From: Paul Durrant <pdurrant@amazon.com>
If the vCPU id is set and the shared_info is mapped using HVA then we can
infer that KVM has the ability to use a default vcpu_info mapping. Hence
we can stop setting the address of the vcpu_info structure.
NOTE: We still explicitly set vcpu_info half way through testing (to point
at exactly the place it already is) to make sure that setting the
attribute does not fail.
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
---
Cc: Sean Christopherson <seanjc@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>
v3:
- Add a guest sync point to set the vcpu_info attribute
v2:
- New in this version.
---
.../testing/selftests/kvm/x86_64/xen_shinfo_test.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
@@ -68,6 +68,7 @@ enum {
TEST_POLL_TIMEOUT,
TEST_POLL_MASKED,
TEST_POLL_WAKE,
+ SET_VCPU_INFO,
TEST_TIMER_PAST,
TEST_LOCKING_SEND_RACE,
TEST_LOCKING_POLL_RACE,
@@ -327,6 +328,10 @@ static void guest_code(void)
GUEST_SYNC(TEST_POLL_WAKE);
+ /* Set the vcpu_info to point at exactly the place it already is to
+ * make sure the attribute is functional. */
+ GUEST_SYNC(SET_VCPU_INFO);
+
/* A timer wake an *unmasked* port which should wake us with an
* actual interrupt, while we're polling on a different port. */
ports[0]++;
@@ -549,7 +554,10 @@ int main(int argc, char *argv[])
.type = KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO,
.u.gpa = VCPU_INFO_ADDR,
};
- vcpu_ioctl(vcpu, KVM_XEN_VCPU_SET_ATTR, &vi);
+
+ if (!has_vcpu_id || !has_shinfo_hva) {
+ vcpu_ioctl(vcpu, KVM_XEN_VCPU_SET_ATTR, &vi);
+ }
struct kvm_xen_vcpu_attr pvclock = {
.type = KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO,
@@ -903,6 +911,10 @@ int main(int argc, char *argv[])
alarm(1);
break;
+ case SET_VCPU_INFO:
+ vcpu_ioctl(vcpu, KVM_XEN_VCPU_SET_ATTR, &vi);
+ break;
+
case TEST_TIMER_PAST:
TEST_ASSERT(!evtchn_irq_expected,
"Expected event channel IRQ but it didn't happen");