From 4d2bd14319e4e0a49fc868c50ca0b2a747b58208 Mon Sep 17 00:00:00 2001 From: David Matlack Date: Thu, 29 Sep 2022 11:12:06 -0700 Subject: [PATCH] KVM: selftests: Add helpers to read kvm_{intel,amd} boolean module parameters Add helper functions for reading the value of kvm_intel and kvm_amd boolean module parameters. Use the kvm_intel variant in vm_is_unrestricted_guest() to simplify the check for kvm_intel.unrestricted_guest. No functional change intended. Signed-off-by: David Matlack Message-Id: <20220929181207.2281449-3-dmatlack@google.com> Signed-off-by: Paolo Bonzini --- .../selftests/kvm/include/kvm_util_base.h | 4 ++ tools/testing/selftests/kvm/lib/kvm_util.c | 39 +++++++++++++++++++ .../selftests/kvm/lib/x86_64/processor.c | 13 +------ 3 files changed, 44 insertions(+), 12 deletions(-) diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h index 24fde97f6121..e42a09cd24a0 100644 --- a/tools/testing/selftests/kvm/include/kvm_util_base.h +++ b/tools/testing/selftests/kvm/include/kvm_util_base.h @@ -175,6 +175,10 @@ extern const struct vm_guest_mode_params vm_guest_mode_params[]; int open_path_or_exit(const char *path, int flags); int open_kvm_dev_path_or_exit(void); + +bool get_kvm_intel_param_bool(const char *param); +bool get_kvm_amd_param_bool(const char *param); + unsigned int kvm_check_cap(long cap); static inline bool kvm_has_cap(long cap) diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index 9889fe0d8919..504c1e1355c3 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -50,6 +50,45 @@ int open_kvm_dev_path_or_exit(void) return _open_kvm_dev_path_or_exit(O_RDONLY); } +static bool get_module_param_bool(const char *module_name, const char *param) +{ + const int path_size = 128; + char path[path_size]; + char value; + ssize_t r; + int fd; + + r = snprintf(path, path_size, "/sys/module/%s/parameters/%s", + module_name, param); + TEST_ASSERT(r < path_size, + "Failed to construct sysfs path in %d bytes.", path_size); + + fd = open_path_or_exit(path, O_RDONLY); + + r = read(fd, &value, 1); + TEST_ASSERT(r == 1, "read(%s) failed", path); + + r = close(fd); + TEST_ASSERT(!r, "close(%s) failed", path); + + if (value == 'Y') + return true; + else if (value == 'N') + return false; + + TEST_FAIL("Unrecognized value '%c' for boolean module param", value); +} + +bool get_kvm_intel_param_bool(const char *param) +{ + return get_module_param_bool("kvm_intel", param); +} + +bool get_kvm_amd_param_bool(const char *param) +{ + return get_module_param_bool("kvm_amd", param); +} + /* * Capability * diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c index 2e6e61bbe81b..fab0f526fb81 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c @@ -1294,20 +1294,9 @@ done: /* Returns true if kvm_intel was loaded with unrestricted_guest=1. */ bool vm_is_unrestricted_guest(struct kvm_vm *vm) { - char val = 'N'; - size_t count; - FILE *f; - /* Ensure that a KVM vendor-specific module is loaded. */ if (vm == NULL) close(open_kvm_dev_path_or_exit()); - f = fopen("/sys/module/kvm_intel/parameters/unrestricted_guest", "r"); - if (f) { - count = fread(&val, sizeof(char), 1, f); - TEST_ASSERT(count == 1, "Unable to read from param file."); - fclose(f); - } - - return val == 'Y'; + return get_kvm_intel_param_bool("unrestricted_guest"); }