[PATCH v13 14/21] KVM: selftests: map Xen's shared_info page using HVA rather than GFN

[Paul Durrant]

From: Paul Durrant <pdurr...@amazon.com>

Using the HVA of the shared_info page is more efficient, so if the
capability (KVM_XEN_HVM_CONFIG_SHARED_INFO_HVA) is present use that method
to do the mapping.

NOTE: Have the juggle_shinfo_state() thread map and unmap using both
      GFN and HVA, to make sure the older mechanism is not broken.

Signed-off-by: Paul Durrant <pdurr...@amazon.com>
Reviewed-by: David Woodhouse <d...@amazon.co.uk>
---
Cc: Sean Christopherson <sea...@google.com>
Cc: Paolo Bonzini <pbonz...@redhat.com>
Cc: David Woodhouse <dw...@infradead.org>

v13:
 - Patch title change.

v3:
 - Re-work the juggle_shinfo_state() thread.

v2:
 - New in this version.
---
 .../selftests/kvm/x86_64/xen_shinfo_test.c    | 44 +++++++++++++++----
 1 file changed, 35 insertions(+), 9 deletions(-)

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 9ec9ab60b63e..a61500ff0822 100644
--- a/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c
+++ b/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c
@@ -389,6 +389,7 @@ static int cmp_timespec(struct timespec *a, struct timespec 
*b)
                return 0;
 }
 
+static struct shared_info *shinfo;
 static struct vcpu_info *vinfo;
 static struct kvm_vcpu *vcpu;
 
@@ -404,20 +405,38 @@ static void *juggle_shinfo_state(void *arg)
 {
        struct kvm_vm *vm = (struct kvm_vm *)arg;
 
-       struct kvm_xen_hvm_attr cache_activate = {
+       struct kvm_xen_hvm_attr cache_activate_gfn = {
                .type = KVM_XEN_ATTR_TYPE_SHARED_INFO,
                .u.shared_info.gfn = SHINFO_REGION_GPA / PAGE_SIZE
        };
 
-       struct kvm_xen_hvm_attr cache_deactivate = {
+       struct kvm_xen_hvm_attr cache_deactivate_gfn = {
                .type = KVM_XEN_ATTR_TYPE_SHARED_INFO,
                .u.shared_info.gfn = KVM_XEN_INVALID_GFN
        };
 
+       struct kvm_xen_hvm_attr cache_activate_hva = {
+               .type = KVM_XEN_ATTR_TYPE_SHARED_INFO_HVA,
+               .u.shared_info.hva = (unsigned long)shinfo
+       };
+
+       struct kvm_xen_hvm_attr cache_deactivate_hva = {
+               .type = KVM_XEN_ATTR_TYPE_SHARED_INFO,
+               .u.shared_info.hva = 0
+       };
+
+       int xen_caps = kvm_check_cap(KVM_CAP_XEN_HVM);
+
        for (;;) {
-               __vm_ioctl(vm, KVM_XEN_HVM_SET_ATTR, &cache_activate);
-               __vm_ioctl(vm, KVM_XEN_HVM_SET_ATTR, &cache_deactivate);
+               __vm_ioctl(vm, KVM_XEN_HVM_SET_ATTR, &cache_activate_gfn);
                pthread_testcancel();
+               __vm_ioctl(vm, KVM_XEN_HVM_SET_ATTR, &cache_deactivate_gfn);
+
+               if (xen_caps & KVM_XEN_HVM_CONFIG_SHARED_INFO_HVA) {
+                       __vm_ioctl(vm, KVM_XEN_HVM_SET_ATTR, 
&cache_activate_hva);
+                       pthread_testcancel();
+                       __vm_ioctl(vm, KVM_XEN_HVM_SET_ATTR, 
&cache_deactivate_hva);
+               }
        }
 
        return NULL;
@@ -442,6 +461,7 @@ int main(int argc, char *argv[])
        bool do_runstate_flag = !!(xen_caps & 
KVM_XEN_HVM_CONFIG_RUNSTATE_UPDATE_FLAG);
        bool do_eventfd_tests = !!(xen_caps & KVM_XEN_HVM_CONFIG_EVTCHN_2LEVEL);
        bool do_evtchn_tests = do_eventfd_tests && !!(xen_caps & 
KVM_XEN_HVM_CONFIG_EVTCHN_SEND);
+       bool has_shinfo_hva = !!(xen_caps & KVM_XEN_HVM_CONFIG_SHARED_INFO_HVA);
 
        clock_gettime(CLOCK_REALTIME, &min_ts);
 
@@ -452,7 +472,7 @@ int main(int argc, char *argv[])
                                    SHINFO_REGION_GPA, SHINFO_REGION_SLOT, 3, 
0);
        virt_map(vm, SHINFO_REGION_GVA, SHINFO_REGION_GPA, 3);
 
-       struct shared_info *shinfo = addr_gpa2hva(vm, SHINFO_VADDR);
+       shinfo = addr_gpa2hva(vm, SHINFO_VADDR);
 
        int zero_fd = open("/dev/zero", O_RDONLY);
        TEST_ASSERT(zero_fd != -1, "Failed to open /dev/zero");
@@ -488,10 +508,16 @@ int main(int argc, char *argv[])
                            "Failed to read back RUNSTATE_UPDATE_FLAG attr");
        }
 
-       struct kvm_xen_hvm_attr ha = {
-               .type = KVM_XEN_ATTR_TYPE_SHARED_INFO,
-               .u.shared_info.gfn = SHINFO_REGION_GPA / PAGE_SIZE,
-       };
+       struct kvm_xen_hvm_attr ha = {};
+
+       if (has_shinfo_hva) {
+               ha.type = KVM_XEN_ATTR_TYPE_SHARED_INFO_HVA;
+               ha.u.shared_info.hva = (unsigned long)shinfo;
+       } else {
+               ha.type = KVM_XEN_ATTR_TYPE_SHARED_INFO;
+               ha.u.shared_info.gfn = SHINFO_ADDR / PAGE_SIZE;
+       }
+
        vm_ioctl(vm, KVM_XEN_HVM_SET_ATTR, &ha);
 
        /*
-- 
2.39.2