On 12/19/2025 12:42 PM, Carlos López wrote:
> Simplify the error paths in snp_handle_guest_req() by using a mutex
> guard, allowing early return instead of using gotos.
>
> Signed-off-by: Carlos López <clopez@suse.de>
Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com>
> ---
> arch/x86/kvm/svm/sev.c | 23 ++++++++---------------
> 1 file changed, 8 insertions(+), 15 deletions(-)
>
> diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
> index 47ff5267ab01..5f46b7f073b0 100644
> --- a/arch/x86/kvm/svm/sev.c
> +++ b/arch/x86/kvm/svm/sev.c
> @@ -4090,12 +4090,10 @@ static int snp_handle_guest_req(struct vcpu_svm *svm, gpa_t req_gpa, gpa_t resp_
> if (!sev_snp_guest(kvm))
> return -EINVAL;
>
> - mutex_lock(&sev->guest_req_mutex);
> + guard(mutex)(&sev->guest_req_mutex);
>
> - if (kvm_read_guest(kvm, req_gpa, sev->guest_req_buf, PAGE_SIZE)) {
> - ret = -EIO;
> - goto out_unlock;
> - }
> + if (kvm_read_guest(kvm, req_gpa, sev->guest_req_buf, PAGE_SIZE))
> + return -EIO;
>
> data.gctx_paddr = __psp_pa(sev->snp_context);
> data.req_paddr = __psp_pa(sev->guest_req_buf);
> @@ -4108,21 +4106,16 @@ static int snp_handle_guest_req(struct vcpu_svm *svm, gpa_t req_gpa, gpa_t resp_
> */
> ret = sev_issue_cmd(kvm, SEV_CMD_SNP_GUEST_REQUEST, &data, &fw_err);
> if (ret && !fw_err)
> - goto out_unlock;
> + return ret;
>
> - if (kvm_write_guest(kvm, resp_gpa, sev->guest_resp_buf, PAGE_SIZE)) {
> - ret = -EIO;
> - goto out_unlock;
> - }
> + if (kvm_write_guest(kvm, resp_gpa, sev->guest_resp_buf, PAGE_SIZE))
> + return -EIO;
>
> /* No action is requested *from KVM* if there was a firmware error. */
> svm_vmgexit_no_action(svm, SNP_GUEST_ERR(0, fw_err));
>
> - ret = 1; /* resume guest */
> -
> -out_unlock:
> - mutex_unlock(&sev->guest_req_mutex);
> - return ret;
> + /* resume guest */
> + return 1;
> }
>
> static int snp_handle_ext_guest_req(struct vcpu_svm *svm, gpa_t req_gpa, gpa_t resp_gpa)