From b78f4a596692f6805e796a4c13f2d921b8a95166 Mon Sep 17 00:00:00 2001 From: Ricardo Koller Date: Thu, 10 Jun 2021 18:10:15 -0700 Subject: [PATCH 1/6] KVM: selftests: Rename vm_handle_exception Rename the vm_handle_exception function to a name that indicates more clearly that it installs something: vm_install_exception_handler. Reported-by: kernel test robot Suggested-by: Marc Zyngier Suggested-by: Andrew Jones Signed-off-by: Ricardo Koller Reviewed-by: Andrew Jones Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20210611011020.3420067-2-ricarkol@google.com --- tools/testing/selftests/kvm/include/x86_64/processor.h | 2 +- tools/testing/selftests/kvm/lib/x86_64/processor.c | 4 ++-- tools/testing/selftests/kvm/x86_64/evmcs_test.c | 4 ++-- tools/testing/selftests/kvm/x86_64/kvm_pv_test.c | 2 +- .../selftests/kvm/x86_64/userspace_msr_exit_test.c | 8 ++++---- tools/testing/selftests/kvm/x86_64/xapic_ipi_test.c | 2 +- 6 files changed, 11 insertions(+), 11 deletions(-) diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h index 0b30b4e15c38..e9f584991332 100644 --- a/tools/testing/selftests/kvm/include/x86_64/processor.h +++ b/tools/testing/selftests/kvm/include/x86_64/processor.h @@ -391,7 +391,7 @@ struct ex_regs { void vm_init_descriptor_tables(struct kvm_vm *vm); void vcpu_init_descriptor_tables(struct kvm_vm *vm, uint32_t vcpuid); -void vm_handle_exception(struct kvm_vm *vm, int vector, +void vm_install_exception_handler(struct kvm_vm *vm, int vector, void (*handler)(struct ex_regs *)); /* diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c index efe235044421..257c5c33d04e 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c @@ -1244,8 +1244,8 @@ void vcpu_init_descriptor_tables(struct kvm_vm *vm, uint32_t vcpuid) *(vm_vaddr_t *)addr_gva2hva(vm, (vm_vaddr_t)(&exception_handlers)) = vm->handlers; } -void vm_handle_exception(struct kvm_vm *vm, int vector, - void (*handler)(struct ex_regs *)) +void vm_install_exception_handler(struct kvm_vm *vm, int vector, + void (*handler)(struct ex_regs *)) { vm_vaddr_t *handlers = (vm_vaddr_t *)addr_gva2hva(vm, vm->handlers); diff --git a/tools/testing/selftests/kvm/x86_64/evmcs_test.c b/tools/testing/selftests/kvm/x86_64/evmcs_test.c index 63096cea26c6..0864b2e3fd9e 100644 --- a/tools/testing/selftests/kvm/x86_64/evmcs_test.c +++ b/tools/testing/selftests/kvm/x86_64/evmcs_test.c @@ -154,8 +154,8 @@ int main(int argc, char *argv[]) vm_init_descriptor_tables(vm); vcpu_init_descriptor_tables(vm, VCPU_ID); - vm_handle_exception(vm, UD_VECTOR, guest_ud_handler); - vm_handle_exception(vm, NMI_VECTOR, guest_nmi_handler); + vm_install_exception_handler(vm, UD_VECTOR, guest_ud_handler); + vm_install_exception_handler(vm, NMI_VECTOR, guest_nmi_handler); pr_info("Running L1 which uses EVMCS to run L2\n"); diff --git a/tools/testing/selftests/kvm/x86_64/kvm_pv_test.c b/tools/testing/selftests/kvm/x86_64/kvm_pv_test.c index 732b244d6956..04ed975662c9 100644 --- a/tools/testing/selftests/kvm/x86_64/kvm_pv_test.c +++ b/tools/testing/selftests/kvm/x86_64/kvm_pv_test.c @@ -227,7 +227,7 @@ int main(void) vm_init_descriptor_tables(vm); vcpu_init_descriptor_tables(vm, VCPU_ID); - vm_handle_exception(vm, GP_VECTOR, guest_gp_handler); + vm_install_exception_handler(vm, GP_VECTOR, guest_gp_handler); enter_guest(vm); kvm_vm_free(vm); 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 index 72c0d0797522..e3e20e8848d0 100644 --- a/tools/testing/selftests/kvm/x86_64/userspace_msr_exit_test.c +++ b/tools/testing/selftests/kvm/x86_64/userspace_msr_exit_test.c @@ -574,7 +574,7 @@ static void test_msr_filter_allow(void) { vm_init_descriptor_tables(vm); vcpu_init_descriptor_tables(vm, VCPU_ID); - vm_handle_exception(vm, GP_VECTOR, guest_gp_handler); + vm_install_exception_handler(vm, GP_VECTOR, guest_gp_handler); /* Process guest code userspace exits. */ run_guest_then_process_rdmsr(vm, MSR_IA32_XSS); @@ -588,12 +588,12 @@ static void test_msr_filter_allow(void) { run_guest_then_process_wrmsr(vm, MSR_NON_EXISTENT); run_guest_then_process_rdmsr(vm, MSR_NON_EXISTENT); - vm_handle_exception(vm, UD_VECTOR, guest_ud_handler); + vm_install_exception_handler(vm, UD_VECTOR, guest_ud_handler); run_guest(vm); - vm_handle_exception(vm, UD_VECTOR, NULL); + vm_install_exception_handler(vm, UD_VECTOR, NULL); if (process_ucall(vm) != UCALL_DONE) { - vm_handle_exception(vm, GP_VECTOR, guest_fep_gp_handler); + vm_install_exception_handler(vm, GP_VECTOR, guest_fep_gp_handler); /* Process emulated rdmsr and wrmsr instructions. */ run_guest_then_process_rdmsr(vm, MSR_IA32_XSS); diff --git a/tools/testing/selftests/kvm/x86_64/xapic_ipi_test.c b/tools/testing/selftests/kvm/x86_64/xapic_ipi_test.c index 2f964cdc273c..ed27269a01bb 100644 --- a/tools/testing/selftests/kvm/x86_64/xapic_ipi_test.c +++ b/tools/testing/selftests/kvm/x86_64/xapic_ipi_test.c @@ -462,7 +462,7 @@ int main(int argc, char *argv[]) vm_init_descriptor_tables(vm); vcpu_init_descriptor_tables(vm, HALTER_VCPU_ID); - vm_handle_exception(vm, IPI_VECTOR, guest_ipi_handler); + vm_install_exception_handler(vm, IPI_VECTOR, guest_ipi_handler); virt_pg_map(vm, APIC_DEFAULT_GPA, APIC_DEFAULT_GPA, 0); From b7326c01122683b88e273a0cc826cd4c01234470 Mon Sep 17 00:00:00 2001 From: Ricardo Koller Date: Thu, 10 Jun 2021 18:10:16 -0700 Subject: [PATCH 2/6] KVM: selftests: Complete x86_64/sync_regs_test ucall The guest in sync_regs_test does raw ucalls by directly accessing the ucall IO port. It makes these ucalls without setting %rdi to a `struct ucall`, which is what a ucall uses to pass messages. The issue is that if the host did a get_ucall (the receiver side), it would try to access the `struct ucall` at %rdi=0 which would lead to an error ("No mapping for vm virtual address, gva: 0x0"). This issue is currently benign as there is no get_ucall in sync_regs_test; however, that will change in the next commit as it changes the unhandled exception reporting mechanism to use ucalls. In that case, every vcpu_run is followed by a get_ucall to check if the guest is trying to report an unhandled exception. Fix this in advance by setting %rdi to a UCALL_NONE struct ucall for the sync_regs_test guest. Tested with gcc-[8,9,10], and clang-[9,11]. Signed-off-by: Ricardo Koller Reviewed-by: Andrew Jones Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20210611011020.3420067-3-ricarkol@google.com --- tools/testing/selftests/kvm/x86_64/sync_regs_test.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/kvm/x86_64/sync_regs_test.c b/tools/testing/selftests/kvm/x86_64/sync_regs_test.c index d672f0a473f8..fc03a150278d 100644 --- a/tools/testing/selftests/kvm/x86_64/sync_regs_test.c +++ b/tools/testing/selftests/kvm/x86_64/sync_regs_test.c @@ -24,6 +24,10 @@ #define UCALL_PIO_PORT ((uint16_t)0x1000) +struct ucall uc_none = { + .cmd = UCALL_NONE, +}; + /* * ucall is embedded here to protect against compiler reshuffling registers * before calling a function. In this test we only need to get KVM_EXIT_IO @@ -34,7 +38,8 @@ void guest_code(void) asm volatile("1: in %[port], %%al\n" "add $0x1, %%rbx\n" "jmp 1b" - : : [port] "d" (UCALL_PIO_PORT) : "rax", "rbx"); + : : [port] "d" (UCALL_PIO_PORT), "D" (&uc_none) + : "rax", "rbx"); } static void compare_regs(struct kvm_regs *left, struct kvm_regs *right) From 75275d7fbef47805b77e8af81a4d51e2d92db70f Mon Sep 17 00:00:00 2001 From: Ricardo Koller Date: Thu, 10 Jun 2021 18:10:17 -0700 Subject: [PATCH 3/6] KVM: selftests: Introduce UCALL_UNHANDLED for unhandled vector reporting x86, the only arch implementing exception handling, reports unhandled vectors using port IO at a specific port number. This replicates what ucall already does. Introduce a new ucall type, UCALL_UNHANDLED, for guests to report unhandled exceptions. Then replace the x86 unhandled vector exception reporting to use it instead of port IO. This new ucall type will be used in the next commits by arm64 to report unhandled vectors as well. Tested: Forcing a page fault in the ./x86_64/xapic_ipi_test halter_guest_code() shows this: $ ./x86_64/xapic_ipi_test ... Unexpected vectored event in guest (vector:0xe) Signed-off-by: Ricardo Koller Reviewed-by: Andrew Jones Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20210611011020.3420067-4-ricarkol@google.com --- tools/testing/selftests/kvm/include/kvm_util.h | 1 + .../selftests/kvm/include/x86_64/processor.h | 2 -- .../selftests/kvm/lib/x86_64/processor.c | 17 +++++++---------- 3 files changed, 8 insertions(+), 12 deletions(-) diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h index fcd8e3855111..beb76d6deaa9 100644 --- a/tools/testing/selftests/kvm/include/kvm_util.h +++ b/tools/testing/selftests/kvm/include/kvm_util.h @@ -349,6 +349,7 @@ enum { UCALL_SYNC, UCALL_ABORT, UCALL_DONE, + UCALL_UNHANDLED, }; #define UCALL_MAX_ARGS 6 diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h index e9f584991332..92a62c6999bc 100644 --- a/tools/testing/selftests/kvm/include/x86_64/processor.h +++ b/tools/testing/selftests/kvm/include/x86_64/processor.h @@ -53,8 +53,6 @@ #define CPUID_PKU (1ul << 3) #define CPUID_LA57 (1ul << 16) -#define UNEXPECTED_VECTOR_PORT 0xfff0u - /* General Registers in 64-Bit Mode */ struct gpr64_regs { u64 rax; diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c index 257c5c33d04e..a217515a9bc2 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c @@ -1201,7 +1201,7 @@ static void set_idt_entry(struct kvm_vm *vm, int vector, unsigned long addr, void kvm_exit_unexpected_vector(uint32_t value) { - outl(UNEXPECTED_VECTOR_PORT, value); + ucall(UCALL_UNHANDLED, 1, value); } void route_exception(struct ex_regs *regs) @@ -1254,16 +1254,13 @@ void vm_install_exception_handler(struct kvm_vm *vm, int vector, void assert_on_unhandled_exception(struct kvm_vm *vm, uint32_t vcpuid) { - if (vcpu_state(vm, vcpuid)->exit_reason == KVM_EXIT_IO - && vcpu_state(vm, vcpuid)->io.port == UNEXPECTED_VECTOR_PORT - && vcpu_state(vm, vcpuid)->io.size == 4) { - /* Grab pointer to io data */ - uint32_t *data = (void *)vcpu_state(vm, vcpuid) - + vcpu_state(vm, vcpuid)->io.data_offset; + struct ucall uc; - TEST_ASSERT(false, - "Unexpected vectored event in guest (vector:0x%x)", - *data); + if (get_ucall(vm, vcpuid, &uc) == UCALL_UNHANDLED) { + uint64_t vector = uc.args[0]; + + TEST_FAIL("Unexpected vectored event in guest (vector:0x%lx)", + vector); } } From 67f709f52bf0b5c19f24d1234163123cbb6af545 Mon Sep 17 00:00:00 2001 From: Ricardo Koller Date: Thu, 10 Jun 2021 18:10:18 -0700 Subject: [PATCH 4/6] KVM: selftests: Move GUEST_ASSERT_EQ to utils header Move GUEST_ASSERT_EQ to a common header, kvm_util.h, for other architectures and tests to use. Also modify __GUEST_ASSERT so it can be reused to implement GUEST_ASSERT_EQ. Signed-off-by: Ricardo Koller Reviewed-by: Andrew Jones Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20210611011020.3420067-5-ricarkol@google.com --- .../testing/selftests/kvm/include/kvm_util.h | 22 ++++++++++--------- .../selftests/kvm/x86_64/tsc_msrs_test.c | 9 -------- 2 files changed, 12 insertions(+), 19 deletions(-) diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h index beb76d6deaa9..ce49e22843d8 100644 --- a/tools/testing/selftests/kvm/include/kvm_util.h +++ b/tools/testing/selftests/kvm/include/kvm_util.h @@ -368,26 +368,28 @@ uint64_t get_ucall(struct kvm_vm *vm, uint32_t vcpu_id, struct ucall *uc); ucall(UCALL_SYNC, 6, "hello", stage, arg1, arg2, arg3, arg4) #define GUEST_SYNC(stage) ucall(UCALL_SYNC, 2, "hello", stage) #define GUEST_DONE() ucall(UCALL_DONE, 0) -#define __GUEST_ASSERT(_condition, _nargs, _args...) do { \ - if (!(_condition)) \ - ucall(UCALL_ABORT, 2 + _nargs, \ - "Failed guest assert: " \ - #_condition, __LINE__, _args); \ +#define __GUEST_ASSERT(_condition, _condstr, _nargs, _args...) do { \ + if (!(_condition)) \ + ucall(UCALL_ABORT, 2 + _nargs, \ + "Failed guest assert: " \ + _condstr, __LINE__, _args); \ } while (0) #define GUEST_ASSERT(_condition) \ - __GUEST_ASSERT((_condition), 0, 0) + __GUEST_ASSERT(_condition, #_condition, 0, 0) #define GUEST_ASSERT_1(_condition, arg1) \ - __GUEST_ASSERT((_condition), 1, (arg1)) + __GUEST_ASSERT(_condition, #_condition, 1, (arg1)) #define GUEST_ASSERT_2(_condition, arg1, arg2) \ - __GUEST_ASSERT((_condition), 2, (arg1), (arg2)) + __GUEST_ASSERT(_condition, #_condition, 2, (arg1), (arg2)) #define GUEST_ASSERT_3(_condition, arg1, arg2, arg3) \ - __GUEST_ASSERT((_condition), 3, (arg1), (arg2), (arg3)) + __GUEST_ASSERT(_condition, #_condition, 3, (arg1), (arg2), (arg3)) #define GUEST_ASSERT_4(_condition, arg1, arg2, arg3, arg4) \ - __GUEST_ASSERT((_condition), 4, (arg1), (arg2), (arg3), (arg4)) + __GUEST_ASSERT(_condition, #_condition, 4, (arg1), (arg2), (arg3), (arg4)) + +#define GUEST_ASSERT_EQ(a, b) __GUEST_ASSERT((a) == (b), #a " == " #b, 2, a, b) #endif /* SELFTEST_KVM_UTIL_H */ diff --git a/tools/testing/selftests/kvm/x86_64/tsc_msrs_test.c b/tools/testing/selftests/kvm/x86_64/tsc_msrs_test.c index e357d8e222d4..5a6a662f2e59 100644 --- a/tools/testing/selftests/kvm/x86_64/tsc_msrs_test.c +++ b/tools/testing/selftests/kvm/x86_64/tsc_msrs_test.c @@ -18,15 +18,6 @@ #define rounded_rdmsr(x) ROUND(rdmsr(x)) #define rounded_host_rdmsr(x) ROUND(vcpu_get_msr(vm, 0, x)) -#define GUEST_ASSERT_EQ(a, b) do { \ - __typeof(a) _a = (a); \ - __typeof(b) _b = (b); \ - if (_a != _b) \ - ucall(UCALL_ABORT, 4, \ - "Failed guest assert: " \ - #a " == " #b, __LINE__, _a, _b); \ - } while(0) - static void guest_code(void) { u64 val = 0; From e3db7579ef355a0b2bfef4448b84d9ac882c8f2c Mon Sep 17 00:00:00 2001 From: Ricardo Koller Date: Thu, 10 Jun 2021 18:10:19 -0700 Subject: [PATCH 5/6] KVM: selftests: Add exception handling support for aarch64 Add the infrastructure needed to enable exception handling in aarch64 selftests. The exception handling defaults to an unhandled-exception handler which aborts the test, just like x86. These handlers can be overridden by calling vm_install_exception_handler(vector) or vm_install_sync_handler(vector, ec). The unhandled exception reporting from the guest is done using the ucall type introduced in a previous commit, UCALL_UNHANDLED. The exception handling code is inspired on kvm-unit-tests. Signed-off-by: Ricardo Koller Reviewed-by: Andrew Jones Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20210611011020.3420067-6-ricarkol@google.com --- tools/testing/selftests/kvm/Makefile | 2 +- .../selftests/kvm/include/aarch64/processor.h | 63 +++++++++ .../selftests/kvm/lib/aarch64/handlers.S | 126 ++++++++++++++++++ .../selftests/kvm/lib/aarch64/processor.c | 97 ++++++++++++++ 4 files changed, 287 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/kvm/lib/aarch64/handlers.S diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index daaee1888b12..a77e6063f7e9 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -35,7 +35,7 @@ endif LIBKVM = lib/assert.c lib/elf.c lib/io.c lib/kvm_util.c lib/rbtree.c lib/sparsebit.c lib/test_util.c lib/guest_modes.c lib/perf_test_util.c LIBKVM_x86_64 = lib/x86_64/processor.c lib/x86_64/vmx.c lib/x86_64/svm.c lib/x86_64/ucall.c lib/x86_64/handlers.S -LIBKVM_aarch64 = lib/aarch64/processor.c lib/aarch64/ucall.c +LIBKVM_aarch64 = lib/aarch64/processor.c lib/aarch64/ucall.c lib/aarch64/handlers.S LIBKVM_s390x = lib/s390x/processor.c lib/s390x/ucall.c lib/s390x/diag318_test_handler.c TEST_GEN_PROGS_x86_64 = x86_64/cr4_cpuid_sync_test diff --git a/tools/testing/selftests/kvm/include/aarch64/processor.h b/tools/testing/selftests/kvm/include/aarch64/processor.h index b7fa0c8551db..b2b3e9d626cb 100644 --- a/tools/testing/selftests/kvm/include/aarch64/processor.h +++ b/tools/testing/selftests/kvm/include/aarch64/processor.h @@ -8,6 +8,7 @@ #define SELFTEST_KVM_PROCESSOR_H #include "kvm_util.h" +#include #define ARM64_CORE_REG(x) (KVM_REG_ARM64 | KVM_REG_SIZE_U64 | \ @@ -18,6 +19,7 @@ #define MAIR_EL1 3, 0, 10, 2, 0 #define TTBR0_EL1 3, 0, 2, 0, 0 #define SCTLR_EL1 3, 0, 1, 0, 0 +#define VBAR_EL1 3, 0, 12, 0, 0 /* * Default MAIR @@ -56,4 +58,65 @@ void aarch64_vcpu_setup(struct kvm_vm *vm, int vcpuid, struct kvm_vcpu_init *ini void aarch64_vcpu_add_default(struct kvm_vm *vm, uint32_t vcpuid, struct kvm_vcpu_init *init, void *guest_code); +struct ex_regs { + u64 regs[31]; + u64 sp; + u64 pc; + u64 pstate; +}; + +#define VECTOR_NUM 16 + +enum { + VECTOR_SYNC_CURRENT_SP0, + VECTOR_IRQ_CURRENT_SP0, + VECTOR_FIQ_CURRENT_SP0, + VECTOR_ERROR_CURRENT_SP0, + + VECTOR_SYNC_CURRENT, + VECTOR_IRQ_CURRENT, + VECTOR_FIQ_CURRENT, + VECTOR_ERROR_CURRENT, + + VECTOR_SYNC_LOWER_64, + VECTOR_IRQ_LOWER_64, + VECTOR_FIQ_LOWER_64, + VECTOR_ERROR_LOWER_64, + + VECTOR_SYNC_LOWER_32, + VECTOR_IRQ_LOWER_32, + VECTOR_FIQ_LOWER_32, + VECTOR_ERROR_LOWER_32, +}; + +#define VECTOR_IS_SYNC(v) ((v) == VECTOR_SYNC_CURRENT_SP0 || \ + (v) == VECTOR_SYNC_CURRENT || \ + (v) == VECTOR_SYNC_LOWER_64 || \ + (v) == VECTOR_SYNC_LOWER_32) + +#define ESR_EC_NUM 64 +#define ESR_EC_SHIFT 26 +#define ESR_EC_MASK (ESR_EC_NUM - 1) + +void vm_init_descriptor_tables(struct kvm_vm *vm); +void vcpu_init_descriptor_tables(struct kvm_vm *vm, uint32_t vcpuid); + +typedef void(*handler_fn)(struct ex_regs *); +void vm_install_exception_handler(struct kvm_vm *vm, + int vector, handler_fn handler); +void vm_install_sync_handler(struct kvm_vm *vm, + int vector, int ec, handler_fn handler); + +#define write_sysreg(reg, val) \ +({ \ + u64 __val = (u64)(val); \ + asm volatile("msr " __stringify(reg) ", %x0" : : "rZ" (__val)); \ +}) + +#define read_sysreg(reg) \ +({ u64 val; \ + asm volatile("mrs %0, "__stringify(reg) : "=r"(val) : : "memory");\ + val; \ +}) + #endif /* SELFTEST_KVM_PROCESSOR_H */ diff --git a/tools/testing/selftests/kvm/lib/aarch64/handlers.S b/tools/testing/selftests/kvm/lib/aarch64/handlers.S new file mode 100644 index 000000000000..0e443eadfac6 --- /dev/null +++ b/tools/testing/selftests/kvm/lib/aarch64/handlers.S @@ -0,0 +1,126 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +.macro save_registers + add sp, sp, #-16 * 17 + + stp x0, x1, [sp, #16 * 0] + stp x2, x3, [sp, #16 * 1] + stp x4, x5, [sp, #16 * 2] + stp x6, x7, [sp, #16 * 3] + stp x8, x9, [sp, #16 * 4] + stp x10, x11, [sp, #16 * 5] + stp x12, x13, [sp, #16 * 6] + stp x14, x15, [sp, #16 * 7] + stp x16, x17, [sp, #16 * 8] + stp x18, x19, [sp, #16 * 9] + stp x20, x21, [sp, #16 * 10] + stp x22, x23, [sp, #16 * 11] + stp x24, x25, [sp, #16 * 12] + stp x26, x27, [sp, #16 * 13] + stp x28, x29, [sp, #16 * 14] + + /* + * This stores sp_el1 into ex_regs.sp so exception handlers can "look" + * at it. It will _not_ be used to restore the sp on return from the + * exception so handlers can not update it. + */ + add x1, sp, #16 * 17 + stp x30, x1, [sp, #16 * 15] /* x30, SP */ + + mrs x1, elr_el1 + mrs x2, spsr_el1 + stp x1, x2, [sp, #16 * 16] /* PC, PSTATE */ +.endm + +.macro restore_registers + ldp x1, x2, [sp, #16 * 16] /* PC, PSTATE */ + msr elr_el1, x1 + msr spsr_el1, x2 + + /* sp is not restored */ + ldp x30, xzr, [sp, #16 * 15] /* x30, SP */ + + ldp x28, x29, [sp, #16 * 14] + ldp x26, x27, [sp, #16 * 13] + ldp x24, x25, [sp, #16 * 12] + ldp x22, x23, [sp, #16 * 11] + ldp x20, x21, [sp, #16 * 10] + ldp x18, x19, [sp, #16 * 9] + ldp x16, x17, [sp, #16 * 8] + ldp x14, x15, [sp, #16 * 7] + ldp x12, x13, [sp, #16 * 6] + ldp x10, x11, [sp, #16 * 5] + ldp x8, x9, [sp, #16 * 4] + ldp x6, x7, [sp, #16 * 3] + ldp x4, x5, [sp, #16 * 2] + ldp x2, x3, [sp, #16 * 1] + ldp x0, x1, [sp, #16 * 0] + + add sp, sp, #16 * 17 + + eret +.endm + +.pushsection ".entry.text", "ax" +.balign 0x800 +.global vectors +vectors: +.popsection + +.set vector, 0 + +/* + * Build an exception handler for vector and append a jump to it into + * vectors (while making sure that it's 0x80 aligned). + */ +.macro HANDLER, label +handler_\label: + save_registers + mov x0, sp + mov x1, #vector + bl route_exception + restore_registers + +.pushsection ".entry.text", "ax" +.balign 0x80 + b handler_\label +.popsection + +.set vector, vector + 1 +.endm + +.macro HANDLER_INVALID +.pushsection ".entry.text", "ax" +.balign 0x80 +/* This will abort so no need to save and restore registers. */ + mov x0, #vector + mov x1, #0 /* ec */ + mov x2, #0 /* valid_ec */ + b kvm_exit_unexpected_exception +.popsection + +.set vector, vector + 1 +.endm + +/* + * Caution: be sure to not add anything between the declaration of vectors + * above and these macro calls that will build the vectors table below it. + */ + HANDLER_INVALID // Synchronous EL1t + HANDLER_INVALID // IRQ EL1t + HANDLER_INVALID // FIQ EL1t + HANDLER_INVALID // Error EL1t + + HANDLER el1h_sync // Synchronous EL1h + HANDLER el1h_irq // IRQ EL1h + HANDLER el1h_fiq // FIQ EL1h + HANDLER el1h_error // Error EL1h + + HANDLER el0_sync_64 // Synchronous 64-bit EL0 + HANDLER el0_irq_64 // IRQ 64-bit EL0 + HANDLER el0_fiq_64 // FIQ 64-bit EL0 + HANDLER el0_error_64 // Error 64-bit EL0 + + HANDLER el0_sync_32 // Synchronous 32-bit EL0 + HANDLER el0_irq_32 // IRQ 32-bit EL0 + HANDLER el0_fiq_32 // FIQ 32-bit EL0 + HANDLER el0_error_32 // Error 32-bit EL0 diff --git a/tools/testing/selftests/kvm/lib/aarch64/processor.c b/tools/testing/selftests/kvm/lib/aarch64/processor.c index cee92d477dc0..48b55c93f858 100644 --- a/tools/testing/selftests/kvm/lib/aarch64/processor.c +++ b/tools/testing/selftests/kvm/lib/aarch64/processor.c @@ -6,6 +6,7 @@ */ #include +#include #include "kvm_util.h" #include "../kvm_util_internal.h" @@ -14,6 +15,8 @@ #define KVM_GUEST_PAGE_TABLE_MIN_PADDR 0x180000 #define DEFAULT_ARM64_GUEST_STACK_VADDR_MIN 0xac0000 +static vm_vaddr_t exception_handlers; + static uint64_t page_align(struct kvm_vm *vm, uint64_t v) { return (v + vm->page_size) & ~(vm->page_size - 1); @@ -334,6 +337,100 @@ void vcpu_args_set(struct kvm_vm *vm, uint32_t vcpuid, unsigned int num, ...) va_end(ap); } +void kvm_exit_unexpected_exception(int vector, uint64_t ec, bool valid_ec) +{ + ucall(UCALL_UNHANDLED, 3, vector, ec, valid_ec); + while (1) + ; +} + void assert_on_unhandled_exception(struct kvm_vm *vm, uint32_t vcpuid) { + struct ucall uc; + + if (get_ucall(vm, vcpuid, &uc) != UCALL_UNHANDLED) + return; + + if (uc.args[2]) /* valid_ec */ { + assert(VECTOR_IS_SYNC(uc.args[0])); + TEST_FAIL("Unexpected exception (vector:0x%lx, ec:0x%lx)", + uc.args[0], uc.args[1]); + } else { + assert(!VECTOR_IS_SYNC(uc.args[0])); + TEST_FAIL("Unexpected exception (vector:0x%lx)", + uc.args[0]); + } +} + +struct handlers { + handler_fn exception_handlers[VECTOR_NUM][ESR_EC_NUM]; +}; + +void vcpu_init_descriptor_tables(struct kvm_vm *vm, uint32_t vcpuid) +{ + extern char vectors; + + set_reg(vm, vcpuid, ARM64_SYS_REG(VBAR_EL1), (uint64_t)&vectors); +} + +void route_exception(struct ex_regs *regs, int vector) +{ + struct handlers *handlers = (struct handlers *)exception_handlers; + bool valid_ec; + int ec = 0; + + switch (vector) { + case VECTOR_SYNC_CURRENT: + case VECTOR_SYNC_LOWER_64: + ec = (read_sysreg(esr_el1) >> ESR_EC_SHIFT) & ESR_EC_MASK; + valid_ec = true; + break; + case VECTOR_IRQ_CURRENT: + case VECTOR_IRQ_LOWER_64: + case VECTOR_FIQ_CURRENT: + case VECTOR_FIQ_LOWER_64: + case VECTOR_ERROR_CURRENT: + case VECTOR_ERROR_LOWER_64: + ec = 0; + valid_ec = false; + break; + default: + valid_ec = false; + goto unexpected_exception; + } + + if (handlers && handlers->exception_handlers[vector][ec]) + return handlers->exception_handlers[vector][ec](regs); + +unexpected_exception: + kvm_exit_unexpected_exception(vector, ec, valid_ec); +} + +void vm_init_descriptor_tables(struct kvm_vm *vm) +{ + vm->handlers = vm_vaddr_alloc(vm, sizeof(struct handlers), + vm->page_size, 0, 0); + + *(vm_vaddr_t *)addr_gva2hva(vm, (vm_vaddr_t)(&exception_handlers)) = vm->handlers; +} + +void vm_install_sync_handler(struct kvm_vm *vm, int vector, int ec, + void (*handler)(struct ex_regs *)) +{ + struct handlers *handlers = addr_gva2hva(vm, vm->handlers); + + assert(VECTOR_IS_SYNC(vector)); + assert(vector < VECTOR_NUM); + assert(ec < ESR_EC_NUM); + handlers->exception_handlers[vector][ec] = handler; +} + +void vm_install_exception_handler(struct kvm_vm *vm, int vector, + void (*handler)(struct ex_regs *)) +{ + struct handlers *handlers = addr_gva2hva(vm, vm->handlers); + + assert(!VECTOR_IS_SYNC(vector)); + assert(vector < VECTOR_NUM); + handlers->exception_handlers[vector][0] = handler; } From 4f05223acaeaabe0a1a188e25fab334735d85c5e Mon Sep 17 00:00:00 2001 From: Ricardo Koller Date: Thu, 10 Jun 2021 18:10:20 -0700 Subject: [PATCH 6/6] KVM: selftests: Add aarch64/debug-exceptions test Covers fundamental tests for debug exceptions. The guest installs and handle its debug exceptions itself, without KVM_SET_GUEST_DEBUG. Signed-off-by: Ricardo Koller Reviewed-by: Andrew Jones Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20210611011020.3420067-7-ricarkol@google.com --- tools/testing/selftests/kvm/.gitignore | 1 + tools/testing/selftests/kvm/Makefile | 1 + .../selftests/kvm/aarch64/debug-exceptions.c | 250 ++++++++++++++++++ .../selftests/kvm/include/aarch64/processor.h | 22 +- 4 files changed, 268 insertions(+), 6 deletions(-) create mode 100644 tools/testing/selftests/kvm/aarch64/debug-exceptions.c diff --git a/tools/testing/selftests/kvm/.gitignore b/tools/testing/selftests/kvm/.gitignore index 524c857a049c..7e2c66155b06 100644 --- a/tools/testing/selftests/kvm/.gitignore +++ b/tools/testing/selftests/kvm/.gitignore @@ -1,4 +1,5 @@ # SPDX-License-Identifier: GPL-2.0-only +/aarch64/debug-exceptions /aarch64/get-reg-list /aarch64/get-reg-list-sve /aarch64/vgic_init diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index a77e6063f7e9..36e4ebcc82f0 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -78,6 +78,7 @@ TEST_GEN_PROGS_x86_64 += memslot_perf_test TEST_GEN_PROGS_x86_64 += set_memory_region_test TEST_GEN_PROGS_x86_64 += steal_time +TEST_GEN_PROGS_aarch64 += aarch64/debug-exceptions TEST_GEN_PROGS_aarch64 += aarch64/get-reg-list TEST_GEN_PROGS_aarch64 += aarch64/get-reg-list-sve TEST_GEN_PROGS_aarch64 += aarch64/vgic_init diff --git a/tools/testing/selftests/kvm/aarch64/debug-exceptions.c b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c new file mode 100644 index 000000000000..e5e6c92b60da --- /dev/null +++ b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c @@ -0,0 +1,250 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include + +#define VCPU_ID 0 + +#define MDSCR_KDE (1 << 13) +#define MDSCR_MDE (1 << 15) +#define MDSCR_SS (1 << 0) + +#define DBGBCR_LEN8 (0xff << 5) +#define DBGBCR_EXEC (0x0 << 3) +#define DBGBCR_EL1 (0x1 << 1) +#define DBGBCR_E (0x1 << 0) + +#define DBGWCR_LEN8 (0xff << 5) +#define DBGWCR_RD (0x1 << 3) +#define DBGWCR_WR (0x2 << 3) +#define DBGWCR_EL1 (0x1 << 1) +#define DBGWCR_E (0x1 << 0) + +#define SPSR_D (1 << 9) +#define SPSR_SS (1 << 21) + +extern unsigned char sw_bp, hw_bp, bp_svc, bp_brk, hw_wp, ss_start; +static volatile uint64_t sw_bp_addr, hw_bp_addr; +static volatile uint64_t wp_addr, wp_data_addr; +static volatile uint64_t svc_addr; +static volatile uint64_t ss_addr[4], ss_idx; +#define PC(v) ((uint64_t)&(v)) + +static void reset_debug_state(void) +{ + asm volatile("msr daifset, #8"); + + write_sysreg(osdlr_el1, 0); + write_sysreg(oslar_el1, 0); + isb(); + + write_sysreg(mdscr_el1, 0); + /* This test only uses the first bp and wp slot. */ + write_sysreg(dbgbvr0_el1, 0); + write_sysreg(dbgbcr0_el1, 0); + write_sysreg(dbgwcr0_el1, 0); + write_sysreg(dbgwvr0_el1, 0); + isb(); +} + +static void install_wp(uint64_t addr) +{ + uint32_t wcr; + uint32_t mdscr; + + wcr = DBGWCR_LEN8 | DBGWCR_RD | DBGWCR_WR | DBGWCR_EL1 | DBGWCR_E; + write_sysreg(dbgwcr0_el1, wcr); + write_sysreg(dbgwvr0_el1, addr); + isb(); + + asm volatile("msr daifclr, #8"); + + mdscr = read_sysreg(mdscr_el1) | MDSCR_KDE | MDSCR_MDE; + write_sysreg(mdscr_el1, mdscr); + isb(); +} + +static void install_hw_bp(uint64_t addr) +{ + uint32_t bcr; + uint32_t mdscr; + + bcr = DBGBCR_LEN8 | DBGBCR_EXEC | DBGBCR_EL1 | DBGBCR_E; + write_sysreg(dbgbcr0_el1, bcr); + write_sysreg(dbgbvr0_el1, addr); + isb(); + + asm volatile("msr daifclr, #8"); + + mdscr = read_sysreg(mdscr_el1) | MDSCR_KDE | MDSCR_MDE; + write_sysreg(mdscr_el1, mdscr); + isb(); +} + +static void install_ss(void) +{ + uint32_t mdscr; + + asm volatile("msr daifclr, #8"); + + mdscr = read_sysreg(mdscr_el1) | MDSCR_KDE | MDSCR_SS; + write_sysreg(mdscr_el1, mdscr); + isb(); +} + +static volatile char write_data; + +static void guest_code(void) +{ + GUEST_SYNC(0); + + /* Software-breakpoint */ + asm volatile("sw_bp: brk #0"); + GUEST_ASSERT_EQ(sw_bp_addr, PC(sw_bp)); + + GUEST_SYNC(1); + + /* Hardware-breakpoint */ + reset_debug_state(); + install_hw_bp(PC(hw_bp)); + asm volatile("hw_bp: nop"); + GUEST_ASSERT_EQ(hw_bp_addr, PC(hw_bp)); + + GUEST_SYNC(2); + + /* Hardware-breakpoint + svc */ + reset_debug_state(); + install_hw_bp(PC(bp_svc)); + asm volatile("bp_svc: svc #0"); + GUEST_ASSERT_EQ(hw_bp_addr, PC(bp_svc)); + GUEST_ASSERT_EQ(svc_addr, PC(bp_svc) + 4); + + GUEST_SYNC(3); + + /* Hardware-breakpoint + software-breakpoint */ + reset_debug_state(); + install_hw_bp(PC(bp_brk)); + asm volatile("bp_brk: brk #0"); + GUEST_ASSERT_EQ(sw_bp_addr, PC(bp_brk)); + GUEST_ASSERT_EQ(hw_bp_addr, PC(bp_brk)); + + GUEST_SYNC(4); + + /* Watchpoint */ + reset_debug_state(); + install_wp(PC(write_data)); + write_data = 'x'; + GUEST_ASSERT_EQ(write_data, 'x'); + GUEST_ASSERT_EQ(wp_data_addr, PC(write_data)); + + GUEST_SYNC(5); + + /* Single-step */ + reset_debug_state(); + install_ss(); + ss_idx = 0; + asm volatile("ss_start:\n" + "mrs x0, esr_el1\n" + "add x0, x0, #1\n" + "msr daifset, #8\n" + : : : "x0"); + GUEST_ASSERT_EQ(ss_addr[0], PC(ss_start)); + GUEST_ASSERT_EQ(ss_addr[1], PC(ss_start) + 4); + GUEST_ASSERT_EQ(ss_addr[2], PC(ss_start) + 8); + + GUEST_DONE(); +} + +static void guest_sw_bp_handler(struct ex_regs *regs) +{ + sw_bp_addr = regs->pc; + regs->pc += 4; +} + +static void guest_hw_bp_handler(struct ex_regs *regs) +{ + hw_bp_addr = regs->pc; + regs->pstate |= SPSR_D; +} + +static void guest_wp_handler(struct ex_regs *regs) +{ + wp_data_addr = read_sysreg(far_el1); + wp_addr = regs->pc; + regs->pstate |= SPSR_D; +} + +static void guest_ss_handler(struct ex_regs *regs) +{ + GUEST_ASSERT_1(ss_idx < 4, ss_idx); + ss_addr[ss_idx++] = regs->pc; + regs->pstate |= SPSR_SS; +} + +static void guest_svc_handler(struct ex_regs *regs) +{ + svc_addr = regs->pc; +} + +static int debug_version(struct kvm_vm *vm) +{ + uint64_t id_aa64dfr0; + + get_reg(vm, VCPU_ID, ARM64_SYS_REG(ID_AA64DFR0_EL1), &id_aa64dfr0); + return id_aa64dfr0 & 0xf; +} + +int main(int argc, char *argv[]) +{ + struct kvm_vm *vm; + struct ucall uc; + int stage; + + vm = vm_create_default(VCPU_ID, 0, guest_code); + ucall_init(vm, NULL); + + vm_init_descriptor_tables(vm); + vcpu_init_descriptor_tables(vm, VCPU_ID); + + if (debug_version(vm) < 6) { + print_skip("Armv8 debug architecture not supported."); + kvm_vm_free(vm); + exit(KSFT_SKIP); + } + + vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT, + ESR_EC_BRK_INS, guest_sw_bp_handler); + vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT, + ESR_EC_HW_BP_CURRENT, guest_hw_bp_handler); + vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT, + ESR_EC_WP_CURRENT, guest_wp_handler); + vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT, + ESR_EC_SSTEP_CURRENT, guest_ss_handler); + vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT, + ESR_EC_SVC64, guest_svc_handler); + + for (stage = 0; stage < 7; stage++) { + vcpu_run(vm, VCPU_ID); + + switch (get_ucall(vm, VCPU_ID, &uc)) { + case UCALL_SYNC: + TEST_ASSERT(uc.args[1] == stage, + "Stage %d: Unexpected sync ucall, got %lx", + stage, (ulong)uc.args[1]); + break; + case UCALL_ABORT: + TEST_FAIL("%s at %s:%ld\n\tvalues: %#lx, %#lx", + (const char *)uc.args[0], + __FILE__, uc.args[1], uc.args[2], uc.args[3]); + break; + case UCALL_DONE: + goto done; + default: + TEST_FAIL("Unknown ucall %lu", uc.cmd); + } + } + +done: + kvm_vm_free(vm); + return 0; +} diff --git a/tools/testing/selftests/kvm/include/aarch64/processor.h b/tools/testing/selftests/kvm/include/aarch64/processor.h index b2b3e9d626cb..27dc5c2e56b9 100644 --- a/tools/testing/selftests/kvm/include/aarch64/processor.h +++ b/tools/testing/selftests/kvm/include/aarch64/processor.h @@ -14,12 +14,14 @@ #define ARM64_CORE_REG(x) (KVM_REG_ARM64 | KVM_REG_SIZE_U64 | \ KVM_REG_ARM_CORE | KVM_REG_ARM_CORE_REG(x)) -#define CPACR_EL1 3, 0, 1, 0, 2 -#define TCR_EL1 3, 0, 2, 0, 2 -#define MAIR_EL1 3, 0, 10, 2, 0 -#define TTBR0_EL1 3, 0, 2, 0, 0 -#define SCTLR_EL1 3, 0, 1, 0, 0 -#define VBAR_EL1 3, 0, 12, 0, 0 +#define CPACR_EL1 3, 0, 1, 0, 2 +#define TCR_EL1 3, 0, 2, 0, 2 +#define MAIR_EL1 3, 0, 10, 2, 0 +#define TTBR0_EL1 3, 0, 2, 0, 0 +#define SCTLR_EL1 3, 0, 1, 0, 0 +#define VBAR_EL1 3, 0, 12, 0, 0 + +#define ID_AA64DFR0_EL1 3, 0, 0, 5, 0 /* * Default MAIR @@ -98,6 +100,12 @@ enum { #define ESR_EC_SHIFT 26 #define ESR_EC_MASK (ESR_EC_NUM - 1) +#define ESR_EC_SVC64 0x15 +#define ESR_EC_HW_BP_CURRENT 0x31 +#define ESR_EC_SSTEP_CURRENT 0x33 +#define ESR_EC_WP_CURRENT 0x35 +#define ESR_EC_BRK_INS 0x3c + void vm_init_descriptor_tables(struct kvm_vm *vm); void vcpu_init_descriptor_tables(struct kvm_vm *vm, uint32_t vcpuid); @@ -119,4 +127,6 @@ void vm_install_sync_handler(struct kvm_vm *vm, val; \ }) +#define isb() asm volatile("isb" : : : "memory") + #endif /* SELFTEST_KVM_PROCESSOR_H */