiMemoryBottom = cpu_to_le64(0),
+        .EfiFreeMemoryTop = cpu_to_le64(0),
+        .EfiFreeMemoryBottom = cpu_to_le64(0),
+        .EfiEndOfHobList = cpu_to_le64(0), /* initialized later */
+    };
+
+    tdvf_hob_add_memory_resources(tdx, &hob);
+
+    last_hob = tdvf_get_area(&hob, sizeof(*last_hob));
+    *last_hob =  (EFI_HOB_GENERIC_HEADER) {
+        .HobType = EFI_HOB_TYPE_END_OF_HOB_LIST,
+        .HobLength = cpu_to_le16(sizeof(*last_hob)),
+        .Reserved = cpu_to_le32(0),
+    };
+    hit->EfiEndOfHobList = tdvf_current_guest_addr(&hob);
+}
diff --git a/hw/i386/tdvf-hob.h b/hw/i386/tdvf-hob.h
new file mode 100644
index 0000000..4fc6a37
--- /dev/null
+++ b/hw/i386/tdvf-hob.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef HW_I386_TD_HOB_H
+#define HW_I386_TD_HOB_H
+
+#include "hw/i386/tdvf.h"
+#include "target/i386/kvm/tdx.h"
+
+void tdvf_hob_create(TdxGuest *tdx, TdxFirmwareEntry *td_hob);
+
+#define EFI_RESOURCE_ATTRIBUTE_TDVF_PRIVATE     \
+    (EFI_RESOURCE_ATTRIBUTE_PRESENT |           \
+     EFI_RESOURCE_ATTRIBUTE_INITIALIZED |       \
+     EFI_RESOURCE_ATTRIBUTE_TESTED)
+
+#define EFI_RESOURCE_ATTRIBUTE_TDVF_UNACCEPTED  \
+    (EFI_RESOURCE_ATTRIBUTE_PRESENT |           \
+     EFI_RESOURCE_ATTRIBUTE_INITIALIZED |       \
+     EFI_RESOURCE_ATTRIBUTE_TESTED)
+
+#define EFI_RESOURCE_ATTRIBUTE_TDVF_MMIO        \
+    (EFI_RESOURCE_ATTRIBUTE_PRESENT     |       \
+     EFI_RESOURCE_ATTRIBUTE_INITIALIZED |       \
+     EFI_RESOURCE_ATTRIBUTE_UNCACHEABLE)
+
+#endif