On Fri, Jun 19, 2020 at 11:55:42AM +0200, Philippe Mathieu-Daudé wrote:
> Since commit d70c996df23f, when enabling the PMU we get:
>
> $ qemu-system-aarch64 -cpu host,pmu=on -M virt,accel=kvm,gic-version=3
> Segmentation fault (core dumped)
>
> Thread 1 "qemu-system-aar" received signal SIGSEGV, Segmentation fault.
> 0x0000aaaaaae356d0 in kvm_ioctl (s=0x0, type=44547) at accel/kvm/kvm-all.c:2588
> 2588 ret = ioctl(s->fd, type, arg);
> (gdb) bt
> #0 0x0000aaaaaae356d0 in kvm_ioctl (s=0x0, type=44547) at accel/kvm/kvm-all.c:2588
> #1 0x0000aaaaaae31568 in kvm_check_extension (s=0x0, extension=126) at accel/kvm/kvm-all.c:916
> #2 0x0000aaaaaafce254 in kvm_arm_pmu_supported (cpu=0xaaaaac214ab0) at target/arm/kvm.c:213
> #3 0x0000aaaaaafc0f94 in arm_set_pmu (obj=0xaaaaac214ab0, value=true, errp=0xffffffffe438) at target/arm/cpu.c:1111
> #4 0x0000aaaaab5533ac in property_set_bool (obj=0xaaaaac214ab0, v=0xaaaaac223a80, name=0xaaaaac11a970 "pmu", opaque=0xaaaaac222730, errp=0xffffffffe438) at qom/object.c:2170
> #5 0x0000aaaaab5512f0 in object_property_set (obj=0xaaaaac214ab0, v=0xaaaaac223a80, name=0xaaaaac11a970 "pmu", errp=0xffffffffe438) at qom/object.c:1328
> #6 0x0000aaaaab551e10 in object_property_parse (obj=0xaaaaac214ab0, string=0xaaaaac11b4c0 "on", name=0xaaaaac11a970 "pmu", errp=0xffffffffe438) at qom/object.c:1561
> #7 0x0000aaaaab54ee8c in object_apply_global_props (obj=0xaaaaac214ab0, props=0xaaaaac018e20, errp=0xaaaaabd6fd88 <error_fatal>) at qom/object.c:407
> #8 0x0000aaaaab1dd5a4 in qdev_prop_set_globals (dev=0xaaaaac214ab0) at hw/core/qdev-properties.c:1218
> #9 0x0000aaaaab1d9fac in device_post_init (obj=0xaaaaac214ab0) at hw/core/qdev.c:1050
> ...
> #15 0x0000aaaaab54f310 in object_initialize_with_type (obj=0xaaaaac214ab0, size=52208, type=0xaaaaabe237f0) at qom/object.c:512
> #16 0x0000aaaaab54fa24 in object_new_with_type (type=0xaaaaabe237f0) at qom/object.c:687
> #17 0x0000aaaaab54fa80 in object_new (typename=0xaaaaabe23970 "host-arm-cpu") at qom/object.c:702
> #18 0x0000aaaaaaf04a74 in machvirt_init (machine=0xaaaaac0a8550) at hw/arm/virt.c:1770
> #19 0x0000aaaaab1e8720 in machine_run_board_init (machine=0xaaaaac0a8550) at hw/core/machine.c:1138
> #20 0x0000aaaaaaf95394 in qemu_init (argc=5, argv=0xffffffffea58, envp=0xffffffffea88) at softmmu/vl.c:4348
> #21 0x0000aaaaaada3f74 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at softmmu/main.c:48
>
> This is because in frame #2, cpu->kvm_state is still NULL
> (the vCPU is not yet realized).
>
> KVM has a hard requirement of all cores supporting the same
> feature set. We only need to check if the accelerator supports
> a feature, not each vCPU individually.
>
> Fix by kvm_arm_<FEATURE>_supported() functions take a AccelState
> argument (already realized/valid at this point) instead of a
> CPUState argument.
>
> Reported-by: Haibo Xu <haibo.xu@xxxxxxxxxx>
> Suggested-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@xxxxxxxxxx>
> ---
> v2: Use global kvm_state (bonzini)
>
> Paolo, does this break migration of encrypted memory assumptions?
>
> Cc: Dr. David Alan Gilbert <dgilbert@xxxxxxxxxx>
> Supersedes: <20200617130800.26355-1-philmd@xxxxxxxxxx>
> ---
> target/arm/kvm_arm.h | 21 +++++++++------------
> target/arm/cpu.c | 2 +-
> target/arm/cpu64.c | 10 +++++-----
> target/arm/kvm.c | 4 ++--
> target/arm/kvm64.c | 14 +++++---------
> 5 files changed, 22 insertions(+), 29 deletions(-)
>
Hi Phil,
Can you also post the attached patch with this one (a two patch series)?
I want to ensure the bug is fixed before the test gets merged, but I
also would like the test to be added in order to catch things like this
in the future.
Thanks,
drew
>From 0bcb766d51b7c1c328218ae735f687b1160d6b42 Mon Sep 17 00:00:00 2001
From: Andrew Jones <drjones@xxxxxxxxxx>
Date: Fri, 19 Jun 2020 13:30:38 +0200
Subject: [PATCH] tests/qtest/arm-cpu-features: Add feature setting tests
A recent regression (-cpu host,pmu=on caused a segfault) inspired
adding these tests.
Signed-off-by: Andrew Jones <drjones@xxxxxxxxxx>
---
tests/qtest/arm-cpu-features.c | 32 +++++++++++++++++++++++++++++---
1 file changed, 29 insertions(+), 3 deletions(-)
diff --git a/tests/qtest/arm-cpu-features.c b/tests/qtest/arm-cpu-features.c
index 469217367661..d6bdbc171893 100644
--- a/tests/qtest/arm-cpu-features.c
+++ b/tests/qtest/arm-cpu-features.c
@@ -159,16 +159,35 @@ static bool resp_get_feature(QDict *resp, const char *feature)
qobject_unref(_resp); \
})
-#define assert_feature(qts, cpu_type, feature, expected_value) \
+#define resp_assert_feature(resp, feature, expected_value) \
({ \
- QDict *_resp, *_props; \
+ QDict *_props; \
\
- _resp = do_query_no_props(qts, cpu_type); \
g_assert(_resp); \
g_assert(resp_has_props(_resp)); \
_props = resp_get_props(_resp); \
g_assert(qdict_get(_props, feature)); \
g_assert(qdict_get_bool(_props, feature) == (expected_value)); \
+})
+
+#define assert_feature(qts, cpu_type, feature, expected_value) \
+({ \
+ QDict *_resp; \
+ \
+ _resp = do_query_no_props(qts, cpu_type); \
+ g_assert(_resp); \
+ resp_assert_feature(_resp, feature, expected_value); \
+ qobject_unref(_resp); \
+})
+
+#define assert_set_feature(qts, cpu_type, feature, value) \
+({ \
+ const char *_fmt = (value) ? "{ %s: true }" : "{ %s: false }"; \
+ QDict *_resp; \
+ \
+ _resp = do_query(qts, cpu_type, _fmt, feature); \
+ g_assert(_resp); \
+ resp_assert_feature(_resp, feature, value); \
qobject_unref(_resp); \
})
@@ -464,7 +483,10 @@ static void test_query_cpu_model_expansion_kvm(const void *data)
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);
+ assert_set_feature(qts, "host", "kvm-no-adjvtime", false);
if (g_str_equal(qtest_get_arch(), "aarch64")) {
bool kvm_supports_sve;
@@ -475,7 +497,11 @@ static void test_query_cpu_model_expansion_kvm(const void *data)
char *error;
assert_has_feature_enabled(qts, "host", "aarch64");
+
+ /* Enabling and disabling pmu should always work. */
assert_has_feature_enabled(qts, "host", "pmu");
+ assert_set_feature(qts, "host", "pmu", true);
+ assert_set_feature(qts, "host", "pmu", false);
assert_error(qts, "cortex-a15",
"We cannot guarantee the CPU type 'cortex-a15' works "
--
2.25.4
