Commit 9397b533 authored by Paul Durrant's avatar Paul Durrant Committed by Sean Christopherson
Browse files

KVM: selftests: map Xen's shared_info page using HVA rather than GFN 



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: default avatarPaul Durrant <pdurrant@amazon.com>
Reviewed-by: default avatarDavid Woodhouse <dwmw@amazon.co.uk>
Link: https://lore.kernel.org/r/20240215152916.1158-15-paul@xen.org


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent 3991f358

tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c

+35 −9
Original line number Diff line number Diff line
@@ -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);



	/*