--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2020, Google LLC.
+ *
+ * Tests for KVM paravirtual feature disablement
+ */
+#include <asm/kvm_para.h>
+#include <linux/kvm_para.h>
+#include <stdint.h>
+
+#include "test_util.h"
+#include "kvm_util.h"
+#include "processor.h"
+
+extern unsigned char rdmsr_start;
+extern unsigned char rdmsr_end;
+
+static u64 do_rdmsr(u32 idx)
+{
+ u32 lo, hi;
+
+ asm volatile("rdmsr_start: rdmsr;"
+ "rdmsr_end:"
+ : "=a"(lo), "=c"(hi)
+ : "c"(idx));
+
+ return (((u64) hi) << 32) | lo;
+}
+
+extern unsigned char wrmsr_start;
+extern unsigned char wrmsr_end;
+
+static void do_wrmsr(u32 idx, u64 val)
+{
+ u32 lo, hi;
+
+ lo = val;
+ hi = val >> 32;
+
+ asm volatile("wrmsr_start: wrmsr;"
+ "wrmsr_end:"
+ : : "a"(lo), "c"(idx), "d"(hi));
+}
+
+static int nr_gp;
+
+static void guest_gp_handler(struct ex_regs *regs)
+{
+ unsigned char *rip = (unsigned char *)regs->rip;
+ bool r, w;
+
+ r = rip == &rdmsr_start;
+ w = rip == &wrmsr_start;
+ GUEST_ASSERT(r || w);
+
+ nr_gp++;
+
+ if (r)
+ regs->rip = (uint64_t)&rdmsr_end;
+ else
+ regs->rip = (uint64_t)&wrmsr_end;
+}
+
+struct msr_data {
+ uint32_t idx;
+ const char *name;
+};
+
+#define TEST_MSR(msr) { .idx = msr, .name = #msr }
+#define UCALL_PR_MSR 0xdeadbeef
+#define PR_MSR(msr) ucall(UCALL_PR_MSR, 1, msr)
+
+/*
+ * KVM paravirtual msrs to test. Expect a #GP if any of these msrs are read or
+ * written, as the KVM_CPUID_FEATURES leaf is cleared.
+ */
+static struct msr_data msrs_to_test[] = {
+ TEST_MSR(MSR_KVM_SYSTEM_TIME),
+ TEST_MSR(MSR_KVM_SYSTEM_TIME_NEW),
+ TEST_MSR(MSR_KVM_WALL_CLOCK),
+ TEST_MSR(MSR_KVM_WALL_CLOCK_NEW),
+ TEST_MSR(MSR_KVM_ASYNC_PF_EN),
+ TEST_MSR(MSR_KVM_STEAL_TIME),
+ TEST_MSR(MSR_KVM_PV_EOI_EN),
+ TEST_MSR(MSR_KVM_POLL_CONTROL),
+ TEST_MSR(MSR_KVM_ASYNC_PF_INT),
+ TEST_MSR(MSR_KVM_ASYNC_PF_ACK),
+};
+
+static void test_msr(struct msr_data *msr)
+{
+ PR_MSR(msr);
+ do_rdmsr(msr->idx);
+ GUEST_ASSERT(READ_ONCE(nr_gp) == 1);
+
+ nr_gp = 0;
+ do_wrmsr(msr->idx, 0);
+ GUEST_ASSERT(READ_ONCE(nr_gp) == 1);
+ nr_gp = 0;
+}
+
+struct hcall_data {
+ uint64_t nr;
+ const char *name;
+};
+
+#define TEST_HCALL(hc) { .nr = hc, .name = #hc }
+#define UCALL_PR_HCALL 0xdeadc0de
+#define PR_HCALL(hc) ucall(UCALL_PR_HCALL, 1, hc)
+
+/*
+ * KVM hypercalls to test. Expect -KVM_ENOSYS when called, as the corresponding
+ * features have been cleared in KVM_CPUID_FEATURES.
+ */
+static struct hcall_data hcalls_to_test[] = {
+ TEST_HCALL(KVM_HC_KICK_CPU),
+ TEST_HCALL(KVM_HC_SEND_IPI),
+ TEST_HCALL(KVM_HC_SCHED_YIELD),
+};
+
+static void test_hcall(struct hcall_data *hc)
+{
+ uint64_t r;
+
+ PR_HCALL(hc);
+ r = kvm_hypercall(hc->nr, 0, 0, 0, 0);
+ GUEST_ASSERT(r == -KVM_ENOSYS);
+}
+
+static void guest_main(void)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(msrs_to_test); i++) {
+ test_msr(&msrs_to_test[i]);
+ }
+
+ for (i = 0; i < ARRAY_SIZE(hcalls_to_test); i++) {
+ test_hcall(&hcalls_to_test[i]);
+ }
+
+ GUEST_DONE();
+}
+
+static void clear_kvm_cpuid_features(struct kvm_cpuid2 *cpuid)
+{
+ struct kvm_cpuid_entry2 ent = {0};
+
+ ent.function = KVM_CPUID_FEATURES;
+ TEST_ASSERT(set_cpuid(cpuid, &ent),
+ "failed to clear KVM_CPUID_FEATURES leaf");
+}
+
+static void pr_msr(struct ucall *uc)
+{
+ struct msr_data *msr = (struct msr_data *)uc->args[0];
+
+ pr_info("testing msr: %s (%#x)\n", msr->name, msr->idx);
+}
+
+static void pr_hcall(struct ucall *uc)
+{
+ struct hcall_data *hc = (struct hcall_data *)uc->args[0];
+
+ pr_info("testing hcall: %s (%lu)\n", hc->name, hc->nr);
+}
+
+static void handle_abort(struct ucall *uc)
+{
+ TEST_FAIL("%s at %s:%ld", (const char *)uc->args[0],
+ __FILE__, uc->args[1]);
+}
+
+#define VCPU_ID 0
+
+static void enter_guest(struct kvm_vm *vm)
+{
+ struct kvm_run *run;
+ struct ucall uc;
+ int r;
+
+ run = vcpu_state(vm, VCPU_ID);
+
+ while (true) {
+ r = _vcpu_run(vm, VCPU_ID);
+ TEST_ASSERT(!r, "vcpu_run failed: %d\n", r);
+ TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
+ "unexpected exit reason: %u (%s)",
+ run->exit_reason, exit_reason_str(run->exit_reason));
+
+ switch (get_ucall(vm, VCPU_ID, &uc)) {
+ case UCALL_PR_MSR:
+ pr_msr(&uc);
+ break;
+ case UCALL_PR_HCALL:
+ pr_hcall(&uc);
+ break;
+ case UCALL_ABORT:
+ handle_abort(&uc);
+ return;
+ case UCALL_DONE:
+ return;
+ }
+ }
+}
+
+int main(void)
+{
+ struct kvm_enable_cap cap = {0};
+ struct kvm_cpuid2 *best;
+ struct kvm_vm *vm;
+
+ if (!kvm_check_cap(KVM_CAP_ENFORCE_PV_FEATURE_CPUID)) {
+ pr_info("will skip kvm paravirt restriction tests.\n");
+ return 0;
+ }
+
+ vm = vm_create_default(VCPU_ID, 0, guest_main);
+
+ cap.cap = KVM_CAP_ENFORCE_PV_FEATURE_CPUID;
+ cap.args[0] = 1;
+ vcpu_enable_cap(vm, VCPU_ID, &cap);
+
+ best = kvm_get_supported_cpuid();
+ clear_kvm_cpuid_features(best);
+ vcpu_set_cpuid(vm, VCPU_ID, best);
+
+ vm_init_descriptor_tables(vm);
+ vcpu_init_descriptor_tables(vm, VCPU_ID);
+ vm_handle_exception(vm, GP_VECTOR, guest_gp_handler);
+
+ enter_guest(vm);
+ kvm_vm_free(vm);
+}
projects / platform / kernel / linux-starfive.git / commitdiff