If virt_map() is called before any call to ____vm_vaddr_alloc() it will create the mapping using an invalid pgd.

Add call to virt_pgd_alloc() as part of virt_map() before creating the mapping, similarly to ____vm_vaddr_alloc()

Reviewed-by: Ira Weiny ira.weiny@intel.com Reviewed-by: Binbin Wu binbin.wu@linux.intel.com Signed-off-by: Sagi Shahar sagis@google.com --- tools/testing/selftests/kvm/lib/kvm_util.c | 1 + 1 file changed, 1 insertion(+)

diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index c3f5142b0a54..b4c8702ba4bd 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -1609,6 +1609,7 @@ void virt_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, TEST_ASSERT(vaddr + size > vaddr, "Vaddr overflow"); TEST_ASSERT(paddr + size > paddr, "Paddr overflow");

+ virt_pgd_alloc(vm); while (npages--) { virt_pg_map(vm, vaddr, paddr); sparsebit_set(vm->vpages_mapped, vaddr >> vm->page_shift);

TDX registers are inaccesible to KVM. Therefore we need a different mechanism to load boot parameters for TDX code. TDX boot code will read the registers values from memory and set the registers manually.

This patch defines the data structures used to communicate between c code and the TDX assembly boot code which will be added in a later patch.

Use kbuild.h to expose the offsets into the structs from c code to assembly code.

Co-developed-by: Ackerley Tng ackerleytng@google.com Signed-off-by: Ackerley Tng ackerleytng@google.com Signed-off-by: Sagi Shahar sagis@google.com --- tools/testing/selftests/kvm/Makefile.kvm | 18 +++++ .../selftests/kvm/include/x86/tdx/td_boot.h | 69 +++++++++++++++++++ .../kvm/lib/x86/tdx/td_boot_offsets.c | 21 ++++++ 3 files changed, 108 insertions(+) create mode 100644 tools/testing/selftests/kvm/include/x86/tdx/td_boot.h create mode 100644 tools/testing/selftests/kvm/lib/x86/tdx/td_boot_offsets.c

diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm index 41b40c676d7f..3f93c093b046 100644 --- a/tools/testing/selftests/kvm/Makefile.kvm +++ b/tools/testing/selftests/kvm/Makefile.kvm @@ -19,6 +19,8 @@ LIBKVM += lib/userfaultfd_util.c

LIBKVM_STRING += lib/string_override.c

+LIBKVM_ASM_DEFS += lib/x86/tdx/td_boot_offsets.c + LIBKVM_x86 += lib/x86/apic.c LIBKVM_x86 += lib/x86/handlers.S LIBKVM_x86 += lib/x86/hyperv.c @@ -230,6 +232,10 @@ OVERRIDE_TARGETS = 1 include ../lib.mk include ../cgroup/lib/libcgroup.mk

+# Enable Kbuild tools. +include $(top_srcdir)/scripts/Kbuild.include +include $(top_srcdir)/scripts/Makefile.lib + INSTALL_HDR_PATH = $(top_srcdir)/usr LINUX_HDR_PATH = $(INSTALL_HDR_PATH)/include/ LINUX_TOOL_INCLUDE = $(top_srcdir)/tools/include @@ -282,6 +288,7 @@ LIBKVM_S := $(filter %.S,$(LIBKVM)) LIBKVM_C_OBJ := $(patsubst %.c, $(OUTPUT)/%.o, $(LIBKVM_C)) LIBKVM_S_OBJ := $(patsubst %.S, $(OUTPUT)/%.o, $(LIBKVM_S)) LIBKVM_STRING_OBJ := $(patsubst %.c, $(OUTPUT)/%.o, $(LIBKVM_STRING)) +LIBKVM_ASM_DEFS_OBJ += $(patsubst %.c, $(OUTPUT)/%.s, $(LIBKVM_ASM_DEFS)) LIBKVM_OBJS = $(LIBKVM_C_OBJ) $(LIBKVM_S_OBJ) $(LIBKVM_STRING_OBJ) $(LIBCGROUP_O) SPLIT_TEST_GEN_PROGS := $(patsubst %, $(OUTPUT)/%, $(SPLIT_TESTS)) SPLIT_TEST_GEN_OBJ := $(patsubst %, $(OUTPUT)/$(ARCH)/%.o, $(SPLIT_TESTS)) @@ -308,6 +315,7 @@ $(SPLIT_TEST_GEN_OBJ): $(OUTPUT)/$(ARCH)/%.o: $(ARCH)/%.c

EXTRA_CLEAN += $(GEN_HDRS) \ $(LIBKVM_OBJS) \ + $(LIBKVM_ASM_DEFS_OBJ) \ $(SPLIT_TEST_GEN_OBJ) \ $(TEST_DEP_FILES) \ $(TEST_GEN_OBJ) \ @@ -319,18 +327,28 @@ $(LIBKVM_C_OBJ): $(OUTPUT)/%.o: %.c $(GEN_HDRS) $(LIBKVM_S_OBJ): $(OUTPUT)/%.o: %.S $(GEN_HDRS) $(CC) $(CFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c $< -o $@

+$(LIBKVM_ASM_DEFS_OBJ): $(OUTPUT)/%.s: %.c FORCE + $(CC) $(CFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -S $< -o $@ + # Compile the string overrides as freestanding to prevent the compiler from # generating self-referential code, e.g. without "freestanding" the compiler may # "optimize" memcmp() by invoking memcmp(), thus causing infinite recursion. $(LIBKVM_STRING_OBJ): $(OUTPUT)/%.o: %.c $(CC) $(CFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c -ffreestanding $< -o $@

+$(OUTPUT)/include/x86/tdx/td_boot_offsets.h: $(OUTPUT)/lib/x86/tdx/td_boot_offsets.s FORCE + $(call filechk,offsets,__TDX_BOOT_OFFSETS_H__) + +EXTRA_CLEAN += $(OUTPUT)/include/x86/tdx/td_boot_offsets.h + $(shell mkdir -p $(sort $(dir $(TEST_GEN_PROGS)))) $(SPLIT_TEST_GEN_OBJ): $(GEN_HDRS) $(TEST_GEN_PROGS): $(LIBKVM_OBJS) $(TEST_GEN_PROGS_EXTENDED): $(LIBKVM_OBJS) $(TEST_GEN_OBJ): $(GEN_HDRS)

+FORCE: + cscope: include_paths = $(LINUX_TOOL_INCLUDE) $(LINUX_HDR_PATH) include lib .. cscope: $(RM) cscope.* diff --git a/tools/testing/selftests/kvm/include/x86/tdx/td_boot.h b/tools/testing/selftests/kvm/include/x86/tdx/td_boot.h new file mode 100644 index 000000000000..8eda3ce10220 --- /dev/null +++ b/tools/testing/selftests/kvm/include/x86/tdx/td_boot.h @@ -0,0 +1,69 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef SELFTEST_TDX_TD_BOOT_H +#define SELFTEST_TDX_TD_BOOT_H + +#include <stdint.h> + +#include <linux/compiler.h> +#include <linux/sizes.h> + +/* + * Layout for boot section (not to scale) + * + * GPA + * _________________________________ 0x1_0000_0000 (4GB) + * | Boot code trampoline | + * |___________________________|____ 0x0_ffff_fff0: Reset vector (16B below 4GB) + * | Boot code | + * |___________________________|____ td_boot will be copied here, so that the + * | | jmp to td_boot is exactly at the reset vector + * | Empty space | + * | | + * |───────────────────────────| + * | | + * | | + * | Boot parameters | + * | | + * | | + * |___________________________|____ 0x0_ffff_0000: TD_BOOT_PARAMETERS_GPA + */ +#define FOUR_GIGABYTES_GPA (SZ_4G) + +/* + * The exact memory layout for LGDT or LIDT instructions. + */ +struct __packed td_boot_parameters_dtr { + uint16_t limit; + uint32_t base; +}; + +/* + * Allows each vCPU to be initialized with different eip and esp. + */ +struct td_per_vcpu_parameters { + uint32_t esp_gva; + uint64_t guest_code; +}; + +/* + * Boot parameters for the TD. + * + * Unlike a regular VM, KVM cannot set registers such as esp, eip, etc + * before boot, so to run selftests, these registers' values have to be + * initialized by the TD. + * + * This struct is loaded in TD private memory at TD_BOOT_PARAMETERS_GPA. + * + * The TD boot code will read off parameters from this struct and set up the + * vCPU for executing selftests. + */ +struct td_boot_parameters { + uint32_t cr0; + uint32_t cr3; + uint32_t cr4; + struct td_boot_parameters_dtr gdtr; + struct td_boot_parameters_dtr idtr; + struct td_per_vcpu_parameters per_vcpu[]; +}; + +#endif /* SELFTEST_TDX_TD_BOOT_H */ diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/td_boot_offsets.c b/tools/testing/selftests/kvm/lib/x86/tdx/td_boot_offsets.c new file mode 100644 index 000000000000..7f76a3585b99 --- /dev/null +++ b/tools/testing/selftests/kvm/lib/x86/tdx/td_boot_offsets.c @@ -0,0 +1,21 @@ +// SPDX-License-Identifier: GPL-2.0 +#define COMPILE_OFFSETS + +#include <linux/kbuild.h> + +#include "tdx/td_boot.h" + +static void __attribute__((used)) common(void) +{ + OFFSET(TD_BOOT_PARAMETERS_CR0, td_boot_parameters, cr0); + OFFSET(TD_BOOT_PARAMETERS_CR3, td_boot_parameters, cr3); + OFFSET(TD_BOOT_PARAMETERS_CR4, td_boot_parameters, cr4); + OFFSET(TD_BOOT_PARAMETERS_GDT, td_boot_parameters, gdtr); + OFFSET(TD_BOOT_PARAMETERS_IDT, td_boot_parameters, idtr); + OFFSET(TD_BOOT_PARAMETERS_PER_VCPU, td_boot_parameters, per_vcpu); + OFFSET(TD_PER_VCPU_PARAMETERS_ESP_GVA, td_per_vcpu_parameters, esp_gva); + OFFSET(TD_PER_VCPU_PARAMETERS_GUEST_CODE, td_per_vcpu_parameters, + guest_code); + DEFINE(SIZEOF_TD_PER_VCPU_PARAMETERS, + sizeof(struct td_per_vcpu_parameters)); +}

From: Erdem Aktas erdemaktas@google.com

Add code to boot a TDX test VM. Since TDX registers are inaccesible to KVM, the boot code loads the relevant values from memory into the registers before jumping to the guest code.

Signed-off-by: Erdem Aktas erdemaktas@google.com Co-developed-by: Ackerley Tng ackerleytng@google.com Signed-off-by: Ackerley Tng ackerleytng@google.com Co-developed-by: Sagi Shahar sagis@google.com Signed-off-by: Sagi Shahar sagis@google.com --- tools/testing/selftests/kvm/Makefile.kvm | 3 + .../selftests/kvm/include/x86/tdx/td_boot.h | 5 ++ .../kvm/include/x86/tdx/td_boot_asm.h | 16 +++++ .../selftests/kvm/lib/x86/tdx/td_boot.S | 60 +++++++++++++++++++ 4 files changed, 84 insertions(+) create mode 100644 tools/testing/selftests/kvm/include/x86/tdx/td_boot_asm.h create mode 100644 tools/testing/selftests/kvm/lib/x86/tdx/td_boot.S

diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm index 3f93c093b046..d11d02e17cc5 100644 --- a/tools/testing/selftests/kvm/Makefile.kvm +++ b/tools/testing/selftests/kvm/Makefile.kvm @@ -31,6 +31,7 @@ LIBKVM_x86 += lib/x86/sev.c LIBKVM_x86 += lib/x86/svm.c LIBKVM_x86 += lib/x86/ucall.c LIBKVM_x86 += lib/x86/vmx.c +LIBKVM_x86 += lib/x86/tdx/td_boot.S

LIBKVM_arm64 += lib/arm64/gic.c LIBKVM_arm64 += lib/arm64/gic_v3.c @@ -336,6 +337,8 @@ $(LIBKVM_ASM_DEFS_OBJ): $(OUTPUT)/%.s: %.c FORCE $(LIBKVM_STRING_OBJ): $(OUTPUT)/%.o: %.c $(CC) $(CFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c -ffreestanding $< -o $@

+$(OUTPUT)/lib/x86/tdx/td_boot.o: $(OUTPUT)/include/x86/tdx/td_boot_offsets.h + $(OUTPUT)/include/x86/tdx/td_boot_offsets.h: $(OUTPUT)/lib/x86/tdx/td_boot_offsets.s FORCE $(call filechk,offsets,__TDX_BOOT_OFFSETS_H__)

diff --git a/tools/testing/selftests/kvm/include/x86/tdx/td_boot.h b/tools/testing/selftests/kvm/include/x86/tdx/td_boot.h index 8eda3ce10220..17c3083da9ca 100644 --- a/tools/testing/selftests/kvm/include/x86/tdx/td_boot.h +++ b/tools/testing/selftests/kvm/include/x86/tdx/td_boot.h @@ -66,4 +66,9 @@ struct td_boot_parameters { struct td_per_vcpu_parameters per_vcpu[]; };

+void td_boot(void); +void td_boot_code_end(void); + +#define TD_BOOT_CODE_SIZE (td_boot_code_end - td_boot) + #endif /* SELFTEST_TDX_TD_BOOT_H */ diff --git a/tools/testing/selftests/kvm/include/x86/tdx/td_boot_asm.h b/tools/testing/selftests/kvm/include/x86/tdx/td_boot_asm.h new file mode 100644 index 000000000000..10b4b527595c --- /dev/null +++ b/tools/testing/selftests/kvm/include/x86/tdx/td_boot_asm.h @@ -0,0 +1,16 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef SELFTEST_TDX_TD_BOOT_ASM_H +#define SELFTEST_TDX_TD_BOOT_ASM_H + +/* + * GPA where TD boot parameters will be loaded. + * + * TD_BOOT_PARAMETERS_GPA is arbitrarily chosen to + * + * + be within the 4GB address space + * + provide enough contiguous memory for the struct td_boot_parameters such + * that there is one struct td_per_vcpu_parameters for KVM_MAX_VCPUS + */ +#define TD_BOOT_PARAMETERS_GPA 0xffff0000 + +#endif // SELFTEST_TDX_TD_BOOT_ASM_H diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/td_boot.S b/tools/testing/selftests/kvm/lib/x86/tdx/td_boot.S new file mode 100644 index 000000000000..7aa33caa9a78 --- /dev/null +++ b/tools/testing/selftests/kvm/lib/x86/tdx/td_boot.S @@ -0,0 +1,60 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#include "tdx/td_boot_asm.h" +#include "tdx/td_boot_offsets.h" +#include "processor_asm.h" + +.code32 + +.globl td_boot +td_boot: + /* In this procedure, edi is used as a temporary register. */ + cli + + /* Paging is off. */ + + movl $TD_BOOT_PARAMETERS_GPA, %ebx + + /* + * Find the address of struct td_per_vcpu_parameters for this + * vCPU based on esi (TDX spec: initialized with vCPU id). Put + * struct address into register for indirect addressing. + */ + movl $SIZEOF_TD_PER_VCPU_PARAMETERS, %eax + mul %esi + leal TD_BOOT_PARAMETERS_PER_VCPU(%ebx), %edi + addl %edi, %eax + + /* Setup stack. */ + movl TD_PER_VCPU_PARAMETERS_ESP_GVA(%eax), %esp + + /* Setup GDT. */ + leal TD_BOOT_PARAMETERS_GDT(%ebx), %edi + lgdt (%edi) + + /* Setup IDT. */ + leal TD_BOOT_PARAMETERS_IDT(%ebx), %edi + lidt (%edi) + + /* + * Set up control registers (There are no instructions to mov from + * memory to control registers, hence use edi as a scratch register). + */ + movl TD_BOOT_PARAMETERS_CR4(%ebx), %edi + movl %edi, %cr4 + movl TD_BOOT_PARAMETERS_CR3(%ebx), %edi + movl %edi, %cr3 + movl TD_BOOT_PARAMETERS_CR0(%ebx), %edi + movl %edi, %cr0 + + /* Switching to 64bit mode after ljmp and then jump to guest code */ + ljmp $(KERNEL_CS),$1f +1: + jmp *TD_PER_VCPU_PARAMETERS_GUEST_CODE(%eax) + +/* Leave marker so size of td_boot code can be computed. */ +.globl td_boot_code_end +td_boot_code_end: + +/* Disable executable stack. */ +.section .note.GNU-stack,"",%progbits

Add memory for TDX boot code in a separate memslot.

Use virt_map() to get identity map in this memory region to allow for seamless transition from paging disabled to paging enabled code.

Copy the boot code into the memory region and set up the reset vectors at this point. While it's possible to separate the memory allocation and boot code initialization into separate functions, having all the calculations for memory size and offsets in one place simplifies the code and avoids duplications.

Handcode the reset vector as suggested by Sean Christopherson.

Suggested-by: Sean Christopherson seanjc@google.com Co-developed-by: Erdem Aktas erdemaktas@google.com Signed-off-by: Erdem Aktas erdemaktas@google.com Signed-off-by: Sagi Shahar sagis@google.com --- tools/testing/selftests/kvm/Makefile.kvm | 1 + .../selftests/kvm/include/x86/tdx/tdx_util.h | 2 + .../selftests/kvm/lib/x86/tdx/tdx_util.c | 54 +++++++++++++++++++ 3 files changed, 57 insertions(+) create mode 100644 tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c

diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm index d11d02e17cc5..52c90f1c0484 100644 --- a/tools/testing/selftests/kvm/Makefile.kvm +++ b/tools/testing/selftests/kvm/Makefile.kvm @@ -31,6 +31,7 @@ LIBKVM_x86 += lib/x86/sev.c LIBKVM_x86 += lib/x86/svm.c LIBKVM_x86 += lib/x86/ucall.c LIBKVM_x86 += lib/x86/vmx.c +LIBKVM_x86 += lib/x86/tdx/tdx_util.c LIBKVM_x86 += lib/x86/tdx/td_boot.S

LIBKVM_arm64 += lib/arm64/gic.c diff --git a/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h index 286d5e3c24b1..ec05bcd59145 100644 --- a/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h +++ b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h @@ -11,4 +11,6 @@ static inline bool is_tdx_vm(struct kvm_vm *vm) return vm->type == KVM_X86_TDX_VM; }

+void vm_tdx_setup_boot_code_region(struct kvm_vm *vm); + #endif // SELFTESTS_TDX_TDX_UTIL_H diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c new file mode 100644 index 000000000000..a1cf12de9d56 --- /dev/null +++ b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c @@ -0,0 +1,54 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include <stdint.h> + +#include "kvm_util.h" +#include "processor.h" +#include "tdx/td_boot.h" +#include "tdx/tdx_util.h" + +/* Arbitrarily selected to avoid overlaps with anything else */ +#define TD_BOOT_CODE_SLOT 20 + +#define X86_RESET_VECTOR 0xfffffff0ul +#define X86_RESET_VECTOR_SIZE 16 + +void vm_tdx_setup_boot_code_region(struct kvm_vm *vm) +{ + size_t total_code_size = TD_BOOT_CODE_SIZE + X86_RESET_VECTOR_SIZE; + vm_paddr_t boot_code_gpa = X86_RESET_VECTOR - TD_BOOT_CODE_SIZE; + vm_paddr_t alloc_gpa = round_down(boot_code_gpa, PAGE_SIZE); + size_t nr_pages = DIV_ROUND_UP(total_code_size, PAGE_SIZE); + vm_paddr_t gpa; + uint8_t *hva; + + vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, + alloc_gpa, + TD_BOOT_CODE_SLOT, nr_pages, + KVM_MEM_GUEST_MEMFD); + + gpa = vm_phy_pages_alloc(vm, nr_pages, alloc_gpa, TD_BOOT_CODE_SLOT); + TEST_ASSERT(gpa == alloc_gpa, "Failed vm_phy_pages_alloc\n"); + + virt_map(vm, alloc_gpa, alloc_gpa, nr_pages); + hva = addr_gpa2hva(vm, boot_code_gpa); + memcpy(hva, td_boot, TD_BOOT_CODE_SIZE); + + hva += TD_BOOT_CODE_SIZE; + TEST_ASSERT(hva == addr_gpa2hva(vm, X86_RESET_VECTOR), + "Expected RESET vector at hva 0x%lx, got %lx", + (unsigned long)addr_gpa2hva(vm, X86_RESET_VECTOR), (unsigned long)hva); + + /* + * Handcode "JMP rel8" at the RESET vector to jump back to the TD boot + * code, as there are only 16 bytes at the RESET vector before RIP will + * wrap back to zero. Insert a trailing int3 so that the vCPU crashes + * in case the JMP somehow falls through. Note! The target address is + * relative to the end of the instruction! + */ + TEST_ASSERT(TD_BOOT_CODE_SIZE + 2 <= 128, + "TD boot code not addressable by 'JMP rel8'"); + hva[0] = 0xeb; + hva[1] = 256 - 2 - TD_BOOT_CODE_SIZE; + hva[2] = 0xcc; +}

Allocate memory for TDX boot parameters and define the utility functions necessary to fill this memory with the boot parameters.

Co-developed-by: Ackerley Tng ackerleytng@google.com Signed-off-by: Ackerley Tng ackerleytng@google.com Signed-off-by: Sagi Shahar sagis@google.com --- .../selftests/kvm/include/x86/tdx/tdx_util.h | 4 + .../selftests/kvm/lib/x86/tdx/tdx_util.c | 75 +++++++++++++++++++ 2 files changed, 79 insertions(+)

diff --git a/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h index ec05bcd59145..dafdc7e46abe 100644 --- a/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h +++ b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h @@ -12,5 +12,9 @@ static inline bool is_tdx_vm(struct kvm_vm *vm) }

void vm_tdx_setup_boot_code_region(struct kvm_vm *vm); +void vm_tdx_setup_boot_parameters_region(struct kvm_vm *vm, uint32_t nr_runnable_vcpus); +void vm_tdx_load_common_boot_parameters(struct kvm_vm *vm); +void vm_tdx_load_vcpu_boot_parameters(struct kvm_vm *vm, struct kvm_vcpu *vcpu); +void vm_tdx_set_vcpu_entry_point(struct kvm_vcpu *vcpu, void *guest_code);

#endif // SELFTESTS_TDX_TDX_UTIL_H diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c index a1cf12de9d56..ff61333bc848 100644 --- a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c +++ b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c @@ -5,10 +5,12 @@ #include "kvm_util.h" #include "processor.h" #include "tdx/td_boot.h" +#include "tdx/td_boot_asm.h" #include "tdx/tdx_util.h"

/* Arbitrarily selected to avoid overlaps with anything else */ #define TD_BOOT_CODE_SLOT 20 +#define TD_BOOT_PARAMETERS_SLOT 21

#define X86_RESET_VECTOR 0xfffffff0ul #define X86_RESET_VECTOR_SIZE 16 @@ -52,3 +54,76 @@ void vm_tdx_setup_boot_code_region(struct kvm_vm *vm) hva[1] = 256 - 2 - TD_BOOT_CODE_SIZE; hva[2] = 0xcc; } + +void vm_tdx_setup_boot_parameters_region(struct kvm_vm *vm, uint32_t nr_runnable_vcpus) +{ + size_t boot_params_size = + sizeof(struct td_boot_parameters) + + nr_runnable_vcpus * sizeof(struct td_per_vcpu_parameters); + int npages = DIV_ROUND_UP(boot_params_size, PAGE_SIZE); + vm_paddr_t gpa; + + vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, + TD_BOOT_PARAMETERS_GPA, + TD_BOOT_PARAMETERS_SLOT, npages, + KVM_MEM_GUEST_MEMFD); + gpa = vm_phy_pages_alloc(vm, npages, TD_BOOT_PARAMETERS_GPA, TD_BOOT_PARAMETERS_SLOT); + TEST_ASSERT(gpa == TD_BOOT_PARAMETERS_GPA, "Failed vm_phy_pages_alloc\n"); + + virt_map(vm, TD_BOOT_PARAMETERS_GPA, TD_BOOT_PARAMETERS_GPA, npages); +} + +void vm_tdx_load_common_boot_parameters(struct kvm_vm *vm) +{ + struct td_boot_parameters *params = + addr_gpa2hva(vm, TD_BOOT_PARAMETERS_GPA); + uint32_t cr4; + + TEST_ASSERT_EQ(vm->mode, VM_MODE_PXXV48_4K); + + cr4 = kvm_get_default_cr4(); + + /* TDX spec 11.6.2: CR4 bit MCE is fixed to 1 */ + cr4 |= X86_CR4_MCE; + + /* Set this because UEFI also sets this up, to handle XMM exceptions */ + cr4 |= X86_CR4_OSXMMEXCPT; + + /* TDX spec 11.6.2: CR4 bit VMXE and SMXE are fixed to 0 */ + cr4 &= ~(X86_CR4_VMXE | X86_CR4_SMXE); + + /* Set parameters! */ + params->cr0 = kvm_get_default_cr0(); + params->cr3 = vm->pgd; + params->cr4 = cr4; + params->idtr.base = vm->arch.idt; + params->idtr.limit = kvm_get_default_idt_limit(); + params->gdtr.base = vm->arch.gdt; + params->gdtr.limit = kvm_get_default_gdt_limit(); + + TEST_ASSERT(params->cr0 != 0, "cr0 should not be 0"); + TEST_ASSERT(params->cr3 != 0, "cr3 should not be 0"); + TEST_ASSERT(params->cr4 != 0, "cr4 should not be 0"); + TEST_ASSERT(params->gdtr.base != 0, "gdt base address should not be 0"); + TEST_ASSERT(params->idtr.base != 0, "idt base address should not be 0"); +} + +void vm_tdx_load_vcpu_boot_parameters(struct kvm_vm *vm, struct kvm_vcpu *vcpu) +{ + struct td_boot_parameters *params = + addr_gpa2hva(vm, TD_BOOT_PARAMETERS_GPA); + struct td_per_vcpu_parameters *vcpu_params = + &params->per_vcpu[vcpu->id]; + + vcpu_params->esp_gva = kvm_allocate_vcpu_stack(vm); +} + +void vm_tdx_set_vcpu_entry_point(struct kvm_vcpu *vcpu, void *guest_code) +{ + struct td_boot_parameters *params = + addr_gpa2hva(vcpu->vm, TD_BOOT_PARAMETERS_GPA); + struct td_per_vcpu_parameters *vcpu_params = + &params->per_vcpu[vcpu->id]; + + vcpu_params->guest_code = (uint64_t)guest_code; +}

From: Isaku Yamahata isaku.yamahata@intel.com

Make sure that all the attributes enabled by the test are reported as supported by the TDX module.

This also exercises the KVM_TDX_CAPABILITIES ioctl.

Signed-off-by: Isaku Yamahata isaku.yamahata@intel.com Co-developed-by: Sagi Shahar sagis@google.com Signed-off-by: Sagi Shahar sagis@google.com --- tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+)

diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c index aa0cb6c2205b..1b5c01faf1cd 100644 --- a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c +++ b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c @@ -234,6 +234,18 @@ static void vm_tdx_filter_cpuid(struct kvm_vm *vm, free(tdx_cap); }

+static void tdx_check_attributes(struct kvm_vm *vm, uint64_t attributes) +{ + struct kvm_tdx_capabilities *tdx_cap; + + tdx_cap = tdx_read_capabilities(vm); + + /* Make sure all the attributes are reported as supported by the TDX module */ + TEST_ASSERT_EQ(attributes & tdx_cap->supported_attrs, attributes); + + free(tdx_cap); +} + void vm_tdx_init_vm(struct kvm_vm *vm, uint64_t attributes) { struct kvm_tdx_init_vm *init_vm; @@ -253,6 +265,8 @@ void vm_tdx_init_vm(struct kvm_vm *vm, uint64_t attributes) memcpy(&init_vm->cpuid, cpuid, kvm_cpuid2_size(cpuid->nent)); free(cpuid);

+ tdx_check_attributes(vm, attributes); + init_vm->attributes = attributes;

vm_tdx_vm_ioctl(vm, KVM_TDX_INIT_VM, 0, init_vm);

From: Ackerley Tng ackerleytng@google.com

TDX protected memory needs to be measured and encrypted before it can be used by the guest. Traverse the VM's memory regions and initialize all the protected ranges by calling KVM_TDX_INIT_MEM_REGION.

Once all the memory is initialized, the VM can be finalized by calling KVM_TDX_FINALIZE_VM.

Signed-off-by: Ackerley Tng ackerleytng@google.com Co-developed-by: Erdem Aktas erdemaktas@google.com Signed-off-by: Erdem Aktas erdemaktas@google.com Co-developed-by: Sagi Shahar sagis@google.com Signed-off-by: Sagi Shahar sagis@google.com --- .../selftests/kvm/include/x86/tdx/tdx_util.h | 2 + .../selftests/kvm/lib/x86/tdx/tdx_util.c | 61 +++++++++++++++++++ 2 files changed, 63 insertions(+)

diff --git a/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h index a2509959c7ce..2467b6c35557 100644 --- a/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h +++ b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h @@ -71,4 +71,6 @@ void vm_tdx_load_common_boot_parameters(struct kvm_vm *vm); void vm_tdx_load_vcpu_boot_parameters(struct kvm_vm *vm, struct kvm_vcpu *vcpu); void vm_tdx_set_vcpu_entry_point(struct kvm_vcpu *vcpu, void *guest_code);

+void vm_tdx_finalize(struct kvm_vm *vm); + #endif // SELFTESTS_TDX_TDX_UTIL_H diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c index 1b5c01faf1cd..d5df2de81a75 100644 --- a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c +++ b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c @@ -273,3 +273,64 @@ void vm_tdx_init_vm(struct kvm_vm *vm, uint64_t attributes)

free(init_vm); } + +static void tdx_init_mem_region(struct kvm_vm *vm, void *source_pages, + uint64_t gpa, uint64_t size) +{ + uint32_t metadata = KVM_TDX_MEASURE_MEMORY_REGION; + struct kvm_tdx_init_mem_region mem_region = { + .source_addr = (uint64_t)source_pages, + .gpa = gpa, + .nr_pages = size / PAGE_SIZE, + }; + struct kvm_vcpu *vcpu; + + vcpu = list_first_entry_or_null(&vm->vcpus, struct kvm_vcpu, list); + + TEST_ASSERT((mem_region.nr_pages > 0) && + ((mem_region.nr_pages * PAGE_SIZE) == size), + "Cannot add partial pages to the guest memory.\n"); + TEST_ASSERT(((uint64_t)source_pages & (PAGE_SIZE - 1)) == 0, + "Source memory buffer is not page aligned\n"); + vm_tdx_vcpu_ioctl(vcpu, KVM_TDX_INIT_MEM_REGION, metadata, &mem_region); +} + +static void load_td_private_memory(struct kvm_vm *vm) +{ + struct userspace_mem_region *region; + int ctr; + + hash_for_each(vm->regions.slot_hash, ctr, region, slot_node) { + const struct sparsebit *protected_pages = region->protected_phy_pages; + const vm_paddr_t gpa_base = region->region.guest_phys_addr; + const uint64_t hva_base = region->region.userspace_addr; + const sparsebit_idx_t lowest_page_in_region = gpa_base >> vm->page_shift; + + sparsebit_idx_t i; + sparsebit_idx_t j; + + if (!sparsebit_any_set(protected_pages)) + continue; + + TEST_ASSERT(region->region.guest_memfd != -1, + "TD private memory must be backed by guest_memfd"); + + sparsebit_for_each_set_range(protected_pages, i, j) { + const uint64_t size_to_load = (j - i + 1) * vm->page_size; + const uint64_t offset = + (i - lowest_page_in_region) * vm->page_size; + const uint64_t hva = hva_base + offset; + const uint64_t gpa = gpa_base + offset; + + vm_set_memory_attributes(vm, gpa, size_to_load, + KVM_MEMORY_ATTRIBUTE_PRIVATE); + tdx_init_mem_region(vm, (void *)hva, gpa, size_to_load); + } + } +} + +void vm_tdx_finalize(struct kvm_vm *vm) +{ + load_td_private_memory(vm); + vm_tdx_vm_ioctl(vm, KVM_TDX_FINALIZE_VM, 0, NULL); +}

TDX VMs need to issue the KVM_TDX_INIT_VM ioctl after VM creation to initialize the TD. This ioctl also sets the cpuids and attributes for the VM.

Signed-off-by: Sagi Shahar sagis@google.com --- tools/testing/selftests/kvm/lib/x86/processor.c | 3 +++ 1 file changed, 3 insertions(+)

diff --git a/tools/testing/selftests/kvm/lib/x86/processor.c b/tools/testing/selftests/kvm/lib/x86/processor.c index 623168ea9a44..c255fe1951be 100644 --- a/tools/testing/selftests/kvm/lib/x86/processor.c +++ b/tools/testing/selftests/kvm/lib/x86/processor.c @@ -641,6 +641,9 @@ void kvm_arch_vm_post_create(struct kvm_vm *vm) vm_sev_ioctl(vm, KVM_SEV_INIT2, &init); }

+ if (is_tdx_vm(vm)) + vm_tdx_init_vm(vm, 0); + r = __vm_ioctl(vm, KVM_GET_TSC_KHZ, NULL); TEST_ASSERT(r > 0, "KVM_GET_TSC_KHZ did not provide a valid TSC frequency."); guest_tsc_khz = r;

TDX VMs need to issue the KVM_TDX_INIT_VCPU ioctl for each vcpu after vcpu creation.

Since the cpuids for TD are managed by the TDX module, read the values virtualized for the TD using KVM_TDX_GET_CPUID and set them in kvm using KVM_SET_CPUID2 so that kvm has an accurate view of the VM cpuid values.

Signed-off-by: Sagi Shahar sagis@google.com --- .../testing/selftests/kvm/lib/x86/processor.c | 35 ++++++++++++++----- 1 file changed, 27 insertions(+), 8 deletions(-)

diff --git a/tools/testing/selftests/kvm/lib/x86/processor.c b/tools/testing/selftests/kvm/lib/x86/processor.c index c255fe1951be..b1e5f4137629 100644 --- a/tools/testing/selftests/kvm/lib/x86/processor.c +++ b/tools/testing/selftests/kvm/lib/x86/processor.c @@ -685,6 +685,19 @@ vm_vaddr_t kvm_allocate_vcpu_stack(struct kvm_vm *vm) return stack_vaddr; }

+static void vm_tdx_vcpu_add(struct kvm_vm *vm, struct kvm_vcpu *vcpu) +{ + struct kvm_cpuid2 *cpuid; + + cpuid = allocate_kvm_cpuid2(MAX_NR_CPUID_ENTRIES); + vm_tdx_vcpu_ioctl(vcpu, KVM_TDX_GET_CPUID, 0, cpuid); + vcpu_init_cpuid(vcpu, cpuid); + free(cpuid); + vm_tdx_vcpu_ioctl(vcpu, KVM_TDX_INIT_VCPU, 0, NULL); + + vm_tdx_load_vcpu_boot_parameters(vm, vcpu); +} + struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id) { struct kvm_mp_state mp_state; @@ -692,15 +705,21 @@ struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id) struct kvm_vcpu *vcpu;

vcpu = __vm_vcpu_add(vm, vcpu_id); - vcpu_init_cpuid(vcpu, kvm_get_supported_cpuid()); - vcpu_init_sregs(vm, vcpu); - vcpu_init_xcrs(vm, vcpu);

- /* Setup guest general purpose registers */ - vcpu_regs_get(vcpu, &regs); - regs.rflags = regs.rflags | 0x2; - regs.rsp = kvm_allocate_vcpu_stack(vm); - vcpu_regs_set(vcpu, &regs); + if (is_tdx_vm(vm)) { + vm_tdx_vcpu_add(vm, vcpu); + } else { + vcpu_init_cpuid(vcpu, kvm_get_supported_cpuid()); + + vcpu_init_sregs(vm, vcpu); + vcpu_init_xcrs(vm, vcpu); + + /* Setup guest general purpose registers */ + vcpu_regs_get(vcpu, &regs); + regs.rflags = regs.rflags | 0x2; + regs.rsp = kvm_allocate_vcpu_stack(vm); + vcpu_regs_set(vcpu, &regs); + }

/* Setup the MP state */ mp_state.mp_state = 0;

From: Erdem Aktas erdemaktas@google.com

Add support for TDX guests to issue TDCALLs to the TDX module.

Signed-off-by: Erdem Aktas erdemaktas@google.com Co-developed-by: Sagi Shahar sagis@google.com Signed-off-by: Sagi Shahar sagis@google.com --- tools/testing/selftests/kvm/Makefile.kvm | 8 ++ .../selftests/kvm/include/x86/tdx/tdcall.h | 34 +++++++ .../selftests/kvm/lib/x86/tdx/tdcall.S | 93 +++++++++++++++++++ .../kvm/lib/x86/tdx/tdcall_offsets.c | 16 ++++ 4 files changed, 151 insertions(+) create mode 100644 tools/testing/selftests/kvm/include/x86/tdx/tdcall.h create mode 100644 tools/testing/selftests/kvm/lib/x86/tdx/tdcall.S create mode 100644 tools/testing/selftests/kvm/lib/x86/tdx/tdcall_offsets.c

diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm index 52c90f1c0484..2d4fd68984a0 100644 --- a/tools/testing/selftests/kvm/Makefile.kvm +++ b/tools/testing/selftests/kvm/Makefile.kvm @@ -20,6 +20,7 @@ LIBKVM += lib/userfaultfd_util.c LIBKVM_STRING += lib/string_override.c

LIBKVM_ASM_DEFS += lib/x86/tdx/td_boot_offsets.c +LIBKVM_ASM_DEFS += lib/x86/tdx/tdcall_offsets.c

LIBKVM_x86 += lib/x86/apic.c LIBKVM_x86 += lib/x86/handlers.S @@ -33,6 +34,7 @@ LIBKVM_x86 += lib/x86/ucall.c LIBKVM_x86 += lib/x86/vmx.c LIBKVM_x86 += lib/x86/tdx/tdx_util.c LIBKVM_x86 += lib/x86/tdx/td_boot.S +LIBKVM_x86 += lib/x86/tdx/tdcall.S

LIBKVM_arm64 += lib/arm64/gic.c LIBKVM_arm64 += lib/arm64/gic_v3.c @@ -343,7 +345,13 @@ $(OUTPUT)/lib/x86/tdx/td_boot.o: $(OUTPUT)/include/x86/tdx/td_boot_offsets.h $(OUTPUT)/include/x86/tdx/td_boot_offsets.h: $(OUTPUT)/lib/x86/tdx/td_boot_offsets.s FORCE $(call filechk,offsets,__TDX_BOOT_OFFSETS_H__)

+$(OUTPUT)/lib/x86/tdx/tdcall.o: $(OUTPUT)/include/x86/tdx/tdcall_offsets.h + +$(OUTPUT)/include/x86/tdx/tdcall_offsets.h: $(OUTPUT)/lib/x86/tdx/tdcall_offsets.s FORCE + $(call filechk,offsets,__TDCALL__OFFSETS_H__) + EXTRA_CLEAN += $(OUTPUT)/include/x86/tdx/td_boot_offsets.h +EXTRA_CLEAN += $(OUTPUT)/include/x86/tdx/tdcall_offsets.h

$(shell mkdir -p $(sort $(dir $(TEST_GEN_PROGS)))) $(SPLIT_TEST_GEN_OBJ): $(GEN_HDRS) diff --git a/tools/testing/selftests/kvm/include/x86/tdx/tdcall.h b/tools/testing/selftests/kvm/include/x86/tdx/tdcall.h new file mode 100644 index 000000000000..60c70646f876 --- /dev/null +++ b/tools/testing/selftests/kvm/include/x86/tdx/tdcall.h @@ -0,0 +1,34 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* Adapted from arch/x86/include/asm/shared/tdx.h */ + +#ifndef SELFTESTS_TDX_TDCALL_H +#define SELFTESTS_TDX_TDCALL_H + +#include <linux/bits.h> + +#define TDX_TDCALL_HAS_OUTPUT BIT(0) + +#ifndef __ASSEMBLY__ + +#include <linux/types.h> + +/* + * Used in __tdx_tdcall() to pass down and get back registers' values of + * the TDCALL instruction when requesting services from the VMM. + * + * This is a software only structure and not part of the TDX module/VMM ABI. + */ +struct tdx_tdcall_args { + u64 r10; + u64 r11; + u64 r12; + u64 r13; + u64 r14; + u64 r15; +}; + +/* Used to request services from the VMM */ +u64 __tdx_tdcall(struct tdx_tdcall_args *args, unsigned long flags); + +#endif // __ASSEMBLY__ +#endif // SELFTESTS_TDX_TDCALL_H diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/tdcall.S b/tools/testing/selftests/kvm/lib/x86/tdx/tdcall.S new file mode 100644 index 000000000000..05869e86b9d8 --- /dev/null +++ b/tools/testing/selftests/kvm/lib/x86/tdx/tdcall.S @@ -0,0 +1,93 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* Adapted from arch/x86/virt/vmx/tdx/tdxcall.S */ + +#ifndef __ASSEMBLY__ +#define __ASSEMBLY__ +#endif + +#include <linux/bits.h> +#include "tdx/tdcall.h" +#include "tdx/tdcall_offsets.h" + +/* + * TDCALL is supported in Binutils >= 2.36, add it for older version. + */ +#define tdcall .byte 0x66,0x0f,0x01,0xcc + +/* + * Bitmasks of exposed registers (with VMM). + */ +#define TDX_R10 BIT(10) +#define TDX_R11 BIT(11) +#define TDX_R12 BIT(12) +#define TDX_R13 BIT(13) +#define TDX_R14 BIT(14) +#define TDX_R15 BIT(15) + +/* + * These registers are clobbered to hold arguments for each + * TDVMCALL. They are safe to expose to the VMM. + * Each bit in this mask represents a register ID. Bit field + * details can be found in TDX GHCI specification, section + * titled "TDCALL [TDG.VP.VMCALL] leaf". + */ +#define TDVMCALL_EXPOSE_REGS_MASK \ + (TDX_R10 | TDX_R11 | TDX_R12 | TDX_R13 | TDX_R14 | TDX_R15) + +.code64 +.section .text + +.globl __tdx_tdcall +.type __tdx_tdcall, @function +__tdx_tdcall: + /* Set up stack frame */ + push %rbp + movq %rsp, %rbp + + /* Save callee-saved GPRs as mandated by the x86_64 ABI */ + push %r15 + push %r14 + push %r13 + push %r12 + + /* Mangle function call ABI into TDCALL ABI: */ + /* Set TDCALL leaf ID (TDVMCALL (0)) in RAX */ + xor %eax, %eax + + /* Copy tdcall registers from arg struct: */ + movq TDX_TDCALL_R10(%rdi), %r10 + movq TDX_TDCALL_R11(%rdi), %r11 + movq TDX_TDCALL_R12(%rdi), %r12 + movq TDX_TDCALL_R13(%rdi), %r13 + movq TDX_TDCALL_R14(%rdi), %r14 + movq TDX_TDCALL_R15(%rdi), %r15 + + movl $TDVMCALL_EXPOSE_REGS_MASK, %ecx + + tdcall + + /* TDVMCALL leaf return code is in R10 */ + movq %r10, %rax + + /* Copy tdcall result registers to arg struct if needed */ + testq $TDX_TDCALL_HAS_OUTPUT, %rsi + jz .Lout + + movq %r10, TDX_TDCALL_R10(%rdi) + movq %r11, TDX_TDCALL_R11(%rdi) + movq %r12, TDX_TDCALL_R12(%rdi) + movq %r13, TDX_TDCALL_R13(%rdi) + movq %r14, TDX_TDCALL_R14(%rdi) + movq %r15, TDX_TDCALL_R15(%rdi) +.Lout: + /* Restore callee-saved GPRs as mandated by the x86_64 ABI */ + pop %r12 + pop %r13 + pop %r14 + pop %r15 + + pop %rbp + ret + +/* Disable executable stack */ +.section .note.GNU-stack,"",%progbits diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/tdcall_offsets.c b/tools/testing/selftests/kvm/lib/x86/tdx/tdcall_offsets.c new file mode 100644 index 000000000000..dcd4457be6e5 --- /dev/null +++ b/tools/testing/selftests/kvm/lib/x86/tdx/tdcall_offsets.c @@ -0,0 +1,16 @@ +// SPDX-License-Identifier: GPL-2.0 +#define COMPILE_OFFSETS + +#include <linux/kbuild.h> + +#include "tdx/tdcall.h" + +static void __attribute__((used)) common(void) +{ + OFFSET(TDX_TDCALL_R10, tdx_tdcall_args, r10); + OFFSET(TDX_TDCALL_R11, tdx_tdcall_args, r11); + OFFSET(TDX_TDCALL_R12, tdx_tdcall_args, r12); + OFFSET(TDX_TDCALL_R13, tdx_tdcall_args, r13); + OFFSET(TDX_TDCALL_R14, tdx_tdcall_args, r14); + OFFSET(TDX_TDCALL_R15, tdx_tdcall_args, r15); +}

From: Ackerley Tng ackerleytng@google.com

ucalls for non-Coco VMs work by having the guest write to the rdi register, then perform an io instruction to exit to the host. The host then reads rdi using kvm_get_regs().

CPU registers can't be read using kvm_get_regs() for TDX, so TDX guests use MMIO to pass the struct ucall's hva to the host. MMIO was chosen because it is one of the simplest (hence unlikely to fail) mechanisms that support passing 8 bytes from guest to host.

Signed-off-by: Ackerley Tng ackerleytng@google.com Co-developed-by: Sagi Shahar sagis@google.com Signed-off-by: Sagi Shahar sagis@google.com --- .../testing/selftests/kvm/include/x86/ucall.h | 4 +- tools/testing/selftests/kvm/lib/x86/ucall.c | 45 ++++++++++++++++--- 2 files changed, 41 insertions(+), 8 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/x86/ucall.h b/tools/testing/selftests/kvm/include/x86/ucall.h index d3825dcc3cd9..0494a4a21557 100644 --- a/tools/testing/selftests/kvm/include/x86/ucall.h +++ b/tools/testing/selftests/kvm/include/x86/ucall.h @@ -6,8 +6,6 @@

#define UCALL_EXIT_REASON KVM_EXIT_IO

-static inline void ucall_arch_init(struct kvm_vm *vm, vm_paddr_t mmio_gpa) -{ -} +void ucall_arch_init(struct kvm_vm *vm, vm_paddr_t mmio_gpa);

#endif diff --git a/tools/testing/selftests/kvm/lib/x86/ucall.c b/tools/testing/selftests/kvm/lib/x86/ucall.c index 1265cecc7dd1..0ad24baaa3c4 100644 --- a/tools/testing/selftests/kvm/lib/x86/ucall.c +++ b/tools/testing/selftests/kvm/lib/x86/ucall.c @@ -5,11 +5,34 @@ * Copyright (C) 2018, Red Hat, Inc. */ #include "kvm_util.h" +#include "tdx/tdx.h"

#define UCALL_PIO_PORT ((uint16_t)0x1000)

+static uint8_t vm_type; +static vm_paddr_t host_ucall_mmio_gpa; +static vm_paddr_t ucall_mmio_gpa; + +void ucall_arch_init(struct kvm_vm *vm, vm_paddr_t mmio_gpa) +{ + vm_type = vm->type; + sync_global_to_guest(vm, vm_type); + + host_ucall_mmio_gpa = ucall_mmio_gpa = mmio_gpa; + + if (vm_type == KVM_X86_TDX_VM) + ucall_mmio_gpa |= vm->arch.s_bit; + + sync_global_to_guest(vm, ucall_mmio_gpa); +} + void ucall_arch_do_ucall(vm_vaddr_t uc) { + if (vm_type == KVM_X86_TDX_VM) { + tdg_vp_vmcall_ve_request_mmio_write(ucall_mmio_gpa, 8, uc); + return; + } + /* * FIXME: Revert this hack (the entire commit that added it) once nVMX * preserves L2 GPRs across a nested VM-Exit. If a ucall from L2, e.g. @@ -46,11 +69,23 @@ void *ucall_arch_get_ucall(struct kvm_vcpu *vcpu) { struct kvm_run *run = vcpu->run;

- if (run->exit_reason == KVM_EXIT_IO && run->io.port == UCALL_PIO_PORT) { - struct kvm_regs regs; + switch (vm_type) { + case KVM_X86_TDX_VM: + if (vcpu->run->exit_reason == KVM_EXIT_MMIO && + vcpu->run->mmio.phys_addr == host_ucall_mmio_gpa && + vcpu->run->mmio.len == 8 && vcpu->run->mmio.is_write) { + uint64_t data = *(uint64_t *)vcpu->run->mmio.data; + + return (void *)data; + } + return NULL; + default: + if (run->exit_reason == KVM_EXIT_IO && run->io.port == UCALL_PIO_PORT) { + struct kvm_regs regs;

- vcpu_regs_get(vcpu, &regs); - return (void *)regs.rdi; + vcpu_regs_get(vcpu, &regs); + return (void *)regs.rdi; + } + return NULL; } - return NULL; }

Adding a test to verify TDX lifecycle by creating a simple TD.

Signed-off-by: Sagi Shahar sagis@google.com --- tools/testing/selftests/kvm/Makefile.kvm | 1 + .../selftests/kvm/include/x86/tdx/tdx_util.h | 10 ++++++ .../selftests/kvm/lib/x86/tdx/tdx_util.c | 18 +++++++++++ tools/testing/selftests/kvm/x86/tdx_vm_test.c | 31 +++++++++++++++++++ 4 files changed, 60 insertions(+) create mode 100644 tools/testing/selftests/kvm/x86/tdx_vm_test.c

diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm index 1a73e08c8437..1a76e9fa45d6 100644 --- a/tools/testing/selftests/kvm/Makefile.kvm +++ b/tools/testing/selftests/kvm/Makefile.kvm @@ -155,6 +155,7 @@ TEST_GEN_PROGS_x86 += rseq_test TEST_GEN_PROGS_x86 += steal_time TEST_GEN_PROGS_x86 += system_counter_offset_test TEST_GEN_PROGS_x86 += pre_fault_memory_test +TEST_GEN_PROGS_x86 += x86/tdx_vm_test

# Compiled outputs used by test targets TEST_GEN_PROGS_EXTENDED_x86 += x86/nx_huge_pages_test diff --git a/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h index 2467b6c35557..775ca249f74d 100644 --- a/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h +++ b/tools/testing/selftests/kvm/include/x86/tdx/tdx_util.h @@ -11,6 +11,14 @@ static inline bool is_tdx_vm(struct kvm_vm *vm) return vm->type == KVM_X86_TDX_VM; }

+/* + * Verify that TDX is supported by KVM. + */ +static inline bool is_tdx_enabled(void) +{ + return !!(kvm_check_cap(KVM_CAP_VM_TYPES) & BIT(KVM_X86_TDX_VM)); +} + /* * TDX ioctls */ @@ -72,5 +80,7 @@ void vm_tdx_load_vcpu_boot_parameters(struct kvm_vm *vm, struct kvm_vcpu *vcpu); void vm_tdx_set_vcpu_entry_point(struct kvm_vcpu *vcpu, void *guest_code);

void vm_tdx_finalize(struct kvm_vm *vm); +struct kvm_vm *vm_tdx_create_with_one_vcpu(void *guest_code, + struct kvm_vcpu **vcpu);

#endif // SELFTESTS_TDX_TDX_UTIL_H diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c index d5df2de81a75..a2764f5d687c 100644 --- a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c +++ b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c @@ -334,3 +334,21 @@ void vm_tdx_finalize(struct kvm_vm *vm) load_td_private_memory(vm); vm_tdx_vm_ioctl(vm, KVM_TDX_FINALIZE_VM, 0, NULL); } + +struct kvm_vm *vm_tdx_create_with_one_vcpu(void *guest_code, + struct kvm_vcpu **vcpu) +{ + struct vm_shape shape = { + .mode = VM_MODE_DEFAULT, + .type = KVM_X86_TDX_VM, + }; + struct kvm_vm *vm; + struct kvm_vcpu *vcpus[1]; + + vm = __vm_create_with_vcpus(shape, 1, 0, guest_code, vcpus); + *vcpu = vcpus[0]; + + vm_tdx_finalize(vm); + + return vm; +} diff --git a/tools/testing/selftests/kvm/x86/tdx_vm_test.c b/tools/testing/selftests/kvm/x86/tdx_vm_test.c new file mode 100644 index 000000000000..a9ee489eea1a --- /dev/null +++ b/tools/testing/selftests/kvm/x86/tdx_vm_test.c @@ -0,0 +1,31 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include "kvm_util.h" +#include "tdx/tdx_util.h" +#include "ucall_common.h" +#include "kselftest_harness.h" + +static void guest_code_lifecycle(void) +{ + GUEST_DONE(); +} + +TEST(verify_td_lifecycle) +{ + struct kvm_vcpu *vcpu; + struct kvm_vm *vm; + struct ucall uc; + + vm = vm_tdx_create_with_one_vcpu(guest_code_lifecycle, &vcpu); + + vcpu_run(vcpu); + TEST_ASSERT_EQ(get_ucall(vcpu, &uc), UCALL_DONE); + + kvm_vm_free(vm); +} + +int main(int argc, char **argv) +{ + TEST_REQUIRE(is_tdx_enabled()); + return test_harness_run(argc, argv); +}