[PATCH 0/2] KVM: selftests: Introduce steal-time tests for x86_64 and AArch64

[PATCH 0/2] KVM: selftests: Introduce steal-time tests for x86_64 and AArch64

[Andrew Jones]

Test steal/stolen-time on x86 and AArch64 to make sure what gets
reported to the guest is consistent with run-delay.

The first patch of this series is just kvm selftests API cleanup. The
series is based on kvm/queue and some in-flight patches that are also
based on kvm/queue
 KVM: selftests: Share common API documentation
 KVM: selftests: Enable printf format warnings for TEST_ASSERT
 KVM: selftests: Use consistent message for test skipping
 KVM: selftests: s390x: Provide additional num-guest-pages adjustment

Thanks,
drew


Andrew Jones (2):
  KVM: selftests: virt_map should take npages, not size
  KVM: selftests: Introduce steal-time test

 tools/testing/selftests/kvm/.gitignore        |   2 +
 tools/testing/selftests/kvm/Makefile          |  12 +-
 .../selftests/kvm/demand_paging_test.c        |   3 +-
 tools/testing/selftests/kvm/dirty_log_test.c  |   3 +-
 .../testing/selftests/kvm/include/kvm_util.h  |   7 +-
 .../testing/selftests/kvm/include/test_util.h |   1 +
 tools/testing/selftests/kvm/lib/kvm_util.c    |  17 +-
 tools/testing/selftests/kvm/lib/test_util.c   |  15 +
 tools/testing/selftests/kvm/steal_time.c      | 352 ++++++++++++++++++
 .../kvm/x86_64/set_memory_region_test.c       |   2 +-
 .../selftests/kvm/x86_64/vmx_dirty_log_test.c |  11 +-
 11 files changed, 401 insertions(+), 24 deletions(-)
 create mode 100644 tools/testing/selftests/kvm/steal_time.c

-- 
2.21.1

[PATCH 1/2] KVM: selftests: virt_map should take npages, not size

[Andrew Jones]

Also correct the comment and prototype for vm_create_default(),
as it takes a number of pages, not a size.

Signed-off-by: Andrew Jones <drjones@redhat.com>
---
 tools/testing/selftests/kvm/demand_paging_test.c      |  3 +--
 tools/testing/selftests/kvm/dirty_log_test.c          |  3 +--
 tools/testing/selftests/kvm/include/kvm_util.h        |  6 +++---
 tools/testing/selftests/kvm/lib/kvm_util.c            | 10 +++++-----
 .../selftests/kvm/x86_64/set_memory_region_test.c     |  2 +-
 .../testing/selftests/kvm/x86_64/vmx_dirty_log_test.c | 11 +++++------
 6 files changed, 16 insertions(+), 19 deletions(-)

diff --git a/tools/testing/selftests/kvm/demand_paging_test.c b/tools/testing/selftests/kvm/demand_paging_test.c
index c4fc96bd064b..d82f7bc060c3 100644
--- a/tools/testing/selftests/kvm/demand_paging_test.c
+++ b/tools/testing/selftests/kvm/demand_paging_test.c
@@ -410,8 +410,7 @@ static void run_test(enum vm_guest_mode mode, bool use_uffd,
 				    guest_num_pages, 0);
 
 	/* Do mapping for the demand paging memory slot */
-	virt_map(vm, guest_test_virt_mem, guest_test_phys_mem,
-		 guest_num_pages * guest_page_size, 0);
+	virt_map(vm, guest_test_virt_mem, guest_test_phys_mem, guest_num_pages, 0);
 
 	ucall_init(vm, NULL);
 
diff --git a/tools/testing/selftests/kvm/dirty_log_test.c b/tools/testing/selftests/kvm/dirty_log_test.c
index 051791e0f5fb..8f5b590805a4 100644
--- a/tools/testing/selftests/kvm/dirty_log_test.c
+++ b/tools/testing/selftests/kvm/dirty_log_test.c
@@ -334,8 +334,7 @@ static void run_test(enum vm_guest_mode mode, unsigned long iterations,
 				    KVM_MEM_LOG_DIRTY_PAGES);
 
 	/* Do mapping for the dirty track memory slot */
-	virt_map(vm, guest_test_virt_mem, guest_test_phys_mem,
-		 guest_num_pages * guest_page_size, 0);
+	virt_map(vm, guest_test_virt_mem, guest_test_phys_mem, guest_num_pages, 0);
 
 	/* Cache the HVA pointer of the region */
 	host_test_mem = addr_gpa2hva(vm, (vm_paddr_t)guest_test_phys_mem);
diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
index 24f7a93671a2..3aa4d1e52284 100644
--- a/tools/testing/selftests/kvm/include/kvm_util.h
+++ b/tools/testing/selftests/kvm/include/kvm_util.h
@@ -117,7 +117,7 @@ void vm_vcpu_add(struct kvm_vm *vm, uint32_t vcpuid);
 vm_vaddr_t vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min,
 			  uint32_t data_memslot, uint32_t pgd_memslot);
 void virt_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
-	      size_t size, uint32_t pgd_memslot);
+	      unsigned int npages, uint32_t pgd_memslot);
 void *addr_gpa2hva(struct kvm_vm *vm, vm_paddr_t gpa);
 void *addr_gva2hva(struct kvm_vm *vm, vm_vaddr_t gva);
 vm_paddr_t addr_hva2gpa(struct kvm_vm *vm, void *hva);
@@ -226,7 +226,7 @@ vm_paddr_t vm_phy_pages_alloc(struct kvm_vm *vm, size_t num,
  *
  * Input Args:
  *   vcpuid - The id of the single VCPU to add to the VM.
- *   extra_mem_pages - The size of extra memories to add (this will
+ *   extra_mem_pages - The number of extra pages to add (this will
  *                     decide how much extra space we will need to
  *                     setup the page tables using memslot 0)
  *   guest_code - The vCPU's entry point
@@ -236,7 +236,7 @@ vm_paddr_t vm_phy_pages_alloc(struct kvm_vm *vm, size_t num,
  * Return:
  *   Pointer to opaque structure that describes the created VM.
  */
-struct kvm_vm *vm_create_default(uint32_t vcpuid, uint64_t extra_mem_size,
+struct kvm_vm *vm_create_default(uint32_t vcpuid, uint64_t extra_mem_pages,
 				 void *guest_code);
 
 /*
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index aa7697212267..e26917ba25bc 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -1015,21 +1015,21 @@ vm_vaddr_t vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min,
  *   vm - Virtual Machine
  *   vaddr - Virtuall address to map
  *   paddr - VM Physical Address
- *   size - The size of the range to map
+ *   npages - The number of pages to map
  *   pgd_memslot - Memory region slot for new virtual translation tables
  *
  * Output Args: None
  *
  * Return: None
  *
- * Within the VM given by vm, creates a virtual translation for the
- * page range starting at vaddr to the page range starting at paddr.
+ * Within the VM given by @vm, creates a virtual translation for
+ * @npages starting at @vaddr to the page range starting at @paddr.
  */
 void virt_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
-	      size_t size, uint32_t pgd_memslot)
+	      unsigned int npages, uint32_t pgd_memslot)
 {
 	size_t page_size = vm->page_size;
-	size_t npages = size / page_size;
+	size_t size = npages * page_size;
 
 	TEST_ASSERT(vaddr + size > vaddr, "Vaddr overflow");
 	TEST_ASSERT(paddr + size > paddr, "Paddr overflow");
diff --git a/tools/testing/selftests/kvm/x86_64/set_memory_region_test.c b/tools/testing/selftests/kvm/x86_64/set_memory_region_test.c
index f2efaa576794..c6691cff4e19 100644
--- a/tools/testing/selftests/kvm/x86_64/set_memory_region_test.c
+++ b/tools/testing/selftests/kvm/x86_64/set_memory_region_test.c
@@ -87,7 +87,7 @@ static void test_move_memory_region(void)
 	gpa = vm_phy_pages_alloc(vm, 2, MEM_REGION_GPA, MEM_REGION_SLOT);
 	TEST_ASSERT(gpa == MEM_REGION_GPA, "Failed vm_phy_pages_alloc\n");
 
-	virt_map(vm, MEM_REGION_GPA, MEM_REGION_GPA, 2 * 4096, 0);
+	virt_map(vm, MEM_REGION_GPA, MEM_REGION_GPA, 2, 0);
 
 	/* Ditto for the host mapping so that both pages can be zeroed. */
 	hva = addr_gpa2hva(vm, MEM_REGION_GPA);
diff --git a/tools/testing/selftests/kvm/x86_64/vmx_dirty_log_test.c b/tools/testing/selftests/kvm/x86_64/vmx_dirty_log_test.c
index d9ca948d0b72..7a3228c80d2d 100644
--- a/tools/testing/selftests/kvm/x86_64/vmx_dirty_log_test.c
+++ b/tools/testing/selftests/kvm/x86_64/vmx_dirty_log_test.c
@@ -21,7 +21,7 @@
 
 /* The memory slot index to track dirty pages */
 #define TEST_MEM_SLOT_INDEX		1
-#define TEST_MEM_SIZE			3
+#define TEST_MEM_PAGES			3
 
 /* L1 guest test virtual memory offset */
 #define GUEST_TEST_MEM			0xc0000000
@@ -91,15 +91,14 @@ int main(int argc, char *argv[])
 	vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
 				    GUEST_TEST_MEM,
 				    TEST_MEM_SLOT_INDEX,
-				    TEST_MEM_SIZE,
+				    TEST_MEM_PAGES,
 				    KVM_MEM_LOG_DIRTY_PAGES);
 
 	/*
 	 * Add an identity map for GVA range [0xc0000000, 0xc0002000).  This
 	 * affects both L1 and L2.  However...
 	 */
-	virt_map(vm, GUEST_TEST_MEM, GUEST_TEST_MEM,
-		 TEST_MEM_SIZE * 4096, 0);
+	virt_map(vm, GUEST_TEST_MEM, GUEST_TEST_MEM, TEST_MEM_PAGES, 0);
 
 	/*
 	 * ... pages in the L2 GPA range [0xc0001000, 0xc0003000) will map to
@@ -113,11 +112,11 @@ int main(int argc, char *argv[])
 	nested_map(vmx, vm, NESTED_TEST_MEM1, GUEST_TEST_MEM, 4096, 0);
 	nested_map(vmx, vm, NESTED_TEST_MEM2, GUEST_TEST_MEM, 4096, 0);
 
-	bmap = bitmap_alloc(TEST_MEM_SIZE);
+	bmap = bitmap_alloc(TEST_MEM_PAGES);
 	host_test_mem = addr_gpa2hva(vm, GUEST_TEST_MEM);
 
 	while (!done) {
-		memset(host_test_mem, 0xaa, TEST_MEM_SIZE * 4096);
+		memset(host_test_mem, 0xaa, TEST_MEM_PAGES * 4096);
 		_vcpu_run(vm, VCPU_ID);
 		TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
 			    "Unexpected exit reason: %u (%s),\n",
-- 
2.21.1

[PATCH 2/2] KVM: selftests: Introduce steal-time test

[Andrew Jones]

The steal-time test confirms what is reported to the guest as stolen
time is consistent with the run_delay reported for the VCPU thread
on the host. Both x86_64 and AArch64 have the concept of steal/stolen
time so this test is introduced for both architectures.

While adding the test we ensure .gitignore has all tests listed
(it was missing s390x/resets) and that the Makefile has all tests
listed in alphabetical order (not really necessary, but it almost
was already...). We also extend the common API with a new num-guest-
pages call and a new timespec call.

Signed-off-by: Andrew Jones <drjones@redhat.com>
---
 tools/testing/selftests/kvm/.gitignore        |   2 +
 tools/testing/selftests/kvm/Makefile          |  12 +-
 .../testing/selftests/kvm/include/kvm_util.h  |   1 +
 .../testing/selftests/kvm/include/test_util.h |   1 +
 tools/testing/selftests/kvm/lib/kvm_util.c    |   7 +
 tools/testing/selftests/kvm/lib/test_util.c   |  15 +
 tools/testing/selftests/kvm/steal_time.c      | 352 ++++++++++++++++++
 7 files changed, 385 insertions(+), 5 deletions(-)
 create mode 100644 tools/testing/selftests/kvm/steal_time.c

diff --git a/tools/testing/selftests/kvm/.gitignore b/tools/testing/selftests/kvm/.gitignore
index 8bc104d39e78..16877c3daabf 100644
--- a/tools/testing/selftests/kvm/.gitignore
+++ b/tools/testing/selftests/kvm/.gitignore
@@ -1,4 +1,5 @@
 /s390x/memop
+/s390x/resets
 /s390x/sync_regs_test
 /x86_64/cr4_cpuid_sync_test
 /x86_64/evmcs_test
@@ -20,3 +21,4 @@
 /demand_paging_test
 /dirty_log_test
 /kvm_create_max_vcpus
+/steal_time
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index a871184ebb6d..712a2ddd2a27 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -21,28 +21,30 @@ TEST_GEN_PROGS_x86_64 += x86_64/set_memory_region_test
 TEST_GEN_PROGS_x86_64 += x86_64/set_sregs_test
 TEST_GEN_PROGS_x86_64 += x86_64/smm_test
 TEST_GEN_PROGS_x86_64 += x86_64/state_test
+TEST_GEN_PROGS_x86_64 += x86_64/svm_vmcall_test
 TEST_GEN_PROGS_x86_64 += x86_64/sync_regs_test
 TEST_GEN_PROGS_x86_64 += x86_64/vmx_close_while_nested_test
 TEST_GEN_PROGS_x86_64 += x86_64/vmx_dirty_log_test
 TEST_GEN_PROGS_x86_64 += x86_64/vmx_set_nested_state_test
 TEST_GEN_PROGS_x86_64 += x86_64/vmx_tsc_adjust_test
 TEST_GEN_PROGS_x86_64 += x86_64/xss_msr_test
-TEST_GEN_PROGS_x86_64 += x86_64/svm_vmcall_test
 TEST_GEN_PROGS_x86_64 += clear_dirty_log_test
-TEST_GEN_PROGS_x86_64 += dirty_log_test
 TEST_GEN_PROGS_x86_64 += demand_paging_test
+TEST_GEN_PROGS_x86_64 += dirty_log_test
 TEST_GEN_PROGS_x86_64 += kvm_create_max_vcpus
+TEST_GEN_PROGS_x86_64 += steal_time
 
 TEST_GEN_PROGS_aarch64 += clear_dirty_log_test
-TEST_GEN_PROGS_aarch64 += dirty_log_test
 TEST_GEN_PROGS_aarch64 += demand_paging_test
+TEST_GEN_PROGS_aarch64 += dirty_log_test
 TEST_GEN_PROGS_aarch64 += kvm_create_max_vcpus
+TEST_GEN_PROGS_aarch64 += steal_time
 
 TEST_GEN_PROGS_s390x = s390x/memop
-TEST_GEN_PROGS_s390x += s390x/sync_regs_test
 TEST_GEN_PROGS_s390x += s390x/resets
-TEST_GEN_PROGS_s390x += dirty_log_test
+TEST_GEN_PROGS_s390x += s390x/sync_regs_test
 TEST_GEN_PROGS_s390x += demand_paging_test
+TEST_GEN_PROGS_s390x += dirty_log_test
 TEST_GEN_PROGS_s390x += kvm_create_max_vcpus
 
 TEST_GEN_PROGS += $(TEST_GEN_PROGS_$(UNAME_M))
diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
index 3aa4d1e52284..a99b875f50d2 100644
--- a/tools/testing/selftests/kvm/include/kvm_util.h
+++ b/tools/testing/selftests/kvm/include/kvm_util.h
@@ -255,6 +255,7 @@ unsigned int vm_get_page_size(struct kvm_vm *vm);
 unsigned int vm_get_page_shift(struct kvm_vm *vm);
 unsigned int vm_get_max_gfn(struct kvm_vm *vm);
 
+unsigned int vm_calc_num_guest_pages(enum vm_guest_mode mode, size_t size);
 unsigned int vm_num_host_pages(enum vm_guest_mode mode, unsigned int num_guest_pages);
 unsigned int vm_num_guest_pages(enum vm_guest_mode mode, unsigned int num_host_pages);
 static inline unsigned int
diff --git a/tools/testing/selftests/kvm/include/test_util.h b/tools/testing/selftests/kvm/include/test_util.h
index 1e1487a30402..f556ec5fe47b 100644
--- a/tools/testing/selftests/kvm/include/test_util.h
+++ b/tools/testing/selftests/kvm/include/test_util.h
@@ -59,5 +59,6 @@ size_t parse_size(const char *size);
 
 int64_t timespec_to_ns(struct timespec ts);
 struct timespec timespec_diff(struct timespec start, struct timespec end);
+struct timespec timespec_add_ns(struct timespec ts, int64_t ns);
 
 #endif /* SELFTEST_KVM_TEST_UTIL_H */
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index e26917ba25bc..35bd42370c21 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -1769,3 +1769,10 @@ vm_num_guest_pages(enum vm_guest_mode mode, unsigned int num_host_pages)
 	return vm_calc_num_pages(num_host_pages, getpageshift(),
 				 vm_guest_mode_params[mode].page_shift, false);
 }
+
+unsigned int vm_calc_num_guest_pages(enum vm_guest_mode mode, size_t size)
+{
+	unsigned int n;
+	n = DIV_ROUND_UP(size, vm_guest_mode_params[mode].page_size);
+	return vm_adjust_num_guest_pages(mode, n);
+}
diff --git a/tools/testing/selftests/kvm/lib/test_util.c b/tools/testing/selftests/kvm/lib/test_util.c
index 26fb3d73dc74..ee12c4b9ae05 100644
--- a/tools/testing/selftests/kvm/lib/test_util.c
+++ b/tools/testing/selftests/kvm/lib/test_util.c
@@ -71,6 +71,21 @@ struct timespec timespec_diff(struct timespec start, struct timespec end)
 	return temp;
 }
 
+struct timespec timespec_add_ns(struct timespec ts, int64_t ns)
+{
+	struct timespec res;
+
+	res.tv_sec = ts.tv_sec;
+	res.tv_nsec = ts.tv_nsec + ns;
+
+	if (res.tv_nsec > 1000000000UL) {
+		res.tv_sec += 1;
+		res.tv_nsec -= 1000000000UL;
+	}
+
+	return res;
+}
+
 void print_skip(const char *fmt, ...)
 {
 	va_list ap;
diff --git a/tools/testing/selftests/kvm/steal_time.c b/tools/testing/selftests/kvm/steal_time.c
new file mode 100644
index 000000000000..f976ac5e896a
--- /dev/null
+++ b/tools/testing/selftests/kvm/steal_time.c
@@ -0,0 +1,352 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * steal/stolen time test
+ *
+ * Copyright (C) 2020, Red Hat, Inc.
+ */
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <time.h>
+#include <sched.h>
+#include <pthread.h>
+#include <linux/kernel.h>
+#include <sys/syscall.h>
+#include <asm/kvm.h>
+#include <asm/kvm_para.h>
+
+#include "test_util.h"
+#include "kvm_util.h"
+#include "processor.h"
+
+#define NR_VCPUS		4
+#define ST_GPA_BASE		(1 << 30)
+#define MIN_RUN_DELAY_NS	200000UL
+
+static void *st_gva[NR_VCPUS];
+static uint64_t guest_stolen_time[NR_VCPUS];
+
+#if defined(__x86_64__)
+
+/* steal_time must have 64-byte alignment */
+#define STEAL_TIME_SIZE		((sizeof(struct kvm_steal_time) + 63) & ~63)
+
+static void check_status(struct kvm_steal_time *st)
+{
+	GUEST_ASSERT(!(READ_ONCE(st->version) & 1));
+	GUEST_ASSERT(READ_ONCE(st->flags) == 0);
+	GUEST_ASSERT(READ_ONCE(st->preempted) == 0);
+}
+
+static void guest_code(int cpu)
+{
+	struct kvm_steal_time *st = st_gva[cpu];
+	uint32_t version;
+
+	GUEST_ASSERT(rdmsr(MSR_KVM_STEAL_TIME) == ((uint64_t)st_gva[cpu] | KVM_MSR_ENABLED));
+
+	memset(st, 0, sizeof(*st));
+	GUEST_SYNC(0);
+
+	check_status(st);
+	WRITE_ONCE(guest_stolen_time[cpu], st->steal);
+	version = READ_ONCE(st->version);
+	check_status(st);
+	GUEST_SYNC(1);
+
+	check_status(st);
+	GUEST_ASSERT(version < READ_ONCE(st->version));
+	WRITE_ONCE(guest_stolen_time[cpu], st->steal);
+	check_status(st);
+	GUEST_DONE();
+}
+
+static void steal_time_init(struct kvm_vm *vm)
+{
+	int i;
+
+	if (!(kvm_get_supported_cpuid_entry(KVM_CPUID_FEATURES)->eax &
+	      KVM_FEATURE_STEAL_TIME)) {
+		print_skip("steal-time not supported");
+		exit(KSFT_SKIP);
+	}
+
+	for (i = 0; i < NR_VCPUS; ++i) {
+		int ret;
+
+		vcpu_set_cpuid(vm, i, kvm_get_supported_cpuid());
+
+		/* ST_GPA_BASE is identity mapped */
+		st_gva[i] = (void *)(ST_GPA_BASE + i * STEAL_TIME_SIZE);
+		sync_global_to_guest(vm, st_gva[i]);
+
+		ret = _vcpu_set_msr(vm, i, MSR_KVM_STEAL_TIME, (ulong)st_gva[i] | KVM_STEAL_RESERVED_MASK);
+		TEST_ASSERT(ret == 0, "Bad GPA didn't fail");
+
+		vcpu_set_msr(vm, i, MSR_KVM_STEAL_TIME, (ulong)st_gva[i] | KVM_MSR_ENABLED);
+	}
+}
+
+static void steal_time_dump(struct kvm_vm *vm, uint32_t vcpuid)
+{
+	struct kvm_steal_time *st = addr_gva2hva(vm, (ulong)st_gva[vcpuid]);
+	int i;
+
+	pr_info("VCPU%d:\n", vcpuid);
+	pr_info("    steal:     %lld\n", st->steal);
+	pr_info("    version:   %d\n", st->version);
+	pr_info("    flags:     %d\n", st->flags);
+	pr_info("    preempted: %d\n", st->preempted);
+	pr_info("    u8_pad:    ");
+	for (i = 0; i < 3; ++i)
+		pr_info("%d", st->u8_pad[i]);
+	pr_info("\n    pad:       ");
+	for (i = 0; i < 11; ++i)
+		pr_info("%d", st->pad[i]);
+	pr_info("\n");
+}
+
+#elif defined(__aarch64__)
+
+/* PV_TIME_ST must have 64-byte alignment */
+#define STEAL_TIME_SIZE		((sizeof(struct st_time) + 63) & ~63)
+
+#define SMCCC_ARCH_FEATURES	0x80000001
+#define PV_TIME_FEATURES	0xc5000020
+#define PV_TIME_ST		0xc5000021
+
+struct st_time {
+	uint32_t rev;
+	uint32_t attr;
+	uint64_t st_time;
+};
+
+static int64_t smccc(uint32_t func, uint32_t arg)
+{
+	unsigned long ret;
+
+	asm volatile(
+		"mov	x0, %1\n"
+		"mov	x1, %2\n"
+		"hvc	#0\n"
+		"mov	%0, x0\n"
+	: "=r" (ret) : "r" (func), "r" (arg) :
+	  "x0", "x1", "x2", "x3");
+
+	return ret;
+}
+
+static void check_status(struct st_time *st)
+{
+	GUEST_ASSERT(READ_ONCE(st->rev) == 0);
+	GUEST_ASSERT(READ_ONCE(st->attr) == 0);
+}
+
+static void guest_code(int cpu)
+{
+	struct st_time *st;
+	int64_t status;
+
+	status = smccc(SMCCC_ARCH_FEATURES, PV_TIME_FEATURES);
+	GUEST_ASSERT(status == 0);
+	status = smccc(PV_TIME_FEATURES, PV_TIME_FEATURES);
+	GUEST_ASSERT(status == 0);
+	status = smccc(PV_TIME_FEATURES, PV_TIME_ST);
+	GUEST_ASSERT(status == 0);
+
+	status = smccc(PV_TIME_ST, 0);
+	GUEST_ASSERT(status != -1);
+	GUEST_ASSERT(status == (ulong)st_gva[cpu]);
+
+	st = (struct st_time *)status;
+	GUEST_SYNC(0);
+
+	check_status(st);
+	WRITE_ONCE(guest_stolen_time[cpu], st->st_time);
+	GUEST_SYNC(1);
+
+	check_status(st);
+	WRITE_ONCE(guest_stolen_time[cpu], st->st_time);
+	GUEST_DONE();
+}
+
+static void steal_time_init(struct kvm_vm *vm)
+{
+	struct kvm_device_attr dev = {
+		.group = KVM_ARM_VCPU_PVTIME_CTRL,
+		.attr = KVM_ARM_VCPU_PVTIME_IPA,
+	};
+	int i, ret;
+
+	ret = _vcpu_ioctl(vm, 0, KVM_HAS_DEVICE_ATTR, &dev);
+	if (ret != 0 && errno == ENXIO) {
+		print_skip("steal-time not supported");
+		exit(KSFT_SKIP);
+	}
+
+	for (i = 0; i < NR_VCPUS; ++i) {
+		uint64_t st_ipa;
+
+		vcpu_ioctl(vm, i, KVM_HAS_DEVICE_ATTR, &dev);
+
+		dev.addr = (uint64_t)&st_ipa;
+
+		/* ST_GPA_BASE is identity mapped */
+		st_gva[i] = (void *)(ST_GPA_BASE + i * STEAL_TIME_SIZE);
+		sync_global_to_guest(vm, st_gva[i]);
+
+		st_ipa = (ulong)st_gva[i] | 1;
+		ret = _vcpu_ioctl(vm, i, KVM_SET_DEVICE_ATTR, &dev);
+		TEST_ASSERT(ret == -1 && errno == EINVAL, "Bad IPA didn't report EINVAL");
+
+		st_ipa = (ulong)st_gva[i];
+		vcpu_ioctl(vm, i, KVM_SET_DEVICE_ATTR, &dev);
+
+		ret = _vcpu_ioctl(vm, i, KVM_SET_DEVICE_ATTR, &dev);
+		TEST_ASSERT(ret == -1 && errno == EEXIST, "Set IPA twice without EEXIST");
+
+	}
+}
+
+static void steal_time_dump(struct kvm_vm *vm, uint32_t vcpuid)
+{
+	struct st_time *st = addr_gva2hva(vm, (ulong)st_gva[vcpuid]);
+
+	pr_info("VCPU%d:\n", vcpuid);
+	pr_info("    rev:     %d\n", st->rev);
+	pr_info("    attr:    %d\n", st->attr);
+	pr_info("    st_time: %ld\n", st->st_time);
+}
+
+#endif
+
+static long get_run_delay(void)
+{
+	char path[64];
+	long val[2];
+	FILE *fp;
+
+	sprintf(path, "/proc/%ld/schedstat", syscall(SYS_gettid));
+	fp = fopen(path, "r");
+	fscanf(fp, "%ld %ld ", &val[0], &val[1]);
+	fclose(fp);
+
+	return val[1];
+}
+
+static void *do_steal_time(void *arg)
+{
+	struct timespec ts, stop;
+
+	clock_gettime(CLOCK_MONOTONIC, &ts);
+	stop = timespec_add_ns(ts, MIN_RUN_DELAY_NS);
+
+	while (1) {
+		clock_gettime(CLOCK_MONOTONIC, &ts);
+		if (ts.tv_sec > stop.tv_sec || ts.tv_nsec >= stop.tv_nsec)
+			break;
+	}
+
+	return NULL;
+}
+
+static void run_vcpu(struct kvm_vm *vm, uint32_t vcpuid)
+{
+	struct ucall uc;
+
+	vcpu_args_set(vm, vcpuid, 1, vcpuid);
+
+	vcpu_ioctl(vm, vcpuid, KVM_RUN, NULL);
+
+	switch (get_ucall(vm, vcpuid, &uc)) {
+	case UCALL_SYNC:
+	case UCALL_DONE:
+		break;
+	case UCALL_ABORT:
+		TEST_ASSERT(false, "%s at %s:%ld", (const char *)uc.args[0],
+			    __FILE__, uc.args[1]);
+	default:
+		TEST_ASSERT(false, "Unexpected exit: %s",
+			    exit_reason_str(vcpu_state(vm, vcpuid)->exit_reason));
+	}
+}
+
+int main(int ac, char **av)
+{
+	struct kvm_vm *vm;
+	pthread_attr_t attr;
+	pthread_t thread;
+	cpu_set_t cpuset;
+	unsigned int gpages;
+	long stolen_time;
+	long run_delay;
+	bool verbose;
+	int i;
+
+	verbose = ac > 1 && (!strncmp(av[1], "-v", 3) || !strncmp(av[1], "--verbose", 10));
+
+	/* Set CPU affinity so we can force preemption of the VCPU */
+	CPU_ZERO(&cpuset);
+	CPU_SET(0, &cpuset);
+	pthread_attr_init(&attr);
+	pthread_attr_setaffinity_np(&attr, sizeof(cpu_set_t), &cpuset);
+	pthread_setaffinity_np(pthread_self(), sizeof(cpu_set_t), &cpuset);
+
+	/* Create a one VCPU guest and an identity mapped memslot for the steal time structure */
+	vm = vm_create_default(0, 0, guest_code);
+	gpages = vm_calc_num_guest_pages(VM_MODE_DEFAULT, STEAL_TIME_SIZE * NR_VCPUS);
+	vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, ST_GPA_BASE, 1, gpages, 0);
+	virt_map(vm, ST_GPA_BASE, ST_GPA_BASE, gpages, 0);
+	ucall_init(vm, NULL);
+
+	/* Add the rest of the VCPUs */
+	for (i = 1; i < NR_VCPUS; ++i)
+		vm_vcpu_add_default(vm, i, guest_code);
+
+	steal_time_init(vm);
+
+	/* Run test on each VCPU */
+	for (i = 0; i < NR_VCPUS; ++i) {
+		/* First VCPU run initializes steal-time */
+		run_vcpu(vm, i);
+
+		/* Second VCPU run, expect guest stolen time to be <= run_delay */
+		run_vcpu(vm, i);
+		sync_global_from_guest(vm, guest_stolen_time[i]);
+		stolen_time = guest_stolen_time[i];
+		run_delay = get_run_delay();
+		TEST_ASSERT(stolen_time <= run_delay,
+			    "Expected stolen time <= %ld, got %ld",
+			    run_delay, stolen_time);
+
+		/* Steal time from the VCPU. The steal time thread has the same CPU affinity as the VCPUs. */
+		run_delay = get_run_delay();
+		pthread_create(&thread, &attr, do_steal_time, NULL);
+		do
+			pthread_yield();
+		while (get_run_delay() - run_delay < MIN_RUN_DELAY_NS);
+		pthread_join(thread, NULL);
+		run_delay = get_run_delay() - run_delay;
+		TEST_ASSERT(run_delay >= MIN_RUN_DELAY_NS,
+			    "Expected run_delay >= %ld, got %ld",
+			    MIN_RUN_DELAY_NS, run_delay);
+
+		/* Run VCPU again to confirm stolen time is consistent with run_delay */
+		run_vcpu(vm, i);
+		sync_global_from_guest(vm, guest_stolen_time[i]);
+		stolen_time = guest_stolen_time[i] - stolen_time;
+		TEST_ASSERT(stolen_time >= run_delay,
+			    "Expected stolen time >= %ld, got %ld",
+			    run_delay, stolen_time);
+
+		if (verbose) {
+			pr_info("VCPU%d: total-stolen-time=%ld test-stolen-time=%ld", i,
+				guest_stolen_time[i], stolen_time);
+			if (stolen_time == run_delay)
+				pr_info(" (BONUS: guest test-stolen-time even exactly matches test-run_delay)");
+			pr_info("\n");
+			steal_time_dump(vm, i);
+		}
+	}
+
+	return 0;
+}
-- 
2.21.1

Re: [PATCH 0/2] KVM: selftests: Introduce steal-time tests for x86_64 and AArch64

[Paolo Bonzini]

On 13/03/20 16:56, Andrew Jones wrote:
> Test steal/stolen-time on x86 and AArch64 to make sure what gets
> reported to the guest is consistent with run-delay.
> 
> The first patch of this series is just kvm selftests API cleanup. The
> series is based on kvm/queue and some in-flight patches that are also
> based on kvm/queue
>  KVM: selftests: Share common API documentation
>  KVM: selftests: Enable printf format warnings for TEST_ASSERT
>  KVM: selftests: Use consistent message for test skipping
>  KVM: selftests: s390x: Provide additional num-guest-pages adjustment
> 
> Thanks,
> drew
> 
> 
> Andrew Jones (2):
>   KVM: selftests: virt_map should take npages, not size
>   KVM: selftests: Introduce steal-time test
> 
>  tools/testing/selftests/kvm/.gitignore        |   2 +
>  tools/testing/selftests/kvm/Makefile          |  12 +-
>  .../selftests/kvm/demand_paging_test.c        |   3 +-
>  tools/testing/selftests/kvm/dirty_log_test.c  |   3 +-
>  .../testing/selftests/kvm/include/kvm_util.h  |   7 +-
>  .../testing/selftests/kvm/include/test_util.h |   1 +
>  tools/testing/selftests/kvm/lib/kvm_util.c    |  17 +-
>  tools/testing/selftests/kvm/lib/test_util.c   |  15 +
>  tools/testing/selftests/kvm/steal_time.c      | 352 ++++++++++++++++++
>  .../kvm/x86_64/set_memory_region_test.c       |   2 +-
>  .../selftests/kvm/x86_64/vmx_dirty_log_test.c |  11 +-
>  11 files changed, 401 insertions(+), 24 deletions(-)
>  create mode 100644 tools/testing/selftests/kvm/steal_time.c
> 

Queued, thanks.

Paolo