Commit fe2de89215 for qemu.org
commit fe2de89215ce045f087e1f916842fa0934b582e0
Author: Luigi Leonardi <leonardi@redhat.com>
Date: Mon Oct 19 11:12:46 2026 +0200
igvm: add command line parameter support
Add a "cmdline" property to the igvm-cfg object and a handler for the
IGVM_VHT_COMMAND_LINE directive, which copies the string into the
parameter area the directive points at.
The command line is passed to whatever software the IGVM file loads,
such as an SVSM. For example, SVSM can use it to select the serial port
it logs to.
Acked-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Luigi Leonardi <leonardi@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Message-ID: <20261019-igvm_command_line-v3-1-29aeacbd6cd7@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
diff --git a/backends/igvm-cfg.c b/backends/igvm-cfg.c
index 935ba54f54..653f79bef5 100644
--- a/backends/igvm-cfg.c
+++ b/backends/igvm-cfg.c
@@ -34,6 +34,19 @@ static void set_igvm(Object *obj, const char *value, Error **errp)
igvm->filename = g_strdup(value);
}
+static char *get_cmdline(Object *obj, Error **errp)
+{
+ IgvmCfg *igvm = IGVM_CFG(obj);
+ return g_strdup(igvm->cmdline);
+}
+
+static void set_cmdline(Object *obj, const char *value, Error **errp)
+{
+ IgvmCfg *igvm = IGVM_CFG(obj);
+ g_free(igvm->cmdline);
+ igvm->cmdline = g_strdup(value);
+}
+
static ResettableState *igvm_reset_state(Object *obj)
{
IgvmCfg *igvm = IGVM_CFG(obj);
@@ -85,6 +98,13 @@ static void igvm_cfg_class_init(ObjectClass *oc, const void *data)
object_class_property_set_description(oc, "file",
"Set the IGVM filename to use");
+ object_class_property_add_str(oc, "cmdline", get_cmdline, set_cmdline);
+ object_class_property_set_description(oc, "cmdline",
+ "Set the command line for the "
+ "software loaded from the IGVM "
+ "file (copied verbatim, not "
+ "parsed by QEMU)");
+
igvmc->process = qigvm_process_file;
rc->get_state = igvm_reset_state;
@@ -112,4 +132,5 @@ static void igvm_cfg_finalize(Object *obj)
igvm_free(igvm->file);
}
g_free(igvm->filename);
+ g_free(igvm->cmdline);
}
diff --git a/backends/igvm.c b/backends/igvm.c
index 5a1416fe8e..4b9d786308 100644
--- a/backends/igvm.c
+++ b/backends/igvm.c
@@ -161,6 +161,8 @@ static int qigvm_directive_snp_id_block(QIgvm *ctx, const uint8_t *header_data,
static int qigvm_initialization_guest_policy(QIgvm *ctx,
const uint8_t *header_data,
Error **errp);
+static int qigvm_directive_command_line(QIgvm *ctx, const uint8_t *header_data,
+ Error **errp);
#ifdef CONFIG_FDT
static int qigvm_directive_device_tree(QIgvm *ctx, const uint8_t *header_data,
Error **errp);
@@ -195,6 +197,8 @@ static struct QIGVMHandler handlers[] = {
qigvm_initialization_guest_policy },
{ IGVM_VHT_MADT, IGVM_HEADER_SECTION_DIRECTIVE,
qigvm_directive_madt },
+ { IGVM_VHT_COMMAND_LINE, IGVM_HEADER_SECTION_DIRECTIVE,
+ qigvm_directive_command_line },
#ifdef CONFIG_FDT
{ IGVM_VHT_DEVICE_TREE, IGVM_HEADER_SECTION_DIRECTIVE,
qigvm_directive_device_tree },
@@ -869,6 +873,33 @@ static int qigvm_directive_snp_id_block(QIgvm *ctx, const uint8_t *header_data,
return 0;
}
+static int qigvm_directive_command_line(QIgvm *ctx, const uint8_t *header_data,
+ Error **errp)
+{
+ const IGVM_VHS_PARAMETER *param = (const IGVM_VHS_PARAMETER *)header_data;
+ const char *cmdline = ctx->cfg->cmdline ? ctx->cfg->cmdline : "";
+ uint8_t *param_data;
+ uint32_t param_size;
+ size_t cmdline_size = strlen(cmdline) + 1;
+
+ param_data = qigvm_get_param_data(ctx, param, ¶m_size, errp);
+ if (!param_data) {
+ return -1;
+ }
+
+ if (cmdline_size > param_size) {
+ error_setg(errp,
+ "IGVM: command line size %zu exceeds the %u byte "
+ "parameter area defined in IGVM file",
+ cmdline_size, param_size);
+ return -1;
+ }
+
+ memcpy(param_data, cmdline, cmdline_size);
+
+ return 0;
+}
+
#ifdef CONFIG_FDT
static int qigvm_directive_device_tree(QIgvm *ctx, const uint8_t *header_data,
Error **errp)
diff --git a/include/system/igvm-internal.h b/include/system/igvm-internal.h
index d88268bf60..7ec6c20472 100644
--- a/include/system/igvm-internal.h
+++ b/include/system/igvm-internal.h
@@ -32,6 +32,11 @@ struct IgvmCfg {
* format.
*/
char *filename;
+ /*
+ * cmdline: Command line for the software loaded from the IGVM file,
+ * if it asks for one.
+ */
+ char *cmdline;
IgvmHandle file;
ResettableState reset_state;
QTAILQ_HEAD(, IgvmMemoryRegion) memory_regions;
diff --git a/qapi/qom.json b/qapi/qom.json
index 49f222796a..4810d53e58 100644
--- a/qapi/qom.json
+++ b/qapi/qom.json
@@ -977,11 +977,16 @@
#
# @file: IGVM file to use to configure guest
#
+# @cmdline: command line for the software loaded from the IGVM file.
+# Its format is specific to that software. Passed verbatim: QEMU
+# does not parse it.
+# Ignored if the IGVM file does not ask for one. (since 11.2)
+#
# Since: 10.1
##
{ 'struct': 'IgvmCfgProperties',
'if': 'CONFIG_IGVM',
- 'data': { 'file': 'str' } }
+ 'data': { 'file': 'str', '*cmdline': 'str' } }
##
# @SevCommonProperties:
diff --git a/qemu-options.hx b/qemu-options.hx
index 2f6863180b..f72f30e246 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -6496,7 +6496,7 @@ SRST
-machine ...,confidential-guest-support=tdx \\
......
- ``-object igvm-cfg,file=file``
+ ``-object igvm-cfg,file=file[,cmdline=string]``
Create an IGVM configuration object that defines the initial state
of the guest using a file in that conforms to the Independent Guest
Virtual Machine (IGVM) file format.
@@ -6509,6 +6509,10 @@ SRST
memory of the virtual machine and, depending on the platform, can
define the initial processor state, memory map and parameters.
+ The optional ``cmdline`` parameter is a command line passed
+ verbatim to the software loaded from the IGVM file, if the file
+ requests one. Its format is specific to that software.
+
The IGVM file is expected to contain the firmware for the virtual
machine, therefore an ``igvm-cfg`` object cannot be provided along
with other ways of specifying firmware, such as the ``-bios``