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[libvirt] [PATCH 2/3] qemu: Format rom.enabled attribute for PCI devices

Andrea Bolognani posted 3 patches 7 years, 8 months ago
[libvirt] [PATCH 2/3] qemu: Format rom.enabled attribute for PCI devices
Posted by Andrea Bolognani 7 years, 8 months ago 
The attribute can be used to disable ROM loading completely
for a device.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1425058
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
---
 src/qemu/qemu_command.c                       | 13 ++++++++++--
 tests/qemuxml2argvdata/pci-rom-disabled.args  | 26 ++++++++++++++++++++++++
 tests/qemuxml2argvdata/pci-rom-disabled.xml   | 20 ++++++++++++++++++
 tests/qemuxml2argvtest.c                      |  1 +
 tests/qemuxml2xmloutdata/pci-rom-disabled.xml | 29 +++++++++++++++++++++++++++
 tests/qemuxml2xmltest.c                       |  1 +
 6 files changed, 88 insertions(+), 2 deletions(-)
 create mode 100644 tests/qemuxml2argvdata/pci-rom-disabled.args
 create mode 100644 tests/qemuxml2argvdata/pci-rom-disabled.xml
 create mode 100644 tests/qemuxml2xmloutdata/pci-rom-disabled.xml

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index b666f3715f..84c4e1e350 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -442,13 +442,20 @@ static int
 qemuBuildRomStr(virBufferPtr buf,
                 virDomainDeviceInfoPtr info)
 {
-    if (info->rombar || info->romfile) {
+    if (info->romenabled || info->rombar || info->romfile) {
         if (info->type != VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI) {
             virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
-                           "%s", _("rombar and romfile are supported only for PCI devices"));
+                           "%s", _("ROM tuning is only supported for PCI devices"));
             return -1;
         }
 
+        /* Passing an empty romfile= tells QEMU to disable ROM entirely for
+         * this device, and makes other settings irrelevant */
+        if (info->romenabled == VIR_TRISTATE_BOOL_NO) {
+            virBufferAddLit(buf, ",romfile=");
+            goto done;
+        }
+
         switch (info->rombar) {
         case VIR_TRISTATE_SWITCH_OFF:
             virBufferAddLit(buf, ",rombar=0");
@@ -464,6 +471,8 @@ qemuBuildRomStr(virBufferPtr buf,
            virQEMUBuildBufferEscapeComma(buf, info->romfile);
         }
     }
+
+ done:
     return 0;
 }
 
diff --git a/tests/qemuxml2argvdata/pci-rom-disabled.args b/tests/qemuxml2argvdata/pci-rom-disabled.args
new file mode 100644
index 0000000000..8c9dc2fb80
--- /dev/null
+++ b/tests/qemuxml2argvdata/pci-rom-disabled.args
@@ -0,0 +1,26 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/home/test \
+USER=test \
+LOGNAME=test \
+QEMU_AUDIO_DRV=none \
+/usr/bin/qemu-system-x86_64 \
+-name guest \
+-S \
+-machine pc,accel=tcg,usb=off,dump-guest-core=off \
+-m 214 \
+-smp 1,sockets=1,cores=1,threads=1 \
+-uuid c7a5fdbd-edaf-9466-926a-d65c16db1809 \
+-display none \
+-no-user-config \
+-nodefaults \
+-chardev socket,id=charmonitor,path=/tmp/lib/domain--1-guest/monitor.sock,\
+server,nowait \
+-mon chardev=charmonitor,id=monitor,mode=control \
+-rtc base=utc \
+-no-shutdown \
+-no-acpi \
+-boot c \
+-netdev user,id=hostnet0 \
+-device virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:24:a5:9f,bus=pci.0,\
+addr=0x3,romfile=
diff --git a/tests/qemuxml2argvdata/pci-rom-disabled.xml b/tests/qemuxml2argvdata/pci-rom-disabled.xml
new file mode 100644
index 0000000000..1c12052382
--- /dev/null
+++ b/tests/qemuxml2argvdata/pci-rom-disabled.xml
@@ -0,0 +1,20 @@
+<domain type='qemu'>
+  <name>guest</name>
+  <uuid>c7a5fdbd-edaf-9466-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>219100</memory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='x86_64' machine='pc'>hvm</type>
+  </os>
+  <devices>
+    <emulator>/usr/bin/qemu-system-x86_64</emulator>
+    <controller type='pci' model='pci-root'/>
+    <controller type='usb' model='none'/>
+    <interface type='user'>
+      <mac address='52:54:00:24:a5:9f'/>
+      <model type='virtio'/>
+      <rom enabled='no'/>
+    </interface>
+    <memballoon model='none'/>
+  </devices>
+</domain>
diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
index 74d930ebe2..ae9893a84e 100644
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@@ -1554,6 +1554,7 @@ mymain(void)
     DO_TEST_PARSE_ERROR("hostdev-mdev-invalid-target-address",
             QEMU_CAPS_DEVICE_VFIO_PCI);
     DO_TEST("pci-rom", NONE);
+    DO_TEST("pci-rom-disabled", NONE);
 
     DO_TEST_FULL("restore-v2", "exec:cat", 7, 0, 0, GIC_NONE, NONE);
     DO_TEST_FULL("restore-v2-fd", "stdio", 7, 0, 0, GIC_NONE, NONE);
diff --git a/tests/qemuxml2xmloutdata/pci-rom-disabled.xml b/tests/qemuxml2xmloutdata/pci-rom-disabled.xml
new file mode 100644
index 0000000000..6a95064ebf
--- /dev/null
+++ b/tests/qemuxml2xmloutdata/pci-rom-disabled.xml
@@ -0,0 +1,29 @@
+<domain type='qemu'>
+  <name>guest</name>
+  <uuid>c7a5fdbd-edaf-9466-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>219100</memory>
+  <currentMemory unit='KiB'>219100</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='x86_64' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu-system-x86_64</emulator>
+    <controller type='pci' index='0' model='pci-root'/>
+    <controller type='usb' index='0' model='none'/>
+    <interface type='user'>
+      <mac address='52:54:00:24:a5:9f'/>
+      <model type='virtio'/>
+      <rom enabled='no'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
+    </interface>
+    <input type='mouse' bus='ps2'/>
+    <input type='keyboard' bus='ps2'/>
+    <memballoon model='none'/>
+  </devices>
+</domain>
diff --git a/tests/qemuxml2xmltest.c b/tests/qemuxml2xmltest.c
index 9e77b9fb13..6c1f0b0fa6 100644
--- a/tests/qemuxml2xmltest.c
+++ b/tests/qemuxml2xmltest.c
@@ -474,6 +474,7 @@ mymain(void)
     DO_TEST("hostdev-vfio", NONE);
     DO_TEST("hostdev-mdev-precreated", NONE);
     DO_TEST("pci-rom", NONE);
+    DO_TEST("pci-rom-disabled", NONE);
     DO_TEST("pci-serial-dev-chardev", NONE);
 
     DO_TEST("encrypted-disk", NONE);
-- 
2.14.3

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Re: [libvirt] [PATCH 2/3] qemu: Format rom.enabled attribute for PCI devices
Posted by Peter Krempa 7 years, 8 months ago 
On Fri, Apr 20, 2018 at 17:44:30 +0200, Andrea Bolognani wrote:
> The attribute can be used to disable ROM loading completely
> for a device.

You could mention that this is necessary because even if you turn the
ROM BAR off, some firmware might still load it.

> 
> Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1425058
> Signed-off-by: Andrea Bolognani <abologna@redhat.com>
> ---
>  src/qemu/qemu_command.c                       | 13 ++++++++++--
>  tests/qemuxml2argvdata/pci-rom-disabled.args  | 26 ++++++++++++++++++++++++
>  tests/qemuxml2argvdata/pci-rom-disabled.xml   | 20 ++++++++++++++++++
>  tests/qemuxml2argvtest.c                      |  1 +
>  tests/qemuxml2xmloutdata/pci-rom-disabled.xml | 29 +++++++++++++++++++++++++++
>  tests/qemuxml2xmltest.c                       |  1 +
>  6 files changed, 88 insertions(+), 2 deletions(-)
>  create mode 100644 tests/qemuxml2argvdata/pci-rom-disabled.args
>  create mode 100644 tests/qemuxml2argvdata/pci-rom-disabled.xml
>  create mode 100644 tests/qemuxml2xmloutdata/pci-rom-disabled.xml
> 
> diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
> index b666f3715f..84c4e1e350 100644
> --- a/src/qemu/qemu_command.c
> +++ b/src/qemu/qemu_command.c
> @@ -442,13 +442,20 @@ static int
>  qemuBuildRomStr(virBufferPtr buf,
>                  virDomainDeviceInfoPtr info)
>  {
> -    if (info->rombar || info->romfile) {
> +    if (info->romenabled || info->rombar || info->romfile) {
>          if (info->type != VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI) {
>              virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
> -                           "%s", _("rombar and romfile are supported only for PCI devices"));
> +                           "%s", _("ROM tuning is only supported for PCI devices"));
>              return -1;
>          }
>  
> +        /* Passing an empty romfile= tells QEMU to disable ROM entirely for
> +         * this device, and makes other settings irrelevant */
> +        if (info->romenabled == VIR_TRISTATE_BOOL_NO) {
> +            virBufferAddLit(buf, ",romfile=");
> +            goto done;

You can return early rather than having to jump. This function needs to
be refactored anyways, so no need to be nice to others comming after
you.

> +        }
> +
>          switch (info->rombar) {
>          case VIR_TRISTATE_SWITCH_OFF:
>              virBufferAddLit(buf, ",rombar=0");
> @@ -464,6 +471,8 @@ qemuBuildRomStr(virBufferPtr buf,
>             virQEMUBuildBufferEscapeComma(buf, info->romfile);
>          }
>      }
> +
> + done:
>      return 0;
>  }

[...]

> diff --git a/tests/qemuxml2argvdata/pci-rom-disabled.xml b/tests/qemuxml2argvdata/pci-rom-disabled.xml
> new file mode 100644
> index 0000000000..1c12052382
> --- /dev/null
> +++ b/tests/qemuxml2argvdata/pci-rom-disabled.xml
> @@ -0,0 +1,20 @@
> +<domain type='qemu'>
> +  <name>guest</name>
> +  <uuid>c7a5fdbd-edaf-9466-926a-d65c16db1809</uuid>
> +  <memory unit='KiB'>219100</memory>
> +  <vcpu placement='static'>1</vcpu>
> +  <os>
> +    <type arch='x86_64' machine='pc'>hvm</type>
> +  </os>
> +  <devices>
> +    <emulator>/usr/bin/qemu-system-x86_64</emulator>
> +    <controller type='pci' model='pci-root'/>
> +    <controller type='usb' model='none'/>
> +    <interface type='user'>
> +      <mac address='52:54:00:24:a5:9f'/>
> +      <model type='virtio'/>
> +      <rom enabled='no'/>

If we are going to explicitly keep around the quirk with the empty file
I think we should add a test case for it. It will not be fun though
since such XML is invalid.

> +    </interface>
> +    <memballoon model='none'/>
> +  </devices>
> +</domain>

ACK if you get rid of that jump.

The test case will need to be added separately anyways.
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Re: [libvirt] [PATCH 2/3] qemu: Format rom.enabled attribute for PCI devices
Posted by Andrea Bolognani 7 years, 8 months ago 
On Mon, 2018-04-23 at 08:58 +0200, Peter Krempa wrote:
> The test case will need to be added separately anyways.

Here it is:

  https://www.redhat.com/archives/libvir-list/2018-April/msg02122.html

-- 
Andrea Bolognani / Red Hat / Virtualization

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