lib: utils/mpxy: bind channel access to owning domainHEADmaster

The MPXY framework currently stores registered channels in a global
list and exposes them to all callers. However, the intended model is
that each channel is assigned to a single supervisor domain at boot and
remains owned by that domain for its lifetime.

Introduce fixed owner-domain tracking in struct sbi_mpxy_channel and
make channel lookup and enumeration domain-aware. A channel is now
visible only when accessed from its owning domain. Also require the
owner to be set before channel registration.

This allows MPXY to support systems where the same hart may be reused by
multiple domains while keeping channel ownership and visibility fixed to
the domain that owns the service.

Signed-off-by: Oza Pawandeep <[email protected]>
Reviewed-by: Rahul Pathak <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Anup Patel <[email protected]>

1 files changed, 44 insertions, 9 deletions

diff --git a/lib/sbi/sbi_mpxy.c b/lib/sbi/sbi_mpxy.c
index ff5c6ab6..19f59f3a 100644
--- a/lib/sbi/sbi_mpxy.c
+++ b/lib/sbi/sbi_mpxy.c
@@ -145,14 +145,36 @@ static inline bool mpxy_is_std_attr(u32 attr_id)
 	return (attr_id >> 31) ? false : true;
 }
 
+static inline bool mpxy_channel_visible(struct sbi_mpxy_channel *channel,
+					struct sbi_domain *dom)
+{
+	return channel->owner_domain == dom;
+}
+
+/** Find channel_id in registered channels list for this domain */
+static struct sbi_mpxy_channel *mpxy_find_channel(u32 channel_id,
+					struct sbi_domain *dom)
+{
+	struct sbi_mpxy_channel *channel;
+
+	sbi_list_for_each_entry(channel, &mpxy_channel_list, head) {
+		if (channel->channel_id == channel_id &&
+		    mpxy_channel_visible(channel, dom))
+			return channel;
+	}
+
+	return NULL;
+}
+
 /** Find channel_id in registered channels list */
-static struct sbi_mpxy_channel *mpxy_find_channel(u32 channel_id)
+struct sbi_mpxy_channel *sbi_mpxy_find_channel_any(u32 channel_id)
 {
 	struct sbi_mpxy_channel *channel;
 
-	sbi_list_for_each_entry(channel, &mpxy_channel_list, head)
+	sbi_list_for_each_entry(channel, &mpxy_channel_list, head) {
 		if (channel->channel_id == channel_id)
 			return channel;
+	}
 
 	return NULL;
 }
@@ -224,7 +246,10 @@ int sbi_mpxy_register_channel(struct sbi_mpxy_channel *channel)
 	if (!channel)
 		return SBI_EINVAL;
 
-	if (mpxy_find_channel(channel->channel_id))
+	if (!channel->owner_domain)
+		return SBI_EINVAL;
+
+	if (sbi_mpxy_find_channel_any(channel->channel_id))
 		return SBI_EALREADY;
 
 	/* Initialize channel specific attributes */
@@ -397,12 +422,15 @@ int sbi_mpxy_get_channel_ids(u32 start_index)
 	struct sbi_mpxy_channel *channel;
 	u32 channels_count = 0;
 	u32 *shmem_base;
+	struct sbi_domain *dom = sbi_domain_thishart_ptr();
 
 	if (!mpxy_shmem_enabled(ms))
 		return SBI_ERR_NO_SHMEM;
 
-	sbi_list_for_each_entry(channel, &mpxy_channel_list, head)
-		channels_count += 1;
+	sbi_list_for_each_entry(channel, &mpxy_channel_list, head) {
+		if (mpxy_channel_visible(channel, dom))
+			channels_count += 1;
+	}
 
 	if (start_index > channels_count)
 		return SBI_ERR_INVALID_PARAM;
@@ -420,6 +448,9 @@ int sbi_mpxy_get_channel_ids(u32 start_index)
 
 	// Iterate over the list of channels to get the channel ids.
 	sbi_list_for_each_entry(channel, &mpxy_channel_list, head) {
+		if (!mpxy_channel_visible(channel, sbi_domain_thishart_ptr()))
+			continue;
+
 		if (node_index >= start_index &&
 			node_index < (start_index + returned)) {
 			shmem_base[2 + node_ret] = cpu_to_le32(channel->channel_id);
@@ -446,11 +477,12 @@ int sbi_mpxy_read_attrs(u32 channel_id, u32 base_attr_id, u32 attr_count)
 	int ret = SBI_SUCCESS;
 	u32 *attr_ptr, end_id;
 	void *shmem_base;
+	struct sbi_domain *dom = sbi_domain_thishart_ptr();
 
 	if (!mpxy_shmem_enabled(ms))
 		return SBI_ERR_NO_SHMEM;
 
-	struct sbi_mpxy_channel *channel = mpxy_find_channel(channel_id);
+	struct sbi_mpxy_channel *channel = mpxy_find_channel(channel_id, dom);
 	if (!channel)
 		return SBI_ERR_NOT_SUPPORTED;
 
@@ -597,11 +629,12 @@ int sbi_mpxy_write_attrs(u32 channel_id, u32 base_attr_id, u32 attr_count)
 	struct sbi_mpxy_channel *channel;
 	int ret, mem_idx;
 	void *shmem_base;
+	struct sbi_domain *dom = sbi_domain_thishart_ptr();
 
 	if (!mpxy_shmem_enabled(ms))
 		return SBI_ERR_NO_SHMEM;
 
-	channel = mpxy_find_channel(channel_id);
+	channel = mpxy_find_channel(channel_id, dom);
 	if (!channel)
 		return SBI_ERR_NOT_SUPPORTED;
 
@@ -686,12 +719,13 @@ int sbi_mpxy_send_message(u32 channel_id, u8 msg_id,
 	struct sbi_mpxy_channel *channel;
 	void *shmem_base, *resp_buf;
 	u32 resp_bufsize;
+	struct sbi_domain *dom = sbi_domain_thishart_ptr();
 	int ret;
 
 	if (!mpxy_shmem_enabled(ms))
 		return SBI_ERR_NO_SHMEM;
 
-	channel = mpxy_find_channel(channel_id);
+	channel = mpxy_find_channel(channel_id, dom);
 	if (!channel)
 		return SBI_ERR_NOT_SUPPORTED;
 
@@ -743,12 +777,13 @@ int sbi_mpxy_get_notification_events(u32 channel_id, unsigned long *events_len)
 	struct mpxy_state *ms = sbi_domain_mpxy_state_thishart_ptr();
 	struct sbi_mpxy_channel *channel;
 	void *eventsbuf, *shmem_base;
+	struct sbi_domain *dom = sbi_domain_thishart_ptr();
 	int ret;
 
 	if (!mpxy_shmem_enabled(ms))
 		return SBI_ERR_NO_SHMEM;
 
-	channel = mpxy_find_channel(channel_id);
+	channel = mpxy_find_channel(channel_id, dom);
 	if (!channel || !channel->get_notification_events)
 		return SBI_ERR_NOT_SUPPORTED;