From 14c47b7530e2db1ab1d42ebbe99b2a58b8443ce7 Mon Sep 17 00:00:00 2001 From: Andrew Jones Date: Tue, 18 Sep 2018 19:54:25 +0200 Subject: [PATCH] kvm: selftests: introduce ucall Rework the guest exit to userspace code to generalize the concept into what it is, a "hypercall to userspace", and provide two implementations of it: the PortIO version currently used, but only useable by x86, and an MMIO version that other architectures (except s390) can use. Signed-off-by: Andrew Jones Signed-off-by: Paolo Bonzini --- tools/testing/selftests/kvm/Makefile | 2 +- tools/testing/selftests/kvm/cr4_cpuid_sync_test.c | 12 +- tools/testing/selftests/kvm/dirty_log_test.c | 5 +- tools/testing/selftests/kvm/include/kvm_util.h | 76 ++++++----- tools/testing/selftests/kvm/lib/kvm_util.c | 15 +-- .../testing/selftests/kvm/lib/kvm_util_internal.h | 1 + tools/testing/selftests/kvm/lib/ucall.c | 144 +++++++++++++++++++++ tools/testing/selftests/kvm/platform_info_test.c | 12 +- tools/testing/selftests/kvm/state_test.c | 23 ++-- tools/testing/selftests/kvm/vmx_tsc_adjust_test.c | 17 ++- 10 files changed, 222 insertions(+), 85 deletions(-) create mode 100644 tools/testing/selftests/kvm/lib/ucall.c diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index ec32dad3c3f0..08426f036353 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -3,7 +3,7 @@ all: top_srcdir = ../../../../ UNAME_M := $(shell uname -m) -LIBKVM = lib/assert.c lib/elf.c lib/io.c lib/kvm_util.c lib/sparsebit.c +LIBKVM = lib/assert.c lib/elf.c lib/io.c lib/kvm_util.c lib/ucall.c lib/sparsebit.c LIBKVM_x86_64 = lib/x86.c lib/vmx.c TEST_GEN_PROGS_x86_64 = platform_info_test diff --git a/tools/testing/selftests/kvm/cr4_cpuid_sync_test.c b/tools/testing/selftests/kvm/cr4_cpuid_sync_test.c index 11ec358bf969..fd4f419fe9ab 100644 --- a/tools/testing/selftests/kvm/cr4_cpuid_sync_test.c +++ b/tools/testing/selftests/kvm/cr4_cpuid_sync_test.c @@ -67,6 +67,7 @@ int main(int argc, char *argv[]) struct kvm_vm *vm; struct kvm_sregs sregs; struct kvm_cpuid_entry2 *entry; + struct ucall uc; int rc; entry = kvm_get_supported_cpuid_entry(1); @@ -87,21 +88,20 @@ int main(int argc, char *argv[]) rc = _vcpu_run(vm, VCPU_ID); if (run->exit_reason == KVM_EXIT_IO) { - switch (run->io.port) { - case GUEST_PORT_SYNC: + switch (get_ucall(vm, VCPU_ID, &uc)) { + case UCALL_SYNC: /* emulate hypervisor clearing CR4.OSXSAVE */ vcpu_sregs_get(vm, VCPU_ID, &sregs); sregs.cr4 &= ~X86_CR4_OSXSAVE; vcpu_sregs_set(vm, VCPU_ID, &sregs); break; - case GUEST_PORT_ABORT: + case UCALL_ABORT: TEST_ASSERT(false, "Guest CR4 bit (OSXSAVE) unsynchronized with CPUID bit."); break; - case GUEST_PORT_DONE: + case UCALL_DONE: goto done; default: - TEST_ASSERT(false, "Unknown port 0x%x.", - run->io.port); + TEST_ASSERT(false, "Unknown ucall 0x%x.", uc.cmd); } } } diff --git a/tools/testing/selftests/kvm/dirty_log_test.c b/tools/testing/selftests/kvm/dirty_log_test.c index 0c2cdc105f96..7cf3e4ae6046 100644 --- a/tools/testing/selftests/kvm/dirty_log_test.c +++ b/tools/testing/selftests/kvm/dirty_log_test.c @@ -110,7 +110,7 @@ void *vcpu_worker(void *data) uint64_t loops, *guest_array, pages_count = 0; struct kvm_vm *vm = data; struct kvm_run *run; - struct guest_args args; + struct ucall uc; run = vcpu_state(vm, VCPU_ID); @@ -124,9 +124,8 @@ void *vcpu_worker(void *data) while (!READ_ONCE(host_quit)) { /* Let the guest to dirty these random pages */ ret = _vcpu_run(vm, VCPU_ID); - guest_args_read(vm, VCPU_ID, &args); if (run->exit_reason == KVM_EXIT_IO && - args.port == GUEST_PORT_SYNC) { + get_ucall(vm, VCPU_ID, &uc) == UCALL_SYNC) { pages_count += TEST_PAGES_PER_LOOP; generate_random_array(guest_array, TEST_PAGES_PER_LOOP); } else { diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h index 3acf9a91704c..22667dd48a9c 100644 --- a/tools/testing/selftests/kvm/include/kvm_util.h +++ b/tools/testing/selftests/kvm/include/kvm_util.h @@ -152,43 +152,49 @@ allocate_kvm_dirty_log(struct kvm_userspace_memory_region *region); int vm_create_device(struct kvm_vm *vm, struct kvm_create_device *cd); -#define GUEST_PORT_SYNC 0x1000 -#define GUEST_PORT_ABORT 0x1001 -#define GUEST_PORT_DONE 0x1002 - -static inline void __exit_to_l0(uint16_t port, uint64_t arg0, uint64_t arg1) -{ - __asm__ __volatile__("in %[port], %%al" - : - : [port]"d"(port), "D"(arg0), "S"(arg1) - : "rax"); -} - -/* - * Allows to pass three arguments to the host: port is 16bit wide, - * arg0 & arg1 are 64bit wide - */ -#define GUEST_SYNC_ARGS(_port, _arg0, _arg1) \ - __exit_to_l0(_port, (uint64_t) (_arg0), (uint64_t) (_arg1)) - -#define GUEST_ASSERT(_condition) do { \ - if (!(_condition)) \ - GUEST_SYNC_ARGS(GUEST_PORT_ABORT, \ - "Failed guest assert: " \ - #_condition, __LINE__); \ - } while (0) - -#define GUEST_SYNC(stage) GUEST_SYNC_ARGS(GUEST_PORT_SYNC, "hello", stage) +#define sync_global_to_guest(vm, g) ({ \ + typeof(g) *_p = addr_gva2hva(vm, (vm_vaddr_t)&(g)); \ + memcpy(_p, &(g), sizeof(g)); \ +}) + +#define sync_global_from_guest(vm, g) ({ \ + typeof(g) *_p = addr_gva2hva(vm, (vm_vaddr_t)&(g)); \ + memcpy(&(g), _p, sizeof(g)); \ +}) + +/* ucall implementation types */ +typedef enum { + UCALL_PIO, + UCALL_MMIO, +} ucall_type_t; + +/* Common ucalls */ +enum { + UCALL_NONE, + UCALL_SYNC, + UCALL_ABORT, + UCALL_DONE, +}; -#define GUEST_DONE() GUEST_SYNC_ARGS(GUEST_PORT_DONE, 0, 0) +#define UCALL_MAX_ARGS 6 -struct guest_args { - uint64_t arg0; - uint64_t arg1; - uint16_t port; -} __attribute__ ((packed)); +struct ucall { + uint64_t cmd; + uint64_t args[UCALL_MAX_ARGS]; +}; -void guest_args_read(struct kvm_vm *vm, uint32_t vcpu_id, - struct guest_args *args); +void ucall_init(struct kvm_vm *vm, ucall_type_t type, void *arg); +void ucall_uninit(struct kvm_vm *vm); +void ucall(uint64_t cmd, int nargs, ...); +uint64_t get_ucall(struct kvm_vm *vm, uint32_t vcpu_id, struct ucall *uc); + +#define GUEST_SYNC(stage) ucall(UCALL_SYNC, 2, "hello", stage) +#define GUEST_DONE() ucall(UCALL_DONE, 0) +#define GUEST_ASSERT(_condition) do { \ + if (!(_condition)) \ + ucall(UCALL_ABORT, 2, \ + "Failed guest assert: " \ + #_condition, __LINE__); \ +} while (0) #endif /* SELFTEST_KVM_UTIL_H */ diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index 6fd8c089cafc..4bd31bf04f53 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -133,6 +133,7 @@ struct kvm_vm *vm_create(enum vm_guest_mode mode, uint64_t phy_pages, int perm) case VM_MODE_FLAT48PG: vm->page_size = 0x1000; vm->page_shift = 12; + vm->va_bits = 48; /* Limit to 48-bit canonical virtual addresses. */ vm->vpages_valid = sparsebit_alloc(); @@ -1669,17 +1670,3 @@ void *addr_gva2hva(struct kvm_vm *vm, vm_vaddr_t gva) { return addr_gpa2hva(vm, addr_gva2gpa(vm, gva)); } - -void guest_args_read(struct kvm_vm *vm, uint32_t vcpu_id, - struct guest_args *args) -{ - struct kvm_run *run = vcpu_state(vm, vcpu_id); - struct kvm_regs regs; - - memset(®s, 0, sizeof(regs)); - vcpu_regs_get(vm, vcpu_id, ®s); - - args->port = run->io.port; - args->arg0 = regs.rdi; - args->arg1 = regs.rsi; -} diff --git a/tools/testing/selftests/kvm/lib/kvm_util_internal.h b/tools/testing/selftests/kvm/lib/kvm_util_internal.h index 542ed606b338..8fa7c9f7567a 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util_internal.h +++ b/tools/testing/selftests/kvm/lib/kvm_util_internal.h @@ -47,6 +47,7 @@ struct kvm_vm { int fd; unsigned int page_size; unsigned int page_shift; + unsigned int va_bits; uint64_t max_gfn; struct vcpu *vcpu_head; struct userspace_mem_region *userspace_mem_region_head; diff --git a/tools/testing/selftests/kvm/lib/ucall.c b/tools/testing/selftests/kvm/lib/ucall.c new file mode 100644 index 000000000000..4777f9bb5194 --- /dev/null +++ b/tools/testing/selftests/kvm/lib/ucall.c @@ -0,0 +1,144 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * ucall support. A ucall is a "hypercall to userspace". + * + * Copyright (C) 2018, Red Hat, Inc. + */ +#include "kvm_util.h" +#include "kvm_util_internal.h" + +#define UCALL_PIO_PORT ((uint16_t)0x1000) + +static ucall_type_t ucall_type; +static vm_vaddr_t *ucall_exit_mmio_addr; + +static bool ucall_mmio_init(struct kvm_vm *vm, vm_paddr_t gpa) +{ + if (kvm_userspace_memory_region_find(vm, gpa, gpa + 1)) + return false; + + virt_pg_map(vm, gpa, gpa, 0); + + ucall_exit_mmio_addr = (vm_vaddr_t *)gpa; + sync_global_to_guest(vm, ucall_exit_mmio_addr); + + return true; +} + +void ucall_init(struct kvm_vm *vm, ucall_type_t type, void *arg) +{ + ucall_type = type; + sync_global_to_guest(vm, ucall_type); + + if (type == UCALL_PIO) + return; + + if (type == UCALL_MMIO) { + vm_paddr_t gpa, start, end, step; + bool ret; + + if (arg) { + gpa = (vm_paddr_t)arg; + ret = ucall_mmio_init(vm, gpa); + TEST_ASSERT(ret, "Can't set ucall mmio address to %lx", gpa); + return; + } + + /* + * Find an address within the allowed virtual address space, + * that does _not_ have a KVM memory region associated with it. + * Identity mapping an address like this allows the guest to + * access it, but as KVM doesn't know what to do with it, it + * will assume it's something userspace handles and exit with + * KVM_EXIT_MMIO. Well, at least that's how it works for AArch64. + * Here we start with a guess that the addresses around two + * thirds of the VA space are unmapped and then work both down + * and up from there in 1/6 VA space sized steps. + */ + start = 1ul << (vm->va_bits * 2 / 3); + end = 1ul << vm->va_bits; + step = 1ul << (vm->va_bits / 6); + for (gpa = start; gpa >= 0; gpa -= step) { + if (ucall_mmio_init(vm, gpa & ~(vm->page_size - 1))) + return; + } + for (gpa = start + step; gpa < end; gpa += step) { + if (ucall_mmio_init(vm, gpa & ~(vm->page_size - 1))) + return; + } + TEST_ASSERT(false, "Can't find a ucall mmio address"); + } +} + +void ucall_uninit(struct kvm_vm *vm) +{ + ucall_type = 0; + sync_global_to_guest(vm, ucall_type); + ucall_exit_mmio_addr = 0; + sync_global_to_guest(vm, ucall_exit_mmio_addr); +} + +static void ucall_pio_exit(struct ucall *uc) +{ +#ifdef __x86_64__ + asm volatile("in %[port], %%al" + : : [port] "d" (UCALL_PIO_PORT), "D" (uc) : "rax"); +#endif +} + +static void ucall_mmio_exit(struct ucall *uc) +{ + *ucall_exit_mmio_addr = (vm_vaddr_t)uc; +} + +void ucall(uint64_t cmd, int nargs, ...) +{ + struct ucall uc = { + .cmd = cmd, + }; + va_list va; + int i; + + nargs = nargs <= UCALL_MAX_ARGS ? nargs : UCALL_MAX_ARGS; + + va_start(va, nargs); + for (i = 0; i < nargs; ++i) + uc.args[i] = va_arg(va, uint64_t); + va_end(va); + + switch (ucall_type) { + case UCALL_PIO: + ucall_pio_exit(&uc); + break; + case UCALL_MMIO: + ucall_mmio_exit(&uc); + break; + }; +} + +uint64_t get_ucall(struct kvm_vm *vm, uint32_t vcpu_id, struct ucall *uc) +{ + struct kvm_run *run = vcpu_state(vm, vcpu_id); + + memset(uc, 0, sizeof(*uc)); + +#ifdef __x86_64__ + if (ucall_type == UCALL_PIO && run->exit_reason == KVM_EXIT_IO && + run->io.port == UCALL_PIO_PORT) { + struct kvm_regs regs; + vcpu_regs_get(vm, vcpu_id, ®s); + memcpy(uc, addr_gva2hva(vm, (vm_vaddr_t)regs.rdi), sizeof(*uc)); + return uc->cmd; + } +#endif + if (ucall_type == UCALL_MMIO && run->exit_reason == KVM_EXIT_MMIO && + run->mmio.phys_addr == (uint64_t)ucall_exit_mmio_addr) { + vm_vaddr_t gva; + TEST_ASSERT(run->mmio.is_write && run->mmio.len == 8, + "Unexpected ucall exit mmio address access"); + gva = *(vm_vaddr_t *)run->mmio.data; + memcpy(uc, addr_gva2hva(vm, gva), sizeof(*uc)); + } + + return uc->cmd; +} diff --git a/tools/testing/selftests/kvm/platform_info_test.c b/tools/testing/selftests/kvm/platform_info_test.c index 3764e7121265..aa6a14331461 100644 --- a/tools/testing/selftests/kvm/platform_info_test.c +++ b/tools/testing/selftests/kvm/platform_info_test.c @@ -48,7 +48,7 @@ static void set_msr_platform_info_enabled(struct kvm_vm *vm, bool enable) static void test_msr_platform_info_enabled(struct kvm_vm *vm) { struct kvm_run *run = vcpu_state(vm, VCPU_ID); - struct guest_args args; + struct ucall uc; set_msr_platform_info_enabled(vm, true); vcpu_run(vm, VCPU_ID); @@ -56,11 +56,11 @@ static void test_msr_platform_info_enabled(struct kvm_vm *vm) "Exit_reason other than KVM_EXIT_IO: %u (%s),\n", run->exit_reason, exit_reason_str(run->exit_reason)); - guest_args_read(vm, VCPU_ID, &args); - TEST_ASSERT(args.port == GUEST_PORT_SYNC, - "Received IO from port other than PORT_HOST_SYNC: %u\n", - run->io.port); - TEST_ASSERT((args.arg1 & MSR_PLATFORM_INFO_MAX_TURBO_RATIO) == + get_ucall(vm, VCPU_ID, &uc); + TEST_ASSERT(uc.cmd == UCALL_SYNC, + "Received ucall other than UCALL_SYNC: %u\n", + ucall); + TEST_ASSERT((uc.args[1] & MSR_PLATFORM_INFO_MAX_TURBO_RATIO) == MSR_PLATFORM_INFO_MAX_TURBO_RATIO, "Expected MSR_PLATFORM_INFO to have max turbo ratio mask: %i.", MSR_PLATFORM_INFO_MAX_TURBO_RATIO); diff --git a/tools/testing/selftests/kvm/state_test.c b/tools/testing/selftests/kvm/state_test.c index 900e3e9dfb9f..cdf82735d6e7 100644 --- a/tools/testing/selftests/kvm/state_test.c +++ b/tools/testing/selftests/kvm/state_test.c @@ -127,6 +127,7 @@ int main(int argc, char *argv[]) struct kvm_vm *vm; struct kvm_run *run; struct kvm_x86_state *state; + struct ucall uc; int stage; struct kvm_cpuid_entry2 *entry = kvm_get_supported_cpuid_entry(1); @@ -155,23 +156,23 @@ int main(int argc, char *argv[]) memset(®s1, 0, sizeof(regs1)); vcpu_regs_get(vm, VCPU_ID, ®s1); - switch (run->io.port) { - case GUEST_PORT_ABORT: - TEST_ASSERT(false, "%s at %s:%d", (const char *) regs1.rdi, - __FILE__, regs1.rsi); + switch (get_ucall(vm, VCPU_ID, &uc)) { + case UCALL_ABORT: + TEST_ASSERT(false, "%s at %s:%d", (const char *)uc.args[0], + __FILE__, uc.args[1]); /* NOT REACHED */ - case GUEST_PORT_SYNC: + case UCALL_SYNC: break; - case GUEST_PORT_DONE: + case UCALL_DONE: goto done; default: - TEST_ASSERT(false, "Unknown port 0x%x.", run->io.port); + TEST_ASSERT(false, "Unknown ucall 0x%x.", uc.cmd); } - /* PORT_SYNC is handled here. */ - TEST_ASSERT(!strcmp((const char *)regs1.rdi, "hello") && - regs1.rsi == stage, "Unexpected register values vmexit #%lx, got %lx", - stage, (ulong) regs1.rsi); + /* UCALL_SYNC is handled here. */ + TEST_ASSERT(!strcmp((const char *)uc.args[0], "hello") && + uc.args[1] == stage, "Unexpected register values vmexit #%lx, got %lx", + stage, (ulong)uc.args[1]); state = vcpu_save_state(vm, VCPU_ID); kvm_vm_release(vm); diff --git a/tools/testing/selftests/kvm/vmx_tsc_adjust_test.c b/tools/testing/selftests/kvm/vmx_tsc_adjust_test.c index 49bcc68b0235..8d487c78796a 100644 --- a/tools/testing/selftests/kvm/vmx_tsc_adjust_test.c +++ b/tools/testing/selftests/kvm/vmx_tsc_adjust_test.c @@ -146,26 +146,25 @@ int main(int argc, char *argv[]) for (;;) { volatile struct kvm_run *run = vcpu_state(vm, VCPU_ID); - struct guest_args args; + struct ucall uc; vcpu_run(vm, VCPU_ID); - guest_args_read(vm, VCPU_ID, &args); TEST_ASSERT(run->exit_reason == KVM_EXIT_IO, "Got exit_reason other than KVM_EXIT_IO: %u (%s)\n", run->exit_reason, exit_reason_str(run->exit_reason)); - switch (args.port) { - case GUEST_PORT_ABORT: - TEST_ASSERT(false, "%s", (const char *) args.arg0); + switch (get_ucall(vm, VCPU_ID, &uc)) { + case UCALL_ABORT: + TEST_ASSERT(false, "%s", (const char *)uc.args[0]); /* NOT REACHED */ - case GUEST_PORT_SYNC: - report(args.arg1); + case UCALL_SYNC: + report(uc.args[1]); break; - case GUEST_PORT_DONE: + case UCALL_DONE: goto done; default: - TEST_ASSERT(false, "Unknown port 0x%x.", args.port); + TEST_ASSERT(false, "Unknown ucall 0x%x.", uc.cmd); } } -- 2.11.0