On 09/03/2019 02:58 PM, Oliver Upton wrote:
Tests to verify that KVM performs the correct checks on Host/Guest state
at VM-entry, as described in SDM 26.3.1.1 "Checks on Guest Control
Registers, Debug Registers, and MSRs" and SDM 26.2.2 "Checks on Host
Control Registers and MSRs".
Test that KVM does the following:
If the "load IA32_PERF_GLOBAL_CTRL" VM-entry control is 1, the
reserved bits of the IA32_PERF_GLOBAL_CTRL MSR must be 0 in the
GUEST_IA32_PERF_GLOBAL_CTRL VMCS field. Otherwise, the VM-entry
should fail with an exit reason of "VM-entry failure due to invalid
guest state" (33). On a successful VM-entry, the correct value
should be observed when the nested VM performs an RDMSR on
IA32_PERF_GLOBAL_CTRL.
If the "load IA32_PERF_GLOBAL_CTRL" VM-exit control is 1, the
reserved bits of the IA32_PERF_GLOBAL_CTRL MSR must be 0 in the
HOST_IA32_PERF_GLOBAL_CTRL VMCS field. Otherwise, the VM-entry
should fail with a VM-instruction error of "VM entry with invalid
host-state field(s)" (8). On a successful VM-exit, the correct value
should be observed when L1 performs an RDMSR on
IA32_PERF_GLOBAL_CTRL.
Suggested-by: Jim Mattson <jmattson@xxxxxxxxxx>
Co-developed-by: Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>
Signed-off-by: Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>
Signed-off-by: Oliver Upton <oupton@xxxxxxxxxx>
---
x86/vmx_tests.c | 199 +++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 197 insertions(+), 2 deletions(-)
diff --git a/x86/vmx_tests.c b/x86/vmx_tests.c
index b72a27583793..73c46eba6be9 100644
--- a/x86/vmx_tests.c
+++ b/x86/vmx_tests.c
@@ -5033,7 +5033,7 @@ static void guest_state_test_main(void)
break;
if (data->enabled) {
- obs = rdmsr(obs);
+ obs = rdmsr(data->msr);
report("Guest state is 0x%lx (expected 0x%lx)",
data->exp == obs, obs, data->exp);
}
@@ -6854,6 +6854,200 @@ static void test_host_efer(void)
test_efer(HOST_EFER, "HOST_EFER", EXI_CONTROLS, EXI_LOAD_EFER);
}
+union cpuid10_eax {
+ struct {
+ unsigned int version_id:8;
+ unsigned int num_counters:8;
It's better to name it num_gpc or num_counters_gp.
+ unsigned int bit_width:8;
+ unsigned int mask_length:8;
+ } split;
+ unsigned int full;
+};
+
+union cpuid10_edx {
+ struct {
+ unsigned int num_counters_fixed:5;
+ unsigned int bit_width_fixed:8;
+ unsigned int reserved:19;
+ } split;
+ unsigned int full;
+};
+
In kvm-unit-test source, the naming of variables, functions etc. seems
to be based on the hex value of the CPUID leaf that they represent. For
example, cpuid_7_ebx, check_cpuid_80000001_edx etc. Isn't it better to
name these structures something like cpuidA_eax and cpuidA_edx ?
+static bool valid_pgc(u64 val)
+{
+ struct cpuid id;
+ union cpuid10_eax eax;
+ union cpuid10_edx edx;
+ u64 mask;
+
+ id = cpuid(0xA);
+ eax.full = id.a;
+ edx.full = id.d;
+ mask = ~(((1ull << eax.split.num_counters) - 1) |
+ (((1ull << edx.split.num_counters_fixed) - 1) << 32));
+
+ return !(val & mask);
+}
+
+static void test_pgc_vmlaunch(u32 xerror, bool xfail, bool host)
+{
+ u32 inst_err;
+ u64 guest_rip, inst_len, obs;
+ bool success;
+ struct load_state_test_data *data = &load_state_test_data;
+
+ if (host) {
+ success = vmlaunch_succeeds();
+ obs = rdmsr(data->msr);
+ if (data->enabled && success)
+ report("Host state is 0x%lx (expected 0x%lx)",
+ data->exp == obs, obs, data->exp);
+ } else {
+ if (xfail)
+ enter_guest_with_invalid_guest_state();
+ else
+ enter_guest();
+ success = VMX_VMCALL == (vmcs_read(EXI_REASON) & 0xff);
+ guest_rip = vmcs_read(GUEST_RIP);
+ inst_len = vmcs_read(EXI_INST_LEN);
+ if (success)
+ vmcs_write(GUEST_RIP, guest_rip + inst_len);
Is it possible to re-use the existing report_guest_state_test() here and
the below code ?
+ }
+ if (!success) {
+ inst_err = vmcs_read(VMX_INST_ERROR);
+ report("vmlaunch failed, VMX Inst Error is %d (expected %d)",
+ xerror == inst_err, inst_err, xerror);
+ } else {
+ report("vmlaunch succeeded", success != xfail);
+ }
+}
+
+/*
+ * test_load_pgc is a generic function for testing the
+ * "load IA32_PERF_GLOBAL_CTRL" VM-{entry,exit} control. This test function
+ * will test the provided ctrl_val disabled and enabled.
+ *
+ * @nr - VMCS field number corresponding to the Host/Guest state field
+ * @name - Name of the above VMCS field for printing in test report
+ * @ctrl_nr - VMCS field number corresponding to the VM-{entry,exit} control
+ * @ctrl_val - Bit to set on the ctrl field.
+ */
+static void test_load_pgc(u32 nr, const char *name, u32 ctrl_nr,
+ const char *ctrl_name, u64 ctrl_val)
+{
+ u64 ctrl_saved = vmcs_read(ctrl_nr);
+ u64 pgc_saved = vmcs_read(nr);
+ u64 i, val;
+ bool host = nr == HOST_PERF_GLOBAL_CTRL;
+ struct load_state_test_data *data = &load_state_test_data;
+
+ data->msr = MSR_CORE_PERF_GLOBAL_CTRL;
+ msr_bmp_init();
+ if (!host) {
+ vmx_set_test_stage(1);
+ test_set_guest(guest_state_test_main);
+ }
+ vmcs_write(ctrl_nr, ctrl_saved & ~ctrl_val);
+ data->enabled = false;
+ report_prefix_pushf("\"load IA32_PERF_GLOBAL_CTRL\"=0 on %s",
+ ctrl_name);
+ for (i = 0; i < 64; i++) {
+ val = 1ull << i;
+ vmcs_write(nr, val);
+ report_prefix_pushf("%s = 0x%lx", name, val);
+ /*
+ * If the "load IA32_PERF_GLOBAL_CTRL" bit is 0 then
+ * the {HOST,GUEST}_IA32_PERF_GLOBAL_CTRL field is ignored,
+ * thus setting reserved bits in this field does not cause
+ * vmlaunch to fail.
+ */
This comment is really not required as it's obvious that there's no
effect on VM-entry if the control bit is not set.
+ test_pgc_vmlaunch(0, false, host);
+ report_prefix_pop();
+ }
+ report_prefix_pop();
+
+ vmcs_write(ctrl_nr, ctrl_saved | ctrl_val);
+ data->enabled = true;
+ report_prefix_pushf("\"load IA32_PERF_GLOBAL_CTRL\"=1 on %s",
+ ctrl_name);
+ for (i = 0; i < 64; i++) {
+ val = 1ull << i;
+ data->exp = val;
+ vmcs_write(nr, val);
+ report_prefix_pushf("%s = 0x%lx", name, val);
+ if (valid_pgc(val)) {
+ test_pgc_vmlaunch(0, false, host);
+ } else {
+ /*
+ * [SDM 30.4]
+ *
+ * Invalid host state fields result in an VM
+ * instruction error with error number 8
+ * (VMXERR_ENTRY_INVALID_HOST_STATE_FIELD)
+ */
+ if (host) {
+ test_pgc_vmlaunch(
+ VMXERR_ENTRY_INVALID_HOST_STATE_FIELD,
+ true, host);
+ /*
+ * [SDM 26.1]
+ *
+ * If a VM-Entry fails according to one of
+ * the guest-state checks, the exit reason on the VMCS
+ * will be set to reason number 33 (VMX_FAIL_STATE)
Again, these comments are probably not necessary.
+ */
+ } else {
+ test_pgc_vmlaunch(
+ 0,
+ true, host);
+ TEST_ASSERT_EQ(
+ VMX_ENTRY_FAILURE | VMX_FAIL_STATE,
+ vmcs_read(EXI_REASON));
+ }
+ }
+ report_prefix_pop();
+ }
+
+ report_prefix_pop();
+
+ if (nr == GUEST_PERF_GLOBAL_CTRL) {
+ /*
+ * Let the guest finish execution
+ */
+ vmx_set_test_stage(2);
+ vmcs_write(ctrl_nr, ctrl_saved);
+ vmcs_write(nr, pgc_saved);
+ enter_guest();
+ }
+
+ vmcs_write(ctrl_nr, ctrl_saved);
+ vmcs_write(nr, pgc_saved);
+}
+
+static void test_load_host_pgc(void)
+{
+ if (!(ctrl_exit_rev.clr & EXI_LOAD_PERF)) {
+ printf("\"load IA32_PERF_GLOBAL_CTRL\" "
+ "exit control not supported\n");
+ return;
+ }
+
+ test_load_pgc(HOST_PERF_GLOBAL_CTRL, "HOST_PERF_GLOBAL_CTRL",
+ EXI_CONTROLS, "EXI_CONTROLS", EXI_LOAD_PERF);
+}
+
+
+static void test_load_guest_pgc(void)
+{
+ if (!(ctrl_enter_rev.clr & ENT_LOAD_PERF)) {
+ printf("\"load IA32_PERF_GLOBAL_CTRL\" "
+ "entry control not supported\n");
+ }
+
+ test_load_pgc(GUEST_PERF_GLOBAL_CTRL, "GUEST_PERF_GLOBAL_CTRL",
+ ENT_CONTROLS, "ENT_CONTROLS", ENT_LOAD_PERF);
+}
+
/*
* PAT values higher than 8 are uninteresting since they're likely lumped
* in with "8". We only test values above 8 one bit at a time,
@@ -7147,6 +7341,7 @@ static void vmx_host_state_area_test(void)
test_sysenter_field(HOST_SYSENTER_EIP, "HOST_SYSENTER_EIP");
test_host_efer();
+ test_load_host_pgc();
I would rename it to test_load_host_perf_global_ctrl to avoid confusion
between "performance counter" and "VMCS control field" though the name
is bit long.
test_load_host_pat();
test_host_segment_regs();
test_host_desc_tables();
@@ -8587,7 +8782,6 @@ static int invalid_msr_entry_failure(struct vmentry_failure *failure)
return VMX_TEST_VMEXIT;
}
-
#define TEST(name) { #name, .v2 = name }
/* name/init/guest_main/exit_handler/syscall_handler/guest_regs */
@@ -8637,6 +8831,7 @@ struct vmx_test vmx_tests[] = {
TEST(vmx_host_state_area_test),
TEST(vmx_guest_state_area_test),
TEST(vmentry_movss_shadow_test),
+ TEST(test_load_guest_pgc),
Same comment as above.
The other comment I have is, why not put this inside of
'vmx_guest_state_area_test' because this VMCS field belongs to Guest
State Area only.
/* APICv tests */
TEST(vmx_eoi_bitmap_ioapic_scan_test),
TEST(vmx_hlt_with_rvi_test),
