KVM: x86/xen: Add runstate tests for 32-bit mode and crossing page boundary

Torture test the cases where the runstate crosses a page boundary, and
and especially the case where it's configured in 32-bit mode and doesn't,
but then switching to 64-bit mode makes it go onto the second page.

To simplify this, make the KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST ioctl
also update the guest runstate area. It already did so if the actual
runstate changed, as a side-effect of kvm_xen_update_runstate(). So
doing it in the plain adjustment case is making it more consistent, as
well as giving us a nice way to trigger the update without actually
running the vCPU again and changing the values.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c
index 7acac5d..60a9bdd 100644 (file)
--- a/arch/x86/kvm/xen.c
+++ b/arch/x86/kvm/xen.c
@@ -884,6 +884,8 @@ int kvm_xen_vcpu_set_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data)
 
                if (data->u.runstate.state <= RUNSTATE_offline)
                        kvm_xen_update_runstate(vcpu, data->u.runstate.state);
+               else if (vcpu->arch.xen.runstate_cache.active)
+                       kvm_xen_update_runstate_guest(vcpu, false);
                r = 0;
                break;
 

diff --git a/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c b/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c
index c9b0110..721f6a6 100644 (file)
--- a/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c
+++ b/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c
@@ -88,14 +88,20 @@ struct pvclock_wall_clock {
 } __attribute__((__packed__));
 
 struct vcpu_runstate_info {
-    uint32_t state;
-    uint64_t state_entry_time;
-    uint64_t time[4];
+       uint32_t state;
+       uint64_t state_entry_time;
+       uint64_t time[5]; /* Extra field for overrun check */
 };
 
+struct compat_vcpu_runstate_info {
+       uint32_t state;
+       uint64_t state_entry_time;
+       uint64_t time[5];
+} __attribute__((__packed__));;
+
 struct arch_vcpu_info {
-    unsigned long cr2;
-    unsigned long pad; /* sizeof(vcpu_info_t) == 64 */
+       unsigned long cr2;
+       unsigned long pad; /* sizeof(vcpu_info_t) == 64 */
 };
 
 struct vcpu_info {
@@ -1013,22 +1019,91 @@ int main(int argc, char *argv[])
                                       runstate_names[i], rs->time[i]);
                        }
                }
-               TEST_ASSERT(rs->state == rst.u.runstate.state, "Runstate mismatch");
-               TEST_ASSERT(rs->state_entry_time == rst.u.runstate.state_entry_time,
-                           "State entry time mismatch");
-               TEST_ASSERT(rs->time[RUNSTATE_running] == rst.u.runstate.time_running,
-                           "Running time mismatch");
-               TEST_ASSERT(rs->time[RUNSTATE_runnable] == rst.u.runstate.time_runnable,
-                           "Runnable time mismatch");
-               TEST_ASSERT(rs->time[RUNSTATE_blocked] == rst.u.runstate.time_blocked,
-                           "Blocked time mismatch");
-               TEST_ASSERT(rs->time[RUNSTATE_offline] == rst.u.runstate.time_offline,
-                           "Offline time mismatch");
-
-               TEST_ASSERT(rs->state_entry_time == rs->time[0] +
-                           rs->time[1] + rs->time[2] + rs->time[3],
-                           "runstate times don't add up");
+
+               /*
+                * Exercise runstate info at all points across the page boundary, in
+                * 32-bit and 64-bit mode. In particular, test the case where it is
+                * configured in 32-bit mode and then switched to 64-bit mode while
+                * active, which takes it onto the second page.
+                */
+               unsigned long runstate_addr;
+               struct compat_vcpu_runstate_info *crs;
+               for (runstate_addr = SHINFO_REGION_GPA + PAGE_SIZE + PAGE_SIZE - sizeof(*rs) - 4;
+                    runstate_addr < SHINFO_REGION_GPA + PAGE_SIZE + PAGE_SIZE + 4; runstate_addr++) {
+
+                       rs = addr_gpa2hva(vm, runstate_addr);
+                       crs = (void *)rs;
+
+                       memset(rs, 0xa5, sizeof(*rs));
+
+                       /* Set to compatibility mode */
+                       lm.u.long_mode = 0;
+                       vm_ioctl(vm, KVM_XEN_HVM_SET_ATTR, &lm);
+
+                       /* Set runstate to new address (kernel will write it) */
+                       struct kvm_xen_vcpu_attr st = {
+                               .type = KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADDR,
+                               .u.gpa = runstate_addr,
+                       };
+                       vcpu_ioctl(vcpu, KVM_XEN_VCPU_SET_ATTR, &st);
+
+                       if (verbose)
+                               printf("Compatibility runstate at %08lx\n", runstate_addr);
+
+                       TEST_ASSERT(crs->state == rst.u.runstate.state, "Runstate mismatch");
+                       TEST_ASSERT(crs->state_entry_time == rst.u.runstate.state_entry_time,
+                                   "State entry time mismatch");
+                       TEST_ASSERT(crs->time[RUNSTATE_running] == rst.u.runstate.time_running,
+                                   "Running time mismatch");
+                       TEST_ASSERT(crs->time[RUNSTATE_runnable] == rst.u.runstate.time_runnable,
+                                   "Runnable time mismatch");
+                       TEST_ASSERT(crs->time[RUNSTATE_blocked] == rst.u.runstate.time_blocked,
+                                   "Blocked time mismatch");
+                       TEST_ASSERT(crs->time[RUNSTATE_offline] == rst.u.runstate.time_offline,
+                                   "Offline time mismatch");
+                       TEST_ASSERT(crs->time[RUNSTATE_offline + 1] == 0xa5a5a5a5a5a5a5a5ULL,
+                                   "Structure overrun");
+                       TEST_ASSERT(crs->state_entry_time == crs->time[0] +
+                                   crs->time[1] + crs->time[2] + crs->time[3],
+                                   "runstate times don't add up");
+
+
+                       /* Now switch to 64-bit mode */
+                       lm.u.long_mode = 1;
+                       vm_ioctl(vm, KVM_XEN_HVM_SET_ATTR, &lm);
+
+                       memset(rs, 0xa5, sizeof(*rs));
+
+                       /* Don't change the address, just trigger a write */
+                       struct kvm_xen_vcpu_attr adj = {
+                               .type = KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST,
+                               .u.runstate.state = (uint64_t)-1
+                       };
+                       vcpu_ioctl(vcpu, KVM_XEN_VCPU_SET_ATTR, &adj);
+
+                       if (verbose)
+                               printf("64-bit runstate at %08lx\n", runstate_addr);
+
+                       TEST_ASSERT(rs->state == rst.u.runstate.state, "Runstate mismatch");
+                       TEST_ASSERT(rs->state_entry_time == rst.u.runstate.state_entry_time,
+                                   "State entry time mismatch");
+                       TEST_ASSERT(rs->time[RUNSTATE_running] == rst.u.runstate.time_running,
+                                   "Running time mismatch");
+                       TEST_ASSERT(rs->time[RUNSTATE_runnable] == rst.u.runstate.time_runnable,
+                                   "Runnable time mismatch");
+                       TEST_ASSERT(rs->time[RUNSTATE_blocked] == rst.u.runstate.time_blocked,
+                                   "Blocked time mismatch");
+                       TEST_ASSERT(rs->time[RUNSTATE_offline] == rst.u.runstate.time_offline,
+                                   "Offline time mismatch");
+                       TEST_ASSERT(rs->time[RUNSTATE_offline + 1] == 0xa5a5a5a5a5a5a5a5ULL,
+                                   "Structure overrun");
+
+                       TEST_ASSERT(rs->state_entry_time == rs->time[0] +
+                                   rs->time[1] + rs->time[2] + rs->time[3],
+                                   "runstate times don't add up");
+               }
        }
+
        kvm_vm_free(vm);
        return 0;
 }