xen_shinfo_test.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * svm_vmcall_test
 *
 * Copyright © 2021 Amazon.com, Inc. or its affiliates.
 *
 * Xen shared_info / pvclock testing
 */

#include "test_util.h"
#include "kvm_util.h"
#include "processor.h"

#include <stdint.h>
#include <time.h>

#define VCPU_ID		5

#define SHINFO_REGION_GPA	0xc0000000ULL
#define SHINFO_REGION_SLOT	10
#define PAGE_SIZE		4096

#define PVTIME_ADDR	(SHINFO_REGION_GPA + PAGE_SIZE)

static struct kvm_vm *vm;

#define XEN_HYPERCALL_MSR	0x40000000

struct pvclock_vcpu_time_info {
        u32   version;
        u32   pad0;
        u64   tsc_timestamp;
        u64   system_time;
        u32   tsc_to_system_mul;
        s8    tsc_shift;
        u8    flags;
        u8    pad[2];
} __attribute__((__packed__)); /* 32 bytes */

struct pvclock_wall_clock {
        u32   version;
        u32   sec;
        u32   nsec;
} __attribute__((__packed__));

static void guest_code(void)
{
	GUEST_DONE();
}

static int cmp_timespec(struct timespec *a, struct timespec *b)
{
	if (a->tv_sec > b->tv_sec)
		return 1;
	else if (a->tv_sec < b->tv_sec)
		return -1;
	else if (a->tv_nsec > b->tv_nsec)
		return 1;
	else if (a->tv_nsec < b->tv_nsec)
		return -1;
	else
		return 0;
}

int main(int argc, char *argv[])
{
	struct timespec min_ts, max_ts, vm_ts;

	if (!(kvm_check_cap(KVM_CAP_XEN_HVM) &
	      KVM_XEN_HVM_CONFIG_SHARED_INFO) ) {
		print_skip("KVM_XEN_HVM_CONFIG_SHARED_INFO not available");
		exit(KSFT_SKIP);
	}

	clock_gettime(CLOCK_REALTIME, &min_ts);

	vm = vm_create_default(VCPU_ID, 0, (void *) guest_code);
	vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());

	/* Map a region for the shared_info page */
	vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
				    SHINFO_REGION_GPA, SHINFO_REGION_SLOT, 2, 0);
	virt_map(vm, SHINFO_REGION_GPA, SHINFO_REGION_GPA, 2, 0);

	struct kvm_xen_hvm_config hvmc = {
		.flags = KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL,
		.msr = XEN_HYPERCALL_MSR,
	};
	vm_ioctl(vm, KVM_XEN_HVM_CONFIG, &hvmc);

	struct kvm_xen_hvm_attr lm = {
		.type = KVM_XEN_ATTR_TYPE_LONG_MODE,
		.u.long_mode = 1,
	};
	vm_ioctl(vm, KVM_XEN_HVM_SET_ATTR, &lm);

	struct kvm_xen_hvm_attr ha = {
		.type = KVM_XEN_ATTR_TYPE_SHARED_INFO,
		.u.shared_info.gfn = SHINFO_REGION_GPA / PAGE_SIZE,
	};
	vm_ioctl(vm, KVM_XEN_HVM_SET_ATTR, &ha);

	struct kvm_xen_vcpu_attr vi = {
		.type = KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO,
		.u.gpa = SHINFO_REGION_GPA + 40,
	};
	vcpu_ioctl(vm, VCPU_ID, KVM_XEN_VCPU_SET_ATTR, &vi);

	struct kvm_xen_vcpu_attr pvclock = {
		.type = KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO,
		.u.gpa = PVTIME_ADDR,
	};
	vcpu_ioctl(vm, VCPU_ID, KVM_XEN_VCPU_SET_ATTR, &pvclock);

	for (;;) {
		volatile struct kvm_run *run = vcpu_state(vm, VCPU_ID);
		struct ucall uc;

		vcpu_run(vm, VCPU_ID);

		TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
			    "Got exit_reason other than KVM_EXIT_IO: %u (%s)\n",
			    run->exit_reason,
			    exit_reason_str(run->exit_reason));

		switch (get_ucall(vm, VCPU_ID, &uc)) {
		case UCALL_ABORT:
			TEST_FAIL("%s", (const char *)uc.args[0]);
			/* NOT REACHED */
		case UCALL_SYNC:
			break;
		case UCALL_DONE:
			goto done;
		default:
			TEST_FAIL("Unknown ucall 0x%lx.", uc.cmd);
		}
	}

 done:
	clock_gettime(CLOCK_REALTIME, &max_ts);

	/*
	 * Just a *really* basic check that things are being put in the
	 * right place. The actual calculations are much the same for
	 * Xen as they are for the KVM variants, so no need to check.
	 */
	struct pvclock_wall_clock *wc;
	struct pvclock_vcpu_time_info *ti, *ti2;

	wc = addr_gva2hva(vm, SHINFO_REGION_GPA + 0xc00);
	ti = addr_gva2hva(vm, SHINFO_REGION_GPA + 0x40 + 0x20);
	ti2 = addr_gva2hva(vm, PVTIME_ADDR);

	vm_ts.tv_sec = wc->sec;
	vm_ts.tv_nsec = wc->nsec;
        TEST_ASSERT(wc->version && !(wc->version & 1),
		    "Bad wallclock version %x", wc->version);
	TEST_ASSERT(cmp_timespec(&min_ts, &vm_ts) <= 0, "VM time too old");
	TEST_ASSERT(cmp_timespec(&max_ts, &vm_ts) >= 0, "VM time too new");

	TEST_ASSERT(ti->version && !(ti->version & 1),
		    "Bad time_info version %x", ti->version);
	TEST_ASSERT(ti2->version && !(ti2->version & 1),
		    "Bad time_info version %x", ti->version);

	kvm_vm_free(vm);
	return 0;
}