selftests: kvm: add selftest for releasing VM file descriptor while in L2

This adds a test for the previous bug.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

3 files changed, 97 insertions, 0 deletions

diff --git a/tools/testing/selftests/kvm/.gitignore b/tools/testing/selftests/kvm/.gitignore
index 6210ba41c29e..2689d1ea6d7a 100644
--- a/tools/testing/selftests/kvm/.gitignore
+++ b/tools/testing/selftests/kvm/.gitignore
@@ -3,6 +3,7 @@
 /x86_64/platform_info_test
 /x86_64/set_sregs_test
 /x86_64/sync_regs_test
+/x86_64/vmx_close_while_nested_test
 /x86_64/vmx_tsc_adjust_test
 /x86_64/state_test
 /dirty_log_test
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index f9a0e9938480..3c1f4bdf9000 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -16,6 +16,7 @@ TEST_GEN_PROGS_x86_64 += x86_64/cr4_cpuid_sync_test
 TEST_GEN_PROGS_x86_64 += x86_64/state_test
 TEST_GEN_PROGS_x86_64 += x86_64/evmcs_test
 TEST_GEN_PROGS_x86_64 += x86_64/hyperv_cpuid
+TEST_GEN_PROGS_x86_64 += x86_64/vmx_close_while_nested_test
 TEST_GEN_PROGS_x86_64 += dirty_log_test
 TEST_GEN_PROGS_x86_64 += clear_dirty_log_test
 
diff --git a/tools/testing/selftests/kvm/x86_64/vmx_close_while_nested_test.c b/tools/testing/selftests/kvm/x86_64/vmx_close_while_nested_test.c
new file mode 100644
index 000000000000..6edec6fd790b
--- /dev/null
+++ b/tools/testing/selftests/kvm/x86_64/vmx_close_while_nested_test.c
@@ -0,0 +1,95 @@
+/*
+ * vmx_close_while_nested
+ *
+ * Copyright (C) 2019, Red Hat, Inc.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ *
+ * Verify that nothing bad happens if a KVM user exits with open
+ * file descriptors while executing a nested guest.
+ */
+
+#include "test_util.h"
+#include "kvm_util.h"
+#include "processor.h"
+#include "vmx.h"
+
+#include <string.h>
+#include <sys/ioctl.h>
+
+#include "kselftest.h"
+
+#define VCPU_ID         5
+
+enum {
+        PORT_L0_EXIT = 0x2000,
+};
+
+/* The virtual machine object. */
+static struct kvm_vm *vm;
+
+static void l2_guest_code(void)
+{
+        /* Exit to L0 */
+        asm volatile("inb %%dx, %%al"
+                     : : [port] "d" (PORT_L0_EXIT) : "rax");
+}
+
+static void l1_guest_code(struct vmx_pages *vmx_pages)
+{
+#define L2_GUEST_STACK_SIZE 64
+        unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
+        uint32_t control;
+        uintptr_t save_cr3;
+
+        GUEST_ASSERT(prepare_for_vmx_operation(vmx_pages));
+        GUEST_ASSERT(load_vmcs(vmx_pages));
+
+        /* Prepare the VMCS for L2 execution. */
+        prepare_vmcs(vmx_pages, l2_guest_code,
+                     &l2_guest_stack[L2_GUEST_STACK_SIZE]);
+
+        GUEST_ASSERT(!vmlaunch());
+        GUEST_ASSERT(0);
+}
+
+int main(int argc, char *argv[])
+{
+        struct vmx_pages *vmx_pages;
+        vm_vaddr_t vmx_pages_gva;
+        struct kvm_cpuid_entry2 *entry = kvm_get_supported_cpuid_entry(1);
+
+        if (!(entry->ecx & CPUID_VMX)) {
+                fprintf(stderr, "nested VMX not enabled, skipping test\n");
+                exit(KSFT_SKIP);
+        }
+
+        vm = vm_create_default(VCPU_ID, 0, (void *) l1_guest_code);
+        vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
+
+        /* Allocate VMX pages and shared descriptors (vmx_pages). */
+        vmx_pages = vcpu_alloc_vmx(vm, &vmx_pages_gva);
+        vcpu_args_set(vm, VCPU_ID, 1, vmx_pages_gva);
+
+        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));
+
+                if (run->io.port == PORT_L0_EXIT)
+                        break;
+
+                switch (get_ucall(vm, VCPU_ID, &uc)) {
+                case UCALL_ABORT:
+                        TEST_ASSERT(false, "%s", (const char *)uc.args[0]);
+                        /* NOT REACHED */
+                default:
+                        TEST_ASSERT(false, "Unknown ucall 0x%x.", uc.cmd);
+                }
+        }
+}