Re: [PATCH v1 2/4] crypto/ccp: Do not initialize SNP for ioctl(SNP_COMMIT)

[Tom Lendacky <thomas.lendacky@amd.com>]

On 4/27/26 11:15, Tycho Andersen wrote:
> From: "Tycho Andersen (AMD)" <tycho@kernel.org>
> 
> Sashiko notes:
> 
>> if SEV initialization fails and KVM is actively running normal VMs, could a
>> userspace process trigger this code path via /dev/sev ioctls (e.g.,
>> SEV_PDH_GEN) and zero out MSR_VM_HSAVE_PA globally? Would the next VMRUN
>> execution for an active VM trigger a general protection fault and crash the
>> host?
> 
> The SNP_COMMIT command does not require the firmware to be in any
> particular state. Skip initializing it if it was previously uninitialized.
> 
> The SEV-SNP firmware specification doc 56860 does not mention SNP_COMMIT in
> Table 5 as a command that is allowed in the UNINIT state, but it is in fact
> allowed and a future documentation update will reflect that.
> 
> Fixes: ceac7fb89e8d ("crypto: ccp - Ensure implicit SEV/SNP init and shutdown in ioctls")
> Reported-by: Sashiko
> Assisted-by: Gemini:gemini-3.1-pro-preview
> Link: https://sashiko.dev/#/patchset/20260324161301.1353976-1-tycho%40kernel.org
> Signed-off-by: Tycho Andersen (AMD) <tycho@kernel.org>

Stable?

Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>

> ---
>  drivers/crypto/ccp/sev-dev.c | 13 +------------
>  1 file changed, 1 insertion(+), 12 deletions(-)
> 
> diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
> index 6891b90bbb88..572f06368d4b 100644
> --- a/drivers/crypto/ccp/sev-dev.c
> +++ b/drivers/crypto/ccp/sev-dev.c
> @@ -2437,24 +2437,13 @@ static int sev_ioctl_do_snp_platform_status(struct sev_issue_cmd *argp)
>  
>  static int sev_ioctl_do_snp_commit(struct sev_issue_cmd *argp)
>  {
> -	struct sev_device *sev = psp_master->sev_data;
>  	struct sev_data_snp_commit buf;
> -	bool shutdown_required = false;
> -	int ret, error;
> -
> -	if (!sev->snp_initialized) {
> -		ret = snp_move_to_init_state(argp, &shutdown_required);
> -		if (ret)
> -			return ret;
> -	}
> +	int ret;
>  
>  	buf.len = sizeof(buf);
>  
>  	ret = __sev_do_cmd_locked(SEV_CMD_SNP_COMMIT, &buf, &argp->error);
>  
> -	if (shutdown_required)
> -		__sev_snp_shutdown_locked(&error, false);
> -
>  	return ret;
>  }
>