igvm: Add common function for finding parameter entries

Move repeating code for finding the parameter entries in the IGVM
backend out of the parameter handlers into a common function.

A warning message is emitted in case a no parameter entry can be found
for a given index.

Reviewed-by: Luigi Leonardi <leonardi@redhat.com>
Signed-off-by: Oliver Steffen <osteffen@redhat.com>
Message-ID: <20260130054714.715928-6-osteffen@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

diff --git a/backends/igvm.c b/backends/igvm.c
index 3a3832dc2dde967965e9a871a310e78d46e3b580..ea3f9d6b008f670d7c86c2fd9c346325bac837ef 100644 (file)
--- a/backends/igvm.c
+++ b/backends/igvm.c
@@ -12,6 +12,7 @@
 #include "qemu/osdep.h"
 
 #include "qapi/error.h"
+#include "qemu/error-report.h"
 #include "qemu/target-info-qapi.h"
 #include "system/igvm.h"
 #include "system/igvm-cfg.h"
@@ -60,6 +61,20 @@ struct QEMU_PACKED sev_id_authentication {
 
 #define IGVM_SEV_ID_BLOCK_VERSION 1
 
+QIgvmParameterData*
+qigvm_find_param_entry(QIgvm *igvm, uint32_t parameter_area_index)
+{
+    QIgvmParameterData *param_entry;
+    QTAILQ_FOREACH(param_entry, &igvm->parameter_data, next)
+    {
+        if (param_entry->index == parameter_area_index) {
+            return param_entry;
+        }
+    }
+    warn_report("IGVM: No parameter area for index %u", parameter_area_index);
+    return NULL;
+}
+
 static int qigvm_directive_page_data(QIgvm *ctx, const uint8_t *header_data,
                                      Error **errp);
 static int qigvm_directive_vp_context(QIgvm *ctx, const uint8_t *header_data,
@@ -534,58 +549,54 @@ static int qigvm_directive_memory_map(QIgvm *ctx, const uint8_t *header_data,
     }
 
     /* Find the parameter area that should hold the memory map */
-    QTAILQ_FOREACH(param_entry, &ctx->parameter_data, next)
-    {
-        if (param_entry->index == param->parameter_area_index) {
-            max_entry_count =
-                param_entry->size / sizeof(IGVM_VHS_MEMORY_MAP_ENTRY);
-            mm_entry = (IGVM_VHS_MEMORY_MAP_ENTRY *)param_entry->data;
-
-            retval = get_mem_map_entry(entry, &cgmm_entry, errp);
-            while (retval == 0) {
-                if (entry >= max_entry_count) {
-                    error_setg(
-                        errp,
-                        "IGVM: guest memory map size exceeds parameter area defined in IGVM file");
-                    return -1;
-                }
-                mm_entry[entry].starting_gpa_page_number = cgmm_entry.gpa >> 12;
-                mm_entry[entry].number_of_pages = cgmm_entry.size >> 12;
-
-                switch (cgmm_entry.type) {
-                case CGS_MEM_RAM:
-                    mm_entry[entry].entry_type =
-                        IGVM_MEMORY_MAP_ENTRY_TYPE_MEMORY;
-                    break;
-                case CGS_MEM_RESERVED:
-                    mm_entry[entry].entry_type =
-                        IGVM_MEMORY_MAP_ENTRY_TYPE_PLATFORM_RESERVED;
-                    break;
-                case CGS_MEM_ACPI:
-                    mm_entry[entry].entry_type =
-                        IGVM_MEMORY_MAP_ENTRY_TYPE_PLATFORM_RESERVED;
-                    break;
-                case CGS_MEM_NVS:
-                    mm_entry[entry].entry_type =
-                        IGVM_MEMORY_MAP_ENTRY_TYPE_PERSISTENT;
-                    break;
-                case CGS_MEM_UNUSABLE:
-                    mm_entry[entry].entry_type =
-                        IGVM_MEMORY_MAP_ENTRY_TYPE_PLATFORM_RESERVED;
-                    break;
-                }
-                retval = get_mem_map_entry(++entry, &cgmm_entry, errp);
-            }
-            if (retval < 0) {
-                return retval;
-            }
-            /* The entries need to be sorted */
-            qsort(mm_entry, entry, sizeof(IGVM_VHS_MEMORY_MAP_ENTRY),
-                  qigvm_cmp_mm_entry);
+    param_entry = qigvm_find_param_entry(ctx, param->parameter_area_index);
+    if (param_entry == NULL) {
+        return 0;
+    }
+
+    max_entry_count = param_entry->size / sizeof(IGVM_VHS_MEMORY_MAP_ENTRY);
+    mm_entry = (IGVM_VHS_MEMORY_MAP_ENTRY *)param_entry->data;
+
+    retval = get_mem_map_entry(entry, &cgmm_entry, errp);
+    while (retval == 0) {
+        if (entry >= max_entry_count) {
+            error_setg(
+                errp,
+                "IGVM: guest memory map size exceeds parameter area defined "
+                "in IGVM file");
+            return -1;
+        }
+        mm_entry[entry].starting_gpa_page_number = cgmm_entry.gpa >> 12;
+        mm_entry[entry].number_of_pages = cgmm_entry.size >> 12;
 
+        switch (cgmm_entry.type) {
+        case CGS_MEM_RAM:
+            mm_entry[entry].entry_type = IGVM_MEMORY_MAP_ENTRY_TYPE_MEMORY;
+            break;
+        case CGS_MEM_RESERVED:
+            mm_entry[entry].entry_type =
+                IGVM_MEMORY_MAP_ENTRY_TYPE_PLATFORM_RESERVED;
+            break;
+        case CGS_MEM_ACPI:
+            mm_entry[entry].entry_type =
+                IGVM_MEMORY_MAP_ENTRY_TYPE_PLATFORM_RESERVED;
+            break;
+        case CGS_MEM_NVS:
+            mm_entry[entry].entry_type = IGVM_MEMORY_MAP_ENTRY_TYPE_PERSISTENT;
+            break;
+        case CGS_MEM_UNUSABLE:
+            mm_entry[entry].entry_type =
+                IGVM_MEMORY_MAP_ENTRY_TYPE_PLATFORM_RESERVED;
             break;
         }
+        retval = get_mem_map_entry(++entry, &cgmm_entry, errp);
+    }
+    if (retval < 0) {
+        return retval;
     }
+    /* The entries need to be sorted */
+    qsort(mm_entry, entry, sizeof(IGVM_VHS_MEMORY_MAP_ENTRY),
+          qigvm_cmp_mm_entry);
     return 0;
 }
 
@@ -597,18 +608,18 @@ static int qigvm_directive_vp_count(QIgvm *ctx, const uint8_t *header_data,
     uint32_t *vp_count;
     CPUState *cpu;
 
-    QTAILQ_FOREACH(param_entry, &ctx->parameter_data, next)
+    param_entry = qigvm_find_param_entry(ctx, param->parameter_area_index);
+    if (param_entry == NULL) {
+        return 0;
+    }
+
+    vp_count = (uint32_t *)(param_entry->data + param->byte_offset);
+    *vp_count = 0;
+    CPU_FOREACH(cpu)
     {
-        if (param_entry->index == param->parameter_area_index) {
-            vp_count = (uint32_t *)(param_entry->data + param->byte_offset);
-            *vp_count = 0;
-            CPU_FOREACH(cpu)
-            {
-                (*vp_count)++;
-            }
-            break;
-        }
+        (*vp_count)++;
     }
+
     return 0;
 }
 
@@ -620,15 +631,15 @@ static int qigvm_directive_environment_info(QIgvm *ctx,
     QIgvmParameterData *param_entry;
     IgvmEnvironmentInfo *environmental_state;
 
-    QTAILQ_FOREACH(param_entry, &ctx->parameter_data, next)
-    {
-        if (param_entry->index == param->parameter_area_index) {
-            environmental_state =
-                (IgvmEnvironmentInfo *)(param_entry->data + param->byte_offset);
-            environmental_state->memory_is_shared = 1;
-            break;
-        }
+    param_entry = qigvm_find_param_entry(ctx, param->parameter_area_index);
+    if (param_entry == NULL) {
+        return 0;
     }
+
+    environmental_state =
+        (IgvmEnvironmentInfo *)(param_entry->data + param->byte_offset);
+    environmental_state->memory_is_shared = 1;
+
     return 0;
 }
 

diff --git a/include/system/igvm-internal.h b/include/system/igvm-internal.h
index 9c8e887d6f60aa777219d248ad5519450baf2e83..019f95e866157775daf288cdeecc9c0e2c8372e8 100644 (file)
--- a/include/system/igvm-internal.h
+++ b/include/system/igvm-internal.h
@@ -70,4 +70,7 @@ typedef struct QIgvm {
 
 IgvmHandle qigvm_file_init(char *filename, Error **errp);
 
+QIgvmParameterData*
+qigvm_find_param_entry(QIgvm *igvm, uint32_t parameter_area_index);
+
 #endif