* [PATCH] KVM: s390: Disallow invalid bits in kvm_valid_regs and kvm_dirty_regs
@ 2019-09-04 7:13 Thomas Huth
2019-09-04 7:33 ` Janosch Frank
2019-09-04 7:54 ` Cornelia Huck
0 siblings, 2 replies; 4+ messages in thread
From: Thomas Huth @ 2019-09-04 7:13 UTC (permalink / raw)
To: kvm, Christian Borntraeger, Janosch Frank
Cc: David Hildenbrand, Cornelia Huck, linux-s390, linux-kernel
If unknown bits are set in kvm_valid_regs or kvm_dirty_regs, this
clearly indicates that something went wrong in the KVM userspace
application. The x86 variant of KVM already contains a check for
bad bits (and the corresponding kselftest checks this), so let's
do the same on s390x now, too.
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
arch/s390/include/uapi/asm/kvm.h | 6 ++++
arch/s390/kvm/kvm-s390.c | 4 +++
.../selftests/kvm/s390x/sync_regs_test.c | 30 +++++++++++++++++++
3 files changed, 40 insertions(+)
diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h
index 47104e5b47fd..436ec7636927 100644
--- a/arch/s390/include/uapi/asm/kvm.h
+++ b/arch/s390/include/uapi/asm/kvm.h
@@ -231,6 +231,12 @@ struct kvm_guest_debug_arch {
#define KVM_SYNC_GSCB (1UL << 9)
#define KVM_SYNC_BPBC (1UL << 10)
#define KVM_SYNC_ETOKEN (1UL << 11)
+
+#define KVM_SYNC_S390_VALID_FIELDS \
+ (KVM_SYNC_PREFIX | KVM_SYNC_GPRS | KVM_SYNC_ACRS | KVM_SYNC_CRS | \
+ KVM_SYNC_ARCH0 | KVM_SYNC_PFAULT | KVM_SYNC_VRS | KVM_SYNC_RICCB | \
+ KVM_SYNC_FPRS | KVM_SYNC_GSCB | KVM_SYNC_BPBC | KVM_SYNC_ETOKEN)
+
/* length and alignment of the sdnx as a power of two */
#define SDNXC 8
#define SDNXL (1UL << SDNXC)
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 49d7722229ae..a7d7dedfe527 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -3998,6 +3998,10 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
if (kvm_run->immediate_exit)
return -EINTR;
+ if (kvm_run->kvm_valid_regs & ~KVM_SYNC_S390_VALID_FIELDS ||
+ kvm_run->kvm_dirty_regs & ~KVM_SYNC_S390_VALID_FIELDS)
+ return -EINVAL;
+
vcpu_load(vcpu);
if (guestdbg_exit_pending(vcpu)) {
diff --git a/tools/testing/selftests/kvm/s390x/sync_regs_test.c b/tools/testing/selftests/kvm/s390x/sync_regs_test.c
index bbc93094519b..d5290b4ad636 100644
--- a/tools/testing/selftests/kvm/s390x/sync_regs_test.c
+++ b/tools/testing/selftests/kvm/s390x/sync_regs_test.c
@@ -85,6 +85,36 @@ int main(int argc, char *argv[])
run = vcpu_state(vm, VCPU_ID);
+ /* Request reading invalid register set from VCPU. */
+ run->kvm_valid_regs = INVALID_SYNC_FIELD;
+ rv = _vcpu_run(vm, VCPU_ID);
+ TEST_ASSERT(rv < 0 && errno == EINVAL,
+ "Invalid kvm_valid_regs did not cause expected KVM_RUN error: %d\n",
+ rv);
+ vcpu_state(vm, VCPU_ID)->kvm_valid_regs = 0;
+
+ run->kvm_valid_regs = INVALID_SYNC_FIELD | TEST_SYNC_FIELDS;
+ rv = _vcpu_run(vm, VCPU_ID);
+ TEST_ASSERT(rv < 0 && errno == EINVAL,
+ "Invalid kvm_valid_regs did not cause expected KVM_RUN error: %d\n",
+ rv);
+ vcpu_state(vm, VCPU_ID)->kvm_valid_regs = 0;
+
+ /* Request setting invalid register set into VCPU. */
+ run->kvm_dirty_regs = INVALID_SYNC_FIELD;
+ rv = _vcpu_run(vm, VCPU_ID);
+ TEST_ASSERT(rv < 0 && errno == EINVAL,
+ "Invalid kvm_dirty_regs did not cause expected KVM_RUN error: %d\n",
+ rv);
+ vcpu_state(vm, VCPU_ID)->kvm_dirty_regs = 0;
+
+ run->kvm_dirty_regs = INVALID_SYNC_FIELD | TEST_SYNC_FIELDS;
+ rv = _vcpu_run(vm, VCPU_ID);
+ TEST_ASSERT(rv < 0 && errno == EINVAL,
+ "Invalid kvm_dirty_regs did not cause expected KVM_RUN error: %d\n",
+ rv);
+ vcpu_state(vm, VCPU_ID)->kvm_dirty_regs = 0;
+
/* Request and verify all valid register sets. */
run->kvm_valid_regs = TEST_SYNC_FIELDS;
rv = _vcpu_run(vm, VCPU_ID);
--
2.18.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] KVM: s390: Disallow invalid bits in kvm_valid_regs and kvm_dirty_regs
2019-09-04 7:13 [PATCH] KVM: s390: Disallow invalid bits in kvm_valid_regs and kvm_dirty_regs Thomas Huth
@ 2019-09-04 7:33 ` Janosch Frank
2019-09-04 7:46 ` Christian Borntraeger
2019-09-04 7:54 ` Cornelia Huck
1 sibling, 1 reply; 4+ messages in thread
From: Janosch Frank @ 2019-09-04 7:33 UTC (permalink / raw)
To: Thomas Huth, kvm, Christian Borntraeger
Cc: David Hildenbrand, Cornelia Huck, linux-s390, linux-kernel
[-- Attachment #1.1: Type: text/plain, Size: 3880 bytes --]
On 9/4/19 9:13 AM, Thomas Huth wrote:
> If unknown bits are set in kvm_valid_regs or kvm_dirty_regs, this
> clearly indicates that something went wrong in the KVM userspace
> application. The x86 variant of KVM already contains a check for
> bad bits (and the corresponding kselftest checks this), so let's
> do the same on s390x now, too.
>
> Signed-off-by: Thomas Huth <thuth@redhat.com>
I think it would make sense to split the kvm changes from the test.
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
> ---
> arch/s390/include/uapi/asm/kvm.h | 6 ++++
> arch/s390/kvm/kvm-s390.c | 4 +++
> .../selftests/kvm/s390x/sync_regs_test.c | 30 +++++++++++++++++++
> 3 files changed, 40 insertions(+)
>
> diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h
> index 47104e5b47fd..436ec7636927 100644
> --- a/arch/s390/include/uapi/asm/kvm.h
> +++ b/arch/s390/include/uapi/asm/kvm.h
> @@ -231,6 +231,12 @@ struct kvm_guest_debug_arch {
> #define KVM_SYNC_GSCB (1UL << 9)
> #define KVM_SYNC_BPBC (1UL << 10)
> #define KVM_SYNC_ETOKEN (1UL << 11)
> +
> +#define KVM_SYNC_S390_VALID_FIELDS \
> + (KVM_SYNC_PREFIX | KVM_SYNC_GPRS | KVM_SYNC_ACRS | KVM_SYNC_CRS | \
> + KVM_SYNC_ARCH0 | KVM_SYNC_PFAULT | KVM_SYNC_VRS | KVM_SYNC_RICCB | \
> + KVM_SYNC_FPRS | KVM_SYNC_GSCB | KVM_SYNC_BPBC | KVM_SYNC_ETOKEN)
> +
> /* length and alignment of the sdnx as a power of two */
> #define SDNXC 8
> #define SDNXL (1UL << SDNXC)
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index 49d7722229ae..a7d7dedfe527 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -3998,6 +3998,10 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
> if (kvm_run->immediate_exit)
> return -EINTR;
>
> + if (kvm_run->kvm_valid_regs & ~KVM_SYNC_S390_VALID_FIELDS ||
> + kvm_run->kvm_dirty_regs & ~KVM_SYNC_S390_VALID_FIELDS)
> + return -EINVAL;
> +
> vcpu_load(vcpu);
>
> if (guestdbg_exit_pending(vcpu)) {
> diff --git a/tools/testing/selftests/kvm/s390x/sync_regs_test.c b/tools/testing/selftests/kvm/s390x/sync_regs_test.c
> index bbc93094519b..d5290b4ad636 100644
> --- a/tools/testing/selftests/kvm/s390x/sync_regs_test.c
> +++ b/tools/testing/selftests/kvm/s390x/sync_regs_test.c
> @@ -85,6 +85,36 @@ int main(int argc, char *argv[])
>
> run = vcpu_state(vm, VCPU_ID);
>
> + /* Request reading invalid register set from VCPU. */
> + run->kvm_valid_regs = INVALID_SYNC_FIELD;
> + rv = _vcpu_run(vm, VCPU_ID);
> + TEST_ASSERT(rv < 0 && errno == EINVAL,
> + "Invalid kvm_valid_regs did not cause expected KVM_RUN error: %d\n",
> + rv);
> + vcpu_state(vm, VCPU_ID)->kvm_valid_regs = 0;
> +
> + run->kvm_valid_regs = INVALID_SYNC_FIELD | TEST_SYNC_FIELDS;
> + rv = _vcpu_run(vm, VCPU_ID);
> + TEST_ASSERT(rv < 0 && errno == EINVAL,
> + "Invalid kvm_valid_regs did not cause expected KVM_RUN error: %d\n",
> + rv);
> + vcpu_state(vm, VCPU_ID)->kvm_valid_regs = 0;
> +
> + /* Request setting invalid register set into VCPU. */
> + run->kvm_dirty_regs = INVALID_SYNC_FIELD;
> + rv = _vcpu_run(vm, VCPU_ID);
> + TEST_ASSERT(rv < 0 && errno == EINVAL,
> + "Invalid kvm_dirty_regs did not cause expected KVM_RUN error: %d\n",
> + rv);
> + vcpu_state(vm, VCPU_ID)->kvm_dirty_regs = 0;
> +
> + run->kvm_dirty_regs = INVALID_SYNC_FIELD | TEST_SYNC_FIELDS;
> + rv = _vcpu_run(vm, VCPU_ID);
> + TEST_ASSERT(rv < 0 && errno == EINVAL,
> + "Invalid kvm_dirty_regs did not cause expected KVM_RUN error: %d\n",
> + rv);
> + vcpu_state(vm, VCPU_ID)->kvm_dirty_regs = 0;
> +
> /* Request and verify all valid register sets. */
> run->kvm_valid_regs = TEST_SYNC_FIELDS;
> rv = _vcpu_run(vm, VCPU_ID);
>
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^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] KVM: s390: Disallow invalid bits in kvm_valid_regs and kvm_dirty_regs
2019-09-04 7:33 ` Janosch Frank
@ 2019-09-04 7:46 ` Christian Borntraeger
0 siblings, 0 replies; 4+ messages in thread
From: Christian Borntraeger @ 2019-09-04 7:46 UTC (permalink / raw)
To: Janosch Frank, Thomas Huth, kvm
Cc: David Hildenbrand, Cornelia Huck, linux-s390, linux-kernel
On 04.09.19 09:33, Janosch Frank wrote:
> On 9/4/19 9:13 AM, Thomas Huth wrote:
>> If unknown bits are set in kvm_valid_regs or kvm_dirty_regs, this
>> clearly indicates that something went wrong in the KVM userspace
>> application. The x86 variant of KVM already contains a check for
>> bad bits (and the corresponding kselftest checks this), so let's
>> do the same on s390x now, too.
>>
>> Signed-off-by: Thomas Huth <thuth@redhat.com>
>
> I think it would make sense to split the kvm changes from the test.
Yes, this would allow to backport the non-kselftest part if necessary.
With that
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
>
> Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
>
>> ---
>> arch/s390/include/uapi/asm/kvm.h | 6 ++++
>> arch/s390/kvm/kvm-s390.c | 4 +++
>> .../selftests/kvm/s390x/sync_regs_test.c | 30 +++++++++++++++++++
>> 3 files changed, 40 insertions(+)
>>
>> diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h
>> index 47104e5b47fd..436ec7636927 100644
>> --- a/arch/s390/include/uapi/asm/kvm.h
>> +++ b/arch/s390/include/uapi/asm/kvm.h
>> @@ -231,6 +231,12 @@ struct kvm_guest_debug_arch {
>> #define KVM_SYNC_GSCB (1UL << 9)
>> #define KVM_SYNC_BPBC (1UL << 10)
>> #define KVM_SYNC_ETOKEN (1UL << 11)
>> +
>> +#define KVM_SYNC_S390_VALID_FIELDS \
>> + (KVM_SYNC_PREFIX | KVM_SYNC_GPRS | KVM_SYNC_ACRS | KVM_SYNC_CRS | \
>> + KVM_SYNC_ARCH0 | KVM_SYNC_PFAULT | KVM_SYNC_VRS | KVM_SYNC_RICCB | \
>> + KVM_SYNC_FPRS | KVM_SYNC_GSCB | KVM_SYNC_BPBC | KVM_SYNC_ETOKEN)
>> +
>> /* length and alignment of the sdnx as a power of two */
>> #define SDNXC 8
>> #define SDNXL (1UL << SDNXC)
>> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
>> index 49d7722229ae..a7d7dedfe527 100644
>> --- a/arch/s390/kvm/kvm-s390.c
>> +++ b/arch/s390/kvm/kvm-s390.c
>> @@ -3998,6 +3998,10 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
>> if (kvm_run->immediate_exit)
>> return -EINTR;
>>
>> + if (kvm_run->kvm_valid_regs & ~KVM_SYNC_S390_VALID_FIELDS ||
>> + kvm_run->kvm_dirty_regs & ~KVM_SYNC_S390_VALID_FIELDS)
>> + return -EINVAL;
>> +
>> vcpu_load(vcpu);
>>
>> if (guestdbg_exit_pending(vcpu)) {
>> diff --git a/tools/testing/selftests/kvm/s390x/sync_regs_test.c b/tools/testing/selftests/kvm/s390x/sync_regs_test.c
>> index bbc93094519b..d5290b4ad636 100644
>> --- a/tools/testing/selftests/kvm/s390x/sync_regs_test.c
>> +++ b/tools/testing/selftests/kvm/s390x/sync_regs_test.c
>> @@ -85,6 +85,36 @@ int main(int argc, char *argv[])
>>
>> run = vcpu_state(vm, VCPU_ID);
>>
>> + /* Request reading invalid register set from VCPU. */
>> + run->kvm_valid_regs = INVALID_SYNC_FIELD;
>> + rv = _vcpu_run(vm, VCPU_ID);
>> + TEST_ASSERT(rv < 0 && errno == EINVAL,
>> + "Invalid kvm_valid_regs did not cause expected KVM_RUN error: %d\n",
>> + rv);
>> + vcpu_state(vm, VCPU_ID)->kvm_valid_regs = 0;
>> +
>> + run->kvm_valid_regs = INVALID_SYNC_FIELD | TEST_SYNC_FIELDS;
>> + rv = _vcpu_run(vm, VCPU_ID);
>> + TEST_ASSERT(rv < 0 && errno == EINVAL,
>> + "Invalid kvm_valid_regs did not cause expected KVM_RUN error: %d\n",
>> + rv);
>> + vcpu_state(vm, VCPU_ID)->kvm_valid_regs = 0;
>> +
>> + /* Request setting invalid register set into VCPU. */
>> + run->kvm_dirty_regs = INVALID_SYNC_FIELD;
>> + rv = _vcpu_run(vm, VCPU_ID);
>> + TEST_ASSERT(rv < 0 && errno == EINVAL,
>> + "Invalid kvm_dirty_regs did not cause expected KVM_RUN error: %d\n",
>> + rv);
>> + vcpu_state(vm, VCPU_ID)->kvm_dirty_regs = 0;
>> +
>> + run->kvm_dirty_regs = INVALID_SYNC_FIELD | TEST_SYNC_FIELDS;
>> + rv = _vcpu_run(vm, VCPU_ID);
>> + TEST_ASSERT(rv < 0 && errno == EINVAL,
>> + "Invalid kvm_dirty_regs did not cause expected KVM_RUN error: %d\n",
>> + rv);
>> + vcpu_state(vm, VCPU_ID)->kvm_dirty_regs = 0;
>> +
>> /* Request and verify all valid register sets. */
>> run->kvm_valid_regs = TEST_SYNC_FIELDS;
>> rv = _vcpu_run(vm, VCPU_ID);
>>
>
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] KVM: s390: Disallow invalid bits in kvm_valid_regs and kvm_dirty_regs
2019-09-04 7:13 [PATCH] KVM: s390: Disallow invalid bits in kvm_valid_regs and kvm_dirty_regs Thomas Huth
2019-09-04 7:33 ` Janosch Frank
@ 2019-09-04 7:54 ` Cornelia Huck
1 sibling, 0 replies; 4+ messages in thread
From: Cornelia Huck @ 2019-09-04 7:54 UTC (permalink / raw)
To: Thomas Huth
Cc: kvm, Christian Borntraeger, Janosch Frank, David Hildenbrand,
linux-s390, linux-kernel
On Wed, 4 Sep 2019 09:13:08 +0200
Thomas Huth <thuth@redhat.com> wrote:
> If unknown bits are set in kvm_valid_regs or kvm_dirty_regs, this
> clearly indicates that something went wrong in the KVM userspace
> application. The x86 variant of KVM already contains a check for
> bad bits (and the corresponding kselftest checks this), so let's
> do the same on s390x now, too.
>
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
> arch/s390/include/uapi/asm/kvm.h | 6 ++++
> arch/s390/kvm/kvm-s390.c | 4 +++
> .../selftests/kvm/s390x/sync_regs_test.c | 30 +++++++++++++++++++
> 3 files changed, 40 insertions(+)
With splitting out the selftest,
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
^ permalink raw reply [flat|nested] 4+ messages in thread
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2019-09-04 7:13 [PATCH] KVM: s390: Disallow invalid bits in kvm_valid_regs and kvm_dirty_regs Thomas Huth
2019-09-04 7:33 ` Janosch Frank
2019-09-04 7:46 ` Christian Borntraeger
2019-09-04 7:54 ` Cornelia Huck
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