From d66e50beb91114f387bd798a371384b2a245e8cc Mon Sep 17 00:00:00 2001 From: Vincent Donnefort Date: Tue, 11 Jun 2024 18:53:17 +0100 Subject: KVM: arm64: FFA: Release hyp rx buffer According to the FF-A spec (Buffer states and ownership), after a producer has written into a buffer, it is "full" and now owned by the consumer. The producer won't be able to use that buffer, until the consumer hands it over with an invocation such as RX_RELEASE. It is clear in the following paragraph (Transfer of buffer ownership), that MEM_RETRIEVE_RESP is transferring the ownership from producer (in our case SPM) to consumer (hypervisor). RX_RELEASE is therefore mandatory here. It is less clear though what is happening with MEM_FRAG_TX. But this invocation, as a response to MEM_FRAG_RX writes into the same hypervisor RX buffer (see paragraph "Transmission of transaction descriptor in fragments"). Also this is matching the TF-A implementation where the RX buffer is marked "full" during a MEM_FRAG_RX. Release the RX hypervisor buffer in those two cases. This will unblock later invocations using this buffer which would otherwise fail. (RETRIEVE_REQ, MEM_FRAG_RX and PARTITION_INFO_GET). Signed-off-by: Vincent Donnefort Reviewed-by: Sudeep Holla Link: https://lore.kernel.org/r/20240611175317.1220842-1-vdonnefort@google.com Signed-off-by: Marc Zyngier --- arch/arm64/kvm/hyp/nvhe/ffa.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'arch/arm64') diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c index 02746f9d0980..efb053af331c 100644 --- a/arch/arm64/kvm/hyp/nvhe/ffa.c +++ b/arch/arm64/kvm/hyp/nvhe/ffa.c @@ -177,6 +177,14 @@ static void ffa_retrieve_req(struct arm_smccc_res *res, u32 len) res); } +static void ffa_rx_release(struct arm_smccc_res *res) +{ + arm_smccc_1_1_smc(FFA_RX_RELEASE, + 0, 0, + 0, 0, 0, 0, 0, + res); +} + static void do_ffa_rxtx_map(struct arm_smccc_res *res, struct kvm_cpu_context *ctxt) { @@ -543,16 +551,19 @@ static void do_ffa_mem_reclaim(struct arm_smccc_res *res, if (WARN_ON(offset > len || fraglen > KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE)) { ret = FFA_RET_ABORTED; + ffa_rx_release(res); goto out_unlock; } if (len > ffa_desc_buf.len) { ret = FFA_RET_NO_MEMORY; + ffa_rx_release(res); goto out_unlock; } buf = ffa_desc_buf.buf; memcpy(buf, hyp_buffers.rx, fraglen); + ffa_rx_release(res); for (fragoff = fraglen; fragoff < len; fragoff += fraglen) { ffa_mem_frag_rx(res, handle_lo, handle_hi, fragoff); @@ -563,6 +574,7 @@ static void do_ffa_mem_reclaim(struct arm_smccc_res *res, fraglen = res->a3; memcpy((void *)buf + fragoff, hyp_buffers.rx, fraglen); + ffa_rx_release(res); } ffa_mem_reclaim(res, handle_lo, handle_hi, flags); -- cgit v1.2.3-58-ga151