The DIAGNOSE 0x0318 instruction, unique to s390x, is a privileged call that must be intercepted via SIE, handled in userspace, and the information set by the instruction is communicated back to KVM.
To test the instruction interception, an ad-hoc handler is defined which simply has a VM execute the instruction and then userspace will extract the necessary info. The handler is defined such that the instruction invocation occurs only once. It is up to the caller to determine how the info returned by this handler should be used.
The diag318 info is communicated from userspace to KVM via a sync_regs call. This is tested During a sync_regs test, where the diag318 info is requested via the handler, then the info is stored in the appropriate register in KVM via a sync registers call.
If KVM does not support diag318, then the tests will print a message stating that diag318 was skipped, and the asserts will simply test against a value of 0.
Signed-off-by: Collin Walling walling@linux.ibm.com --- tools/testing/selftests/kvm/Makefile | 2 +- .../kvm/include/s390x/diag318_test_handler.h | 13 +++ .../kvm/lib/s390x/diag318_test_handler.c | 82 +++++++++++++++++++ .../selftests/kvm/s390x/sync_regs_test.c | 16 +++- 4 files changed, 111 insertions(+), 2 deletions(-) create mode 100644 tools/testing/selftests/kvm/include/s390x/diag318_test_handler.h create mode 100644 tools/testing/selftests/kvm/lib/s390x/diag318_test_handler.c
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index 3d14ef77755e..426c78449044 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -36,7 +36,7 @@ endif LIBKVM = lib/assert.c lib/elf.c lib/io.c lib/kvm_util.c lib/sparsebit.c lib/test_util.c LIBKVM_x86_64 = lib/x86_64/processor.c lib/x86_64/vmx.c lib/x86_64/svm.c lib/x86_64/ucall.c lib/x86_64/handlers.S LIBKVM_aarch64 = lib/aarch64/processor.c lib/aarch64/ucall.c -LIBKVM_s390x = lib/s390x/processor.c lib/s390x/ucall.c +LIBKVM_s390x = lib/s390x/processor.c lib/s390x/ucall.c lib/s390x/diag318_test_handler.c
TEST_GEN_PROGS_x86_64 = x86_64/cr4_cpuid_sync_test TEST_GEN_PROGS_x86_64 += x86_64/evmcs_test diff --git a/tools/testing/selftests/kvm/include/s390x/diag318_test_handler.h b/tools/testing/selftests/kvm/include/s390x/diag318_test_handler.h new file mode 100644 index 000000000000..b0ed71302722 --- /dev/null +++ b/tools/testing/selftests/kvm/include/s390x/diag318_test_handler.h @@ -0,0 +1,13 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later + * + * Test handler for the s390x DIAGNOSE 0x0318 instruction. + * + * Copyright (C) 2020, IBM + */ + +#ifndef SELFTEST_KVM_DIAG318_TEST_HANDLER +#define SELFTEST_KVM_DIAG318_TEST_HANDLER + +uint64_t get_diag318_info(void); + +#endif diff --git a/tools/testing/selftests/kvm/lib/s390x/diag318_test_handler.c b/tools/testing/selftests/kvm/lib/s390x/diag318_test_handler.c new file mode 100644 index 000000000000..86b9e611ad87 --- /dev/null +++ b/tools/testing/selftests/kvm/lib/s390x/diag318_test_handler.c @@ -0,0 +1,82 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Test handler for the s390x DIAGNOSE 0x0318 instruction. + * + * Copyright (C) 2020, IBM + */ + +#include "test_util.h" +#include "kvm_util.h" + +#define VCPU_ID 6 + +#define ICPT_INSTRUCTION 0x04 +#define IPA0_DIAG 0x8300 + +static void guest_code(void) +{ + uint64_t diag318_info = 0x12345678; + + asm volatile ("diag %0,0,0x318\n" : : "d" (diag318_info)); +} + +/* + * The DIAGNOSE 0x0318 instruction call must be handled via userspace. As such, + * we create an ad-hoc VM here to handle the instruction then extract the + * necessary data. It is up to the caller to decide what to do with that data. + */ +static uint64_t diag318_handler(void) +{ + struct kvm_vm *vm; + struct kvm_run *run; + uint64_t reg; + uint64_t diag318_info; + + vm = vm_create_default(VCPU_ID, 0, guest_code); + vcpu_run(vm, VCPU_ID); + run = vcpu_state(vm, VCPU_ID); + + TEST_ASSERT(run->exit_reason == KVM_EXIT_S390_SIEIC, + "DIAGNOSE 0x0318 instruction was not intercepted"); + TEST_ASSERT(run->s390_sieic.icptcode == ICPT_INSTRUCTION, + "Unexpected intercept code: 0x%x", run->s390_sieic.icptcode); + TEST_ASSERT((run->s390_sieic.ipa & 0xff00) == IPA0_DIAG, + "Unexpected IPA0 code: 0x%x", (run->s390_sieic.ipa & 0xff00)); + + reg = (run->s390_sieic.ipa & 0x00f0) >> 4; + diag318_info = run->s.regs.gprs[reg]; + + TEST_ASSERT(diag318_info != 0, "DIAGNOSE 0x0318 info not set"); + + kvm_vm_free(vm); + + return diag318_info; +} + +uint64_t get_diag318_info(void) +{ + static uint64_t diag318_info; + static bool printed_skip; + + /* + * If KVM does not support diag318, then return 0 to + * ensure tests do not break. + */ + if (!kvm_check_cap(KVM_CAP_S390_DIAG318)) { + if (!printed_skip) { + fprintf(stdout, "KVM_CAP_S390_DIAG318 not supported. " + "Skipping diag318 test.\n"); + printed_skip = true; + } + return 0; + } + + /* + * If a test has previously requested the diag318 info, + * then don't bother spinning up a temporary VM again. + */ + if (!diag318_info) + diag318_info = diag318_handler(); + + return diag318_info; +} diff --git a/tools/testing/selftests/kvm/s390x/sync_regs_test.c b/tools/testing/selftests/kvm/s390x/sync_regs_test.c index 5731ccf34917..caf7b8859a94 100644 --- a/tools/testing/selftests/kvm/s390x/sync_regs_test.c +++ b/tools/testing/selftests/kvm/s390x/sync_regs_test.c @@ -20,6 +20,7 @@
#include "test_util.h" #include "kvm_util.h" +#include "diag318_test_handler.h"
#define VCPU_ID 5
@@ -70,7 +71,7 @@ static void compare_sregs(struct kvm_sregs *left, struct kvm_sync_regs *right)
#undef REG_COMPARE
-#define TEST_SYNC_FIELDS (KVM_SYNC_GPRS|KVM_SYNC_ACRS|KVM_SYNC_CRS) +#define TEST_SYNC_FIELDS (KVM_SYNC_GPRS|KVM_SYNC_ACRS|KVM_SYNC_CRS|KVM_SYNC_DIAG318) #define INVALID_SYNC_FIELD 0x80000000
int main(int argc, char *argv[]) @@ -152,6 +153,12 @@ int main(int argc, char *argv[])
run->kvm_valid_regs = TEST_SYNC_FIELDS; run->kvm_dirty_regs = KVM_SYNC_GPRS | KVM_SYNC_ACRS; + + if (get_diag318_info() > 0) { + run->s.regs.diag318 = get_diag318_info(); + run->kvm_dirty_regs |= KVM_SYNC_DIAG318; + } + rv = _vcpu_run(vm, VCPU_ID); TEST_ASSERT(rv == 0, "vcpu_run failed: %d\n", rv); TEST_ASSERT(run->exit_reason == KVM_EXIT_S390_SIEIC, @@ -164,6 +171,9 @@ int main(int argc, char *argv[]) TEST_ASSERT(run->s.regs.acrs[0] == 1 << 11, "acr0 sync regs value incorrect 0x%x.", run->s.regs.acrs[0]); + TEST_ASSERT(run->s.regs.diag318 == get_diag318_info(), + "diag318 sync regs value incorrect 0x%llx.", + run->s.regs.diag318);
vcpu_regs_get(vm, VCPU_ID, ®s); compare_regs(®s, &run->s.regs); @@ -177,6 +187,7 @@ int main(int argc, char *argv[]) run->kvm_valid_regs = TEST_SYNC_FIELDS; run->kvm_dirty_regs = 0; run->s.regs.gprs[11] = 0xDEADBEEF; + run->s.regs.diag318 = 0x4B1D; rv = _vcpu_run(vm, VCPU_ID); TEST_ASSERT(rv == 0, "vcpu_run failed: %d\n", rv); TEST_ASSERT(run->exit_reason == KVM_EXIT_S390_SIEIC, @@ -186,6 +197,9 @@ int main(int argc, char *argv[]) TEST_ASSERT(run->s.regs.gprs[11] != 0xDEADBEEF, "r11 sync regs value incorrect 0x%llx.", run->s.regs.gprs[11]); + TEST_ASSERT(run->s.regs.diag318 != 0x4B1D, + "diag318 sync regs value incorrect 0x%llx.", + run->s.regs.diag318);
kvm_vm_free(vm);
On 12/7/20 10:41 AM, Collin Walling wrote:
The DIAGNOSE 0x0318 instruction, unique to s390x, is a privileged call that must be intercepted via SIE, handled in userspace, and the information set by the instruction is communicated back to KVM.
To test the instruction interception, an ad-hoc handler is defined which simply has a VM execute the instruction and then userspace will extract the necessary info. The handler is defined such that the instruction invocation occurs only once. It is up to the caller to determine how the info returned by this handler should be used.
The diag318 info is communicated from userspace to KVM via a sync_regs call. This is tested During a sync_regs test, where the diag318 info is requested via the handler, then the info is stored in the appropriate register in KVM via a sync registers call.
If KVM does not support diag318, then the tests will print a message stating that diag318 was skipped, and the asserts will simply test against a value of 0.
Signed-off-by: Collin Walling walling@linux.ibm.com
Please add
Acked-by: Janosch Frank frankja@linux.ibm.com
[...]
On Mon, 7 Dec 2020 10:41:25 -0500 Collin Walling walling@linux.ibm.com wrote:
The DIAGNOSE 0x0318 instruction, unique to s390x, is a privileged call that must be intercepted via SIE, handled in userspace, and the information set by the instruction is communicated back to KVM.
To test the instruction interception, an ad-hoc handler is defined which simply has a VM execute the instruction and then userspace will extract the necessary info. The handler is defined such that the instruction invocation occurs only once. It is up to the caller to determine how the info returned by this handler should be used.
The diag318 info is communicated from userspace to KVM via a sync_regs call. This is tested During a sync_regs test, where the diag318 info is
s/During/during/
requested via the handler, then the info is stored in the appropriate register in KVM via a sync registers call.
If KVM does not support diag318, then the tests will print a message stating that diag318 was skipped, and the asserts will simply test against a value of 0.
Signed-off-by: Collin Walling walling@linux.ibm.com
tools/testing/selftests/kvm/Makefile | 2 +- .../kvm/include/s390x/diag318_test_handler.h | 13 +++ .../kvm/lib/s390x/diag318_test_handler.c | 82 +++++++++++++++++++ .../selftests/kvm/s390x/sync_regs_test.c | 16 +++- 4 files changed, 111 insertions(+), 2 deletions(-) create mode 100644 tools/testing/selftests/kvm/include/s390x/diag318_test_handler.h create mode 100644 tools/testing/selftests/kvm/lib/s390x/diag318_test_handler.c
Looks reasonable to me.
Acked-by: Cornelia Huck cohuck@redhat.com
On 12/7/20 11:55 AM, Cornelia Huck wrote:
On Mon, 7 Dec 2020 10:41:25 -0500 Collin Walling walling@linux.ibm.com wrote:
The DIAGNOSE 0x0318 instruction, unique to s390x, is a privileged call that must be intercepted via SIE, handled in userspace, and the information set by the instruction is communicated back to KVM.
To test the instruction interception, an ad-hoc handler is defined which simply has a VM execute the instruction and then userspace will extract the necessary info. The handler is defined such that the instruction invocation occurs only once. It is up to the caller to determine how the info returned by this handler should be used.
The diag318 info is communicated from userspace to KVM via a sync_regs call. This is tested During a sync_regs test, where the diag318 info is
s/During/during/
requested via the handler, then the info is stored in the appropriate register in KVM via a sync registers call.
If KVM does not support diag318, then the tests will print a message stating that diag318 was skipped, and the asserts will simply test against a value of 0.
Signed-off-by: Collin Walling walling@linux.ibm.com
tools/testing/selftests/kvm/Makefile | 2 +- .../kvm/include/s390x/diag318_test_handler.h | 13 +++ .../kvm/lib/s390x/diag318_test_handler.c | 82 +++++++++++++++++++ .../selftests/kvm/s390x/sync_regs_test.c | 16 +++- 4 files changed, 111 insertions(+), 2 deletions(-) create mode 100644 tools/testing/selftests/kvm/include/s390x/diag318_test_handler.h create mode 100644 tools/testing/selftests/kvm/lib/s390x/diag318_test_handler.c
Looks reasonable to me.
Acked-by: Cornelia Huck cohuck@redhat.com
Thanks. I'll resubmit the entire patch as a reply to the top-most email with the proposed commit message changes.
The DIAGNOSE 0x0318 instruction, unique to s390x, is a privileged instruction that must be intercepted via SIE, handled in userspace, and the information set by the instruction is communicated back to KVM.
To test the instruction interception, an ad-hoc handler is defined which simply has a VM execute the instruction and then userspace will extract the necessary info. The handler is defined such that the instruction invocation occurs only once. It is up to the caller to determine how the info returned by this handler should be used.
The diag318 info is communicated from userspace to KVM via a sync_regs call. This is tested during a sync_regs test, where the diag318 info is requested via the handler, then the info is stored in the appropriate register in KVM via a sync registers call.
If KVM does not support diag318, then the tests will print a message stating that diag318 was skipped, and the asserts will simply test against a value of 0.
Signed-off-by: Collin Walling walling@linux.ibm.com Acked-by: Janosch Frank frankja@linux.ibm.com Acked-by: Cornelia Huck cohuck@redhat.com ---
@Christian: if you haven't picked the patch yet, here is the entire patch with the properly updated commit message.
--- tools/testing/selftests/kvm/Makefile | 2 +- .../kvm/include/s390x/diag318_test_handler.h | 13 +++ .../kvm/lib/s390x/diag318_test_handler.c | 82 +++++++++++++++++++ .../selftests/kvm/s390x/sync_regs_test.c | 16 +++- 4 files changed, 111 insertions(+), 2 deletions(-) create mode 100644 tools/testing/selftests/kvm/include/s390x/diag318_test_handler.h create mode 100644 tools/testing/selftests/kvm/lib/s390x/diag318_test_handler.c
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index 3d14ef77755e..426c78449044 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -36,7 +36,7 @@ endif LIBKVM = lib/assert.c lib/elf.c lib/io.c lib/kvm_util.c lib/sparsebit.c lib/test_util.c LIBKVM_x86_64 = lib/x86_64/processor.c lib/x86_64/vmx.c lib/x86_64/svm.c lib/x86_64/ucall.c lib/x86_64/handlers.S LIBKVM_aarch64 = lib/aarch64/processor.c lib/aarch64/ucall.c -LIBKVM_s390x = lib/s390x/processor.c lib/s390x/ucall.c +LIBKVM_s390x = lib/s390x/processor.c lib/s390x/ucall.c lib/s390x/diag318_test_handler.c
TEST_GEN_PROGS_x86_64 = x86_64/cr4_cpuid_sync_test TEST_GEN_PROGS_x86_64 += x86_64/evmcs_test diff --git a/tools/testing/selftests/kvm/include/s390x/diag318_test_handler.h b/tools/testing/selftests/kvm/include/s390x/diag318_test_handler.h new file mode 100644 index 000000000000..b0ed71302722 --- /dev/null +++ b/tools/testing/selftests/kvm/include/s390x/diag318_test_handler.h @@ -0,0 +1,13 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later + * + * Test handler for the s390x DIAGNOSE 0x0318 instruction. + * + * Copyright (C) 2020, IBM + */ + +#ifndef SELFTEST_KVM_DIAG318_TEST_HANDLER +#define SELFTEST_KVM_DIAG318_TEST_HANDLER + +uint64_t get_diag318_info(void); + +#endif diff --git a/tools/testing/selftests/kvm/lib/s390x/diag318_test_handler.c b/tools/testing/selftests/kvm/lib/s390x/diag318_test_handler.c new file mode 100644 index 000000000000..86b9e611ad87 --- /dev/null +++ b/tools/testing/selftests/kvm/lib/s390x/diag318_test_handler.c @@ -0,0 +1,82 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Test handler for the s390x DIAGNOSE 0x0318 instruction. + * + * Copyright (C) 2020, IBM + */ + +#include "test_util.h" +#include "kvm_util.h" + +#define VCPU_ID 6 + +#define ICPT_INSTRUCTION 0x04 +#define IPA0_DIAG 0x8300 + +static void guest_code(void) +{ + uint64_t diag318_info = 0x12345678; + + asm volatile ("diag %0,0,0x318\n" : : "d" (diag318_info)); +} + +/* + * The DIAGNOSE 0x0318 instruction call must be handled via userspace. As such, + * we create an ad-hoc VM here to handle the instruction then extract the + * necessary data. It is up to the caller to decide what to do with that data. + */ +static uint64_t diag318_handler(void) +{ + struct kvm_vm *vm; + struct kvm_run *run; + uint64_t reg; + uint64_t diag318_info; + + vm = vm_create_default(VCPU_ID, 0, guest_code); + vcpu_run(vm, VCPU_ID); + run = vcpu_state(vm, VCPU_ID); + + TEST_ASSERT(run->exit_reason == KVM_EXIT_S390_SIEIC, + "DIAGNOSE 0x0318 instruction was not intercepted"); + TEST_ASSERT(run->s390_sieic.icptcode == ICPT_INSTRUCTION, + "Unexpected intercept code: 0x%x", run->s390_sieic.icptcode); + TEST_ASSERT((run->s390_sieic.ipa & 0xff00) == IPA0_DIAG, + "Unexpected IPA0 code: 0x%x", (run->s390_sieic.ipa & 0xff00)); + + reg = (run->s390_sieic.ipa & 0x00f0) >> 4; + diag318_info = run->s.regs.gprs[reg]; + + TEST_ASSERT(diag318_info != 0, "DIAGNOSE 0x0318 info not set"); + + kvm_vm_free(vm); + + return diag318_info; +} + +uint64_t get_diag318_info(void) +{ + static uint64_t diag318_info; + static bool printed_skip; + + /* + * If KVM does not support diag318, then return 0 to + * ensure tests do not break. + */ + if (!kvm_check_cap(KVM_CAP_S390_DIAG318)) { + if (!printed_skip) { + fprintf(stdout, "KVM_CAP_S390_DIAG318 not supported. " + "Skipping diag318 test.\n"); + printed_skip = true; + } + return 0; + } + + /* + * If a test has previously requested the diag318 info, + * then don't bother spinning up a temporary VM again. + */ + if (!diag318_info) + diag318_info = diag318_handler(); + + return diag318_info; +} diff --git a/tools/testing/selftests/kvm/s390x/sync_regs_test.c b/tools/testing/selftests/kvm/s390x/sync_regs_test.c index 5731ccf34917..caf7b8859a94 100644 --- a/tools/testing/selftests/kvm/s390x/sync_regs_test.c +++ b/tools/testing/selftests/kvm/s390x/sync_regs_test.c @@ -20,6 +20,7 @@
#include "test_util.h" #include "kvm_util.h" +#include "diag318_test_handler.h"
#define VCPU_ID 5
@@ -70,7 +71,7 @@ static void compare_sregs(struct kvm_sregs *left, struct kvm_sync_regs *right)
#undef REG_COMPARE
-#define TEST_SYNC_FIELDS (KVM_SYNC_GPRS|KVM_SYNC_ACRS|KVM_SYNC_CRS) +#define TEST_SYNC_FIELDS (KVM_SYNC_GPRS|KVM_SYNC_ACRS|KVM_SYNC_CRS|KVM_SYNC_DIAG318) #define INVALID_SYNC_FIELD 0x80000000
int main(int argc, char *argv[]) @@ -152,6 +153,12 @@ int main(int argc, char *argv[])
run->kvm_valid_regs = TEST_SYNC_FIELDS; run->kvm_dirty_regs = KVM_SYNC_GPRS | KVM_SYNC_ACRS; + + if (get_diag318_info() > 0) { + run->s.regs.diag318 = get_diag318_info(); + run->kvm_dirty_regs |= KVM_SYNC_DIAG318; + } + rv = _vcpu_run(vm, VCPU_ID); TEST_ASSERT(rv == 0, "vcpu_run failed: %d\n", rv); TEST_ASSERT(run->exit_reason == KVM_EXIT_S390_SIEIC, @@ -164,6 +171,9 @@ int main(int argc, char *argv[]) TEST_ASSERT(run->s.regs.acrs[0] == 1 << 11, "acr0 sync regs value incorrect 0x%x.", run->s.regs.acrs[0]); + TEST_ASSERT(run->s.regs.diag318 == get_diag318_info(), + "diag318 sync regs value incorrect 0x%llx.", + run->s.regs.diag318);
vcpu_regs_get(vm, VCPU_ID, ®s); compare_regs(®s, &run->s.regs); @@ -177,6 +187,7 @@ int main(int argc, char *argv[]) run->kvm_valid_regs = TEST_SYNC_FIELDS; run->kvm_dirty_regs = 0; run->s.regs.gprs[11] = 0xDEADBEEF; + run->s.regs.diag318 = 0x4B1D; rv = _vcpu_run(vm, VCPU_ID); TEST_ASSERT(rv == 0, "vcpu_run failed: %d\n", rv); TEST_ASSERT(run->exit_reason == KVM_EXIT_S390_SIEIC, @@ -186,6 +197,9 @@ int main(int argc, char *argv[]) TEST_ASSERT(run->s.regs.gprs[11] != 0xDEADBEEF, "r11 sync regs value incorrect 0x%llx.", run->s.regs.gprs[11]); + TEST_ASSERT(run->s.regs.diag318 != 0x4B1D, + "diag318 sync regs value incorrect 0x%llx.", + run->s.regs.diag318);
kvm_vm_free(vm);
On 07.12.20 20:12, Collin Walling wrote:
The DIAGNOSE 0x0318 instruction, unique to s390x, is a privileged instruction that must be intercepted via SIE, handled in userspace, and the information set by the instruction is communicated back to KVM.
To test the instruction interception, an ad-hoc handler is defined which simply has a VM execute the instruction and then userspace will extract the necessary info. The handler is defined such that the instruction invocation occurs only once. It is up to the caller to determine how the info returned by this handler should be used.
The diag318 info is communicated from userspace to KVM via a sync_regs call. This is tested during a sync_regs test, where the diag318 info is requested via the handler, then the info is stored in the appropriate register in KVM via a sync registers call.
If KVM does not support diag318, then the tests will print a message stating that diag318 was skipped, and the asserts will simply test against a value of 0.
Signed-off-by: Collin Walling walling@linux.ibm.com Acked-by: Janosch Frank frankja@linux.ibm.com Acked-by: Cornelia Huck cohuck@redhat.com
@Christian: if you haven't picked the patch yet, here is the entire patch with the properly updated commit message.
No worries, I already picked and fixed this.
Reviewed-by: Christian Borntraeger borntraeger@de.ibm.com
thanks applied.
tools/testing/selftests/kvm/Makefile | 2 +- .../kvm/include/s390x/diag318_test_handler.h | 13 +++ .../kvm/lib/s390x/diag318_test_handler.c | 82 +++++++++++++++++++ .../selftests/kvm/s390x/sync_regs_test.c | 16 +++- 4 files changed, 111 insertions(+), 2 deletions(-) create mode 100644 tools/testing/selftests/kvm/include/s390x/diag318_test_handler.h create mode 100644 tools/testing/selftests/kvm/lib/s390x/diag318_test_handler.c
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index 3d14ef77755e..426c78449044 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -36,7 +36,7 @@ endif LIBKVM = lib/assert.c lib/elf.c lib/io.c lib/kvm_util.c lib/sparsebit.c lib/test_util.c LIBKVM_x86_64 = lib/x86_64/processor.c lib/x86_64/vmx.c lib/x86_64/svm.c lib/x86_64/ucall.c lib/x86_64/handlers.S LIBKVM_aarch64 = lib/aarch64/processor.c lib/aarch64/ucall.c -LIBKVM_s390x = lib/s390x/processor.c lib/s390x/ucall.c +LIBKVM_s390x = lib/s390x/processor.c lib/s390x/ucall.c lib/s390x/diag318_test_handler.c
TEST_GEN_PROGS_x86_64 = x86_64/cr4_cpuid_sync_test TEST_GEN_PROGS_x86_64 += x86_64/evmcs_test diff --git a/tools/testing/selftests/kvm/include/s390x/diag318_test_handler.h b/tools/testing/selftests/kvm/include/s390x/diag318_test_handler.h new file mode 100644 index 000000000000..b0ed71302722 --- /dev/null +++ b/tools/testing/selftests/kvm/include/s390x/diag318_test_handler.h @@ -0,0 +1,13 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later
- Test handler for the s390x DIAGNOSE 0x0318 instruction.
- Copyright (C) 2020, IBM
- */
+#ifndef SELFTEST_KVM_DIAG318_TEST_HANDLER +#define SELFTEST_KVM_DIAG318_TEST_HANDLER
+uint64_t get_diag318_info(void);
+#endif diff --git a/tools/testing/selftests/kvm/lib/s390x/diag318_test_handler.c b/tools/testing/selftests/kvm/lib/s390x/diag318_test_handler.c new file mode 100644 index 000000000000..86b9e611ad87 --- /dev/null +++ b/tools/testing/selftests/kvm/lib/s390x/diag318_test_handler.c @@ -0,0 +1,82 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/*
- Test handler for the s390x DIAGNOSE 0x0318 instruction.
- Copyright (C) 2020, IBM
- */
+#include "test_util.h" +#include "kvm_util.h"
+#define VCPU_ID 6
+#define ICPT_INSTRUCTION 0x04 +#define IPA0_DIAG 0x8300
+static void guest_code(void) +{
- uint64_t diag318_info = 0x12345678;
- asm volatile ("diag %0,0,0x318\n" : : "d" (diag318_info));
+}
+/*
- The DIAGNOSE 0x0318 instruction call must be handled via userspace.
As such,
- we create an ad-hoc VM here to handle the instruction then extract the
- necessary data. It is up to the caller to decide what to do with
that data.
- */
+static uint64_t diag318_handler(void) +{
- struct kvm_vm *vm;
- struct kvm_run *run;
- uint64_t reg;
- uint64_t diag318_info;
- vm = vm_create_default(VCPU_ID, 0, guest_code);
- vcpu_run(vm, VCPU_ID);
- run = vcpu_state(vm, VCPU_ID);
- TEST_ASSERT(run->exit_reason == KVM_EXIT_S390_SIEIC,
"DIAGNOSE 0x0318 instruction was not intercepted");- TEST_ASSERT(run->s390_sieic.icptcode == ICPT_INSTRUCTION,
"Unexpected intercept code: 0x%x", run->s390_sieic.icptcode);- TEST_ASSERT((run->s390_sieic.ipa & 0xff00) == IPA0_DIAG,
"Unexpected IPA0 code: 0x%x", (run->s390_sieic.ipa & 0xff00));- reg = (run->s390_sieic.ipa & 0x00f0) >> 4;
- diag318_info = run->s.regs.gprs[reg];
- TEST_ASSERT(diag318_info != 0, "DIAGNOSE 0x0318 info not set");
- kvm_vm_free(vm);
- return diag318_info;
+}
+uint64_t get_diag318_info(void) +{
- static uint64_t diag318_info;
- static bool printed_skip;
- /*
* If KVM does not support diag318, then return 0 to* ensure tests do not break.*/- if (!kvm_check_cap(KVM_CAP_S390_DIAG318)) {
if (!printed_skip) {fprintf(stdout, "KVM_CAP_S390_DIAG318 not supported. ""Skipping diag318 test.\n");printed_skip = true;}return 0;- }
- /*
* If a test has previously requested the diag318 info,* then don't bother spinning up a temporary VM again.*/- if (!diag318_info)
diag318_info = diag318_handler();- return diag318_info;
+} diff --git a/tools/testing/selftests/kvm/s390x/sync_regs_test.c b/tools/testing/selftests/kvm/s390x/sync_regs_test.c index 5731ccf34917..caf7b8859a94 100644 --- a/tools/testing/selftests/kvm/s390x/sync_regs_test.c +++ b/tools/testing/selftests/kvm/s390x/sync_regs_test.c @@ -20,6 +20,7 @@
#include "test_util.h" #include "kvm_util.h" +#include "diag318_test_handler.h"
#define VCPU_ID 5
@@ -70,7 +71,7 @@ static void compare_sregs(struct kvm_sregs *left, struct kvm_sync_regs *right)
#undef REG_COMPARE
-#define TEST_SYNC_FIELDS (KVM_SYNC_GPRS|KVM_SYNC_ACRS|KVM_SYNC_CRS) +#define TEST_SYNC_FIELDS (KVM_SYNC_GPRS|KVM_SYNC_ACRS|KVM_SYNC_CRS|KVM_SYNC_DIAG318) #define INVALID_SYNC_FIELD 0x80000000
int main(int argc, char *argv[]) @@ -152,6 +153,12 @@ int main(int argc, char *argv[])
run->kvm_valid_regs = TEST_SYNC_FIELDS; run->kvm_dirty_regs = KVM_SYNC_GPRS | KVM_SYNC_ACRS;
- if (get_diag318_info() > 0) {
run->s.regs.diag318 = get_diag318_info();run->kvm_dirty_regs |= KVM_SYNC_DIAG318;- }
- rv = _vcpu_run(vm, VCPU_ID); TEST_ASSERT(rv == 0, "vcpu_run failed: %d\n", rv); TEST_ASSERT(run->exit_reason == KVM_EXIT_S390_SIEIC,
@@ -164,6 +171,9 @@ int main(int argc, char *argv[]) TEST_ASSERT(run->s.regs.acrs[0] == 1 << 11, "acr0 sync regs value incorrect 0x%x.", run->s.regs.acrs[0]);
TEST_ASSERT(run->s.regs.diag318 == get_diag318_info(),
"diag318 sync regs value incorrect 0x%llx.",run->s.regs.diag318);vcpu_regs_get(vm, VCPU_ID, ®s); compare_regs(®s, &run->s.regs);
@@ -177,6 +187,7 @@ int main(int argc, char *argv[]) run->kvm_valid_regs = TEST_SYNC_FIELDS; run->kvm_dirty_regs = 0; run->s.regs.gprs[11] = 0xDEADBEEF;
- run->s.regs.diag318 = 0x4B1D; rv = _vcpu_run(vm, VCPU_ID); TEST_ASSERT(rv == 0, "vcpu_run failed: %d\n", rv); TEST_ASSERT(run->exit_reason == KVM_EXIT_S390_SIEIC,
@@ -186,6 +197,9 @@ int main(int argc, char *argv[]) TEST_ASSERT(run->s.regs.gprs[11] != 0xDEADBEEF, "r11 sync regs value incorrect 0x%llx.", run->s.regs.gprs[11]);
TEST_ASSERT(run->s.regs.diag318 != 0x4B1D,
"diag318 sync regs value incorrect 0x%llx.",run->s.regs.diag318);kvm_vm_free(vm);
On 07.12.20 16:41, Collin Walling wrote:
The DIAGNOSE 0x0318 instruction, unique to s390x, is a privileged call that must be intercepted via SIE, handled in userspace, and the information set by the instruction is communicated back to KVM.
To test the instruction interception, an ad-hoc handler is defined which simply has a VM execute the instruction and then userspace will extract the necessary info. The handler is defined such that the instruction invocation occurs only once. It is up to the caller to determine how the info returned by this handler should be used.
The diag318 info is communicated from userspace to KVM via a sync_regs call. This is tested During a sync_regs test, where the diag318 info is requested via the handler, then the info is stored in the appropriate register in KVM via a sync registers call.
If KVM does not support diag318, then the tests will print a message stating that diag318 was skipped, and the asserts will simply test against a value of 0.
Signed-off-by: Collin Walling walling@linux.ibm.com
Interestingly enough, this testcase actually trigger a bug: While we gracefully handle this (no crash) debugfs: Directory 'kvm-200206' with parent 's390dbf' already present! is certainly not ideal....
tools/testing/selftests/kvm/Makefile | 2 +- .../kvm/include/s390x/diag318_test_handler.h | 13 +++ .../kvm/lib/s390x/diag318_test_handler.c | 82 +++++++++++++++++++ .../selftests/kvm/s390x/sync_regs_test.c | 16 +++- 4 files changed, 111 insertions(+), 2 deletions(-) create mode 100644 tools/testing/selftests/kvm/include/s390x/diag318_test_handler.h create mode 100644 tools/testing/selftests/kvm/lib/s390x/diag318_test_handler.c
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index 3d14ef77755e..426c78449044 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -36,7 +36,7 @@ endif LIBKVM = lib/assert.c lib/elf.c lib/io.c lib/kvm_util.c lib/sparsebit.c lib/test_util.c LIBKVM_x86_64 = lib/x86_64/processor.c lib/x86_64/vmx.c lib/x86_64/svm.c lib/x86_64/ucall.c lib/x86_64/handlers.S LIBKVM_aarch64 = lib/aarch64/processor.c lib/aarch64/ucall.c -LIBKVM_s390x = lib/s390x/processor.c lib/s390x/ucall.c +LIBKVM_s390x = lib/s390x/processor.c lib/s390x/ucall.c lib/s390x/diag318_test_handler.c
TEST_GEN_PROGS_x86_64 = x86_64/cr4_cpuid_sync_test TEST_GEN_PROGS_x86_64 += x86_64/evmcs_test diff --git a/tools/testing/selftests/kvm/include/s390x/diag318_test_handler.h b/tools/testing/selftests/kvm/include/s390x/diag318_test_handler.h new file mode 100644 index 000000000000..b0ed71302722 --- /dev/null +++ b/tools/testing/selftests/kvm/include/s390x/diag318_test_handler.h @@ -0,0 +1,13 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later
- Test handler for the s390x DIAGNOSE 0x0318 instruction.
- Copyright (C) 2020, IBM
- */
+#ifndef SELFTEST_KVM_DIAG318_TEST_HANDLER +#define SELFTEST_KVM_DIAG318_TEST_HANDLER
+uint64_t get_diag318_info(void);
+#endif diff --git a/tools/testing/selftests/kvm/lib/s390x/diag318_test_handler.c b/tools/testing/selftests/kvm/lib/s390x/diag318_test_handler.c new file mode 100644 index 000000000000..86b9e611ad87 --- /dev/null +++ b/tools/testing/selftests/kvm/lib/s390x/diag318_test_handler.c @@ -0,0 +1,82 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/*
- Test handler for the s390x DIAGNOSE 0x0318 instruction.
- Copyright (C) 2020, IBM
- */
+#include "test_util.h" +#include "kvm_util.h"
+#define VCPU_ID 6
+#define ICPT_INSTRUCTION 0x04 +#define IPA0_DIAG 0x8300
+static void guest_code(void) +{
- uint64_t diag318_info = 0x12345678;
- asm volatile ("diag %0,0,0x318\n" : : "d" (diag318_info));
+}
+/*
- The DIAGNOSE 0x0318 instruction call must be handled via userspace. As such,
- we create an ad-hoc VM here to handle the instruction then extract the
- necessary data. It is up to the caller to decide what to do with that data.
- */
+static uint64_t diag318_handler(void) +{
- struct kvm_vm *vm;
- struct kvm_run *run;
- uint64_t reg;
- uint64_t diag318_info;
- vm = vm_create_default(VCPU_ID, 0, guest_code);
- vcpu_run(vm, VCPU_ID);
- run = vcpu_state(vm, VCPU_ID);
- TEST_ASSERT(run->exit_reason == KVM_EXIT_S390_SIEIC,
"DIAGNOSE 0x0318 instruction was not intercepted");- TEST_ASSERT(run->s390_sieic.icptcode == ICPT_INSTRUCTION,
"Unexpected intercept code: 0x%x", run->s390_sieic.icptcode);- TEST_ASSERT((run->s390_sieic.ipa & 0xff00) == IPA0_DIAG,
"Unexpected IPA0 code: 0x%x", (run->s390_sieic.ipa & 0xff00));- reg = (run->s390_sieic.ipa & 0x00f0) >> 4;
- diag318_info = run->s.regs.gprs[reg];
- TEST_ASSERT(diag318_info != 0, "DIAGNOSE 0x0318 info not set");
- kvm_vm_free(vm);
- return diag318_info;
+}
+uint64_t get_diag318_info(void) +{
- static uint64_t diag318_info;
- static bool printed_skip;
- /*
* If KVM does not support diag318, then return 0 to* ensure tests do not break.*/- if (!kvm_check_cap(KVM_CAP_S390_DIAG318)) {
if (!printed_skip) {fprintf(stdout, "KVM_CAP_S390_DIAG318 not supported. ""Skipping diag318 test.\n");printed_skip = true;}return 0;- }
- /*
* If a test has previously requested the diag318 info,* then don't bother spinning up a temporary VM again.*/- if (!diag318_info)
diag318_info = diag318_handler();- return diag318_info;
+} diff --git a/tools/testing/selftests/kvm/s390x/sync_regs_test.c b/tools/testing/selftests/kvm/s390x/sync_regs_test.c index 5731ccf34917..caf7b8859a94 100644 --- a/tools/testing/selftests/kvm/s390x/sync_regs_test.c +++ b/tools/testing/selftests/kvm/s390x/sync_regs_test.c @@ -20,6 +20,7 @@
#include "test_util.h" #include "kvm_util.h" +#include "diag318_test_handler.h"
#define VCPU_ID 5
@@ -70,7 +71,7 @@ static void compare_sregs(struct kvm_sregs *left, struct kvm_sync_regs *right)
#undef REG_COMPARE
-#define TEST_SYNC_FIELDS (KVM_SYNC_GPRS|KVM_SYNC_ACRS|KVM_SYNC_CRS) +#define TEST_SYNC_FIELDS (KVM_SYNC_GPRS|KVM_SYNC_ACRS|KVM_SYNC_CRS|KVM_SYNC_DIAG318) #define INVALID_SYNC_FIELD 0x80000000
int main(int argc, char *argv[]) @@ -152,6 +153,12 @@ int main(int argc, char *argv[])
run->kvm_valid_regs = TEST_SYNC_FIELDS; run->kvm_dirty_regs = KVM_SYNC_GPRS | KVM_SYNC_ACRS;
- if (get_diag318_info() > 0) {
run->s.regs.diag318 = get_diag318_info();run->kvm_dirty_regs |= KVM_SYNC_DIAG318;- }
- rv = _vcpu_run(vm, VCPU_ID); TEST_ASSERT(rv == 0, "vcpu_run failed: %d\n", rv); TEST_ASSERT(run->exit_reason == KVM_EXIT_S390_SIEIC,
@@ -164,6 +171,9 @@ int main(int argc, char *argv[]) TEST_ASSERT(run->s.regs.acrs[0] == 1 << 11, "acr0 sync regs value incorrect 0x%x.", run->s.regs.acrs[0]);
TEST_ASSERT(run->s.regs.diag318 == get_diag318_info(),
"diag318 sync regs value incorrect 0x%llx.",run->s.regs.diag318);vcpu_regs_get(vm, VCPU_ID, ®s); compare_regs(®s, &run->s.regs);
@@ -177,6 +187,7 @@ int main(int argc, char *argv[]) run->kvm_valid_regs = TEST_SYNC_FIELDS; run->kvm_dirty_regs = 0; run->s.regs.gprs[11] = 0xDEADBEEF;
- run->s.regs.diag318 = 0x4B1D; rv = _vcpu_run(vm, VCPU_ID); TEST_ASSERT(rv == 0, "vcpu_run failed: %d\n", rv); TEST_ASSERT(run->exit_reason == KVM_EXIT_S390_SIEIC,
@@ -186,6 +197,9 @@ int main(int argc, char *argv[]) TEST_ASSERT(run->s.regs.gprs[11] != 0xDEADBEEF, "r11 sync regs value incorrect 0x%llx.", run->s.regs.gprs[11]);
TEST_ASSERT(run->s.regs.diag318 != 0x4B1D,
"diag318 sync regs value incorrect 0x%llx.",run->s.regs.diag318);kvm_vm_free(vm);
On 12/7/20 2:32 PM, Christian Borntraeger wrote:
On 07.12.20 16:41, Collin Walling wrote:
The DIAGNOSE 0x0318 instruction, unique to s390x, is a privileged call that must be intercepted via SIE, handled in userspace, and the information set by the instruction is communicated back to KVM.
To test the instruction interception, an ad-hoc handler is defined which simply has a VM execute the instruction and then userspace will extract the necessary info. The handler is defined such that the instruction invocation occurs only once. It is up to the caller to determine how the info returned by this handler should be used.
The diag318 info is communicated from userspace to KVM via a sync_regs call. This is tested During a sync_regs test, where the diag318 info is requested via the handler, then the info is stored in the appropriate register in KVM via a sync registers call.
If KVM does not support diag318, then the tests will print a message stating that diag318 was skipped, and the asserts will simply test against a value of 0.
Signed-off-by: Collin Walling walling@linux.ibm.com
Interestingly enough, this testcase actually trigger a bug: While we gracefully handle this (no crash) debugfs: Directory 'kvm-200206' with parent 's390dbf' already present! is certainly not ideal....
Odd... I wonder what triggered this behavior?
I run my tests with a simple command:
make summary=0 TARGETS=kvm kselftest
This must have something to do with spinning up another VM to get the diag318 data. I think if I have the sync_regs test call the diag handler first, and then have the sync regs create a VM, that might solve that issue...
May I ask how you encountered this bug so I may replicate in on my end?
tools/testing/selftests/kvm/Makefile | 2 +- .../kvm/include/s390x/diag318_test_handler.h | 13 +++ .../kvm/lib/s390x/diag318_test_handler.c | 82 +++++++++++++++++++ .../selftests/kvm/s390x/sync_regs_test.c | 16 +++- 4 files changed, 111 insertions(+), 2 deletions(-) create mode 100644 tools/testing/selftests/kvm/include/s390x/diag318_test_handler.h create mode 100644 tools/testing/selftests/kvm/lib/s390x/diag318_test_handler.c
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index 3d14ef77755e..426c78449044 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -36,7 +36,7 @@ endif LIBKVM = lib/assert.c lib/elf.c lib/io.c lib/kvm_util.c lib/sparsebit.c lib/test_util.c LIBKVM_x86_64 = lib/x86_64/processor.c lib/x86_64/vmx.c lib/x86_64/svm.c lib/x86_64/ucall.c lib/x86_64/handlers.S LIBKVM_aarch64 = lib/aarch64/processor.c lib/aarch64/ucall.c -LIBKVM_s390x = lib/s390x/processor.c lib/s390x/ucall.c +LIBKVM_s390x = lib/s390x/processor.c lib/s390x/ucall.c lib/s390x/diag318_test_handler.c
TEST_GEN_PROGS_x86_64 = x86_64/cr4_cpuid_sync_test TEST_GEN_PROGS_x86_64 += x86_64/evmcs_test diff --git a/tools/testing/selftests/kvm/include/s390x/diag318_test_handler.h b/tools/testing/selftests/kvm/include/s390x/diag318_test_handler.h new file mode 100644 index 000000000000..b0ed71302722 --- /dev/null +++ b/tools/testing/selftests/kvm/include/s390x/diag318_test_handler.h @@ -0,0 +1,13 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later
- Test handler for the s390x DIAGNOSE 0x0318 instruction.
- Copyright (C) 2020, IBM
- */
+#ifndef SELFTEST_KVM_DIAG318_TEST_HANDLER +#define SELFTEST_KVM_DIAG318_TEST_HANDLER
+uint64_t get_diag318_info(void);
+#endif diff --git a/tools/testing/selftests/kvm/lib/s390x/diag318_test_handler.c b/tools/testing/selftests/kvm/lib/s390x/diag318_test_handler.c new file mode 100644 index 000000000000..86b9e611ad87 --- /dev/null +++ b/tools/testing/selftests/kvm/lib/s390x/diag318_test_handler.c @@ -0,0 +1,82 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/*
- Test handler for the s390x DIAGNOSE 0x0318 instruction.
- Copyright (C) 2020, IBM
- */
+#include "test_util.h" +#include "kvm_util.h"
+#define VCPU_ID 6
+#define ICPT_INSTRUCTION 0x04 +#define IPA0_DIAG 0x8300
+static void guest_code(void) +{
- uint64_t diag318_info = 0x12345678;
- asm volatile ("diag %0,0,0x318\n" : : "d" (diag318_info));
+}
+/*
- The DIAGNOSE 0x0318 instruction call must be handled via userspace. As such,
- we create an ad-hoc VM here to handle the instruction then extract the
- necessary data. It is up to the caller to decide what to do with that data.
- */
+static uint64_t diag318_handler(void) +{
- struct kvm_vm *vm;
- struct kvm_run *run;
- uint64_t reg;
- uint64_t diag318_info;
- vm = vm_create_default(VCPU_ID, 0, guest_code);
- vcpu_run(vm, VCPU_ID);
- run = vcpu_state(vm, VCPU_ID);
- TEST_ASSERT(run->exit_reason == KVM_EXIT_S390_SIEIC,
"DIAGNOSE 0x0318 instruction was not intercepted");- TEST_ASSERT(run->s390_sieic.icptcode == ICPT_INSTRUCTION,
"Unexpected intercept code: 0x%x", run->s390_sieic.icptcode);- TEST_ASSERT((run->s390_sieic.ipa & 0xff00) == IPA0_DIAG,
"Unexpected IPA0 code: 0x%x", (run->s390_sieic.ipa & 0xff00));- reg = (run->s390_sieic.ipa & 0x00f0) >> 4;
- diag318_info = run->s.regs.gprs[reg];
- TEST_ASSERT(diag318_info != 0, "DIAGNOSE 0x0318 info not set");
- kvm_vm_free(vm);
- return diag318_info;
+}
+uint64_t get_diag318_info(void) +{
- static uint64_t diag318_info;
- static bool printed_skip;
- /*
* If KVM does not support diag318, then return 0 to* ensure tests do not break.*/- if (!kvm_check_cap(KVM_CAP_S390_DIAG318)) {
if (!printed_skip) {fprintf(stdout, "KVM_CAP_S390_DIAG318 not supported. ""Skipping diag318 test.\n");printed_skip = true;}return 0;- }
- /*
* If a test has previously requested the diag318 info,* then don't bother spinning up a temporary VM again.*/- if (!diag318_info)
diag318_info = diag318_handler();- return diag318_info;
+} diff --git a/tools/testing/selftests/kvm/s390x/sync_regs_test.c b/tools/testing/selftests/kvm/s390x/sync_regs_test.c index 5731ccf34917..caf7b8859a94 100644 --- a/tools/testing/selftests/kvm/s390x/sync_regs_test.c +++ b/tools/testing/selftests/kvm/s390x/sync_regs_test.c @@ -20,6 +20,7 @@
#include "test_util.h" #include "kvm_util.h" +#include "diag318_test_handler.h"
#define VCPU_ID 5
@@ -70,7 +71,7 @@ static void compare_sregs(struct kvm_sregs *left, struct kvm_sync_regs *right)
#undef REG_COMPARE
-#define TEST_SYNC_FIELDS (KVM_SYNC_GPRS|KVM_SYNC_ACRS|KVM_SYNC_CRS) +#define TEST_SYNC_FIELDS (KVM_SYNC_GPRS|KVM_SYNC_ACRS|KVM_SYNC_CRS|KVM_SYNC_DIAG318) #define INVALID_SYNC_FIELD 0x80000000
int main(int argc, char *argv[]) @@ -152,6 +153,12 @@ int main(int argc, char *argv[])
run->kvm_valid_regs = TEST_SYNC_FIELDS; run->kvm_dirty_regs = KVM_SYNC_GPRS | KVM_SYNC_ACRS;
- if (get_diag318_info() > 0) {
run->s.regs.diag318 = get_diag318_info();run->kvm_dirty_regs |= KVM_SYNC_DIAG318;- }
- rv = _vcpu_run(vm, VCPU_ID); TEST_ASSERT(rv == 0, "vcpu_run failed: %d\n", rv); TEST_ASSERT(run->exit_reason == KVM_EXIT_S390_SIEIC,
@@ -164,6 +171,9 @@ int main(int argc, char *argv[]) TEST_ASSERT(run->s.regs.acrs[0] == 1 << 11, "acr0 sync regs value incorrect 0x%x.", run->s.regs.acrs[0]);
TEST_ASSERT(run->s.regs.diag318 == get_diag318_info(),
"diag318 sync regs value incorrect 0x%llx.",run->s.regs.diag318);vcpu_regs_get(vm, VCPU_ID, ®s); compare_regs(®s, &run->s.regs);
@@ -177,6 +187,7 @@ int main(int argc, char *argv[]) run->kvm_valid_regs = TEST_SYNC_FIELDS; run->kvm_dirty_regs = 0; run->s.regs.gprs[11] = 0xDEADBEEF;
- run->s.regs.diag318 = 0x4B1D; rv = _vcpu_run(vm, VCPU_ID); TEST_ASSERT(rv == 0, "vcpu_run failed: %d\n", rv); TEST_ASSERT(run->exit_reason == KVM_EXIT_S390_SIEIC,
@@ -186,6 +197,9 @@ int main(int argc, char *argv[]) TEST_ASSERT(run->s.regs.gprs[11] != 0xDEADBEEF, "r11 sync regs value incorrect 0x%llx.", run->s.regs.gprs[11]);
TEST_ASSERT(run->s.regs.diag318 != 0x4B1D,
"diag318 sync regs value incorrect 0x%llx.",run->s.regs.diag318);kvm_vm_free(vm);
On 07.12.20 21:06, Collin Walling wrote:
On 12/7/20 2:32 PM, Christian Borntraeger wrote:
On 07.12.20 16:41, Collin Walling wrote:
The DIAGNOSE 0x0318 instruction, unique to s390x, is a privileged call that must be intercepted via SIE, handled in userspace, and the information set by the instruction is communicated back to KVM.
To test the instruction interception, an ad-hoc handler is defined which simply has a VM execute the instruction and then userspace will extract the necessary info. The handler is defined such that the instruction invocation occurs only once. It is up to the caller to determine how the info returned by this handler should be used.
The diag318 info is communicated from userspace to KVM via a sync_regs call. This is tested During a sync_regs test, where the diag318 info is requested via the handler, then the info is stored in the appropriate register in KVM via a sync registers call.
If KVM does not support diag318, then the tests will print a message stating that diag318 was skipped, and the asserts will simply test against a value of 0.
Signed-off-by: Collin Walling walling@linux.ibm.com
Interestingly enough, this testcase actually trigger a bug: While we gracefully handle this (no crash) debugfs: Directory 'kvm-200206' with parent 's390dbf' already present! is certainly not ideal....
Odd... I wonder what triggered this behavior?
I run my tests with a simple command:
make summary=0 TARGETS=kvm kselftest
This must have something to do with spinning up another VM to get the diag318 data. I think if I have the sync_regs test call the diag handler first, and then have the sync regs create a VM, that might solve that issue...
Yes, the s390dbf code will try to create a file named kvm-%pid. With 2 VMs the 2nd one fails. Luckily the kvm will be created anyway and also the shutdown seems to be fine, still....
May I ask how you encountered this bug so I may replicate in on my end?
I just did make TARGETS=kvm selftests
and then the error is on dmesg.
On 12/7/20 3:09 PM, Christian Borntraeger wrote:
On 07.12.20 21:06, Collin Walling wrote:
On 12/7/20 2:32 PM, Christian Borntraeger wrote:
On 07.12.20 16:41, Collin Walling wrote:
The DIAGNOSE 0x0318 instruction, unique to s390x, is a privileged call that must be intercepted via SIE, handled in userspace, and the information set by the instruction is communicated back to KVM.
To test the instruction interception, an ad-hoc handler is defined which simply has a VM execute the instruction and then userspace will extract the necessary info. The handler is defined such that the instruction invocation occurs only once. It is up to the caller to determine how the info returned by this handler should be used.
The diag318 info is communicated from userspace to KVM via a sync_regs call. This is tested During a sync_regs test, where the diag318 info is requested via the handler, then the info is stored in the appropriate register in KVM via a sync registers call.
If KVM does not support diag318, then the tests will print a message stating that diag318 was skipped, and the asserts will simply test against a value of 0.
Signed-off-by: Collin Walling walling@linux.ibm.com
Interestingly enough, this testcase actually trigger a bug: While we gracefully handle this (no crash) debugfs: Directory 'kvm-200206' with parent 's390dbf' already present! is certainly not ideal....
Odd... I wonder what triggered this behavior?
I run my tests with a simple command:
make summary=0 TARGETS=kvm kselftest
This must have something to do with spinning up another VM to get the diag318 data. I think if I have the sync_regs test call the diag handler first, and then have the sync regs create a VM, that might solve that issue...
Yes, the s390dbf code will try to create a file named kvm-%pid. With 2 VMs the 2nd one fails. Luckily the kvm will be created anyway and also the shutdown seems to be fine, still....
May I ask how you encountered this bug so I may replicate in on my end?
I just did make TARGETS=kvm selftests
and then the error is on dmesg.
Thanks. v5 with fix incoming.
On 07.12.20 21:13, Collin Walling wrote:
On 12/7/20 3:09 PM, Christian Borntraeger wrote:
On 07.12.20 21:06, Collin Walling wrote:
On 12/7/20 2:32 PM, Christian Borntraeger wrote:
On 07.12.20 16:41, Collin Walling wrote:
The DIAGNOSE 0x0318 instruction, unique to s390x, is a privileged call that must be intercepted via SIE, handled in userspace, and the information set by the instruction is communicated back to KVM.
To test the instruction interception, an ad-hoc handler is defined which simply has a VM execute the instruction and then userspace will extract the necessary info. The handler is defined such that the instruction invocation occurs only once. It is up to the caller to determine how the info returned by this handler should be used.
The diag318 info is communicated from userspace to KVM via a sync_regs call. This is tested During a sync_regs test, where the diag318 info is requested via the handler, then the info is stored in the appropriate register in KVM via a sync registers call.
If KVM does not support diag318, then the tests will print a message stating that diag318 was skipped, and the asserts will simply test against a value of 0.
Signed-off-by: Collin Walling walling@linux.ibm.com
Interestingly enough, this testcase actually trigger a bug: While we gracefully handle this (no crash) debugfs: Directory 'kvm-200206' with parent 's390dbf' already present! is certainly not ideal....
Odd... I wonder what triggered this behavior?
I run my tests with a simple command:
make summary=0 TARGETS=kvm kselftest
This must have something to do with spinning up another VM to get the diag318 data. I think if I have the sync_regs test call the diag handler first, and then have the sync regs create a VM, that might solve that issue...
Yes, the s390dbf code will try to create a file named kvm-%pid. With 2 VMs the 2nd one fails. Luckily the kvm will be created anyway and also the shutdown seems to be fine, still....
May I ask how you encountered this bug so I may replicate in on my end?
I just did make TARGETS=kvm selftests
and then the error is on dmesg.
Thanks. v5 with fix incoming.
I think the test is actually fine and we should rather fix the kvm module to gracefully handle a userspace that starts up 2 or more guests.
On 12/7/20 3:16 PM, Christian Borntraeger wrote:
On 07.12.20 21:13, Collin Walling wrote:
On 12/7/20 3:09 PM, Christian Borntraeger wrote:
On 07.12.20 21:06, Collin Walling wrote:
On 12/7/20 2:32 PM, Christian Borntraeger wrote:
On 07.12.20 16:41, Collin Walling wrote:
The DIAGNOSE 0x0318 instruction, unique to s390x, is a privileged call that must be intercepted via SIE, handled in userspace, and the information set by the instruction is communicated back to KVM.
To test the instruction interception, an ad-hoc handler is defined which simply has a VM execute the instruction and then userspace will extract the necessary info. The handler is defined such that the instruction invocation occurs only once. It is up to the caller to determine how the info returned by this handler should be used.
The diag318 info is communicated from userspace to KVM via a sync_regs call. This is tested During a sync_regs test, where the diag318 info is requested via the handler, then the info is stored in the appropriate register in KVM via a sync registers call.
If KVM does not support diag318, then the tests will print a message stating that diag318 was skipped, and the asserts will simply test against a value of 0.
Signed-off-by: Collin Walling walling@linux.ibm.com
Interestingly enough, this testcase actually trigger a bug: While we gracefully handle this (no crash) debugfs: Directory 'kvm-200206' with parent 's390dbf' already present! is certainly not ideal....
Odd... I wonder what triggered this behavior?
I run my tests with a simple command:
make summary=0 TARGETS=kvm kselftest
This must have something to do with spinning up another VM to get the diag318 data. I think if I have the sync_regs test call the diag handler first, and then have the sync regs create a VM, that might solve that issue...
Yes, the s390dbf code will try to create a file named kvm-%pid. With 2 VMs the 2nd one fails. Luckily the kvm will be created anyway and also the shutdown seems to be fine, still....
May I ask how you encountered this bug so I may replicate in on my end?
I just did make TARGETS=kvm selftests
and then the error is on dmesg.
Thanks. v5 with fix incoming.
I think the test is actually fine and we should rather fix the kvm module to gracefully handle a userspace that starts up 2 or more guests.
Looks like the root cause is within the inode.c file used for the debug filesystem. Essentially, the 2nd VM starts / ends just fine as you mentioned, but doesn't get a dbfs.
Since this touches the dbfs related area, and I'm unsure how common this problem is out in the wild, should we ping the kernel list and see if it catches anyone's attention?
A first thought would be to append a per-userspace incrementing value to the end of the kvm-%pid part to account for any collisions, but that's up to the folks that know more than I do.
On 12/7/20 9:59 PM, Collin Walling wrote:
On 12/7/20 3:16 PM, Christian Borntraeger wrote:
On 07.12.20 21:13, Collin Walling wrote:
On 12/7/20 3:09 PM, Christian Borntraeger wrote:
On 07.12.20 21:06, Collin Walling wrote:
On 12/7/20 2:32 PM, Christian Borntraeger wrote:
On 07.12.20 16:41, Collin Walling wrote: > The DIAGNOSE 0x0318 instruction, unique to s390x, is a privileged call > that must be intercepted via SIE, handled in userspace, and the > information set by the instruction is communicated back to KVM. > > To test the instruction interception, an ad-hoc handler is defined which > simply has a VM execute the instruction and then userspace will extract > the necessary info. The handler is defined such that the instruction > invocation occurs only once. It is up to the caller to determine how the > info returned by this handler should be used. > > The diag318 info is communicated from userspace to KVM via a sync_regs > call. This is tested During a sync_regs test, where the diag318 info is > requested via the handler, then the info is stored in the appropriate > register in KVM via a sync registers call. > > If KVM does not support diag318, then the tests will print a message > stating that diag318 was skipped, and the asserts will simply test > against a value of 0. > > Signed-off-by: Collin Walling walling@linux.ibm.com
Interestingly enough, this testcase actually trigger a bug: While we gracefully handle this (no crash) debugfs: Directory 'kvm-200206' with parent 's390dbf' already present! is certainly not ideal....
Odd... I wonder what triggered this behavior?
I run my tests with a simple command:
make summary=0 TARGETS=kvm kselftest
This must have something to do with spinning up another VM to get the diag318 data. I think if I have the sync_regs test call the diag handler first, and then have the sync regs create a VM, that might solve that issue...
Yes, the s390dbf code will try to create a file named kvm-%pid. With 2 VMs the 2nd one fails. Luckily the kvm will be created anyway and also the shutdown seems to be fine, still....
May I ask how you encountered this bug so I may replicate in on my end?
I just did make TARGETS=kvm selftests
and then the error is on dmesg.
Thanks. v5 with fix incoming.
I think the test is actually fine and we should rather fix the kvm module to gracefully handle a userspace that starts up 2 or more guests.
Looks like the root cause is within the inode.c file used for the debug filesystem. Essentially, the 2nd VM starts / ends just fine as you mentioned, but doesn't get a dbfs.
Since this touches the dbfs related area, and I'm unsure how common this problem is out in the wild, should we ping the kernel list and see if it catches anyone's attention?
A first thought would be to append a per-userspace incrementing value to the end of the kvm-%pid part to account for any collisions, but that's up to the folks that know more than I do.
Seems like I have a deja-vu, I remember having to fix that for the common code :-) For the KVM debugfs I solved that by appending the file descriptor after the pid. Maybe we can steal the string from the dentry.
Have a look into vm_create_vm_debugfs(struct kvm *kvm, int fd).
linux-kselftest-mirror@lists.linaro.org
-
Christian Borntraeger -
Collin Walling -
Cornelia Huck -
Janosch Frank