From 2040f414d12f31be3e73eb3f5048d2b1cdec48f6 Mon Sep 17 00:00:00 2001 From: Thomas Huth Date: Wed, 31 Jul 2019 17:15:23 +0200 Subject: KVM: selftests: Split ucall.c into architecture specific files The way we exit from a guest to userspace is very specific to the architecture: On x86, we use PIO, on aarch64 we are using MMIO and on s390x we're going to use an instruction instead. The possibility to select a type via the ucall_type_t enum is currently also completely unused, so the code in ucall.c currently looks more complex than required. Let's split this up into architecture specific ucall.c files instead, so we can get rid of the #ifdefs and the unnecessary ucall_type_t handling. Reviewed-by: Andrew Jones Signed-off-by: Thomas Huth Acked-by: Paolo Bonzini Link: https://lore.kernel.org/r/20190731151525.17156-2-thuth@redhat.com Signed-off-by: Christian Borntraeger --- tools/testing/selftests/kvm/lib/aarch64/ucall.c | 112 +++++++++++++++++ tools/testing/selftests/kvm/lib/ucall.c | 157 ------------------------ tools/testing/selftests/kvm/lib/x86_64/ucall.c | 56 +++++++++ 3 files changed, 168 insertions(+), 157 deletions(-) create mode 100644 tools/testing/selftests/kvm/lib/aarch64/ucall.c delete mode 100644 tools/testing/selftests/kvm/lib/ucall.c create mode 100644 tools/testing/selftests/kvm/lib/x86_64/ucall.c (limited to 'tools/testing/selftests/kvm/lib') diff --git a/tools/testing/selftests/kvm/lib/aarch64/ucall.c b/tools/testing/selftests/kvm/lib/aarch64/ucall.c new file mode 100644 index 000000000000..6cd91970fbad --- /dev/null +++ b/tools/testing/selftests/kvm/lib/aarch64/ucall.c @@ -0,0 +1,112 @@ +// 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" + +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, void *arg) +{ + vm_paddr_t gpa, start, end, step, offset; + unsigned int bits; + 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 physical and virtual address + * spaces, 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 5/8th + * of the allowed space are unmapped and then work both down and + * up from there in 1/16th allowed space sized steps. + * + * Note, we need to use VA-bits - 1 when calculating the allowed + * virtual address space for an identity mapping because the upper + * half of the virtual address space is the two's complement of the + * lower and won't match physical addresses. + */ + bits = vm->va_bits - 1; + bits = vm->pa_bits < bits ? vm->pa_bits : bits; + end = 1ul << bits; + start = end * 5 / 8; + step = end / 16; + for (offset = 0; offset < end - start; offset += step) { + if (ucall_mmio_init(vm, start - offset)) + return; + if (ucall_mmio_init(vm, start + offset)) + return; + } + TEST_ASSERT(false, "Can't find a ucall mmio address"); +} + +void ucall_uninit(struct kvm_vm *vm) +{ + ucall_exit_mmio_addr = 0; + sync_global_to_guest(vm, ucall_exit_mmio_addr); +} + +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); + + *ucall_exit_mmio_addr = (vm_vaddr_t)&uc; +} + +uint64_t get_ucall(struct kvm_vm *vm, uint32_t vcpu_id, struct ucall *uc) +{ + struct kvm_run *run = vcpu_state(vm, vcpu_id); + struct ucall ucall = {}; + + if (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"); + memcpy(&gva, run->mmio.data, sizeof(gva)); + memcpy(&ucall, addr_gva2hva(vm, gva), sizeof(ucall)); + + vcpu_run_complete_io(vm, vcpu_id); + if (uc) + memcpy(uc, &ucall, sizeof(ucall)); + } + + return ucall.cmd; +} diff --git a/tools/testing/selftests/kvm/lib/ucall.c b/tools/testing/selftests/kvm/lib/ucall.c deleted file mode 100644 index dd9a66700f96..000000000000 --- a/tools/testing/selftests/kvm/lib/ucall.c +++ /dev/null @@ -1,157 +0,0 @@ -// 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, offset; - unsigned bits; - 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 physical and virtual address - * spaces, 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 5/8th - * of the allowed space are unmapped and then work both down and - * up from there in 1/16th allowed space sized steps. - * - * Note, we need to use VA-bits - 1 when calculating the allowed - * virtual address space for an identity mapping because the upper - * half of the virtual address space is the two's complement of the - * lower and won't match physical addresses. - */ - bits = vm->va_bits - 1; - bits = vm->pa_bits < bits ? vm->pa_bits : bits; - end = 1ul << bits; - start = end * 5 / 8; - step = end / 16; - for (offset = 0; offset < end - start; offset += step) { - if (ucall_mmio_init(vm, start - offset)) - return; - if (ucall_mmio_init(vm, start + offset)) - 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); - struct ucall ucall = {}; - bool got_ucall = false; - -#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(&ucall, addr_gva2hva(vm, (vm_vaddr_t)regs.rdi), sizeof(ucall)); - got_ucall = true; - } -#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"); - memcpy(&gva, run->mmio.data, sizeof(gva)); - memcpy(&ucall, addr_gva2hva(vm, gva), sizeof(ucall)); - got_ucall = true; - } - - if (got_ucall) { - vcpu_run_complete_io(vm, vcpu_id); - if (uc) - memcpy(uc, &ucall, sizeof(ucall)); - } - - return ucall.cmd; -} diff --git a/tools/testing/selftests/kvm/lib/x86_64/ucall.c b/tools/testing/selftests/kvm/lib/x86_64/ucall.c new file mode 100644 index 000000000000..4bfc9a90b1de --- /dev/null +++ b/tools/testing/selftests/kvm/lib/x86_64/ucall.c @@ -0,0 +1,56 @@ +// 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" + +#define UCALL_PIO_PORT ((uint16_t)0x1000) + +void ucall_init(struct kvm_vm *vm, void *arg) +{ +} + +void ucall_uninit(struct kvm_vm *vm) +{ +} + +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); + + asm volatile("in %[port], %%al" + : : [port] "d" (UCALL_PIO_PORT), "D" (&uc) : "rax"); +} + +uint64_t get_ucall(struct kvm_vm *vm, uint32_t vcpu_id, struct ucall *uc) +{ + struct kvm_run *run = vcpu_state(vm, vcpu_id); + struct ucall ucall = {}; + + if (run->exit_reason == KVM_EXIT_IO && run->io.port == UCALL_PIO_PORT) { + struct kvm_regs regs; + + vcpu_regs_get(vm, vcpu_id, ®s); + memcpy(&ucall, addr_gva2hva(vm, (vm_vaddr_t)regs.rdi), + sizeof(ucall)); + + vcpu_run_complete_io(vm, vcpu_id); + if (uc) + memcpy(uc, &ucall, sizeof(ucall)); + } + + return ucall.cmd; +} -- cgit v1.2.3-59-g8ed1b From f90f57b3971a3370be5a3cf02ae783b4bf728b7f Mon Sep 17 00:00:00 2001 From: Thomas Huth Date: Wed, 31 Jul 2019 17:15:24 +0200 Subject: KVM: selftests: Implement ucall() for s390x On s390x, we can neither exit via PIO nor MMIO, but have to use an instruction like DIAGNOSE. Now that ucall() is implemented, we can use it in the sync_reg_test on s390x, too. Reviewed-by: Andrew Jones Signed-off-by: Thomas Huth Link: https://lore.kernel.org/r/20190731151525.17156-3-thuth@redhat.com Signed-off-by: Christian Borntraeger --- tools/testing/selftests/kvm/Makefile | 2 +- tools/testing/selftests/kvm/lib/s390x/ucall.c | 56 ++++++++++++++++++++++ tools/testing/selftests/kvm/s390x/sync_regs_test.c | 6 ++- 3 files changed, 61 insertions(+), 3 deletions(-) create mode 100644 tools/testing/selftests/kvm/lib/s390x/ucall.c (limited to 'tools/testing/selftests/kvm/lib') diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index a51e3b83df40..75ea1ecbf85a 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -10,7 +10,7 @@ UNAME_M := $(shell uname -m) LIBKVM = lib/assert.c lib/elf.c lib/io.c lib/kvm_util.c lib/sparsebit.c LIBKVM_x86_64 = lib/x86_64/processor.c lib/x86_64/vmx.c lib/x86_64/ucall.c LIBKVM_aarch64 = lib/aarch64/processor.c lib/aarch64/ucall.c -LIBKVM_s390x = lib/s390x/processor.c +LIBKVM_s390x = lib/s390x/processor.c lib/s390x/ucall.c TEST_GEN_PROGS_x86_64 = x86_64/cr4_cpuid_sync_test TEST_GEN_PROGS_x86_64 += x86_64/evmcs_test diff --git a/tools/testing/selftests/kvm/lib/s390x/ucall.c b/tools/testing/selftests/kvm/lib/s390x/ucall.c new file mode 100644 index 000000000000..fd589dc9bfab --- /dev/null +++ b/tools/testing/selftests/kvm/lib/s390x/ucall.c @@ -0,0 +1,56 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * ucall support. A ucall is a "hypercall to userspace". + * + * Copyright (C) 2019 Red Hat, Inc. + */ +#include "kvm_util.h" + +void ucall_init(struct kvm_vm *vm, void *arg) +{ +} + +void ucall_uninit(struct kvm_vm *vm) +{ +} + +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); + + /* Exit via DIAGNOSE 0x501 (normally used for breakpoints) */ + asm volatile ("diag 0,%0,0x501" : : "a"(&uc) : "memory"); +} + +uint64_t get_ucall(struct kvm_vm *vm, uint32_t vcpu_id, struct ucall *uc) +{ + struct kvm_run *run = vcpu_state(vm, vcpu_id); + struct ucall ucall = {}; + + if (run->exit_reason == KVM_EXIT_S390_SIEIC && + run->s390_sieic.icptcode == 4 && + (run->s390_sieic.ipa >> 8) == 0x83 && /* 0x83 means DIAGNOSE */ + (run->s390_sieic.ipb >> 16) == 0x501) { + int reg = run->s390_sieic.ipa & 0xf; + + memcpy(&ucall, addr_gva2hva(vm, run->s.regs.gprs[reg]), + sizeof(ucall)); + + vcpu_run_complete_io(vm, vcpu_id); + if (uc) + memcpy(uc, &ucall, sizeof(ucall)); + } + + return ucall.cmd; +} diff --git a/tools/testing/selftests/kvm/s390x/sync_regs_test.c b/tools/testing/selftests/kvm/s390x/sync_regs_test.c index e85ff0d69548..bbc93094519b 100644 --- a/tools/testing/selftests/kvm/s390x/sync_regs_test.c +++ b/tools/testing/selftests/kvm/s390x/sync_regs_test.c @@ -25,9 +25,11 @@ static void guest_code(void) { + register u64 stage asm("11") = 0; + for (;;) { - asm volatile ("diag 0,0,0x501"); - asm volatile ("ahi 11,1"); + GUEST_SYNC(0); + asm volatile ("ahi %0,1" : : "r"(stage)); } } -- cgit v1.2.3-59-g8ed1b