Xen devel - May 2013 - [PATCH 0/3] Xen related fixes

Hi all,
I have few simple fixes for Xen for the next release:

- the first one fixes a regression in qemu-char;
- the second one is just a cleanup (that is needed to simplify preprocessor
  dependencies);
- the last one avoids setting nonblocking on Xen (as is already done for
  KVM).

The last two patches should be backported to older branches.


Stefano Stabellini (3):
      qemu_chr_new_from_opts: do not overwrite existing chr->filename
      xen: simplify xen_enabled
      main_loop: do not set nonblocking if xen_enabled()

 include/hw/xen/xen.h |    4 ----
 qemu-char.c          |    5 +++--
 vl.c                 |    2 +-
 3 files changed, 4 insertions(+), 7 deletions(-)

- Stefano

Set the new filename only if it hasn''t been already set (for example by
qemu_chr_open_pty).

This fixes a regression that prevents Xen HVM domains from booting.
It was introduced by:

commit 2b220025993e76d4116781ca91a4fabc5ad9c722
Author: Lei Li <lilei@linux.vnet.ibm.com>
Date:   Tue May 21 18:27:59 2013 +0800

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
---
 qemu-char.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/qemu-char.c b/qemu-char.c
index 4f8382e..06ffd93 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -3276,7 +3276,6 @@ CharDriverState *qemu_chr_new_from_opts(QemuOpts *opts,
         ChardevReturn *ret = NULL;
         const char *id = qemu_opts_id(opts);
         const char *bid = NULL;
-        char *filename = g_strdup(qemu_opt_get(opts, "backend"));
 
         if (qemu_opt_get_bool(opts, "mux", 0)) {
             bid = g_strdup_printf("%s-base", id);
@@ -3309,7 +3308,9 @@ CharDriverState *qemu_chr_new_from_opts(QemuOpts *opts,
         }
 
         chr = qemu_chr_find(id);
-        chr->filename = filename;
+        if (!chr->filename) {
+            chr->filename = g_strdup(qemu_opt_get(opts,
"backend"));
+        }
 
     qapi_out:
         qapi_free_ChardevBackend(backend);
-- 
1.7.2.5

No need for preprocessor conditionals in xen_enabled: xen_allowed is
always defined.

Please backport this patch to stable branches (it is needed by the
following patch to remove the dependency on a preprocessor identifier
defined by config-target.h).

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
CC: qemu-stable@nongnu.org
---
 include/hw/xen/xen.h |    4 ----
 1 files changed, 0 insertions(+), 4 deletions(-)

diff --git a/include/hw/xen/xen.h b/include/hw/xen/xen.h
index 7451c5a..b42b0fd 100644
--- a/include/hw/xen/xen.h
+++ b/include/hw/xen/xen.h
@@ -25,11 +25,7 @@ extern bool xen_allowed;
 
 static inline bool xen_enabled(void)
 {
-#if defined(CONFIG_XEN_BACKEND) && defined(CONFIG_XEN)
     return xen_allowed;
-#else
-    return 0;
-#endif
 }
 
 int xen_pci_slot_get_pirq(PCIDevice *pci_dev, int irq_num);
-- 
1.7.2.5

Please backport this patch to stable branches.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
CC: qemu-stable@nongnu.org
---
 vl.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/vl.c b/vl.c
index 510d2c2..47ab45d 100644
--- a/vl.c
+++ b/vl.c
@@ -2022,7 +2022,7 @@ static void main_loop(void)
     int64_t ti;
 #endif
     do {
-        nonblocking = !kvm_enabled() && last_io > 0;
+        nonblocking = !kvm_enabled() && !xen_enabled() &&
last_io > 0;
 #ifdef CONFIG_PROFILER
         ti = profile_getclock();
 #endif
-- 
1.7.2.5

On 05/27/13 20:13, Stefano Stabellini wrote:
> Set the new filename only if it hasn''t been already set (for
example by
> qemu_chr_open_pty).
> 
> This fixes a regression that prevents Xen HVM domains from booting.
> It was introduced by:
> 
> commit 2b220025993e76d4116781ca91a4fabc5ad9c722
> Author: Lei Li <lilei@linux.vnet.ibm.com>
> Date:   Tue May 21 18:27:59 2013 +0800
FYI: just posted a pull req which reverts this one (you are cc''ed).

cheers,
  Gerd

On Tue, 28 May 2013, Gerd Hoffmann wrote:
> On 05/27/13 20:13, Stefano Stabellini wrote:
> > Set the new filename only if it hasn''t been already set (for
example by
> > qemu_chr_open_pty).
> > 
> > This fixes a regression that prevents Xen HVM domains from booting.
> > It was introduced by:
> > 
> > commit 2b220025993e76d4116781ca91a4fabc5ad9c722
> > Author: Lei Li <lilei@linux.vnet.ibm.com>
> > Date:   Tue May 21 18:27:59 2013 +0800
> 
> FYI: just posted a pull req which reverts this one (you are
cc''ed).
Right, your two patches also solve the problem I was seeing.
I''ll drop the first patch of my series.

On Mon, 27 May 2013, Stefano Stabellini wrote:
> Set the new filename only if it hasn''t been already set (for
example by
> qemu_chr_open_pty).
> 
> This fixes a regression that prevents Xen HVM domains from booting.
> It was introduced by:
> 
> commit 2b220025993e76d4116781ca91a4fabc5ad9c722
> Author: Lei Li <lilei@linux.vnet.ibm.com>
> Date:   Tue May 21 18:27:59 2013 +0800
> 
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Gerd submitted an alternative fix to this issue here:

http://marc.info/?l=qemu-devel&m=136972286727453

I''ll drop this patch.

>  qemu-char.c |    5 +++--
>  1 files changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/qemu-char.c b/qemu-char.c
> index 4f8382e..06ffd93 100644
> --- a/qemu-char.c
> +++ b/qemu-char.c
> @@ -3276,7 +3276,6 @@ CharDriverState *qemu_chr_new_from_opts(QemuOpts
*opts,
>          ChardevReturn *ret = NULL;
>          const char *id = qemu_opts_id(opts);
>          const char *bid = NULL;
> -        char *filename = g_strdup(qemu_opt_get(opts,
"backend"));
>  
>          if (qemu_opt_get_bool(opts, "mux", 0)) {
>              bid = g_strdup_printf("%s-base", id);
> @@ -3309,7 +3308,9 @@ CharDriverState *qemu_chr_new_from_opts(QemuOpts
*opts,
>          }
>  
>          chr = qemu_chr_find(id);
> -        chr->filename = filename;
> +        if (!chr->filename) {
> +            chr->filename = g_strdup(qemu_opt_get(opts,
"backend"));
> +        }
>  
>      qapi_out:
>          qapi_free_ChardevBackend(backend);
> -- 
> 1.7.2.5
>