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

[Binbin Wu <binbin.wu@linux.intel.com>]

On 12/6/2024 5:31 PM, Xu Yilun wrote:
>> +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 for catching it!

>
> 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;
>> +}