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Sampat" , Reinette Chatre , Rick Edgecombe , Roger Wang , Ryan Afranji , Sagi Shahar , Sean Christopherson , Shuah Khan , Xiaoyao Li , Oliver Upton Cc: Jeremiah McReynolds , kvm@vger.kernel.org, linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, x86@kernel.org, Lisa Wang , Ira Weiny Content-Type: text/plain; charset="utf-8" From: Sagi Shahar Introduce kvm_allocate_vcpu_stack() to allocate a vCPU's stack in preparation for TDX to allocate a vCPU's stack and initialize its stack pointer. TDX VMs' registers are protected state and cannot be initialized using the KVM_SET_REGS ioctl() that is used for normal VMs. A TDX vCPU's stack address will be a property of the TDX specific boot code that initializes the vCPUs' stack pointers at boot. Signed-off-by: Sagi Shahar Signed-off-by: Lisa Wang Reviewed-by: Binbin Wu Reviewed-by: Ira Weiny Reviewed-by: Xiaoyao Li --- .../testing/selftests/kvm/include/x86/processor.h | 2 ++ tools/testing/selftests/kvm/lib/x86/processor.c | 25 +++++++++++++++++++--- 2 files changed, 24 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/kvm/include/x86/processor.h b/tools/testing/selftests/kvm/include/x86/processor.h index 8854ee052d29..1eb380dd216c 100644 --- a/tools/testing/selftests/kvm/include/x86/processor.h +++ b/tools/testing/selftests/kvm/include/x86/processor.h @@ -1212,6 +1212,8 @@ static inline void vcpu_clear_cpuid_feature(struct kvm_vcpu *vcpu, vcpu_set_or_clear_cpuid_feature(vcpu, feature, false); } +gva_t kvm_allocate_vcpu_stack(struct kvm_vm *vm); + u64 vcpu_get_msr(struct kvm_vcpu *vcpu, u64 msr_index); int _vcpu_set_msr(struct kvm_vcpu *vcpu, u64 msr_index, u64 msr_value); diff --git a/tools/testing/selftests/kvm/lib/x86/processor.c b/tools/testing/selftests/kvm/lib/x86/processor.c index da430d4e7765..4a753fb43007 100644 --- a/tools/testing/selftests/kvm/lib/x86/processor.c +++ b/tools/testing/selftests/kvm/lib/x86/processor.c @@ -851,12 +851,31 @@ void vcpu_arch_set_entry_point(struct kvm_vcpu *vcpu, void *guest_code) vcpu_regs_set(vcpu, ®s); } -struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, u32 vcpu_id) +gva_t kvm_allocate_vcpu_stack(struct kvm_vm *vm) { struct kvm_mp_state mp_state; struct kvm_regs regs; + gva_t stack_gva; struct kvm_vcpu *vcpu; + stack_gva = __vm_alloc(vm, DEFAULT_STACK_PGS * getpagesize(), + DEFAULT_GUEST_STACK_VADDR_MIN, MEM_REGION_DATA); + + stack_gva += DEFAULT_STACK_PGS * getpagesize(); + + /* + * Align stack to match calling sequence requirements in section "The + * Stack Frame" of the System V ABI AMD64 Architecture Processor + * Supplement, which requires the value (%rsp + 8) to be a multiple of + * 16 when control is transferred to the function entry point. + * + * If this code is ever used to launch a vCPU with 32-bit entry point it + * may need to subtract 4 bytes instead of 8 bytes. + */ + TEST_ASSERT(IS_ALIGNED(stack_gva, PAGE_SIZE), + "__vm_alloc() did not provide a page-aligned address"); + stack_gva -= 8; + vcpu = __vm_vcpu_add(vm, vcpu_id); vcpu_init_cpuid(vcpu, kvm_get_supported_cpuid()); vcpu_init_sregs(vm, vcpu); @@ -864,8 +883,8 @@ struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, u32 vcpu_id) /* Setup guest general purpose registers */ vcpu_regs_get(vcpu, ®s); - regs.rflags = regs.rflags | X86_EFLAGS_FIXED; - regs.rsp = vm_alloc_stack(vm, DEFAULT_STACK_PGS); + regs.rflags = regs.rflags | 0x2; + regs.rsp = kvm_allocate_vcpu_stack(vm); vcpu_regs_set(vcpu, ®s); /* Setup the MP state */ -- 2.56.0.rc1.315.gc6ed9934b7-goog