Re: [PATCH 3/4] crypto: ccp - Refactor out sev_fw_alloc()

[Marc Orr]

On Thu, Oct 28, 2021 at 10:58 AM Peter Gonda <pgonda@xxxxxxxxxx> wrote:
>
> Creates a helper function sev_fw_alloc() which can be used to allocate
> aligned memory regions for use by the PSP firmware. Currently only used
> for the SEV-ES TMR region but will be used for the SEV_INIT_EX NV memory
> region.
>
> Signed-off-by: Peter Gonda <pgonda@xxxxxxxxxx>
> Acked-by: David Rientjes <rientjes@xxxxxxxxxx>
> Cc: Tom Lendacky <thomas.lendacky@xxxxxxx>
> Cc: Brijesh Singh <brijesh.singh@xxxxxxx>
> Cc: Marc Orr <marcorr@xxxxxxxxxx>
> Cc: Joerg Roedel <jroedel@xxxxxxx>
> Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
> Cc: David Rientjes <rientjes@xxxxxxxxxx>
> Cc: John Allen <john.allen@xxxxxxx>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx> (
> Cc: linux-crypto@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> ---
>  drivers/crypto/ccp/sev-dev.c | 24 +++++++++++++++++-------
>  1 file changed, 17 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
> index e4bc833949a0..b568ae734857 100644
> --- a/drivers/crypto/ccp/sev-dev.c
> +++ b/drivers/crypto/ccp/sev-dev.c
> @@ -141,6 +141,21 @@ static int sev_cmd_buffer_len(int cmd)
>         return 0;
>  }
>
> +static void *sev_fw_alloc(unsigned long len)
> +{
> +       const int order = get_order(len);
> +       struct page *page;
> +
> +       if (order > MAX_ORDER-1)
> +               return NULL;
> +
> +       page = alloc_pages(GFP_KERNEL, order);
> +       if (!page)
> +               return NULL;
> +
> +       return page_address(page);
> +}
> +
>  static int __sev_do_cmd_locked(int cmd, void *data, int *psp_ret)
>  {
>         struct psp_device *psp = psp_master;
> @@ -1076,7 +1091,6 @@ EXPORT_SYMBOL_GPL(sev_issue_cmd_external_user);
>  void sev_pci_init(void)
>  {
>         struct sev_device *sev = psp_master->sev_data;
> -       struct page *tmr_page;
>         int error = 0, rc;
>
>         if (!sev)
> @@ -1092,14 +1106,10 @@ void sev_pci_init(void)
>                 sev_get_api_version();
>
>         /* Obtain the TMR memory area for SEV-ES use */
> -       tmr_page = alloc_pages(GFP_KERNEL, get_order(SEV_ES_TMR_SIZE));
> -       if (tmr_page) {
> -               sev_es_tmr = page_address(tmr_page);
> -       } else {
> -               sev_es_tmr = NULL;
> +       sev_es_tmr = sev_fw_alloc(SEV_ES_TMR_SIZE);
> +       if (!sev_es_tmr)
>                 dev_warn(sev->dev,
>                          "SEV: TMR allocation failed, SEV-ES support unavailable\n");
> -       }
>
>         /* Initialize the platform */
>         rc = sev_platform_init(&error);
> --
> 2.33.1.1089.g2158813163f-goog
>

Reviewed-by: Marc Orr <marcorr@xxxxxxxxxx>