[PATCH-for-6.1? v2 0/3] hw/core: fix error checkig in smp_parse

[PATCH-for-6.1? v2 0/3] hw/core: fix error checkig in smp_parse

[Philippe Mathieu-Daudé]

Respin of Daniel's series checking MachineClass::smp_parse()
return value instead of *errp.

Daniel P. Berrangé (1):
  hw/core: fix error checkig in smp_parse

Philippe Mathieu-Daudé (2):
  hw/core: Add missing return on error
  hw/core: Have MachineClass::smp_parse() return boolean on error

 include/hw/boards.h |  2 +-
 hw/core/machine.c   | 14 ++++++++------
 hw/i386/pc.c        | 10 ++++++----
 3 files changed, 15 insertions(+), 11 deletions(-)

-- 
2.31.1

[PATCH-for-6.1? v2 1/3] hw/core: Add missing return on error

[Philippe Mathieu-Daudé]

If dies is not supported by this machine's CPU topology, don't
keep processing options and return directly.

Fixes: 0aebebb561c ("machine: reject -smp dies!=1 for non-PC machines")
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 hw/core/machine.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/hw/core/machine.c b/hw/core/machine.c
index 943974d411c..abaeda589b7 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -752,6 +752,7 @@ static void smp_parse(MachineState *ms, SMPConfiguration *config, Error **errp)
 
     if (config->has_dies && config->dies != 0 && config->dies != 1) {
         error_setg(errp, "dies not supported by this machine's CPU topology");
+        return;
     }
 
     /* compute missing values, prefer sockets over cores over threads */
-- 
2.31.1

[PATCH-for-6.1? v2 2/3] hw/core: Have MachineClass::smp_parse() return boolean on error

[Philippe Mathieu-Daudé]

Just for consistency, following the example documented since
commit e3fe3988d7 ("error: Document Error API usage rules"),
return a boolean value indicating an error is set or not.
Directly pass errp as the local_err is not requested in our
case.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 include/hw/boards.h |  2 +-
 hw/core/machine.c   | 12 +++++++-----
 hw/i386/pc.c        | 10 ++++++----
 3 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/include/hw/boards.h b/include/hw/boards.h
index accd6eff35a..d5b7058c2e2 100644
--- a/include/hw/boards.h
+++ b/include/hw/boards.h
@@ -209,7 +209,7 @@ struct MachineClass {
     void (*reset)(MachineState *state);
     void (*wakeup)(MachineState *state);
     int (*kvm_type)(MachineState *machine, const char *arg);
-    void (*smp_parse)(MachineState *ms, SMPConfiguration *config, Error **errp);
+    bool (*smp_parse)(MachineState *ms, SMPConfiguration *config, Error **errp);
 
     BlockInterfaceType block_default_type;
     int units_per_default_bus;
diff --git a/hw/core/machine.c b/hw/core/machine.c
index abaeda589b7..159c6b098e2 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -743,7 +743,7 @@ void machine_set_cpu_numa_node(MachineState *machine,
     }
 }
 
-static void smp_parse(MachineState *ms, SMPConfiguration *config, Error **errp)
+static bool smp_parse(MachineState *ms, SMPConfiguration *config, Error **errp)
 {
     unsigned cpus    = config->has_cpus ? config->cpus : 0;
     unsigned sockets = config->has_sockets ? config->sockets : 0;
@@ -752,7 +752,7 @@ static void smp_parse(MachineState *ms, SMPConfiguration *config, Error **errp)
 
     if (config->has_dies && config->dies != 0 && config->dies != 1) {
         error_setg(errp, "dies not supported by this machine's CPU topology");
-        return;
+        return true;
     }
 
     /* compute missing values, prefer sockets over cores over threads */
@@ -778,14 +778,14 @@ static void smp_parse(MachineState *ms, SMPConfiguration *config, Error **errp)
                    "sockets (%u) * cores (%u) * threads (%u) < "
                    "smp_cpus (%u)",
                    sockets, cores, threads, cpus);
-        return;
+        return true;
     }
 
     ms->smp.max_cpus = config->has_maxcpus ? config->maxcpus : cpus;
 
     if (ms->smp.max_cpus < cpus) {
         error_setg(errp, "maxcpus must be equal to or greater than smp");
-        return;
+        return true;
     }
 
     if (sockets * cores * threads != ms->smp.max_cpus) {
@@ -794,13 +794,15 @@ static void smp_parse(MachineState *ms, SMPConfiguration *config, Error **errp)
                    "!= maxcpus (%u)",
                    sockets, cores, threads,
                    ms->smp.max_cpus);
-        return;
+        return true;
     }
 
     ms->smp.cpus = cpus;
     ms->smp.cores = cores;
     ms->smp.threads = threads;
     ms->smp.sockets = sockets;
+
+    return false;
 }
 
 static void machine_get_smp(Object *obj, Visitor *v, const char *name,
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index c2b9d62a358..84138a8bfd2 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -712,7 +712,7 @@ void pc_acpi_smi_interrupt(void *opaque, int irq, int level)
  * This function is very similar to smp_parse()
  * in hw/core/machine.c but includes CPU die support.
  */
-static void pc_smp_parse(MachineState *ms, SMPConfiguration *config, Error **errp)
+static bool pc_smp_parse(MachineState *ms, SMPConfiguration *config, Error **errp)
 {
     unsigned cpus    = config->has_cpus ? config->cpus : 0;
     unsigned sockets = config->has_sockets ? config->sockets : 0;
@@ -743,14 +743,14 @@ static void pc_smp_parse(MachineState *ms, SMPConfiguration *config, Error **err
                    "sockets (%u) * dies (%u) * cores (%u) * threads (%u) < "
                    "smp_cpus (%u)",
                    sockets, dies, cores, threads, cpus);
-        return;
+        return true;
     }
 
     ms->smp.max_cpus = config->has_maxcpus ? config->maxcpus : cpus;
 
     if (ms->smp.max_cpus < cpus) {
         error_setg(errp, "maxcpus must be equal to or greater than smp");
-        return;
+        return true;
     }
 
     if (sockets * dies * cores * threads != ms->smp.max_cpus) {
@@ -759,7 +759,7 @@ static void pc_smp_parse(MachineState *ms, SMPConfiguration *config, Error **err
                    "!= maxcpus (%u)",
                    sockets, dies, cores, threads,
                    ms->smp.max_cpus);
-        return;
+        return true;
     }
 
     ms->smp.cpus = cpus;
@@ -767,6 +767,8 @@ static void pc_smp_parse(MachineState *ms, SMPConfiguration *config, Error **err
     ms->smp.threads = threads;
     ms->smp.sockets = sockets;
     ms->smp.dies = dies;
+
+    return false;
 }
 
 static
-- 
2.31.1

[PATCH-for-6.1? v2 3/3] hw/core: fix error checkig in smp_parse

[Philippe Mathieu-Daudé]

From: Daniel P. Berrangé <berrange@redhat.com>

The machine_set_smp() mistakenly checks 'errp' not '*errp',
and so thinks there is an error every single time it runs.
This causes it to jump to the end of the method, skipping
the max CPUs checks. The caller meanwhile sees no error
and so carries on execution. The result of all this is:

 $ qemu-system-x86_64 -smp -1
 qemu-system-x86_64: GLib: ../glib/gmem.c:142: failed to allocate 481036337048 bytes

instead of

 $ qemu-system-x86_64 -smp -1
 qemu-system-x86_64: Invalid SMP CPUs -1. The max CPUs supported by machine 'pc-i440fx-6.1' is 255

This is a regression from

  commit fe68090e8fbd6e831aaf3fc3bb0459c5cccf14cf
  Author: Paolo Bonzini <pbonzini@redhat.com>
  Date:   Thu May 13 09:03:48 2021 -0400

    machine: add smp compound property

Closes: https://gitlab.com/qemu-project/qemu/-/issues/524
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20210812175353.4128471-1-berrange@redhat.com>
[PMD: Check MachineClass::smp_parse() returned value]
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 hw/core/machine.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/hw/core/machine.c b/hw/core/machine.c
index 159c6b098e2..29edf655140 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -834,8 +834,7 @@ static void machine_set_smp(Object *obj, Visitor *v, const char *name,
         return;
     }
 
-    mc->smp_parse(ms, config, errp);
-    if (errp) {
+    if (mc->smp_parse(ms, config, errp)) {
         goto out_free;
     }
 
-- 
2.31.1

Re: [PATCH-for-6.1? v2 2/3] hw/core: Have MachineClass::smp_parse() return boolean on error

[Paolo Bonzini]

On 13/08/21 13:26, Philippe Mathieu-Daudé wrote:
> Just for consistency, following the example documented since
> commit e3fe3988d7 ("error: Document Error API usage rules"),
> return a boolean value indicating an error is set or not.
> Directly pass errp as the local_err is not requested in our
> case.
> 
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

This was intentional; no one should invoke mc->smp_parse directly except 
for machine_set_smp, therefore if mc->smp_parse returns bool there are 
more places where things can go wrong (instead of just the one that is 
fixed by patch 3).

Paolo

> ---
>   include/hw/boards.h |  2 +-
>   hw/core/machine.c   | 12 +++++++-----
>   hw/i386/pc.c        | 10 ++++++----
>   3 files changed, 14 insertions(+), 10 deletions(-)
> 
> diff --git a/include/hw/boards.h b/include/hw/boards.h
> index accd6eff35a..d5b7058c2e2 100644
> --- a/include/hw/boards.h
> +++ b/include/hw/boards.h
> @@ -209,7 +209,7 @@ struct MachineClass {
>       void (*reset)(MachineState *state);
>       void (*wakeup)(MachineState *state);
>       int (*kvm_type)(MachineState *machine, const char *arg);
> -    void (*smp_parse)(MachineState *ms, SMPConfiguration *config, Error **errp);
> +    bool (*smp_parse)(MachineState *ms, SMPConfiguration *config, Error **errp);
>   
>       BlockInterfaceType block_default_type;
>       int units_per_default_bus;
> diff --git a/hw/core/machine.c b/hw/core/machine.c
> index abaeda589b7..159c6b098e2 100644
> --- a/hw/core/machine.c
> +++ b/hw/core/machine.c
> @@ -743,7 +743,7 @@ void machine_set_cpu_numa_node(MachineState *machine,
>       }
>   }
>   
> -static void smp_parse(MachineState *ms, SMPConfiguration *config, Error **errp)
> +static bool smp_parse(MachineState *ms, SMPConfiguration *config, Error **errp)
>   {
>       unsigned cpus    = config->has_cpus ? config->cpus : 0;
>       unsigned sockets = config->has_sockets ? config->sockets : 0;
> @@ -752,7 +752,7 @@ static void smp_parse(MachineState *ms, SMPConfiguration *config, Error **errp)
>   
>       if (config->has_dies && config->dies != 0 && config->dies != 1) {
>           error_setg(errp, "dies not supported by this machine's CPU topology");
> -        return;
> +        return true;
>       }
>   
>       /* compute missing values, prefer sockets over cores over threads */
> @@ -778,14 +778,14 @@ static void smp_parse(MachineState *ms, SMPConfiguration *config, Error **errp)
>                      "sockets (%u) * cores (%u) * threads (%u) < "
>                      "smp_cpus (%u)",
>                      sockets, cores, threads, cpus);
> -        return;
> +        return true;
>       }
>   
>       ms->smp.max_cpus = config->has_maxcpus ? config->maxcpus : cpus;
>   
>       if (ms->smp.max_cpus < cpus) {
>           error_setg(errp, "maxcpus must be equal to or greater than smp");
> -        return;
> +        return true;
>       }
>   
>       if (sockets * cores * threads != ms->smp.max_cpus) {
> @@ -794,13 +794,15 @@ static void smp_parse(MachineState *ms, SMPConfiguration *config, Error **errp)
>                      "!= maxcpus (%u)",
>                      sockets, cores, threads,
>                      ms->smp.max_cpus);
> -        return;
> +        return true;
>       }
>   
>       ms->smp.cpus = cpus;
>       ms->smp.cores = cores;
>       ms->smp.threads = threads;
>       ms->smp.sockets = sockets;
> +
> +    return false;
>   }
>   
>   static void machine_get_smp(Object *obj, Visitor *v, const char *name,
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index c2b9d62a358..84138a8bfd2 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -712,7 +712,7 @@ void pc_acpi_smi_interrupt(void *opaque, int irq, int level)
>    * This function is very similar to smp_parse()
>    * in hw/core/machine.c but includes CPU die support.
>    */
> -static void pc_smp_parse(MachineState *ms, SMPConfiguration *config, Error **errp)
> +static bool pc_smp_parse(MachineState *ms, SMPConfiguration *config, Error **errp)
>   {
>       unsigned cpus    = config->has_cpus ? config->cpus : 0;
>       unsigned sockets = config->has_sockets ? config->sockets : 0;
> @@ -743,14 +743,14 @@ static void pc_smp_parse(MachineState *ms, SMPConfiguration *config, Error **err
>                      "sockets (%u) * dies (%u) * cores (%u) * threads (%u) < "
>                      "smp_cpus (%u)",
>                      sockets, dies, cores, threads, cpus);
> -        return;
> +        return true;
>       }
>   
>       ms->smp.max_cpus = config->has_maxcpus ? config->maxcpus : cpus;
>   
>       if (ms->smp.max_cpus < cpus) {
>           error_setg(errp, "maxcpus must be equal to or greater than smp");
> -        return;
> +        return true;
>       }
>   
>       if (sockets * dies * cores * threads != ms->smp.max_cpus) {
> @@ -759,7 +759,7 @@ static void pc_smp_parse(MachineState *ms, SMPConfiguration *config, Error **err
>                      "!= maxcpus (%u)",
>                      sockets, dies, cores, threads,
>                      ms->smp.max_cpus);
> -        return;
> +        return true;
>       }
>   
>       ms->smp.cpus = cpus;
> @@ -767,6 +767,8 @@ static void pc_smp_parse(MachineState *ms, SMPConfiguration *config, Error **err
>       ms->smp.threads = threads;
>       ms->smp.sockets = sockets;
>       ms->smp.dies = dies;
> +
> +    return false;
>   }
>   
>   static
> 

Re: [PATCH-for-6.1? v2 1/3] hw/core: Add missing return on error

[Paolo Bonzini]

On 13/08/21 13:26, Philippe Mathieu-Daudé wrote:
> If dies is not supported by this machine's CPU topology, don't
> keep processing options and return directly.
> 
> Fixes: 0aebebb561c ("machine: reject -smp dies!=1 for non-PC machines")
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
>   hw/core/machine.c | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/hw/core/machine.c b/hw/core/machine.c
> index 943974d411c..abaeda589b7 100644
> --- a/hw/core/machine.c
> +++ b/hw/core/machine.c
> @@ -752,6 +752,7 @@ static void smp_parse(MachineState *ms, SMPConfiguration *config, Error **errp)
>   
>       if (config->has_dies && config->dies != 0 && config->dies != 1) {
>           error_setg(errp, "dies not supported by this machine's CPU topology");
> +        return;
>       }
>   
>       /* compute missing values, prefer sockets over cores over threads */
> 

Queued, thanks.

Paolo