[libvirt] [PATCH 3/3] qemu: Process new mode='append' for char dev with output to a file

By default, QEMU truncates serial file on open. Sometimes, it could be weird - for example, when we are trying to investigate some event, which occured several restarts ago. This patch adds an ability to preserve previous content. Signed-off-by: Dmitry Mishin <dim(a)virtuozzo.com&gt; --- src/qemu/qemu_capabilities.c | 2 ++ src/qemu/qemu_capabilities.h | 1 + src/qemu/qemu_command.c | 10 ++++++++++ tests/qemucapabilitiesdata/caps_2.6.0-1.caps | 1 + 4 files changed, 14 insertions(+) diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c index 6e5d203..7b30441 100644 --- a/src/qemu/qemu_capabilities.c +++ b/src/qemu/qemu_capabilities.c @@ -308,6 +308,7 @@ VIR_ENUM_IMPL(virQEMUCaps, QEMU_CAPS_LAST, "virtio-tablet", /* 205 */ "virtio-input-host", + "chardev-file-append", ); @@ -2600,6 +2601,7 @@ static struct virQEMUCapsCommandLineProps virQEMUCapsCommandLine[] = { { "drive", "throttling.bps-total-max", QEMU_CAPS_DRIVE_IOTUNE_MAX}, { "machine", "aes-key-wrap", QEMU_CAPS_AES_KEY_WRAP }, { "machine", "dea-key-wrap", QEMU_CAPS_DEA_KEY_WRAP }, + { "chardev", "append", QEMU_CAPS_CHARDEV_FILE_APPEND }, }; static int diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h index 61d6379..c148f2d 100644 --- a/src/qemu/qemu_capabilities.h +++ b/src/qemu/qemu_capabilities.h @@ -335,6 +335,7 @@ typedef enum { /* 205 */ QEMU_CAPS_VIRTIO_TABLET, /* -device virtio-tablet-{device,pci} */ QEMU_CAPS_VIRTIO_INPUT_HOST, /* -device virtio-input-host-{device,pci} */ + QEMU_CAPS_CHARDEV_FILE_APPEND, /* -chardev file,append=on|off */ QEMU_CAPS_LAST /* this must always be the last item */ } virQEMUCapsFlags; diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index 9822cf7..d401981 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -6555,6 +6555,16 @@ qemuBuildChrChardevStr(virDomainChrSourceDefPtr dev, const char *alias, case VIR_DOMAIN_CHR_TYPE_FILE: virBufferAsprintf(&buf, "file,id=char%s,path=%s", alias, dev->data.file.path); + if (dev->data.file.append) { + if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_CHARDEV_FILE_APPEND)) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", + _("append not supported in this QEMU binary")); + goto error; + } + + virBufferAsprintf(&buf, ",append=%s", + virTristateSwitchTypeToString(dev->data.file.append)); + } break; case VIR_DOMAIN_CHR_TYPE_PIPE: diff --git a/tests/qemucapabilitiesdata/caps_2.6.0-1.caps b/tests/qemucapabilitiesdata/caps_2.6.0-1.caps index d9a8f3f..e296efc 100644 --- a/tests/qemucapabilitiesdata/caps_2.6.0-1.caps +++ b/tests/qemucapabilitiesdata/caps_2.6.0-1.caps @@ -169,4 +169,5 @@ <flag name='virtio-mouse'/> <flag name='virtio-tablet'/> <flag name='virtio-input-host'/> + <flag name='chardev-file-append'/> </qemuCaps> -- 1.8.3.1