libvirt/libvirt-qemu_firmware-Retain-user-specified-NVRAM-format.patch

From b853a05f7fcf8c6c1a4f5b51071ab951d174e041 Mon Sep 17 00:00:00 2001
Message-ID: <b853a05f7fcf8c6c1a4f5b51071ab951d174e041.1772815313.git.jdenemar@redhat.com>
From: Andrea Bolognani <abologna@redhat.com>
Date: Mon, 1 Dec 2025 16:30:43 +0100
Subject: [PATCH] qemu_firmware: Retain user-specified NVRAM format

Right now we throw the entire definition away if the path is
not present, including the format. This effectively results in
discarding user-provided information.

This change fixes the firmware-auto-efi-format-mismatch test
case. Until now, the NVRAM format ended up being raw (matching
the NVRAM template) despite the user explicitly asking for it
to be qcow2 instead.

While this means that libvirt will no longer be able to start
such a VM without user intervention, since it does not
automatically perform conversion between formats, that's still
preferrable to silently overriding an explicit user's request.

Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
(cherry picked from commit 91b6dee6d14cd804529d1cd7fdd010af58643543)

https://issues.redhat.com/browse/RHEL-82645

Signed-off-by: Andrea Bolognani <abologna@redhat.com>
---
 src/qemu/qemu_firmware.c                       | 18 +++++++++++++-----
 ...auto-efi-format-mismatch.x86_64-latest.args |  5 +++--
 ...-auto-efi-format-mismatch.x86_64-latest.xml |  2 +-
 3 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/src/qemu/qemu_firmware.c b/src/qemu/qemu_firmware.c
index b08fb95585..dca0a79868 100644
--- a/src/qemu/qemu_firmware.c
+++ b/src/qemu/qemu_firmware.c
@@ -971,6 +971,7 @@ qemuFirmwareEnsureNVRAM(virDomainDef *def,
 {
     g_autoptr(virQEMUDriverConfig) cfg = virQEMUDriverGetConfig(driver);
     virDomainLoaderDef *loader = def->os.loader;
+    virStorageFileFormat nvramFormat = VIR_STORAGE_FILE_NONE;
     const char *ext = NULL;
 
     if (!loader)
@@ -999,19 +1000,26 @@ qemuFirmwareEnsureNVRAM(virDomainDef *def,
             return;
         }
 
-        /* otherwise we want to reset and re-populate the definition */
+        /* Otherwise we want to reset and re-populate the definition.
+         * In this case we still retain a single piece of information:
+         * the user-provided NVRAM format */
+        nvramFormat = loader->nvram->format;
+
         virObjectUnref(loader->nvram);
     }
 
     loader->nvram = virStorageSourceNew();
     loader->nvram->type = VIR_STORAGE_TYPE_FILE;
+    loader->nvram->format = nvramFormat;
 
     /* The nvram template format should be always present but as a failsafe,
      * duplicate the loader format if it is not available. */
-    if (loader->nvramTemplateFormat > VIR_STORAGE_FILE_NONE)
-        loader->nvram->format = loader->nvramTemplateFormat;
-    else
-        loader->nvram->format = loader->format;
+    if (!loader->nvram->format) {
+        if (loader->nvramTemplateFormat)
+            loader->nvram->format = loader->nvramTemplateFormat;
+        else
+            loader->nvram->format = loader->format;
+    }
 
     if (loader->nvram->format == VIR_STORAGE_FILE_RAW) {
         /* The extension used by raw edk2 builds has historically
diff --git a/tests/qemuxmlconfdata/firmware-auto-efi-format-mismatch.x86_64-latest.args b/tests/qemuxmlconfdata/firmware-auto-efi-format-mismatch.x86_64-latest.args
index e7c9110c95..468d7ee048 100644
--- a/tests/qemuxmlconfdata/firmware-auto-efi-format-mismatch.x86_64-latest.args
+++ b/tests/qemuxmlconfdata/firmware-auto-efi-format-mismatch.x86_64-latest.args
@@ -12,8 +12,9 @@ XDG_CONFIG_HOME=/var/lib/libvirt/qemu/domain--1-guest/.config \
 -object '{"qom-type":"secret","id":"masterKey0","format":"raw","file":"/var/lib/libvirt/qemu/domain--1-guest/master-key.aes"}' \
 -blockdev '{"driver":"file","filename":"/usr/share/edk2/ovmf/OVMF_CODE.secboot.fd","node-name":"libvirt-pflash0-storage","auto-read-only":true,"discard":"unmap"}' \
 -blockdev '{"node-name":"libvirt-pflash0-format","read-only":true,"driver":"raw","file":"libvirt-pflash0-storage"}' \
--blockdev '{"driver":"file","filename":"/var/lib/libvirt/qemu/nvram/guest_VARS.fd","node-name":"libvirt-pflash1-storage","read-only":false}' \
--machine pc-q35-10.0,usb=off,smm=on,dump-guest-core=off,memory-backend=pc.ram,pflash0=libvirt-pflash0-format,pflash1=libvirt-pflash1-storage,acpi=on \
+-blockdev '{"driver":"file","filename":"/var/lib/libvirt/qemu/nvram/guest_VARS.qcow2","node-name":"libvirt-pflash1-storage","auto-read-only":true,"discard":"unmap"}' \
+-blockdev '{"node-name":"libvirt-pflash1-format","read-only":false,"driver":"qcow2","file":"libvirt-pflash1-storage","backing":null}' \
+-machine pc-q35-10.0,usb=off,smm=on,dump-guest-core=off,memory-backend=pc.ram,pflash0=libvirt-pflash0-format,pflash1=libvirt-pflash1-format,acpi=on \
 -accel kvm \
 -cpu qemu64 \
 -global driver=cfi.pflash01,property=secure,value=on \
diff --git a/tests/qemuxmlconfdata/firmware-auto-efi-format-mismatch.x86_64-latest.xml b/tests/qemuxmlconfdata/firmware-auto-efi-format-mismatch.x86_64-latest.xml
index f4df8c07ed..3a7536db2a 100644
--- a/tests/qemuxmlconfdata/firmware-auto-efi-format-mismatch.x86_64-latest.xml
+++ b/tests/qemuxmlconfdata/firmware-auto-efi-format-mismatch.x86_64-latest.xml
@@ -11,7 +11,7 @@
       <feature enabled='yes' name='secure-boot'/>
     </firmware>
     <loader readonly='yes' secure='yes' type='pflash' format='raw'>/usr/share/edk2/ovmf/OVMF_CODE.secboot.fd</loader>
-    <nvram template='/usr/share/edk2/ovmf/OVMF_VARS.secboot.fd' templateFormat='raw' format='raw'>/var/lib/libvirt/qemu/nvram/guest_VARS.fd</nvram>
+    <nvram template='/usr/share/edk2/ovmf/OVMF_VARS.secboot.fd' templateFormat='raw' format='qcow2'>/var/lib/libvirt/qemu/nvram/guest_VARS.qcow2</nvram>
     <boot dev='hd'/>
   </os>
   <features>
-- 
2.53.0