Re: [PATCH 5/7] KVM: TDX: Handle TDG.VP.VMCALL

Xu Yilun
2024-12-06T09:34:55Z

> +static int tdx_report_fatal_error(struct kvm_vcpu *vcpu)
> +{
> + u64 reg_mask = kvm_rcx_read(vcpu);
> + u64* opt_regs;
> +
> + /*
> + * Skip sanity checks and let userspace decide what to do if sanity
> + * checks fail.
> + */
> + vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
> + vcpu->run->system_event.type = KVM_SYSTEM_EVENT_TDX_FATAL;
> + vcpu->run->system_event.ndata = 10;
> + /* Error codes. */
> + vcpu->run->system_event.data[0] = tdvmcall_a0_read(vcpu);
> + /* GPA of additional information page. */
> + vcpu->run->system_event.data[1] = tdvmcall_a1_read(vcpu);
> + /* Information passed via registers (up to 64 bytes). */
> + opt_regs = &vcpu->run->system_event.data[2];
> +
> +#define COPY_REG(REG, MASK) \
> + do { \
> + if (reg_mask & MASK) \
> + *opt_regs = kvm_ ## REG ## _read(vcpu); \
> + else \
> + *opt_regs = 0; \
> + opt_regs++; \
> + } while (0)
> +
> + /* The order is defined in GHCI. */
> + COPY_REG(r14, BIT_ULL(14));
> + COPY_REG(r15, BIT_ULL(15));
> + COPY_REG(rbx, BIT_ULL(3));
> + COPY_REG(rdi, BIT_ULL(7));
> + COPY_REG(rsi, BIT_ULL(6));
> + COPY_REG(r8, BIT_ULL(8));
> + COPY_REG(r9, BIT_ULL(9));
> + COPY_REG(rdx, BIT_ULL(2));

Nit:

#undef COPY_REG

Thanks,
Yilun

> +
> + /*
> + * Set the status code according to GHCI spec, although the vCPU may
> + * not return back to guest.
> + */
> + tdvmcall_set_return_code(vcpu, TDVMCALL_STATUS_SUCCESS);
> +
> + /* Forward request to userspace. */
> + return 0;
> +}