* [kvm-unit-tests v2 PATCH] s390x: sie: Test whether the epoch extension field is working as expected
@ 2022-12-08 17:05 Thomas Huth
2022-12-09 12:47 ` Claudio Imbrenda
2023-03-24 8:53 ` Nico Boehr
0 siblings, 2 replies; 3+ messages in thread
From: Thomas Huth @ 2022-12-08 17:05 UTC (permalink / raw)
To: kvm, Janosch Frank, Claudio Imbrenda; +Cc: linux-s390, David Hildenbrand
We recently discovered a bug with the time management in nested scenarios
which got fixed by kernel commit "KVM: s390: vsie: Fix the initialization
of the epoch extension (epdx) field". This adds a simple test for this
bug so that it is easier to determine whether the host kernel of a machine
has already been fixed or not.
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
v2: Remove the spurious "2" from the diag 44 opcode
s390x/sie.c | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
diff --git a/s390x/sie.c b/s390x/sie.c
index 87575b29..cd3cea10 100644
--- a/s390x/sie.c
+++ b/s390x/sie.c
@@ -58,6 +58,33 @@ static void test_diags(void)
}
}
+static void test_epoch_ext(void)
+{
+ u32 instr[] = {
+ 0xb2780000, /* STCKE 0 */
+ 0x83000044 /* DIAG 0x44 to intercept */
+ };
+
+ if (!test_facility(139)) {
+ report_skip("epdx: Multiple Epoch Facility is not available");
+ return;
+ }
+
+ guest[0] = 0x00;
+ memcpy(guest_instr, instr, sizeof(instr));
+
+ vm.sblk->gpsw.addr = PAGE_SIZE * 2;
+ vm.sblk->gpsw.mask = PSW_MASK_64;
+
+ vm.sblk->ecd |= ECD_MEF;
+ vm.sblk->epdx = 0x47; /* Setting the epoch extension here ... */
+
+ sie(&vm);
+
+ /* ... should result in the same epoch extension here: */
+ report(guest[0] == 0x47, "epdx: different epoch is visible in the guest");
+}
+
static void setup_guest(void)
{
setup_vm();
@@ -80,6 +107,7 @@ int main(void)
setup_guest();
test_diags();
+ test_epoch_ext();
sie_guest_destroy(&vm);
done:
--
2.31.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [kvm-unit-tests v2 PATCH] s390x: sie: Test whether the epoch extension field is working as expected
2022-12-08 17:05 [kvm-unit-tests v2 PATCH] s390x: sie: Test whether the epoch extension field is working as expected Thomas Huth
@ 2022-12-09 12:47 ` Claudio Imbrenda
2023-03-24 8:53 ` Nico Boehr
1 sibling, 0 replies; 3+ messages in thread
From: Claudio Imbrenda @ 2022-12-09 12:47 UTC (permalink / raw)
To: Thomas Huth; +Cc: kvm, Janosch Frank, linux-s390, David Hildenbrand
On Thu, 8 Dec 2022 18:05:02 +0100
Thomas Huth <thuth@redhat.com> wrote:
> We recently discovered a bug with the time management in nested scenarios
> which got fixed by kernel commit "KVM: s390: vsie: Fix the initialization
> of the epoch extension (epdx) field". This adds a simple test for this
> bug so that it is easier to determine whether the host kernel of a machine
> has already been fixed or not.
>
> Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
> ---
> v2: Remove the spurious "2" from the diag 44 opcode
>
> s390x/sie.c | 28 ++++++++++++++++++++++++++++
> 1 file changed, 28 insertions(+)
>
> diff --git a/s390x/sie.c b/s390x/sie.c
> index 87575b29..cd3cea10 100644
> --- a/s390x/sie.c
> +++ b/s390x/sie.c
> @@ -58,6 +58,33 @@ static void test_diags(void)
> }
> }
>
> +static void test_epoch_ext(void)
> +{
> + u32 instr[] = {
> + 0xb2780000, /* STCKE 0 */
> + 0x83000044 /* DIAG 0x44 to intercept */
> + };
> +
> + if (!test_facility(139)) {
> + report_skip("epdx: Multiple Epoch Facility is not available");
> + return;
> + }
> +
> + guest[0] = 0x00;
> + memcpy(guest_instr, instr, sizeof(instr));
> +
> + vm.sblk->gpsw.addr = PAGE_SIZE * 2;
> + vm.sblk->gpsw.mask = PSW_MASK_64;
> +
> + vm.sblk->ecd |= ECD_MEF;
> + vm.sblk->epdx = 0x47; /* Setting the epoch extension here ... */
> +
> + sie(&vm);
> +
> + /* ... should result in the same epoch extension here: */
> + report(guest[0] == 0x47, "epdx: different epoch is visible in the guest");
> +}
> +
> static void setup_guest(void)
> {
> setup_vm();
> @@ -80,6 +107,7 @@ int main(void)
>
> setup_guest();
> test_diags();
> + test_epoch_ext();
> sie_guest_destroy(&vm);
>
> done:
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [kvm-unit-tests v2 PATCH] s390x: sie: Test whether the epoch extension field is working as expected
2022-12-08 17:05 [kvm-unit-tests v2 PATCH] s390x: sie: Test whether the epoch extension field is working as expected Thomas Huth
2022-12-09 12:47 ` Claudio Imbrenda
@ 2023-03-24 8:53 ` Nico Boehr
1 sibling, 0 replies; 3+ messages in thread
From: Nico Boehr @ 2023-03-24 8:53 UTC (permalink / raw)
To: Claudio Imbrenda, Janosch Frank, Thomas Huth, kvm
Cc: linux-s390, David Hildenbrand
Quoting Thomas Huth (2022-12-08 18:05:02)
> We recently discovered a bug with the time management in nested scenarios
> which got fixed by kernel commit "KVM: s390: vsie: Fix the initialization
> of the epoch extension (epdx) field". This adds a simple test for this
> bug so that it is easier to determine whether the host kernel of a machine
> has already been fixed or not.
>
> Signed-off-by: Thomas Huth <thuth@redhat.com>
Thanks, I have pushed this to our CI and will queue it as soon as it's stable there.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2023-03-24 8:53 ` Nico Boehr
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