diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 4c1c2c06e96bb261ee0884adf192f06e231c0c78..2796dde06302a901a2dba41df1e7bb64d04992c9 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -902,8 +902,6 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
entry->edx = 0;
}
break;
- case 9:
- break;
case 0xa: { /* Architectural Performance Monitoring */
union cpuid10_eax eax;
union cpuid10_edx edx;
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 4c122f1b17378011beca374acdc7035bbe76e5ab..6448cb9f710f5fc9095a872edaaa52589094f00a 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -48,6 +48,8 @@ LIBKVM += lib/rbtree.c
LIBKVM += lib/sparsebit.c
LIBKVM += lib/test_util.c
+LIBKVM_STRING += lib/string_override.c
+
LIBKVM_x86_64 += lib/x86_64/apic.c
LIBKVM_x86_64 += lib/x86_64/handlers.S
LIBKVM_x86_64 += lib/x86_64/perf_test_util.c
@@ -220,7 +222,8 @@ LIBKVM_C := $(filter %.c,$(LIBKVM))
LIBKVM_S := $(filter %.S,$(LIBKVM))
LIBKVM_C_OBJ := $(patsubst %.c, $(OUTPUT)/%.o, $(LIBKVM_C))
LIBKVM_S_OBJ := $(patsubst %.S, $(OUTPUT)/%.o, $(LIBKVM_S))
-LIBKVM_OBJS = $(LIBKVM_C_OBJ) $(LIBKVM_S_OBJ)
+LIBKVM_STRING_OBJ := $(patsubst %.c, $(OUTPUT)/%.o, $(LIBKVM_STRING))
+LIBKVM_OBJS = $(LIBKVM_C_OBJ) $(LIBKVM_S_OBJ) $(LIBKVM_STRING_OBJ)
EXTRA_CLEAN += $(LIBKVM_OBJS) cscope.*
@@ -231,6 +234,12 @@ $(LIBKVM_C_OBJ): $(OUTPUT)/%.o: %.c
$(LIBKVM_S_OBJ): $(OUTPUT)/%.o: %.S
$(CC) $(CFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c $< -o $@
+# Compile the string overrides as freestanding to prevent the compiler from
+# generating self-referential code, e.g. without "freestanding" the compiler may
+# "optimize" memcmp() by invoking memcmp(), thus causing infinite recursion.
+$(LIBKVM_STRING_OBJ): $(OUTPUT)/%.o: %.c
+ $(CC) $(CFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c -ffreestanding $< -o $@
+
x := $(shell mkdir -p $(sort $(dir $(TEST_GEN_PROGS))))
$(TEST_GEN_PROGS): $(LIBKVM_OBJS)
$(TEST_GEN_PROGS_EXTENDED): $(LIBKVM_OBJS)
diff --git a/tools/testing/selftests/kvm/access_tracking_perf_test.c b/tools/testing/selftests/kvm/access_tracking_perf_test.c
index 1c2749b1481ac2f8a3e94f80ff67a3a753a5717d..76c583a07ea2211e9a2e66bd08c986a040d6e7cf 100644
--- a/tools/testing/selftests/kvm/access_tracking_perf_test.c
+++ b/tools/testing/selftests/kvm/access_tracking_perf_test.c
@@ -31,8 +31,9 @@
* These limitations are worked around in this test by using a large enough
* region of memory for each vCPU such that the number of translations cached in
* the TLB and the number of pages held in pagevecs are a small fraction of the
- * overall workload. And if either of those conditions are not true this test
- * will fail rather than silently passing.
+ * overall workload. And if either of those conditions are not true (for example
+ * in nesting, where TLB size is unlimited) this test will print a warning
+ * rather than silently passing.
*/
#include <inttypes.h>
#include <limits.h>
@@ -172,17 +173,23 @@ static void mark_vcpu_memory_idle(struct kvm_vm *vm,
vcpu_idx, no_pfn, pages);
/*
- * Test that at least 90% of memory has been marked idle (the rest might
- * not be marked idle because the pages have not yet made it to an LRU
- * list or the translations are still cached in the TLB). 90% is
+ * Check that at least 90% of memory has been marked idle (the rest
+ * might not be marked idle because the pages have not yet made it to an
+ * LRU list or the translations are still cached in the TLB). 90% is
* arbitrary; high enough that we ensure most memory access went through
* access tracking but low enough as to not make the test too brittle
* over time and across architectures.
+ *
+ * Note that when run in nested virtualization, this check will trigger
+ * much more frequently because TLB size is unlimited and since no flush
+ * happens, much more pages are cached there and guest won't see the
+ * "idle" bit cleared.
*/
- TEST_ASSERT(still_idle < pages / 10,
- "vCPU%d: Too many pages still idle (%"PRIu64 " out of %"
- PRIu64 ").\n",
- vcpu_idx, still_idle, pages);
+ if (still_idle < pages / 10)
+ printf("WARNING: vCPU%d: Too many pages still idle (%" PRIu64
+ "out of %" PRIu64 "), this will affect performance results"
+ ".\n",
+ vcpu_idx, still_idle, pages);
close(page_idle_fd);
close(pagemap_fd);
diff --git a/tools/testing/selftests/kvm/include/x86_64/vmx.h b/tools/testing/selftests/kvm/include/x86_64/vmx.h
index 99fa1410964cac2d9d0bca6a05fbec1f279cbc8c..790c6d1ecb3482b1219f61f94516c9c2a297f67f 100644
--- a/tools/testing/selftests/kvm/include/x86_64/vmx.h
+++ b/tools/testing/selftests/kvm/include/x86_64/vmx.h
@@ -617,6 +617,7 @@ void nested_map_memslot(struct vmx_pages *vmx, struct kvm_vm *vm,
uint32_t memslot);
void nested_identity_map_1g(struct vmx_pages *vmx, struct kvm_vm *vm,
uint64_t addr, uint64_t size);
+bool kvm_vm_has_ept(struct kvm_vm *vm);
void prepare_eptp(struct vmx_pages *vmx, struct kvm_vm *vm,
uint32_t eptp_memslot);
void prepare_virtualize_apic_accesses(struct vmx_pages *vmx, struct kvm_vm *vm);
diff --git a/tools/testing/selftests/kvm/lib/assert.c b/tools/testing/selftests/kvm/lib/assert.c
index 71ade6100fd397ba1da8f7d02f1b8b2c2d37e60d..2bd25b191d150c99caf011661b1d201b27da3ce6 100644
--- a/tools/testing/selftests/kvm/lib/assert.c
+++ b/tools/testing/selftests/kvm/lib/assert.c
@@ -22,7 +22,7 @@ static void test_dump_stack(void)
* Build and run this command:
*
* addr2line -s -e /proc/$PPID/exe -fpai {backtrace addresses} | \
- * grep -v test_dump_stack | cat -n 1>&2
+ * cat -n 1>&2
*
* Note that the spacing is different and there's no newline.
*/
@@ -36,18 +36,24 @@ static void test_dump_stack(void)
n * (((sizeof(void *)) * 2) + 1) +
/* Null terminator: */
1];
- char *c;
+ char *c = cmd;
n = backtrace(stack, n);
- c = &cmd[0];
- c += sprintf(c, "%s", addr2line);
/*
- * Skip the first 3 frames: backtrace, test_dump_stack, and
- * test_assert. We hope that backtrace isn't inlined and the other two
- * we've declared noinline.
+ * Skip the first 2 frames, which should be test_dump_stack() and
+ * test_assert(); both of which are declared noinline. Bail if the
+ * resulting stack trace would be empty. Otherwise, addr2line will block
+ * waiting for addresses to be passed in via stdin.
*/
+ if (n <= 2) {
+ fputs(" (stack trace empty)\n", stderr);
+ return;
+ }
+
+ c += sprintf(c, "%s", addr2line);
for (i = 2; i < n; i++)
c += sprintf(c, " %lx", ((unsigned long) stack[i]) - 1);
+
c += sprintf(c, "%s", pipeline);
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-result"
diff --git a/tools/testing/selftests/kvm/lib/string_override.c b/tools/testing/selftests/kvm/lib/string_override.c
new file mode 100644
index 0000000000000000000000000000000000000000..632398adc2295c356991d0cc59d203f7b58e4240
--- /dev/null
+++ b/tools/testing/selftests/kvm/lib/string_override.c
@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <stddef.h>
+
+/*
+ * Override the "basic" built-in string helpers so that they can be used in
+ * guest code. KVM selftests don't support dynamic loading in guest code and
+ * will jump into the weeds if the compiler decides to insert an out-of-line
+ * call via the PLT.
+ */
+int memcmp(const void *cs, const void *ct, size_t count)
+{
+ const unsigned char *su1, *su2;
+ int res = 0;
+
+ for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--) {
+ if ((res = *su1 - *su2) != 0)
+ break;
+ }
+ return res;
+}
+
+void *memcpy(void *dest, const void *src, size_t count)
+{
+ char *tmp = dest;
+ const char *s = src;
+
+ while (count--)
+ *tmp++ = *s++;
+ return dest;
+}
+
+void *memset(void *s, int c, size_t count)
+{
+ char *xs = s;
+
+ while (count--)
+ *xs++ = c;
+ return s;
+}
diff --git a/tools/testing/selftests/kvm/lib/x86_64/vmx.c b/tools/testing/selftests/kvm/lib/x86_64/vmx.c
index 80a568c439b832ebc05cd77d7cec580b16687c5a..d21049c38fc5637b9804b539a08e69fdfcddb38b 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/vmx.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/vmx.c
@@ -5,6 +5,8 @@
* Copyright (C) 2018, Google LLC.
*/
+#include <asm/msr-index.h>
+
#include "test_util.h"
#include "kvm_util.h"
#include "processor.h"
@@ -542,9 +544,27 @@ void nested_identity_map_1g(struct vmx_pages *vmx, struct kvm_vm *vm,
__nested_map(vmx, vm, addr, addr, size, PG_LEVEL_1G);
}
+bool kvm_vm_has_ept(struct kvm_vm *vm)
+{
+ struct kvm_vcpu *vcpu;
+ uint64_t ctrl;
+
+ vcpu = list_first_entry(&vm->vcpus, struct kvm_vcpu, list);
+ TEST_ASSERT(vcpu, "Cannot determine EPT support without vCPUs.\n");
+
+ ctrl = vcpu_get_msr(vcpu, MSR_IA32_VMX_TRUE_PROCBASED_CTLS) >> 32;
+ if (!(ctrl & CPU_BASED_ACTIVATE_SECONDARY_CONTROLS))
+ return false;
+
+ ctrl = vcpu_get_msr(vcpu, MSR_IA32_VMX_PROCBASED_CTLS2) >> 32;
+ return ctrl & SECONDARY_EXEC_ENABLE_EPT;
+}
+
void prepare_eptp(struct vmx_pages *vmx, struct kvm_vm *vm,
uint32_t eptp_memslot)
{
+ TEST_REQUIRE(kvm_vm_has_ept(vm));
+
vmx->eptp = (void *)vm_vaddr_alloc_page(vm);
vmx->eptp_hva = addr_gva2hva(vm, (uintptr_t)vmx->eptp);
vmx->eptp_gpa = addr_gva2gpa(vm, (uintptr_t)vmx->eptp);
diff --git a/tools/testing/selftests/kvm/x86_64/fix_hypercall_test.c b/tools/testing/selftests/kvm/x86_64/fix_hypercall_test.c
index b1905d280ef55891a90a957b5e96e2f3fec5014a..e0004bd265360dec3175c4ce00f5d6148c13a22c 100644
--- a/tools/testing/selftests/kvm/x86_64/fix_hypercall_test.c
+++ b/tools/testing/selftests/kvm/x86_64/fix_hypercall_test.c
@@ -14,6 +14,9 @@
#include "kvm_util.h"
#include "processor.h"
+/* VMCALL and VMMCALL are both 3-byte opcodes. */
+#define HYPERCALL_INSN_SIZE 3
+
static bool ud_expected;
static void guest_ud_handler(struct ex_regs *regs)
@@ -22,7 +25,7 @@ static void guest_ud_handler(struct ex_regs *regs)
GUEST_DONE();
}
-extern unsigned char svm_hypercall_insn;
+extern uint8_t svm_hypercall_insn[HYPERCALL_INSN_SIZE];
static uint64_t svm_do_sched_yield(uint8_t apic_id)
{
uint64_t ret;
@@ -39,7 +42,7 @@ static uint64_t svm_do_sched_yield(uint8_t apic_id)
return ret;
}
-extern unsigned char vmx_hypercall_insn;
+extern uint8_t vmx_hypercall_insn[HYPERCALL_INSN_SIZE];
static uint64_t vmx_do_sched_yield(uint8_t apic_id)
{
uint64_t ret;
@@ -56,30 +59,20 @@ static uint64_t vmx_do_sched_yield(uint8_t apic_id)
return ret;
}
-static void assert_hypercall_insn(unsigned char *exp_insn, unsigned char *obs_insn)
-{
- uint32_t exp = 0, obs = 0;
-
- memcpy(&exp, exp_insn, sizeof(exp));
- memcpy(&obs, obs_insn, sizeof(obs));
-
- GUEST_ASSERT_EQ(exp, obs);
-}
-
static void guest_main(void)
{
- unsigned char *native_hypercall_insn, *hypercall_insn;
+ uint8_t *native_hypercall_insn, *hypercall_insn;
uint8_t apic_id;
apic_id = GET_APIC_ID_FIELD(xapic_read_reg(APIC_ID));
if (is_intel_cpu()) {
- native_hypercall_insn = &vmx_hypercall_insn;
- hypercall_insn = &svm_hypercall_insn;
+ native_hypercall_insn = vmx_hypercall_insn;
+ hypercall_insn = svm_hypercall_insn;
svm_do_sched_yield(apic_id);
} else if (is_amd_cpu()) {
- native_hypercall_insn = &svm_hypercall_insn;
- hypercall_insn = &vmx_hypercall_insn;
+ native_hypercall_insn = svm_hypercall_insn;
+ hypercall_insn = vmx_hypercall_insn;
vmx_do_sched_yield(apic_id);
} else {
GUEST_ASSERT(0);
@@ -87,8 +80,13 @@ static void guest_main(void)
return;
}
+ /*
+ * The hypercall didn't #UD (guest_ud_handler() signals "done" if a #UD
+ * occurs). Verify that a #UD is NOT expected and that KVM patched in
+ * the native hypercall.
+ */
GUEST_ASSERT(!ud_expected);
- assert_hypercall_insn(native_hypercall_insn, hypercall_insn);
+ GUEST_ASSERT(!memcmp(native_hypercall_insn, hypercall_insn, HYPERCALL_INSN_SIZE));
GUEST_DONE();
}