[PATCH v2 08/10] KVM: arm64: Handle FFA_MEM_LEND calls from the host

Will Deacon
2023-04-19T12:22:50Z

Handle FFA_MEM_LEND calls from the host by treating them identically to
FFA_MEM_SHARE calls for the purposes of the host stage-2 page-table, but
forwarding on the original request to EL3.

Signed-off-by: Will Deacon <will@kernel.org>
---
arch/arm64/kvm/hyp/nvhe/ffa.c | 22 +++++++++++++++-------
1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
index b23e3869ce63..45a2726d73ff 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -116,10 +116,10 @@ static int spmd_unmap_ffa_buffers(void)
return res.a0 == FFA_SUCCESS ? FFA_RET_SUCCESS : res.a2;
}

-static void spmd_mem_share(struct arm_smccc_res *res, u32 len, u32 fraglen)
+static void spmd_mem_xfer(struct arm_smccc_res *res, u64 func_id, u32 len,
+ u32 fraglen)
{
- arm_smccc_1_1_smc(FFA_FN64_MEM_SHARE,
- len, fraglen,
+ arm_smccc_1_1_smc(func_id, len, fraglen,
0, 0, 0, 0, 0,
res);
}
@@ -317,8 +317,9 @@ static int ffa_host_unshare_ranges(struct ffa_mem_region_addr_range *ranges,
return ret;
}

-static void do_ffa_mem_share(struct arm_smccc_res *res,
- struct kvm_cpu_context *ctxt)
+static __always_inline void do_ffa_mem_xfer(const u64 func_id,
+ struct arm_smccc_res *res,
+ struct kvm_cpu_context *ctxt)
{
DECLARE_REG(u32, len, ctxt, 1);
DECLARE_REG(u32, fraglen, ctxt, 2);
@@ -329,6 +330,9 @@ static void do_ffa_mem_share(struct arm_smccc_res *res,
int ret = 0;
u32 offset;

+ BUILD_BUG_ON(func_id != FFA_FN64_MEM_SHARE &&
+ func_id != FFA_FN64_MEM_LEND);
+
if (addr_mbz || npages_mbz || fraglen > len ||
fraglen > KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE) {
ret = FFA_RET_INVALID_PARAMETERS;
@@ -378,7 +382,7 @@ static void do_ffa_mem_share(struct arm_smccc_res *res,
if (ret)
goto out_unlock;

- spmd_mem_share(res, len, fraglen);
+ spmd_mem_xfer(res, func_id, len, fraglen);
if (res->a0 != FFA_SUCCESS) {
WARN_ON(ffa_host_unshare_ranges(reg->constituents,
reg->addr_range_cnt));
@@ -502,11 +506,15 @@ bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt)
goto out_handled;
case FFA_MEM_SHARE:
case FFA_FN64_MEM_SHARE:
- do_ffa_mem_share(&res, host_ctxt);
+ do_ffa_mem_xfer(FFA_FN64_MEM_SHARE, &res, host_ctxt);
goto out_handled;
case FFA_MEM_RECLAIM:
do_ffa_mem_reclaim(&res, host_ctxt);
goto out_handled;
+ case FFA_MEM_LEND:
+ case FFA_FN64_MEM_LEND:
+ do_ffa_mem_xfer(FFA_FN64_MEM_LEND, &res, host_ctxt);
+ goto out_handled;
}

if (ffa_call_supported(func_id))