Re: [PATCH v7 1/3] KVM: arm64: Block host-initiated FF-A direct responses

From
Fuad Tabba <fuad.tabba@linux.dev>
Date
2026-09-14 16:24:02
Also in
kvmarm, lkml
Reply to
Per Larsen, 2026-08-30
Hi Per,

On Mon, 31 Aug 2026 at 00:08, Per Larsen via B4 Relay
[off-list ref] wrote:
...
quoted hunk ↗ jump to hunk
@@ -686,8 +686,10 @@ static bool ffa_call_supported(u64 func_id)
  case FFA_MSG_SEND:
  case FFA_MSG_POLL:
  case FFA_MSG_WAIT:
- /* 32-bit variants of 64-bit calls */
+ /* The host is never the target of a direct request */
  case FFA_MSG_SEND_DIRECT_RESP:
+ case FFA_FN64_MSG_SEND_DIRECT_RESP:
+ /* 32-bit variants of 64-bit calls */
  case FFA_RXTX_MAP:
  case FFA_MEM_DONATE:
  case FFA_MEM_RETRIEVE_REQ:
Sashiko asked whether the interfaces it listed should be added to the
blocklist too. For FFA_FN64_NOTIFICATION_INFO_GET the answer looks
like yes: FFA_FN_NATIVE() is FFA_FN64_##name on arm64, and
ffa_notification_info_get() is the only in-tree caller, so the 32-bit
entry a few lines below never matches what the host sends. Could you
add it here?

The other three aren't the same case. FFA_RX_RELEASE has to keep going
through, since the host's release is what frees the hypervisor's RX
buffer after do_ffa_part_get().

Cheers,
/fuad
Thread (9 messages) 9 messages, 3 authors, last reply 2026-09-15
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