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-rw-r--r--tools/testing/selftests/kvm/x86_64/userspace_msr_exit_test.c748
1 files changed, 748 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/x86_64/userspace_msr_exit_test.c b/tools/testing/selftests/kvm/x86_64/userspace_msr_exit_test.c
new file mode 100644
index 000000000000..a4f06370a245
--- /dev/null
+++ b/tools/testing/selftests/kvm/x86_64/userspace_msr_exit_test.c
@@ -0,0 +1,748 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020, Google LLC.
+ *
+ * Tests for exiting into userspace on registered MSRs
+ */
+
+#define _GNU_SOURCE /* for program_invocation_short_name */
+#include <sys/ioctl.h>
+
+#include "test_util.h"
+#include "kvm_util.h"
+#include "vmx.h"
+
+/* Forced emulation prefix, used to invoke the emulator unconditionally. */
+#define KVM_FEP "ud2; .byte 'k', 'v', 'm';"
+#define KVM_FEP_LENGTH 5
+static int fep_available = 1;
+
+#define MSR_NON_EXISTENT 0x474f4f00
+
+static u64 deny_bits = 0;
+struct kvm_msr_filter filter_allow = {
+ .flags = KVM_MSR_FILTER_DEFAULT_ALLOW,
+ .ranges = {
+ {
+ .flags = KVM_MSR_FILTER_READ |
+ KVM_MSR_FILTER_WRITE,
+ .nmsrs = 1,
+ /* Test an MSR the kernel knows about. */
+ .base = MSR_IA32_XSS,
+ .bitmap = (uint8_t*)&deny_bits,
+ }, {
+ .flags = KVM_MSR_FILTER_READ |
+ KVM_MSR_FILTER_WRITE,
+ .nmsrs = 1,
+ /* Test an MSR the kernel doesn't know about. */
+ .base = MSR_IA32_FLUSH_CMD,
+ .bitmap = (uint8_t*)&deny_bits,
+ }, {
+ .flags = KVM_MSR_FILTER_READ |
+ KVM_MSR_FILTER_WRITE,
+ .nmsrs = 1,
+ /* Test a fabricated MSR that no one knows about. */
+ .base = MSR_NON_EXISTENT,
+ .bitmap = (uint8_t*)&deny_bits,
+ },
+ },
+};
+
+struct kvm_msr_filter filter_fs = {
+ .flags = KVM_MSR_FILTER_DEFAULT_ALLOW,
+ .ranges = {
+ {
+ .flags = KVM_MSR_FILTER_READ,
+ .nmsrs = 1,
+ .base = MSR_FS_BASE,
+ .bitmap = (uint8_t*)&deny_bits,
+ },
+ },
+};
+
+struct kvm_msr_filter filter_gs = {
+ .flags = KVM_MSR_FILTER_DEFAULT_ALLOW,
+ .ranges = {
+ {
+ .flags = KVM_MSR_FILTER_READ,
+ .nmsrs = 1,
+ .base = MSR_GS_BASE,
+ .bitmap = (uint8_t*)&deny_bits,
+ },
+ },
+};
+
+static uint64_t msr_non_existent_data;
+static int guest_exception_count;
+static u32 msr_reads, msr_writes;
+
+static u8 bitmap_00000000[KVM_MSR_FILTER_MAX_BITMAP_SIZE];
+static u8 bitmap_00000000_write[KVM_MSR_FILTER_MAX_BITMAP_SIZE];
+static u8 bitmap_40000000[KVM_MSR_FILTER_MAX_BITMAP_SIZE];
+static u8 bitmap_c0000000[KVM_MSR_FILTER_MAX_BITMAP_SIZE];
+static u8 bitmap_c0000000_read[KVM_MSR_FILTER_MAX_BITMAP_SIZE];
+static u8 bitmap_deadbeef[1] = { 0x1 };
+
+static void deny_msr(uint8_t *bitmap, u32 msr)
+{
+ u32 idx = msr & (KVM_MSR_FILTER_MAX_BITMAP_SIZE - 1);
+
+ bitmap[idx / 8] &= ~(1 << (idx % 8));
+}
+
+static void prepare_bitmaps(void)
+{
+ memset(bitmap_00000000, 0xff, sizeof(bitmap_00000000));
+ memset(bitmap_00000000_write, 0xff, sizeof(bitmap_00000000_write));
+ memset(bitmap_40000000, 0xff, sizeof(bitmap_40000000));
+ memset(bitmap_c0000000, 0xff, sizeof(bitmap_c0000000));
+ memset(bitmap_c0000000_read, 0xff, sizeof(bitmap_c0000000_read));
+
+ deny_msr(bitmap_00000000_write, MSR_IA32_POWER_CTL);
+ deny_msr(bitmap_c0000000_read, MSR_SYSCALL_MASK);
+ deny_msr(bitmap_c0000000_read, MSR_GS_BASE);
+}
+
+struct kvm_msr_filter filter_deny = {
+ .flags = KVM_MSR_FILTER_DEFAULT_DENY,
+ .ranges = {
+ {
+ .flags = KVM_MSR_FILTER_READ,
+ .base = 0x00000000,
+ .nmsrs = KVM_MSR_FILTER_MAX_BITMAP_SIZE * BITS_PER_BYTE,
+ .bitmap = bitmap_00000000,
+ }, {
+ .flags = KVM_MSR_FILTER_WRITE,
+ .base = 0x00000000,
+ .nmsrs = KVM_MSR_FILTER_MAX_BITMAP_SIZE * BITS_PER_BYTE,
+ .bitmap = bitmap_00000000_write,
+ }, {
+ .flags = KVM_MSR_FILTER_READ | KVM_MSR_FILTER_WRITE,
+ .base = 0x40000000,
+ .nmsrs = KVM_MSR_FILTER_MAX_BITMAP_SIZE * BITS_PER_BYTE,
+ .bitmap = bitmap_40000000,
+ }, {
+ .flags = KVM_MSR_FILTER_READ,
+ .base = 0xc0000000,
+ .nmsrs = KVM_MSR_FILTER_MAX_BITMAP_SIZE * BITS_PER_BYTE,
+ .bitmap = bitmap_c0000000_read,
+ }, {
+ .flags = KVM_MSR_FILTER_WRITE,
+ .base = 0xc0000000,
+ .nmsrs = KVM_MSR_FILTER_MAX_BITMAP_SIZE * BITS_PER_BYTE,
+ .bitmap = bitmap_c0000000,
+ }, {
+ .flags = KVM_MSR_FILTER_WRITE | KVM_MSR_FILTER_READ,
+ .base = 0xdeadbeef,
+ .nmsrs = 1,
+ .bitmap = bitmap_deadbeef,
+ },
+ },
+};
+
+struct kvm_msr_filter no_filter_deny = {
+ .flags = KVM_MSR_FILTER_DEFAULT_ALLOW,
+};
+
+/*
+ * Note: Force test_rdmsr() to not be inlined to prevent the labels,
+ * rdmsr_start and rdmsr_end, from being defined multiple times.
+ */
+static noinline uint64_t test_rdmsr(uint32_t msr)
+{
+ uint32_t a, d;
+
+ guest_exception_count = 0;
+
+ __asm__ __volatile__("rdmsr_start: rdmsr; rdmsr_end:" :
+ "=a"(a), "=d"(d) : "c"(msr) : "memory");
+
+ return a | ((uint64_t) d << 32);
+}
+
+/*
+ * Note: Force test_wrmsr() to not be inlined to prevent the labels,
+ * wrmsr_start and wrmsr_end, from being defined multiple times.
+ */
+static noinline void test_wrmsr(uint32_t msr, uint64_t value)
+{
+ uint32_t a = value;
+ uint32_t d = value >> 32;
+
+ guest_exception_count = 0;
+
+ __asm__ __volatile__("wrmsr_start: wrmsr; wrmsr_end:" ::
+ "a"(a), "d"(d), "c"(msr) : "memory");
+}
+
+extern char rdmsr_start, rdmsr_end;
+extern char wrmsr_start, wrmsr_end;
+
+/*
+ * Note: Force test_em_rdmsr() to not be inlined to prevent the labels,
+ * rdmsr_start and rdmsr_end, from being defined multiple times.
+ */
+static noinline uint64_t test_em_rdmsr(uint32_t msr)
+{
+ uint32_t a, d;
+
+ guest_exception_count = 0;
+
+ __asm__ __volatile__(KVM_FEP "em_rdmsr_start: rdmsr; em_rdmsr_end:" :
+ "=a"(a), "=d"(d) : "c"(msr) : "memory");
+
+ return a | ((uint64_t) d << 32);
+}
+
+/*
+ * Note: Force test_em_wrmsr() to not be inlined to prevent the labels,
+ * wrmsr_start and wrmsr_end, from being defined multiple times.
+ */
+static noinline void test_em_wrmsr(uint32_t msr, uint64_t value)
+{
+ uint32_t a = value;
+ uint32_t d = value >> 32;
+
+ guest_exception_count = 0;
+
+ __asm__ __volatile__(KVM_FEP "em_wrmsr_start: wrmsr; em_wrmsr_end:" ::
+ "a"(a), "d"(d), "c"(msr) : "memory");
+}
+
+extern char em_rdmsr_start, em_rdmsr_end;
+extern char em_wrmsr_start, em_wrmsr_end;
+
+static void guest_code_filter_allow(void)
+{
+ uint64_t data;
+
+ /*
+ * Test userspace intercepting rdmsr / wrmsr for MSR_IA32_XSS.
+ *
+ * A GP is thrown if anything other than 0 is written to
+ * MSR_IA32_XSS.
+ */
+ data = test_rdmsr(MSR_IA32_XSS);
+ GUEST_ASSERT(data == 0);
+ GUEST_ASSERT(guest_exception_count == 0);
+
+ test_wrmsr(MSR_IA32_XSS, 0);
+ GUEST_ASSERT(guest_exception_count == 0);
+
+ test_wrmsr(MSR_IA32_XSS, 1);
+ GUEST_ASSERT(guest_exception_count == 1);
+
+ /*
+ * Test userspace intercepting rdmsr / wrmsr for MSR_IA32_FLUSH_CMD.
+ *
+ * A GP is thrown if MSR_IA32_FLUSH_CMD is read
+ * from or if a value other than 1 is written to it.
+ */
+ test_rdmsr(MSR_IA32_FLUSH_CMD);
+ GUEST_ASSERT(guest_exception_count == 1);
+
+ test_wrmsr(MSR_IA32_FLUSH_CMD, 0);
+ GUEST_ASSERT(guest_exception_count == 1);
+
+ test_wrmsr(MSR_IA32_FLUSH_CMD, 1);
+ GUEST_ASSERT(guest_exception_count == 0);
+
+ /*
+ * Test userspace intercepting rdmsr / wrmsr for MSR_NON_EXISTENT.
+ *
+ * Test that a fabricated MSR can pass through the kernel
+ * and be handled in userspace.
+ */
+ test_wrmsr(MSR_NON_EXISTENT, 2);
+ GUEST_ASSERT(guest_exception_count == 0);
+
+ data = test_rdmsr(MSR_NON_EXISTENT);
+ GUEST_ASSERT(data == 2);
+ GUEST_ASSERT(guest_exception_count == 0);
+
+ /*
+ * Test to see if the instruction emulator is available (ie: the module
+ * parameter 'kvm.force_emulation_prefix=1' is set). This instruction
+ * will #UD if it isn't available.
+ */
+ __asm__ __volatile__(KVM_FEP "nop");
+
+ if (fep_available) {
+ /* Let userspace know we aren't done. */
+ GUEST_SYNC(0);
+
+ /*
+ * Now run the same tests with the instruction emulator.
+ */
+ data = test_em_rdmsr(MSR_IA32_XSS);
+ GUEST_ASSERT(data == 0);
+ GUEST_ASSERT(guest_exception_count == 0);
+ test_em_wrmsr(MSR_IA32_XSS, 0);
+ GUEST_ASSERT(guest_exception_count == 0);
+ test_em_wrmsr(MSR_IA32_XSS, 1);
+ GUEST_ASSERT(guest_exception_count == 1);
+
+ test_em_rdmsr(MSR_IA32_FLUSH_CMD);
+ GUEST_ASSERT(guest_exception_count == 1);
+ test_em_wrmsr(MSR_IA32_FLUSH_CMD, 0);
+ GUEST_ASSERT(guest_exception_count == 1);
+ test_em_wrmsr(MSR_IA32_FLUSH_CMD, 1);
+ GUEST_ASSERT(guest_exception_count == 0);
+
+ test_em_wrmsr(MSR_NON_EXISTENT, 2);
+ GUEST_ASSERT(guest_exception_count == 0);
+ data = test_em_rdmsr(MSR_NON_EXISTENT);
+ GUEST_ASSERT(data == 2);
+ GUEST_ASSERT(guest_exception_count == 0);
+ }
+
+ GUEST_DONE();
+}
+
+static void guest_msr_calls(bool trapped)
+{
+ /* This goes into the in-kernel emulation */
+ wrmsr(MSR_SYSCALL_MASK, 0);
+
+ if (trapped) {
+ /* This goes into user space emulation */
+ GUEST_ASSERT(rdmsr(MSR_SYSCALL_MASK) == MSR_SYSCALL_MASK);
+ GUEST_ASSERT(rdmsr(MSR_GS_BASE) == MSR_GS_BASE);
+ } else {
+ GUEST_ASSERT(rdmsr(MSR_SYSCALL_MASK) != MSR_SYSCALL_MASK);
+ GUEST_ASSERT(rdmsr(MSR_GS_BASE) != MSR_GS_BASE);
+ }
+
+ /* If trapped == true, this goes into user space emulation */
+ wrmsr(MSR_IA32_POWER_CTL, 0x1234);
+
+ /* This goes into the in-kernel emulation */
+ rdmsr(MSR_IA32_POWER_CTL);
+
+ /* Invalid MSR, should always be handled by user space exit */
+ GUEST_ASSERT(rdmsr(0xdeadbeef) == 0xdeadbeef);
+ wrmsr(0xdeadbeef, 0x1234);
+}
+
+static void guest_code_filter_deny(void)
+{
+ guest_msr_calls(true);
+
+ /*
+ * Disable msr filtering, so that the kernel
+ * handles everything in the next round
+ */
+ GUEST_SYNC(0);
+
+ guest_msr_calls(false);
+
+ GUEST_DONE();
+}
+
+static void guest_code_permission_bitmap(void)
+{
+ uint64_t data;
+
+ data = test_rdmsr(MSR_FS_BASE);
+ GUEST_ASSERT(data == MSR_FS_BASE);
+ data = test_rdmsr(MSR_GS_BASE);
+ GUEST_ASSERT(data != MSR_GS_BASE);
+
+ /* Let userspace know to switch the filter */
+ GUEST_SYNC(0);
+
+ data = test_rdmsr(MSR_FS_BASE);
+ GUEST_ASSERT(data != MSR_FS_BASE);
+ data = test_rdmsr(MSR_GS_BASE);
+ GUEST_ASSERT(data == MSR_GS_BASE);
+
+ GUEST_DONE();
+}
+
+static void __guest_gp_handler(struct ex_regs *regs,
+ char *r_start, char *r_end,
+ char *w_start, char *w_end)
+{
+ if (regs->rip == (uintptr_t)r_start) {
+ regs->rip = (uintptr_t)r_end;
+ regs->rax = 0;
+ regs->rdx = 0;
+ } else if (regs->rip == (uintptr_t)w_start) {
+ regs->rip = (uintptr_t)w_end;
+ } else {
+ GUEST_ASSERT(!"RIP is at an unknown location!");
+ }
+
+ ++guest_exception_count;
+}
+
+static void guest_gp_handler(struct ex_regs *regs)
+{
+ __guest_gp_handler(regs, &rdmsr_start, &rdmsr_end,
+ &wrmsr_start, &wrmsr_end);
+}
+
+static void guest_fep_gp_handler(struct ex_regs *regs)
+{
+ __guest_gp_handler(regs, &em_rdmsr_start, &em_rdmsr_end,
+ &em_wrmsr_start, &em_wrmsr_end);
+}
+
+static void guest_ud_handler(struct ex_regs *regs)
+{
+ fep_available = 0;
+ regs->rip += KVM_FEP_LENGTH;
+}
+
+static void check_for_guest_assert(struct kvm_vcpu *vcpu)
+{
+ struct ucall uc;
+
+ if (vcpu->run->exit_reason == KVM_EXIT_IO &&
+ get_ucall(vcpu, &uc) == UCALL_ABORT) {
+ REPORT_GUEST_ASSERT(uc);
+ }
+}
+
+static void process_rdmsr(struct kvm_vcpu *vcpu, uint32_t msr_index)
+{
+ struct kvm_run *run = vcpu->run;
+
+ check_for_guest_assert(vcpu);
+
+ TEST_ASSERT(run->exit_reason == KVM_EXIT_X86_RDMSR,
+ "Unexpected exit reason: %u (%s),\n",
+ run->exit_reason,
+ exit_reason_str(run->exit_reason));
+ TEST_ASSERT(run->msr.index == msr_index,
+ "Unexpected msr (0x%04x), expected 0x%04x",
+ run->msr.index, msr_index);
+
+ switch (run->msr.index) {
+ case MSR_IA32_XSS:
+ run->msr.data = 0;
+ break;
+ case MSR_IA32_FLUSH_CMD:
+ run->msr.error = 1;
+ break;
+ case MSR_NON_EXISTENT:
+ run->msr.data = msr_non_existent_data;
+ break;
+ case MSR_FS_BASE:
+ run->msr.data = MSR_FS_BASE;
+ break;
+ case MSR_GS_BASE:
+ run->msr.data = MSR_GS_BASE;
+ break;
+ default:
+ TEST_ASSERT(false, "Unexpected MSR: 0x%04x", run->msr.index);
+ }
+}
+
+static void process_wrmsr(struct kvm_vcpu *vcpu, uint32_t msr_index)
+{
+ struct kvm_run *run = vcpu->run;
+
+ check_for_guest_assert(vcpu);
+
+ TEST_ASSERT(run->exit_reason == KVM_EXIT_X86_WRMSR,
+ "Unexpected exit reason: %u (%s),\n",
+ run->exit_reason,
+ exit_reason_str(run->exit_reason));
+ TEST_ASSERT(run->msr.index == msr_index,
+ "Unexpected msr (0x%04x), expected 0x%04x",
+ run->msr.index, msr_index);
+
+ switch (run->msr.index) {
+ case MSR_IA32_XSS:
+ if (run->msr.data != 0)
+ run->msr.error = 1;
+ break;
+ case MSR_IA32_FLUSH_CMD:
+ if (run->msr.data != 1)
+ run->msr.error = 1;
+ break;
+ case MSR_NON_EXISTENT:
+ msr_non_existent_data = run->msr.data;
+ break;
+ default:
+ TEST_ASSERT(false, "Unexpected MSR: 0x%04x", run->msr.index);
+ }
+}
+
+static void process_ucall_done(struct kvm_vcpu *vcpu)
+{
+ struct kvm_run *run = vcpu->run;
+ struct ucall uc;
+
+ check_for_guest_assert(vcpu);
+
+ TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
+ "Unexpected exit reason: %u (%s)",
+ run->exit_reason,
+ exit_reason_str(run->exit_reason));
+
+ TEST_ASSERT(get_ucall(vcpu, &uc) == UCALL_DONE,
+ "Unexpected ucall command: %lu, expected UCALL_DONE (%d)",
+ uc.cmd, UCALL_DONE);
+}
+
+static uint64_t process_ucall(struct kvm_vcpu *vcpu)
+{
+ struct kvm_run *run = vcpu->run;
+ struct ucall uc = {};
+
+ check_for_guest_assert(vcpu);
+
+ 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(vcpu, &uc)) {
+ case UCALL_SYNC:
+ break;
+ case UCALL_ABORT:
+ check_for_guest_assert(vcpu);
+ break;
+ case UCALL_DONE:
+ process_ucall_done(vcpu);
+ break;
+ default:
+ TEST_ASSERT(false, "Unexpected ucall");
+ }
+
+ return uc.cmd;
+}
+
+static void run_guest_then_process_rdmsr(struct kvm_vcpu *vcpu,
+ uint32_t msr_index)
+{
+ vcpu_run(vcpu);
+ process_rdmsr(vcpu, msr_index);
+}
+
+static void run_guest_then_process_wrmsr(struct kvm_vcpu *vcpu,
+ uint32_t msr_index)
+{
+ vcpu_run(vcpu);
+ process_wrmsr(vcpu, msr_index);
+}
+
+static uint64_t run_guest_then_process_ucall(struct kvm_vcpu *vcpu)
+{
+ vcpu_run(vcpu);
+ return process_ucall(vcpu);
+}
+
+static void run_guest_then_process_ucall_done(struct kvm_vcpu *vcpu)
+{
+ vcpu_run(vcpu);
+ process_ucall_done(vcpu);
+}
+
+static void test_msr_filter_allow(void)
+{
+ struct kvm_vcpu *vcpu;
+ struct kvm_vm *vm;
+ int rc;
+
+ vm = vm_create_with_one_vcpu(&vcpu, guest_code_filter_allow);
+
+ rc = kvm_check_cap(KVM_CAP_X86_USER_SPACE_MSR);
+ TEST_ASSERT(rc, "KVM_CAP_X86_USER_SPACE_MSR is available");
+ vm_enable_cap(vm, KVM_CAP_X86_USER_SPACE_MSR, KVM_MSR_EXIT_REASON_FILTER);
+
+ rc = kvm_check_cap(KVM_CAP_X86_MSR_FILTER);
+ TEST_ASSERT(rc, "KVM_CAP_X86_MSR_FILTER is available");
+
+ vm_ioctl(vm, KVM_X86_SET_MSR_FILTER, &filter_allow);
+
+ vm_init_descriptor_tables(vm);
+ vcpu_init_descriptor_tables(vcpu);
+
+ vm_install_exception_handler(vm, GP_VECTOR, guest_gp_handler);
+
+ /* Process guest code userspace exits. */
+ run_guest_then_process_rdmsr(vcpu, MSR_IA32_XSS);
+ run_guest_then_process_wrmsr(vcpu, MSR_IA32_XSS);
+ run_guest_then_process_wrmsr(vcpu, MSR_IA32_XSS);
+
+ run_guest_then_process_rdmsr(vcpu, MSR_IA32_FLUSH_CMD);
+ run_guest_then_process_wrmsr(vcpu, MSR_IA32_FLUSH_CMD);
+ run_guest_then_process_wrmsr(vcpu, MSR_IA32_FLUSH_CMD);
+
+ run_guest_then_process_wrmsr(vcpu, MSR_NON_EXISTENT);
+ run_guest_then_process_rdmsr(vcpu, MSR_NON_EXISTENT);
+
+ vm_install_exception_handler(vm, UD_VECTOR, guest_ud_handler);
+ vcpu_run(vcpu);
+ vm_install_exception_handler(vm, UD_VECTOR, NULL);
+
+ if (process_ucall(vcpu) != UCALL_DONE) {
+ vm_install_exception_handler(vm, GP_VECTOR, guest_fep_gp_handler);
+
+ /* Process emulated rdmsr and wrmsr instructions. */
+ run_guest_then_process_rdmsr(vcpu, MSR_IA32_XSS);
+ run_guest_then_process_wrmsr(vcpu, MSR_IA32_XSS);
+ run_guest_then_process_wrmsr(vcpu, MSR_IA32_XSS);
+
+ run_guest_then_process_rdmsr(vcpu, MSR_IA32_FLUSH_CMD);
+ run_guest_then_process_wrmsr(vcpu, MSR_IA32_FLUSH_CMD);
+ run_guest_then_process_wrmsr(vcpu, MSR_IA32_FLUSH_CMD);
+
+ run_guest_then_process_wrmsr(vcpu, MSR_NON_EXISTENT);
+ run_guest_then_process_rdmsr(vcpu, MSR_NON_EXISTENT);
+
+ /* Confirm the guest completed without issues. */
+ run_guest_then_process_ucall_done(vcpu);
+ } else {
+ printf("To run the instruction emulated tests set the module parameter 'kvm.force_emulation_prefix=1'\n");
+ }
+
+ kvm_vm_free(vm);
+}
+
+static int handle_ucall(struct kvm_vcpu *vcpu)
+{
+ struct ucall uc;
+
+ switch (get_ucall(vcpu, &uc)) {
+ case UCALL_ABORT:
+ REPORT_GUEST_ASSERT(uc);
+ break;
+ case UCALL_SYNC:
+ vm_ioctl(vcpu->vm, KVM_X86_SET_MSR_FILTER, &no_filter_deny);
+ break;
+ case UCALL_DONE:
+ return 1;
+ default:
+ TEST_FAIL("Unknown ucall %lu", uc.cmd);
+ }
+
+ return 0;
+}
+
+static void handle_rdmsr(struct kvm_run *run)
+{
+ run->msr.data = run->msr.index;
+ msr_reads++;
+
+ if (run->msr.index == MSR_SYSCALL_MASK ||
+ run->msr.index == MSR_GS_BASE) {
+ TEST_ASSERT(run->msr.reason == KVM_MSR_EXIT_REASON_FILTER,
+ "MSR read trap w/o access fault");
+ }
+
+ if (run->msr.index == 0xdeadbeef) {
+ TEST_ASSERT(run->msr.reason == KVM_MSR_EXIT_REASON_UNKNOWN,
+ "MSR deadbeef read trap w/o inval fault");
+ }
+}
+
+static void handle_wrmsr(struct kvm_run *run)
+{
+ /* ignore */
+ msr_writes++;
+
+ if (run->msr.index == MSR_IA32_POWER_CTL) {
+ TEST_ASSERT(run->msr.data == 0x1234,
+ "MSR data for MSR_IA32_POWER_CTL incorrect");
+ TEST_ASSERT(run->msr.reason == KVM_MSR_EXIT_REASON_FILTER,
+ "MSR_IA32_POWER_CTL trap w/o access fault");
+ }
+
+ if (run->msr.index == 0xdeadbeef) {
+ TEST_ASSERT(run->msr.data == 0x1234,
+ "MSR data for deadbeef incorrect");
+ TEST_ASSERT(run->msr.reason == KVM_MSR_EXIT_REASON_UNKNOWN,
+ "deadbeef trap w/o inval fault");
+ }
+}
+
+static void test_msr_filter_deny(void)
+{
+ struct kvm_vcpu *vcpu;
+ struct kvm_vm *vm;
+ struct kvm_run *run;
+ int rc;
+
+ vm = vm_create_with_one_vcpu(&vcpu, guest_code_filter_deny);
+ run = vcpu->run;
+
+ rc = kvm_check_cap(KVM_CAP_X86_USER_SPACE_MSR);
+ TEST_ASSERT(rc, "KVM_CAP_X86_USER_SPACE_MSR is available");
+ vm_enable_cap(vm, KVM_CAP_X86_USER_SPACE_MSR, KVM_MSR_EXIT_REASON_INVAL |
+ KVM_MSR_EXIT_REASON_UNKNOWN |
+ KVM_MSR_EXIT_REASON_FILTER);
+
+ rc = kvm_check_cap(KVM_CAP_X86_MSR_FILTER);
+ TEST_ASSERT(rc, "KVM_CAP_X86_MSR_FILTER is available");
+
+ prepare_bitmaps();
+ vm_ioctl(vm, KVM_X86_SET_MSR_FILTER, &filter_deny);
+
+ while (1) {
+ vcpu_run(vcpu);
+
+ switch (run->exit_reason) {
+ case KVM_EXIT_X86_RDMSR:
+ handle_rdmsr(run);
+ break;
+ case KVM_EXIT_X86_WRMSR:
+ handle_wrmsr(run);
+ break;
+ case KVM_EXIT_IO:
+ if (handle_ucall(vcpu))
+ goto done;
+ break;
+ }
+
+ }
+
+done:
+ TEST_ASSERT(msr_reads == 4, "Handled 4 rdmsr in user space");
+ TEST_ASSERT(msr_writes == 3, "Handled 3 wrmsr in user space");
+
+ kvm_vm_free(vm);
+}
+
+static void test_msr_permission_bitmap(void)
+{
+ struct kvm_vcpu *vcpu;
+ struct kvm_vm *vm;
+ int rc;
+
+ vm = vm_create_with_one_vcpu(&vcpu, guest_code_permission_bitmap);
+
+ rc = kvm_check_cap(KVM_CAP_X86_USER_SPACE_MSR);
+ TEST_ASSERT(rc, "KVM_CAP_X86_USER_SPACE_MSR is available");
+ vm_enable_cap(vm, KVM_CAP_X86_USER_SPACE_MSR, KVM_MSR_EXIT_REASON_FILTER);
+
+ rc = kvm_check_cap(KVM_CAP_X86_MSR_FILTER);
+ TEST_ASSERT(rc, "KVM_CAP_X86_MSR_FILTER is available");
+
+ vm_ioctl(vm, KVM_X86_SET_MSR_FILTER, &filter_fs);
+ run_guest_then_process_rdmsr(vcpu, MSR_FS_BASE);
+ TEST_ASSERT(run_guest_then_process_ucall(vcpu) == UCALL_SYNC,
+ "Expected ucall state to be UCALL_SYNC.");
+ vm_ioctl(vm, KVM_X86_SET_MSR_FILTER, &filter_gs);
+ run_guest_then_process_rdmsr(vcpu, MSR_GS_BASE);
+ run_guest_then_process_ucall_done(vcpu);
+
+ kvm_vm_free(vm);
+}
+
+int main(int argc, char *argv[])
+{
+ /* Tell stdout not to buffer its content */
+ setbuf(stdout, NULL);
+
+ test_msr_filter_allow();
+
+ test_msr_filter_deny();
+
+ test_msr_permission_bitmap();
+
+ return 0;
+}
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