On 12/13/2024 5:32 PM, Xiaoyao Li wrote:
On 12/1/2024 11:53 AM, Binbin Wu wrote:
[...]
+ +static int tdx_map_gpa(struct kvm_vcpu *vcpu) +{ + struct vcpu_tdx * tdx = to_tdx(vcpu); + u64 gpa = tdvmcall_a0_read(vcpu);We can use kvm_r12_read() directly, which is more intuitive. And we can drop the MACRO for a0/a1/a2/a3 accessors in patch 022.
I am neutral about it.
+ u64 size = tdvmcall_a1_read(vcpu); + u64 ret; + + /* + * Converting TDVMCALL_MAP_GPA to KVM_HC_MAP_GPA_RANGE requires + * userspace to enable KVM_CAP_EXIT_HYPERCALL with KVM_HC_MAP_GPA_RANGE + * bit set. If not, the error code is not defined in GHCI for TDX, use + * TDVMCALL_STATUS_INVALID_OPERAND for this case. + */ + if (!user_exit_on_hypercall(vcpu->kvm, KVM_HC_MAP_GPA_RANGE)) { + ret = TDVMCALL_STATUS_INVALID_OPERAND; + goto error; + } + + if (gpa + size <= gpa || !kvm_vcpu_is_legal_gpa(vcpu, gpa) || + !kvm_vcpu_is_legal_gpa(vcpu, gpa + size -1) || + (vt_is_tdx_private_gpa(vcpu->kvm, gpa) != + vt_is_tdx_private_gpa(vcpu->kvm, gpa + size -1))) { + ret = TDVMCALL_STATUS_INVALID_OPERAND; + goto error; + } + + if (!PAGE_ALIGNED(gpa) || !PAGE_ALIGNED(size)) { + ret = TDVMCALL_STATUS_ALIGN_ERROR; + goto error; + } + + tdx->map_gpa_end = gpa + size; + tdx->map_gpa_next = gpa; + + __tdx_map_gpa(tdx); + /* Forward request to userspace. */ + return 0;Maybe let __tdx_map_gpa() return a int to decide whether it needs to return to userspace and return __tdx_map_gpa(tdx); ?
To save one line of code and the comment? Because MapGPA always goes to userspace, I don't want to make a function return a int that is a fixed value. And if the multiple comments bother you, I think the comments can be removed.
+ +error: + tdvmcall_set_return_code(vcpu, ret); + kvm_r11_write(vcpu, gpa); + return 1; +} + static int handle_tdvmcall(struct kvm_vcpu *vcpu) { if (tdvmcall_exit_type(vcpu)) return tdx_emulate_vmcall(vcpu); switch (tdvmcall_leaf(vcpu)) { + case TDVMCALL_MAP_GPA: + return tdx_map_gpa(vcpu); default: break; } diff --git a/arch/x86/kvm/vmx/tdx.h b/arch/x86/kvm/vmx/tdx.h index 1abc94b046a0..bfae70887695 100644 --- a/arch/x86/kvm/vmx/tdx.h +++ b/arch/x86/kvm/vmx/tdx.h @@ -71,6 +71,9 @@ struct vcpu_tdx { enum tdx_prepare_switch_state prep_switch_state; u64 msr_host_kernel_gs_base; + + u64 map_gpa_next; + u64 map_gpa_end; }; void tdh_vp_rd_failed(struct vcpu_tdx *tdx, char *uclass, u32 field, u64 err);
