Hi Jens,
> On 17 Jul 2023, at 09:20, Jens Wiklander <jens.wiklan...@linaro.org> wrote:
>
> Adds support for the FF-A function FFA_ID_GET to return the ID of the
> calling client.
>
> Signed-off-by: Jens Wiklander <jens.wiklan...@linaro.org>
Reviewed-by: Bertrand Marquis <bertrand.marq...@arm.com>
Cheers
Bertrand
> ---
> xen/arch/arm/tee/ffa.c | 21 +++++++++++++++++++++
> 1 file changed, 21 insertions(+)
>
> diff --git a/xen/arch/arm/tee/ffa.c b/xen/arch/arm/tee/ffa.c
> index f0a2715d4bbf..e157ed20ad8b 100644
> --- a/xen/arch/arm/tee/ffa.c
> +++ b/xen/arch/arm/tee/ffa.c
> @@ -181,6 +181,12 @@ static bool ffa_get_version(uint32_t *vers)
> return true;
> }
>
> +static uint16_t get_vm_id(const struct domain *d)
> +{
> + /* +1 since 0 is reserved for the hypervisor in FF-A */
> + return d->domain_id + 1;
> +}
> +
> static void set_regs(struct cpu_user_regs *regs, register_t v0, register_t v1,
> register_t v2, register_t v3, register_t v4, register_t
> v5,
> register_t v6, register_t v7)
> @@ -195,6 +201,12 @@ static void set_regs(struct cpu_user_regs *regs,
> register_t v0, register_t v1,
> set_user_reg(regs, 7, v7);
> }
>
> +static void set_regs_success(struct cpu_user_regs *regs, uint32_t w2,
> + uint32_t w3)
> +{
> + set_regs(regs, FFA_SUCCESS_32, 0, w2, w3, 0, 0, 0, 0);
> +}
> +
> static void handle_version(struct cpu_user_regs *regs)
> {
> struct domain *d = current->domain;
> @@ -224,6 +236,9 @@ static bool ffa_handle_call(struct cpu_user_regs *regs)
> case FFA_VERSION:
> handle_version(regs);
> return true;
> + case FFA_ID_GET:
> + set_regs_success(regs, get_vm_id(d), 0);
> + return true;
>
> default:
> gprintk(XENLOG_ERR, "ffa: unhandled fid 0x%x\n", fid);
> @@ -237,6 +252,12 @@ static int ffa_domain_init(struct domain *d)
>
> if ( !ffa_version )
> return -ENODEV;
> + /*
> + * We can't use that last possible domain ID or get_vm_id() would cause
> + * an overflow.
> + */
> + if ( d->domain_id >= UINT16_MAX)
> + return -ERANGE;
>
> ctx = xzalloc(struct ffa_ctx);
> if ( !ctx )
> --
> 2.34.1
>
