[libvirt] [PATCH] qemu: don't use chardev FD passing with standalone args

[Eric Blake]

On 06/28/2018 06:50 AM, Daniel P. Berrangé wrote:
> When using domxml-to-native, we must generate CLI args that can be used
> in a standalone scenario. This means no FD passing can be used. To
> achieve this we must clear the QEMU_CAPS_CHARDEV_FD_PASS capability bit.
> 
> Signed-off-by: Daniel P. Berrangé <berrange at redhat.com>
> ---
>   src/qemu/qemu_process.c | 5 +++++
>   src/qemu/qemu_process.h | 2 ++
>   2 files changed, 7 insertions(+)
> 
> diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
> index ac32dafcbe..40d35cbe6b 100644
> --- a/src/qemu/qemu_process.c
> +++ b/src/qemu/qemu_process.c
> @@ -5124,6 +5124,9 @@ qemuProcessInit(virQEMUDriverPtr driver,
>                                                         vm->def->os.machine)))
>           goto cleanup;
>   
> +    if (flags & VIR_QEMU_PROCESS_START_STANDALONE)
> +        virQEMUCapsClear(priv->qemuCaps, QEMU_CAPS_CHARDEV_FD_PASS);
> +

Is priv->qemuCaps a transient copy, or do you need counterpart code to 
reinstate the capability as needed after the current API call is completed?

>       if (qemuDomainUpdateCPU(vm, updatedCPU, &origCPU) < 0)
>           goto cleanup;
>   
> @@ -6632,6 +6635,8 @@ qemuProcessCreatePretendCmd(virQEMUDriverPtr driver,
>   
>       flags |= VIR_QEMU_PROCESS_START_PRETEND;
>       flags |= VIR_QEMU_PROCESS_START_NEW;
> +    if (standalone)
> +        flags |= VIR_QEMU_PROCESS_START_STANDALONE;
>   
>       if (qemuProcessInit(driver, vm, NULL, QEMU_ASYNC_JOB_NONE,
>                           !!migrateURI, flags) < 0)
> diff --git a/src/qemu/qemu_process.h b/src/qemu/qemu_process.h
> index 531c2a0cc7..07ce3a9915 100644
> --- a/src/qemu/qemu_process.h
> +++ b/src/qemu/qemu_process.h
> @@ -81,6 +81,8 @@ typedef enum {
>       VIR_QEMU_PROCESS_START_PRETEND      = 1 << 3,
>       VIR_QEMU_PROCESS_START_NEW          = 1 << 4, /* internal, new VM is starting */
>       VIR_QEMU_PROCESS_START_GEN_VMID     = 1 << 5, /* Generate a new VMID */
> +    VIR_QEMU_PROCESS_START_STANDALONE   = 1 << 6, /* Require CLI args to be usable standalone,
> +                                                     ie no FD passing and the like */
>   } qemuProcessStartFlags;
>   
>   int qemuProcessStart(virConnectPtr conn,
> 

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org