@@ -57,6 +57,13 @@ In the Google kernel, we have a kvm-like subsystem designed especially
for gVisor. This change is the first step of integrating it into the KVM
code base and making it available to all Linux users.
+Cc: Paolo Bonzini <pbonzini@redhat.com>
+Cc: Sean Christopherson <seanjc@google.com>
+Cc: Wanpeng Li <wanpengli@tencent.com>
+Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
+Cc: Jianfeng Tan <henry.tjf@antfin.com>
+Cc: Adin Scannell <ascannell@google.com>
+
Andrei Vagin (5):
kernel: add a new helper to execute system calls from kernel code
kvm: add controls to enable/disable paravirtualized system calls
@@ -21,6 +21,7 @@
/x86_64/get_msr_index_features
/x86_64/kvm_clock_test
/x86_64/kvm_pv_test
+/x86_64/kvm_pv_syscall_test
/x86_64/hyperv_clock
/x86_64/hyperv_cpuid
/x86_64/hyperv_features
@@ -82,6 +82,7 @@ TEST_GEN_PROGS_x86_64 += x86_64/hyperv_features
TEST_GEN_PROGS_x86_64 += x86_64/hyperv_svm_test
TEST_GEN_PROGS_x86_64 += x86_64/kvm_clock_test
TEST_GEN_PROGS_x86_64 += x86_64/kvm_pv_test
+TEST_GEN_PROGS_x86_64 += x86_64/kvm_pv_syscall_test
TEST_GEN_PROGS_x86_64 += x86_64/mmio_warning_test
TEST_GEN_PROGS_x86_64 += x86_64/mmu_role_test
TEST_GEN_PROGS_x86_64 += x86_64/platform_info_test
@@ -17,6 +17,7 @@
#include "../kvm_util.h"
+#ifndef X86_EFLAGS_FIXED
#define X86_EFLAGS_FIXED (1u << 1)
#define X86_CR4_VME (1ul << 0)
@@ -40,6 +41,7 @@
#define X86_CR4_SMEP (1ul << 20)
#define X86_CR4_SMAP (1ul << 21)
#define X86_CR4_PKE (1ul << 22)
+#endif
/* CPUID.1.ECX */
#define CPUID_VMX (1ul << 5)
@@ -503,6 +505,7 @@ void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, int level)
/*
* Basic CPU control in CR0
*/
+#ifndef X86_CR0_PE
#define X86_CR0_PE (1UL<<0) /* Protection Enable */
#define X86_CR0_MP (1UL<<1) /* Monitor Coprocessor */
#define X86_CR0_EM (1UL<<2) /* Emulation */
@@ -514,6 +517,7 @@ void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, int level)
#define X86_CR0_NW (1UL<<29) /* Not Write-through */
#define X86_CR0_CD (1UL<<30) /* Cache Disable */
#define X86_CR0_PG (1UL<<31) /* Paging */
+#endif
#define XSTATE_XTILE_CFG_BIT 17
#define XSTATE_XTILE_DATA_BIT 18
new file mode 100644
@@ -0,0 +1,145 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2020, Google LLC.
+ *
+ * Tests for KVM paravirtual feature disablement
+ */
+#include <asm/kvm_para.h>
+#include <asm/ptrace.h>
+#include <linux/kvm_para.h>
+#include <stdint.h>
+
+#include <linux/unistd.h>
+
+#include "test_util.h"
+#include "kvm_util.h"
+#include "processor.h"
+
+struct pt_regs regs_dup = {
+ .rax = __NR_dup,
+ .rdi = -1,
+};
+
+struct pt_regs regs_nosys = {
+ .rax = -1,
+};
+
+struct hcall_data {
+ const char *name;
+ struct pt_regs *regs;
+ long ret;
+};
+
+#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[] = {
+ {.name = "dup", .regs = ®s_dup, .ret = -EBADF},
+ {.name = "enosys", .regs = ®s_nosys, .ret = -ENOSYS},
+};
+
+static void test_hcall(struct hcall_data *hc)
+{
+ uint64_t r;
+
+ PR_HCALL(hc);
+ r = kvm_hypercall(KVM_HC_HOST_SYSCALL, (unsigned long)hc->regs, 0, 0, 0);
+ GUEST_ASSERT(r == 0);
+}
+
+static void guest_main(void)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(hcalls_to_test); i++)
+ test_hcall(&hcalls_to_test[i]);
+
+ GUEST_DONE();
+}
+
+static void pr_hcall(struct ucall *uc)
+{
+ struct hcall_data *hc = (struct hcall_data *)uc->args[0];
+
+ pr_info("testing hcall: %s\n", hc->name);
+}
+
+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, i;
+
+ 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_HCALL:
+ pr_hcall(&uc);
+ break;
+ case UCALL_ABORT:
+ handle_abort(&uc);
+ return;
+ case UCALL_DONE:
+ goto out;
+ }
+ }
+
+out:
+ for (i = 0; i < ARRAY_SIZE(hcalls_to_test); i++) {
+ struct hcall_data *hc = &hcalls_to_test[i];
+
+ TEST_ASSERT(hc->ret == hc->regs->rax, "%s: ret %ld (expected %ld)",
+ hc->name, hc->ret, hc->regs->rax);
+ }
+}
+
+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();
+ vcpu_set_cpuid(vm, VCPU_ID, best);
+
+ cap.cap = KVM_CAP_PV_HOST_SYSCALL;
+ cap.args[0] = 1;
+ vcpu_enable_cap(vm, VCPU_ID, &cap);
+
+ vm_init_descriptor_tables(vm);
+ vcpu_init_descriptor_tables(vm, VCPU_ID);
+
+ enter_guest(vm);
+ kvm_vm_free(vm);
+}
* check that syscall are executed. * check that non-existing syscalls return ENOSYS. Signed-off-by: Andrei Vagin <avagin@google.com> --- 0000-kvm-host-syscall.patch | 7 + tools/testing/selftests/kvm/.gitignore | 1 + tools/testing/selftests/kvm/Makefile | 1 + .../selftests/kvm/include/x86_64/processor.h | 4 + .../kvm/x86_64/kvm_pv_syscall_test.c | 145 ++++++++++++++++++ 5 files changed, 158 insertions(+) create mode 100644 tools/testing/selftests/kvm/x86_64/kvm_pv_syscall_test.c