MachineClass::kvm_type() can return -1 on failure.
Document it, and add a check in kvm_init().
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
include/hw/boards.h | 3 ++-
accel/kvm/kvm-all.c | 6 ++++++
2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/include/hw/boards.h b/include/hw/boards.h
index a46dfe5d1a6..68d3d10f6b0 100644
--- a/include/hw/boards.h
+++ b/include/hw/boards.h
@@ -127,7 +127,8 @@ typedef struct {
* implement and a stub device is required.
* @kvm_type:
* Return the type of KVM corresponding to the kvm-type string option or
- * computed based on other criteria such as the host kernel capabilities.
+ * computed based on other criteria such as the host kernel capabilities
+ * (which can't be negative), or -1 on error.
* @numa_mem_supported:
* true if '--numa node.mem' option is supported and false otherwise
* @smp_parse:
diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 84c943fcdb2..b069938d881 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -2057,6 +2057,12 @@ static int kvm_init(MachineState *ms)
"kvm-type",
&error_abort);
type = mc->kvm_type(ms, kvm_type);
+ if (type < 0) {
+ ret = -EINVAL;
+ fprintf(stderr, "Failed to detect kvm-type for machine '%s'\n",
+ mc->name);
+ goto err;
+ }
}
do {
--
2.26.2
On Fri, 19 Feb 2021 18:38:37 +0100
Philippe Mathieu-Daudé <philmd@redhat.com> wrote:
> MachineClass::kvm_type() can return -1 on failure.
> Document it, and add a check in kvm_init().
>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
> include/hw/boards.h | 3 ++-
> accel/kvm/kvm-all.c | 6 ++++++
> 2 files changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/include/hw/boards.h b/include/hw/boards.h
> index a46dfe5d1a6..68d3d10f6b0 100644
> --- a/include/hw/boards.h
> +++ b/include/hw/boards.h
> @@ -127,7 +127,8 @@ typedef struct {
> * implement and a stub device is required.
> * @kvm_type:
> * Return the type of KVM corresponding to the kvm-type string option or
> - * computed based on other criteria such as the host kernel capabilities.
> + * computed based on other criteria such as the host kernel capabilities
> + * (which can't be negative), or -1 on error.
> * @numa_mem_supported:
> * true if '--numa node.mem' option is supported and false otherwise
> * @smp_parse:
> diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
> index 84c943fcdb2..b069938d881 100644
> --- a/accel/kvm/kvm-all.c
> +++ b/accel/kvm/kvm-all.c
> @@ -2057,6 +2057,12 @@ static int kvm_init(MachineState *ms)
> "kvm-type",
> &error_abort);
> type = mc->kvm_type(ms, kvm_type);
> + if (type < 0) {
> + ret = -EINVAL;
> + fprintf(stderr, "Failed to detect kvm-type for machine '%s'\n",
> + mc->name);
> + goto err;
> + }
> }
>
> do {
No objection to this patch; but I'm wondering why some non-pseries
machines implement the kvm_type callback, when I see the kvm-type
property only for pseries? Am I holding my git grep wrong?
On 2/22/21 6:24 PM, Cornelia Huck wrote:
> On Fri, 19 Feb 2021 18:38:37 +0100
> Philippe Mathieu-Daudé <philmd@redhat.com> wrote:
>
>> MachineClass::kvm_type() can return -1 on failure.
>> Document it, and add a check in kvm_init().
>>
>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>> ---
>> include/hw/boards.h | 3 ++-
>> accel/kvm/kvm-all.c | 6 ++++++
>> 2 files changed, 8 insertions(+), 1 deletion(-)
>>
>> diff --git a/include/hw/boards.h b/include/hw/boards.h
>> index a46dfe5d1a6..68d3d10f6b0 100644
>> --- a/include/hw/boards.h
>> +++ b/include/hw/boards.h
>> @@ -127,7 +127,8 @@ typedef struct {
>> * implement and a stub device is required.
>> * @kvm_type:
>> * Return the type of KVM corresponding to the kvm-type string option or
>> - * computed based on other criteria such as the host kernel capabilities.
>> + * computed based on other criteria such as the host kernel capabilities
>> + * (which can't be negative), or -1 on error.
>> * @numa_mem_supported:
>> * true if '--numa node.mem' option is supported and false otherwise
>> * @smp_parse:
>> diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
>> index 84c943fcdb2..b069938d881 100644
>> --- a/accel/kvm/kvm-all.c
>> +++ b/accel/kvm/kvm-all.c
>> @@ -2057,6 +2057,12 @@ static int kvm_init(MachineState *ms)
>> "kvm-type",
>> &error_abort);
>> type = mc->kvm_type(ms, kvm_type);
>> + if (type < 0) {
>> + ret = -EINVAL;
>> + fprintf(stderr, "Failed to detect kvm-type for machine '%s'\n",
>> + mc->name);
>> + goto err;
>> + }
>> }
>>
>> do {
>
> No objection to this patch; but I'm wondering why some non-pseries
> machines implement the kvm_type callback, when I see the kvm-type
> property only for pseries? Am I holding my git grep wrong?
Can it be what David commented here?
https://www.mail-archive.com/qemu-devel@nongnu.org/msg784508.html
On Mon, 22 Feb 2021 18:41:07 +0100
Philippe Mathieu-Daudé <philmd@redhat.com> wrote:
> On 2/22/21 6:24 PM, Cornelia Huck wrote:
> > On Fri, 19 Feb 2021 18:38:37 +0100
> > Philippe Mathieu-Daudé <philmd@redhat.com> wrote:
> >
> >> MachineClass::kvm_type() can return -1 on failure.
> >> Document it, and add a check in kvm_init().
> >>
> >> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> >> ---
> >> include/hw/boards.h | 3 ++-
> >> accel/kvm/kvm-all.c | 6 ++++++
> >> 2 files changed, 8 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/include/hw/boards.h b/include/hw/boards.h
> >> index a46dfe5d1a6..68d3d10f6b0 100644
> >> --- a/include/hw/boards.h
> >> +++ b/include/hw/boards.h
> >> @@ -127,7 +127,8 @@ typedef struct {
> >> * implement and a stub device is required.
> >> * @kvm_type:
> >> * Return the type of KVM corresponding to the kvm-type string option or
> >> - * computed based on other criteria such as the host kernel capabilities.
> >> + * computed based on other criteria such as the host kernel capabilities
> >> + * (which can't be negative), or -1 on error.
> >> * @numa_mem_supported:
> >> * true if '--numa node.mem' option is supported and false otherwise
> >> * @smp_parse:
> >> diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
> >> index 84c943fcdb2..b069938d881 100644
> >> --- a/accel/kvm/kvm-all.c
> >> +++ b/accel/kvm/kvm-all.c
> >> @@ -2057,6 +2057,12 @@ static int kvm_init(MachineState *ms)
> >> "kvm-type",
> >> &error_abort);
> >> type = mc->kvm_type(ms, kvm_type);
> >> + if (type < 0) {
> >> + ret = -EINVAL;
> >> + fprintf(stderr, "Failed to detect kvm-type for machine '%s'\n",
> >> + mc->name);
> >> + goto err;
> >> + }
> >> }
> >>
> >> do {
> >
> > No objection to this patch; but I'm wondering why some non-pseries
> > machines implement the kvm_type callback, when I see the kvm-type
> > property only for pseries? Am I holding my git grep wrong?
>
> Can it be what David commented here?
> https://www.mail-archive.com/qemu-devel@nongnu.org/msg784508.html
>
Ok, I might be confused about the other ppc machines; but I'm wondering
about the kvm_type callback for mips and arm/virt. Maybe I'm just
confused by the whole mechanism?
On 2/22/21 6:50 PM, Cornelia Huck wrote:
> On Mon, 22 Feb 2021 18:41:07 +0100
> Philippe Mathieu-Daudé <philmd@redhat.com> wrote:
>
>> On 2/22/21 6:24 PM, Cornelia Huck wrote:
>>> On Fri, 19 Feb 2021 18:38:37 +0100
>>> Philippe Mathieu-Daudé <philmd@redhat.com> wrote:
>>>
>>>> MachineClass::kvm_type() can return -1 on failure.
>>>> Document it, and add a check in kvm_init().
>>>>
>>>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>>>> ---
>>>> include/hw/boards.h | 3 ++-
>>>> accel/kvm/kvm-all.c | 6 ++++++
>>>> 2 files changed, 8 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/include/hw/boards.h b/include/hw/boards.h
>>>> index a46dfe5d1a6..68d3d10f6b0 100644
>>>> --- a/include/hw/boards.h
>>>> +++ b/include/hw/boards.h
>>>> @@ -127,7 +127,8 @@ typedef struct {
>>>> * implement and a stub device is required.
>>>> * @kvm_type:
>>>> * Return the type of KVM corresponding to the kvm-type string option or
>>>> - * computed based on other criteria such as the host kernel capabilities.
>>>> + * computed based on other criteria such as the host kernel capabilities
>>>> + * (which can't be negative), or -1 on error.
>>>> * @numa_mem_supported:
>>>> * true if '--numa node.mem' option is supported and false otherwise
>>>> * @smp_parse:
>>>> diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
>>>> index 84c943fcdb2..b069938d881 100644
>>>> --- a/accel/kvm/kvm-all.c
>>>> +++ b/accel/kvm/kvm-all.c
>>>> @@ -2057,6 +2057,12 @@ static int kvm_init(MachineState *ms)
>>>> "kvm-type",
>>>> &error_abort);
>>>> type = mc->kvm_type(ms, kvm_type);
>>>> + if (type < 0) {
>>>> + ret = -EINVAL;
>>>> + fprintf(stderr, "Failed to detect kvm-type for machine '%s'\n",
>>>> + mc->name);
>>>> + goto err;
>>>> + }
>>>> }
>>>>
>>>> do {
>>>
>>> No objection to this patch; but I'm wondering why some non-pseries
>>> machines implement the kvm_type callback, when I see the kvm-type
>>> property only for pseries? Am I holding my git grep wrong?
>>
>> Can it be what David commented here?
>> https://www.mail-archive.com/qemu-devel@nongnu.org/msg784508.html
>>
>
> Ok, I might be confused about the other ppc machines; but I'm wondering
> about the kvm_type callback for mips and arm/virt. Maybe I'm just
> confused by the whole mechanism?
For MIPS see https://www.linux-kvm.org/images/f/f2/01x08a-MIPS.pdf
and Jiaxun comment here:
https://lore.kernel.org/linux-mips/a2a2cfe3-5618-43b1-a6a4-cc768fc1b9fb@www.fastmail.com/
TE KVM: Trap-and-Emul guest kernel
VZ KVM: HW Virtualized
For "the whole mechanism" I'll defer to Paolo =)
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