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[PATCH v4 3/5] igvm: Add common function for finding parameter entries

Oliver Steffen posted 5 patches 3 weeks, 5 days ago
Maintainers: Gerd Hoffmann <kraxel@redhat.com>, Stefano Garzarella <sgarzare@redhat.com>, Ani Sinha <anisinha@redhat.com>, "Michael S. Tsirkin" <mst@redhat.com>, Igor Mammedov <imammedo@redhat.com>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, Paolo Bonzini <pbonzini@redhat.com>, Richard Henderson <richard.henderson@linaro.org>, Eduardo Habkost <eduardo@habkost.net>, Zhao Liu <zhao1.liu@intel.com>, Marcelo Tosatti <mtosatti@redhat.com>
There is a newer version of this series
[PATCH v4 3/5] igvm: Add common function for finding parameter entries
Posted by Oliver Steffen 3 weeks, 5 days ago 
Move repeating code for finding the parameter entries in the IGVM
backend out of the parameter handlers into a common function.

Signed-off-by: Oliver Steffen <osteffen@redhat.com>
---
 backends/igvm.c | 117 +++++++++++++++++++++++++-----------------------
 1 file changed, 61 insertions(+), 56 deletions(-)

diff --git a/backends/igvm.c b/backends/igvm.c
index a350c890cc..ccb2f51cd9 100644
--- a/backends/igvm.c
+++ b/backends/igvm.c
@@ -95,6 +95,19 @@ typedef struct QIgvm {
     unsigned region_page_count;
 } QIgvm;
 
+static QIgvmParameterData*
+qigvm_find_param_entry(QIgvm *igvm, const IGVM_VHS_PARAMETER *param)
+{
+    QIgvmParameterData *param_entry;
+    QTAILQ_FOREACH(param_entry, &igvm->parameter_data, next)
+    {
+        if (param_entry->index == param->parameter_area_index) {
+            return param_entry;
+        }
+    }
+    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,
@@ -569,58 +582,53 @@ 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);
+    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;
 }
 
@@ -655,14 +663,11 @@ 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);
+    if (param_entry != NULL) {
+        environmental_state =
+            (IgvmEnvironmentInfo *)(param_entry->data + param->byte_offset);
+        environmental_state->memory_is_shared = 1;
     }
     return 0;
 }
-- 
2.52.0
Re: [PATCH v4 3/5] igvm: Add common function for finding parameter entries
Posted by Luigi Leonardi 3 weeks, 4 days ago 
Hi Oliver,

On Wed, Jan 14, 2026 at 06:50:05PM +0100, Oliver Steffen wrote:
>Move repeating code for finding the parameter entries in the IGVM
>backend out of the parameter handlers into a common function.
>
>Signed-off-by: Oliver Steffen <osteffen@redhat.com>
>---
> backends/igvm.c | 117 +++++++++++++++++++++++++-----------------------
> 1 file changed, 61 insertions(+), 56 deletions(-)
>
>diff --git a/backends/igvm.c b/backends/igvm.c
>index a350c890cc..ccb2f51cd9 100644
>--- a/backends/igvm.c
>+++ b/backends/igvm.c
>@@ -95,6 +95,19 @@ typedef struct QIgvm {
>     unsigned region_page_count;
> } QIgvm;
>
>+static QIgvmParameterData*
>+qigvm_find_param_entry(QIgvm *igvm, const IGVM_VHS_PARAMETER *param)
>+{
>+    QIgvmParameterData *param_entry;
>+    QTAILQ_FOREACH(param_entry, &igvm->parameter_data, next)
>+    {
>+        if (param_entry->index == param->parameter_area_index) {
>+            return param_entry;
>+        }
>+    }
>+    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,
>@@ -569,58 +582,53 @@ 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);
>+    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;
> }
>
>@@ -655,14 +663,11 @@ 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);
>+    if (param_entry != NULL) {

What about an early return?

>+        environmental_state =
>+            (IgvmEnvironmentInfo *)(param_entry->data + 
>param->byte_offset);
>+        environmental_state->memory_is_shared = 1;
>     }
>     return 0;
> }
>-- 2.52.0
>

Can we reuse `qigvm_find_param_entry` for 
`qigvm_directive_parameter_insert` and `qigvm_directive_vp_count` as 
well?

Luigi

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