diff mbox series

[v16,04/99] qtest/arm-cpu-features: Use generic qtest_has_accel() to check for KVM

Message ID 20210604155312.15902-5-alex.bennee@linaro.org
State New
Headers show
Series arm tcg/kvm refactor and split with kvm only support | expand

Commit Message

Alex Bennée June 4, 2021, 3:51 p.m. UTC
From: Philippe Mathieu-Daudé <philmd@redhat.com>


Use the recently added generic qtest_has_accel() method to
check if KVM is available.

Suggested-by: Claudio Fontana <cfontana@suse.de>
Reviewed-by: Andrew Jones <drjones@redhat.com>

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

Message-Id: <20210505125806.1263441-5-philmd@redhat.com>
---
 tests/qtest/arm-cpu-features.c | 25 +------------------------
 1 file changed, 1 insertion(+), 24 deletions(-)

-- 
2.20.1

Comments

Richard Henderson June 4, 2021, 9:01 p.m. UTC | #1
On 6/4/21 8:51 AM, Alex Bennée wrote:
> From: Philippe Mathieu-Daudé<philmd@redhat.com>

> 

> Use the recently added generic qtest_has_accel() method to

> check if KVM is available.

> 

> Suggested-by: Claudio Fontana<cfontana@suse.de>

> Reviewed-by: Andrew Jones<drjones@redhat.com>

> Reviewed-by: Alex Bennée<alex.bennee@linaro.org>

> Signed-off-by: Philippe Mathieu-Daudé<philmd@redhat.com>

> Signed-off-by: Alex Bennée<alex.bennee@linaro.org>

> Message-Id:<20210505125806.1263441-5-philmd@redhat.com>

> ---

>   tests/qtest/arm-cpu-features.c | 25 +------------------------

>   1 file changed, 1 insertion(+), 24 deletions(-)


Reviewed-by: Richard Henderson <richard.henderson@linaro.org>


r~
Thomas Huth June 7, 2021, 1:22 p.m. UTC | #2
On 04/06/2021 17.51, Alex Bennée wrote:
> From: Philippe Mathieu-Daudé <philmd@redhat.com>

> 

> Use the recently added generic qtest_has_accel() method to

> check if KVM is available.

> 

> Suggested-by: Claudio Fontana <cfontana@suse.de>

> Reviewed-by: Andrew Jones <drjones@redhat.com>

> Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

> Message-Id: <20210505125806.1263441-5-philmd@redhat.com>

> ---

>   tests/qtest/arm-cpu-features.c | 25 +------------------------

>   1 file changed, 1 insertion(+), 24 deletions(-)

> 

> diff --git a/tests/qtest/arm-cpu-features.c b/tests/qtest/arm-cpu-features.c

> index 8252b85bb8..7f4b252127 100644

> --- a/tests/qtest/arm-cpu-features.c

> +++ b/tests/qtest/arm-cpu-features.c

> @@ -26,21 +26,6 @@

>                       "  'arguments': { 'type': 'full', "

>   #define QUERY_TAIL  "}}"

>   

> -static bool kvm_enabled(QTestState *qts)

> -{

> -    QDict *resp, *qdict;

> -    bool enabled;

> -

> -    resp = qtest_qmp(qts, "{ 'execute': 'query-kvm' }");

> -    g_assert(qdict_haskey(resp, "return"));

> -    qdict = qdict_get_qdict(resp, "return");

> -    g_assert(qdict_haskey(qdict, "enabled"));

> -    enabled = qdict_get_bool(qdict, "enabled");

> -    qobject_unref(resp);

> -

> -    return enabled;

> -}

> -

>   static QDict *do_query_no_props(QTestState *qts, const char *cpu_type)

>   {

>       return qtest_qmp(qts, QUERY_HEAD "'model': { 'name': %s }"

> @@ -493,14 +478,6 @@ static void test_query_cpu_model_expansion_kvm(const void *data)

>   

>       qts = qtest_init(MACHINE_KVM "-cpu max");

>   

> -    /*

> -     * These tests target the 'host' CPU type, so KVM must be enabled.

> -     */

> -    if (!kvm_enabled(qts)) {

> -        qtest_quit(qts);

> -        return;

> -    }

> -

>       /* Enabling and disabling kvm-no-adjvtime should always work. */

>       assert_has_feature_disabled(qts, "host", "kvm-no-adjvtime");

>       assert_set_feature(qts, "host", "kvm-no-adjvtime", true);

> @@ -624,7 +601,7 @@ int main(int argc, char **argv)

>        * order avoid attempting to run an AArch32 QEMU with KVM on

>        * AArch64 hosts. That won't work and isn't easy to detect.

>        */

> -    if (g_str_equal(qtest_get_arch(), "aarch64")) {

> +    if (g_str_equal(qtest_get_arch(), "aarch64") && qtest_has_accel("kvm")) {

>           qtest_add_data_func("/arm/kvm/query-cpu-model-expansion",

>                               NULL, test_query_cpu_model_expansion_kvm);


I think this is wrong: query-kvm checks whether kvm is *enabled*, while your 
new function only checks whether kvm has been built into the binary. There 
is still the possibility that kvm has been built into the binary, but is not 
available on the host, so in that case the test will fail now.

Thus please drop / rework this patch.

  Thomas
Philippe Mathieu-Daudé June 8, 2021, 8:22 a.m. UTC | #3
On 6/7/21 3:22 PM, Thomas Huth wrote:
> On 04/06/2021 17.51, Alex Bennée wrote:

>> From: Philippe Mathieu-Daudé <philmd@redhat.com>

>>

>> Use the recently added generic qtest_has_accel() method to

>> check if KVM is available.

>>

>> Suggested-by: Claudio Fontana <cfontana@suse.de>

>> Reviewed-by: Andrew Jones <drjones@redhat.com>

>> Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

>> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

>> Message-Id: <20210505125806.1263441-5-philmd@redhat.com>

>> ---

>>   tests/qtest/arm-cpu-features.c | 25 +------------------------

>>   1 file changed, 1 insertion(+), 24 deletions(-)

>>

>> diff --git a/tests/qtest/arm-cpu-features.c

>> b/tests/qtest/arm-cpu-features.c

>> index 8252b85bb8..7f4b252127 100644

>> --- a/tests/qtest/arm-cpu-features.c

>> +++ b/tests/qtest/arm-cpu-features.c

>> @@ -26,21 +26,6 @@

>>                       "  'arguments': { 'type': 'full', "

>>   #define QUERY_TAIL  "}}"

>>   -static bool kvm_enabled(QTestState *qts)

>> -{

>> -    QDict *resp, *qdict;

>> -    bool enabled;

>> -

>> -    resp = qtest_qmp(qts, "{ 'execute': 'query-kvm' }");

>> -    g_assert(qdict_haskey(resp, "return"));

>> -    qdict = qdict_get_qdict(resp, "return");

>> -    g_assert(qdict_haskey(qdict, "enabled"));

>> -    enabled = qdict_get_bool(qdict, "enabled");

>> -    qobject_unref(resp);

>> -

>> -    return enabled;

>> -}

>> -

>>   static QDict *do_query_no_props(QTestState *qts, const char *cpu_type)

>>   {

>>       return qtest_qmp(qts, QUERY_HEAD "'model': { 'name': %s }"

>> @@ -493,14 +478,6 @@ static void

>> test_query_cpu_model_expansion_kvm(const void *data)

>>         qts = qtest_init(MACHINE_KVM "-cpu max");

>>   -    /*

>> -     * These tests target the 'host' CPU type, so KVM must be enabled.

>> -     */

>> -    if (!kvm_enabled(qts)) {

>> -        qtest_quit(qts);

>> -        return;

>> -    }

>> -

>>       /* Enabling and disabling kvm-no-adjvtime should always work. */

>>       assert_has_feature_disabled(qts, "host", "kvm-no-adjvtime");

>>       assert_set_feature(qts, "host", "kvm-no-adjvtime", true);

>> @@ -624,7 +601,7 @@ int main(int argc, char **argv)

>>        * order avoid attempting to run an AArch32 QEMU with KVM on

>>        * AArch64 hosts. That won't work and isn't easy to detect.

>>        */

>> -    if (g_str_equal(qtest_get_arch(), "aarch64")) {

>> +    if (g_str_equal(qtest_get_arch(), "aarch64") &&

>> qtest_has_accel("kvm")) {

>>           qtest_add_data_func("/arm/kvm/query-cpu-model-expansion",

>>                               NULL, test_query_cpu_model_expansion_kvm);

> 

> I think this is wrong: query-kvm checks whether kvm is *enabled*, while

> your new function only checks whether kvm has been built into the

> binary. There is still the possibility that kvm has been built into the

> binary, but is not available on the host, so in that case the test will

> fail now.

> 

> Thus please drop / rework this patch.


Indeed, this is unfortunate :(
Philippe Mathieu-Daudé June 8, 2021, 10:49 a.m. UTC | #4
On 6/8/21 10:22 AM, Philippe Mathieu-Daudé wrote:
> On 6/7/21 3:22 PM, Thomas Huth wrote:

>> On 04/06/2021 17.51, Alex Bennée wrote:

>>> From: Philippe Mathieu-Daudé <philmd@redhat.com>

>>>

>>> Use the recently added generic qtest_has_accel() method to

>>> check if KVM is available.

>>>

>>> Suggested-by: Claudio Fontana <cfontana@suse.de>

>>> Reviewed-by: Andrew Jones <drjones@redhat.com>

>>> Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

>>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

>>> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

>>> Message-Id: <20210505125806.1263441-5-philmd@redhat.com>

>>> ---

>>>   tests/qtest/arm-cpu-features.c | 25 +------------------------

>>>   1 file changed, 1 insertion(+), 24 deletions(-)

>>>

>>> diff --git a/tests/qtest/arm-cpu-features.c

>>> b/tests/qtest/arm-cpu-features.c

>>> index 8252b85bb8..7f4b252127 100644

>>> --- a/tests/qtest/arm-cpu-features.c

>>> +++ b/tests/qtest/arm-cpu-features.c

>>> @@ -26,21 +26,6 @@

>>>                       "  'arguments': { 'type': 'full', "

>>>   #define QUERY_TAIL  "}}"

>>>   -static bool kvm_enabled(QTestState *qts)

>>> -{

>>> -    QDict *resp, *qdict;

>>> -    bool enabled;

>>> -

>>> -    resp = qtest_qmp(qts, "{ 'execute': 'query-kvm' }");

>>> -    g_assert(qdict_haskey(resp, "return"));

>>> -    qdict = qdict_get_qdict(resp, "return");

>>> -    g_assert(qdict_haskey(qdict, "enabled"));

>>> -    enabled = qdict_get_bool(qdict, "enabled");

>>> -    qobject_unref(resp);

>>> -

>>> -    return enabled;

>>> -}

>>> -

>>>   static QDict *do_query_no_props(QTestState *qts, const char *cpu_type)

>>>   {

>>>       return qtest_qmp(qts, QUERY_HEAD "'model': { 'name': %s }"

>>> @@ -493,14 +478,6 @@ static void

>>> test_query_cpu_model_expansion_kvm(const void *data)

>>>         qts = qtest_init(MACHINE_KVM "-cpu max");

>>>   -    /*

>>> -     * These tests target the 'host' CPU type, so KVM must be enabled.

>>> -     */

>>> -    if (!kvm_enabled(qts)) {

>>> -        qtest_quit(qts);

>>> -        return;

>>> -    }

>>> -

>>>       /* Enabling and disabling kvm-no-adjvtime should always work. */

>>>       assert_has_feature_disabled(qts, "host", "kvm-no-adjvtime");

>>>       assert_set_feature(qts, "host", "kvm-no-adjvtime", true);

>>> @@ -624,7 +601,7 @@ int main(int argc, char **argv)

>>>        * order avoid attempting to run an AArch32 QEMU with KVM on

>>>        * AArch64 hosts. That won't work and isn't easy to detect.

>>>        */

>>> -    if (g_str_equal(qtest_get_arch(), "aarch64")) {

>>> +    if (g_str_equal(qtest_get_arch(), "aarch64") &&

>>> qtest_has_accel("kvm")) {

>>>           qtest_add_data_func("/arm/kvm/query-cpu-model-expansion",

>>>                               NULL, test_query_cpu_model_expansion_kvm);

>>

>> I think this is wrong: query-kvm checks whether kvm is *enabled*, while

>> your new function only checks whether kvm has been built into the

>> binary. There is still the possibility that kvm has been built into the

>> binary, but is not available on the host, so in that case the test will

>> fail now.


Not enough coffee earlier. I think this is a documentation problem,
query-kvm returns a list of *runtime* accelerators:
https://www.mail-archive.com/qemu-devel@nongnu.org/msg811144.html

IIUC what Paolo said, if something asks for an accelerator that
is not present at build-time, then this is a configuration problem,
not relevant for the management interface.

>>

>> Thus please drop / rework this patch.

> 

> Indeed, this is unfortunate :(

>
Philippe Mathieu-Daudé June 8, 2021, 12:39 p.m. UTC | #5
On 6/8/21 12:49 PM, Philippe Mathieu-Daudé wrote:
> On 6/8/21 10:22 AM, Philippe Mathieu-Daudé wrote:

>> On 6/7/21 3:22 PM, Thomas Huth wrote:

>>> On 04/06/2021 17.51, Alex Bennée wrote:

>>>> From: Philippe Mathieu-Daudé <philmd@redhat.com>

>>>>

>>>> Use the recently added generic qtest_has_accel() method to

>>>> check if KVM is available.

>>>>

>>>> Suggested-by: Claudio Fontana <cfontana@suse.de>

>>>> Reviewed-by: Andrew Jones <drjones@redhat.com>

>>>> Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

>>>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

>>>> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

>>>> Message-Id: <20210505125806.1263441-5-philmd@redhat.com>

>>>> ---

>>>>   tests/qtest/arm-cpu-features.c | 25 +------------------------

>>>>   1 file changed, 1 insertion(+), 24 deletions(-)

>>>>

>>>> diff --git a/tests/qtest/arm-cpu-features.c

>>>> b/tests/qtest/arm-cpu-features.c

>>>> index 8252b85bb8..7f4b252127 100644

>>>> --- a/tests/qtest/arm-cpu-features.c

>>>> +++ b/tests/qtest/arm-cpu-features.c

>>>> @@ -26,21 +26,6 @@

>>>>                       "  'arguments': { 'type': 'full', "

>>>>   #define QUERY_TAIL  "}}"

>>>>   -static bool kvm_enabled(QTestState *qts)

>>>> -{

>>>> -    QDict *resp, *qdict;

>>>> -    bool enabled;

>>>> -

>>>> -    resp = qtest_qmp(qts, "{ 'execute': 'query-kvm' }");

>>>> -    g_assert(qdict_haskey(resp, "return"));

>>>> -    qdict = qdict_get_qdict(resp, "return");

>>>> -    g_assert(qdict_haskey(qdict, "enabled"));

>>>> -    enabled = qdict_get_bool(qdict, "enabled");

>>>> -    qobject_unref(resp);

>>>> -

>>>> -    return enabled;

>>>> -}

>>>> -

>>>>   static QDict *do_query_no_props(QTestState *qts, const char *cpu_type)

>>>>   {

>>>>       return qtest_qmp(qts, QUERY_HEAD "'model': { 'name': %s }"

>>>> @@ -493,14 +478,6 @@ static void

>>>> test_query_cpu_model_expansion_kvm(const void *data)

>>>>         qts = qtest_init(MACHINE_KVM "-cpu max");

>>>>   -    /*

>>>> -     * These tests target the 'host' CPU type, so KVM must be enabled.

>>>> -     */

>>>> -    if (!kvm_enabled(qts)) {

>>>> -        qtest_quit(qts);

>>>> -        return;

>>>> -    }

>>>> -

>>>>       /* Enabling and disabling kvm-no-adjvtime should always work. */

>>>>       assert_has_feature_disabled(qts, "host", "kvm-no-adjvtime");

>>>>       assert_set_feature(qts, "host", "kvm-no-adjvtime", true);

>>>> @@ -624,7 +601,7 @@ int main(int argc, char **argv)

>>>>        * order avoid attempting to run an AArch32 QEMU with KVM on

>>>>        * AArch64 hosts. That won't work and isn't easy to detect.

>>>>        */

>>>> -    if (g_str_equal(qtest_get_arch(), "aarch64")) {

>>>> +    if (g_str_equal(qtest_get_arch(), "aarch64") &&

>>>> qtest_has_accel("kvm")) {

>>>>           qtest_add_data_func("/arm/kvm/query-cpu-model-expansion",

>>>>                               NULL, test_query_cpu_model_expansion_kvm);

>>>

>>> I think this is wrong: query-kvm checks whether kvm is *enabled*, while

>>> your new function only checks whether kvm has been built into the

>>> binary. There is still the possibility that kvm has been built into the

>>> binary, but is not available on the host, so in that case the test will

>>> fail now.

> 

> Not enough coffee earlier. I think this is a documentation problem,

> query-kvm returns a list of *runtime* accelerators:

> https://www.mail-archive.com/qemu-devel@nongnu.org/msg811144.html

> 

> IIUC what Paolo said, if something asks for an accelerator that

> is not present at build-time, then this is a configuration problem,

> not relevant for the management interface.


Argh no... sigh. So we have 4 cases:

1- accelerator not built
2- accelerator built in as module but not loaded
3- accelerator built in & loaded but not usable
4- accelerator built in & loaded and usable

QMP query-accels returns "accelerator built in & loaded"
without precising it is usable.

qtest kvm_enabled() checks if the accelerator is enabled
without checking it is built-in.

QMP query-kvm returns 'present' as in built-in (so case 1),
and 'enabled' (a.k.a. 'allowed') updated once init_machine()
succeeded (so case 4).

So, again, IIUC Paolo, what he said is for the management layer
1 and 2 are the same, the accelerator is not present.

For qtests, we want the 'usable' case (4) right? Whether the
accelerator is builtin / loaded is irrelevant.

Could we improve the terminology here? Maybe is_present() and
is_usable()? Suggestions?

Do we need to add both query-present-accels query-usable-accels
commands? Is it actually possible to return an array of 'usable'
accelerators?

Maybe simply add query-present-accels() -> [] and
query-usable-accel(accel) -> bool.

> 

>>>

>>> Thus please drop / rework this patch.

>>

>> Indeed, this is unfortunate :(

>>
Eric Blake June 8, 2021, 2:28 p.m. UTC | #6
On Tue, Jun 08, 2021 at 02:39:03PM +0200, Philippe Mathieu-Daudé wrote:
> > 

> > Not enough coffee earlier. I think this is a documentation problem,

> > query-kvm returns a list of *runtime* accelerators:

> > https://www.mail-archive.com/qemu-devel@nongnu.org/msg811144.html

> > 

> > IIUC what Paolo said, if something asks for an accelerator that

> > is not present at build-time, then this is a configuration problem,

> > not relevant for the management interface.

> 

> Argh no... sigh. So we have 4 cases:

> 

> 1- accelerator not built

> 2- accelerator built in as module but not loaded

> 3- accelerator built in & loaded but not usable

> 4- accelerator built in & loaded and usable

> 

> QMP query-accels returns "accelerator built in & loaded"

> without precising it is usable.

> 

> qtest kvm_enabled() checks if the accelerator is enabled

> without checking it is built-in.

> 

> QMP query-kvm returns 'present' as in built-in (so case 1),

> and 'enabled' (a.k.a. 'allowed') updated once init_machine()

> succeeded (so case 4).

> 

> So, again, IIUC Paolo, what he said is for the management layer

> 1 and 2 are the same, the accelerator is not present.


Isn't 3 in the same boat?  Really, the management app cares if it can
use the accelerator, not whether it is present.

> 

> For qtests, we want the 'usable' case (4) right? Whether the

> accelerator is builtin / loaded is irrelevant.

> 

> Could we improve the terminology here? Maybe is_present() and

> is_usable()? Suggestions?

> 

> Do we need to add both query-present-accels query-usable-accels

> commands? Is it actually possible to return an array of 'usable'

> accelerators?

> 

> Maybe simply add query-present-accels() -> [] and

> query-usable-accel(accel) -> bool.


Can you just make query-accels return both pieces of information?

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org
Claudio Fontana June 8, 2021, 5:20 p.m. UTC | #7
On 6/8/21 2:39 PM, Philippe Mathieu-Daudé wrote:
> On 6/8/21 12:49 PM, Philippe Mathieu-Daudé wrote:

>> On 6/8/21 10:22 AM, Philippe Mathieu-Daudé wrote:

>>> On 6/7/21 3:22 PM, Thomas Huth wrote:

>>>> On 04/06/2021 17.51, Alex Bennée wrote:

>>>>> From: Philippe Mathieu-Daudé <philmd@redhat.com>

>>>>>

>>>>> Use the recently added generic qtest_has_accel() method to

>>>>> check if KVM is available.

>>>>>

>>>>> Suggested-by: Claudio Fontana <cfontana@suse.de>

>>>>> Reviewed-by: Andrew Jones <drjones@redhat.com>

>>>>> Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

>>>>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

>>>>> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

>>>>> Message-Id: <20210505125806.1263441-5-philmd@redhat.com>

>>>>> ---

>>>>>   tests/qtest/arm-cpu-features.c | 25 +------------------------

>>>>>   1 file changed, 1 insertion(+), 24 deletions(-)

>>>>>

>>>>> diff --git a/tests/qtest/arm-cpu-features.c

>>>>> b/tests/qtest/arm-cpu-features.c

>>>>> index 8252b85bb8..7f4b252127 100644

>>>>> --- a/tests/qtest/arm-cpu-features.c

>>>>> +++ b/tests/qtest/arm-cpu-features.c

>>>>> @@ -26,21 +26,6 @@

>>>>>                       "  'arguments': { 'type': 'full', "

>>>>>   #define QUERY_TAIL  "}}"

>>>>>   -static bool kvm_enabled(QTestState *qts)

>>>>> -{

>>>>> -    QDict *resp, *qdict;

>>>>> -    bool enabled;

>>>>> -

>>>>> -    resp = qtest_qmp(qts, "{ 'execute': 'query-kvm' }");

>>>>> -    g_assert(qdict_haskey(resp, "return"));

>>>>> -    qdict = qdict_get_qdict(resp, "return");

>>>>> -    g_assert(qdict_haskey(qdict, "enabled"));

>>>>> -    enabled = qdict_get_bool(qdict, "enabled");

>>>>> -    qobject_unref(resp);

>>>>> -

>>>>> -    return enabled;

>>>>> -}

>>>>> -

>>>>>   static QDict *do_query_no_props(QTestState *qts, const char *cpu_type)

>>>>>   {

>>>>>       return qtest_qmp(qts, QUERY_HEAD "'model': { 'name': %s }"

>>>>> @@ -493,14 +478,6 @@ static void

>>>>> test_query_cpu_model_expansion_kvm(const void *data)

>>>>>         qts = qtest_init(MACHINE_KVM "-cpu max");

>>>>>   -    /*

>>>>> -     * These tests target the 'host' CPU type, so KVM must be enabled.

>>>>> -     */

>>>>> -    if (!kvm_enabled(qts)) {

>>>>> -        qtest_quit(qts);

>>>>> -        return;

>>>>> -    }

>>>>> -

>>>>>       /* Enabling and disabling kvm-no-adjvtime should always work. */

>>>>>       assert_has_feature_disabled(qts, "host", "kvm-no-adjvtime");

>>>>>       assert_set_feature(qts, "host", "kvm-no-adjvtime", true);

>>>>> @@ -624,7 +601,7 @@ int main(int argc, char **argv)

>>>>>        * order avoid attempting to run an AArch32 QEMU with KVM on

>>>>>        * AArch64 hosts. That won't work and isn't easy to detect.

>>>>>        */

>>>>> -    if (g_str_equal(qtest_get_arch(), "aarch64")) {

>>>>> +    if (g_str_equal(qtest_get_arch(), "aarch64") &&

>>>>> qtest_has_accel("kvm")) {

>>>>>           qtest_add_data_func("/arm/kvm/query-cpu-model-expansion",

>>>>>                               NULL, test_query_cpu_model_expansion_kvm);

>>>>

>>>> I think this is wrong: query-kvm checks whether kvm is *enabled*, while

>>>> your new function only checks whether kvm has been built into the

>>>> binary. There is still the possibility that kvm has been built into the

>>>> binary, but is not available on the host, so in that case the test will

>>>> fail now.

>>

>> Not enough coffee earlier. I think this is a documentation problem,

>> query-kvm returns a list of *runtime* accelerators:

>> https://www.mail-archive.com/qemu-devel@nongnu.org/msg811144.html

>>

>> IIUC what Paolo said, if something asks for an accelerator that

>> is not present at build-time, then this is a configuration problem,

>> not relevant for the management interface.

> 

> Argh no... sigh. So we have 4 cases:

> 

> 1- accelerator not built

> 2- accelerator built in as module but not loaded

> 3- accelerator built in & loaded but not usable

> 4- accelerator built in & loaded and usable

> 

> QMP query-accels returns "accelerator built in & loaded"

> without precising it is usable.

> 

> qtest kvm_enabled() checks if the accelerator is enabled

> without checking it is built-in.

> 

> QMP query-kvm returns 'present' as in built-in (so case 1),

> and 'enabled' (a.k.a. 'allowed') updated once init_machine()

> succeeded (so case 4).

> 

> So, again, IIUC Paolo, what he said is for the management layer

> 1 and 2 are the same, the accelerator is not present.

> 

> For qtests, we want the 'usable' case (4) right? Whether the

> accelerator is builtin / loaded is irrelevant.

> 

> Could we improve the terminology here? Maybe is_present() and

> is_usable()? Suggestions?



Let me try some terms:

1 - bool accelerator_built()      ->   accelerator has been part of this QEMU build.
2 - bool accelerator_loaded()     ->   accelerator has been loaded, either because it is built-in, or because its code has been dynamically loaded

and probably the management layers do not care about the distinction between 1, 2.

Maybe instead of "usable", "available" is better?

3 - bool accelerator_available()

Then we have the accelerator that is actually active, selected or chosen.

4 - bool accelerator_enabled()? bool accelerator_active()? bool accelerator_chosen()? bool accelerator_used()?

We already use the term "allowed", with different meaning and implementations depending on --enable-xxx,
which is quite confusing I think..


Ciao,

Claudoi


> 

> Do we need to add both query-present-accels query-usable-accels

> commands? Is it actually possible to return an array of 'usable'

> accelerators?

> 

> Maybe simply add query-present-accels() -> [] and

> query-usable-accel(accel) -> bool.

> 

>>

>>>>

>>>> Thus please drop / rework this patch.

>>>

>>> Indeed, this is unfortunate :(

>>>

>
diff mbox series

Patch

diff --git a/tests/qtest/arm-cpu-features.c b/tests/qtest/arm-cpu-features.c
index 8252b85bb8..7f4b252127 100644
--- a/tests/qtest/arm-cpu-features.c
+++ b/tests/qtest/arm-cpu-features.c
@@ -26,21 +26,6 @@ 
                     "  'arguments': { 'type': 'full', "
 #define QUERY_TAIL  "}}"
 
-static bool kvm_enabled(QTestState *qts)
-{
-    QDict *resp, *qdict;
-    bool enabled;
-
-    resp = qtest_qmp(qts, "{ 'execute': 'query-kvm' }");
-    g_assert(qdict_haskey(resp, "return"));
-    qdict = qdict_get_qdict(resp, "return");
-    g_assert(qdict_haskey(qdict, "enabled"));
-    enabled = qdict_get_bool(qdict, "enabled");
-    qobject_unref(resp);
-
-    return enabled;
-}
-
 static QDict *do_query_no_props(QTestState *qts, const char *cpu_type)
 {
     return qtest_qmp(qts, QUERY_HEAD "'model': { 'name': %s }"
@@ -493,14 +478,6 @@  static void test_query_cpu_model_expansion_kvm(const void *data)
 
     qts = qtest_init(MACHINE_KVM "-cpu max");
 
-    /*
-     * These tests target the 'host' CPU type, so KVM must be enabled.
-     */
-    if (!kvm_enabled(qts)) {
-        qtest_quit(qts);
-        return;
-    }
-
     /* Enabling and disabling kvm-no-adjvtime should always work. */
     assert_has_feature_disabled(qts, "host", "kvm-no-adjvtime");
     assert_set_feature(qts, "host", "kvm-no-adjvtime", true);
@@ -624,7 +601,7 @@  int main(int argc, char **argv)
      * order avoid attempting to run an AArch32 QEMU with KVM on
      * AArch64 hosts. That won't work and isn't easy to detect.
      */
-    if (g_str_equal(qtest_get_arch(), "aarch64")) {
+    if (g_str_equal(qtest_get_arch(), "aarch64") && qtest_has_accel("kvm")) {
         qtest_add_data_func("/arm/kvm/query-cpu-model-expansion",
                             NULL, test_query_cpu_model_expansion_kvm);
     }