diff options
Diffstat (limited to 'arch/arm64/kvm/hyp/nvhe/ffa.c')
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/ffa.c | 993 |
1 files changed, 993 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c new file mode 100644 index 000000000000..f731cc4c3f28 --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/ffa.c @@ -0,0 +1,993 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * FF-A v1.0 proxy to filter out invalid memory-sharing SMC calls issued by + * the host. FF-A is a slightly more palatable abbreviation of "Arm Firmware + * Framework for Arm A-profile", which is specified by Arm in document + * number DEN0077. + * + * Copyright (C) 2022 - Google LLC + * Author: Andrew Walbran <qwandor@google.com> + * + * This driver hooks into the SMC trapping logic for the host and intercepts + * all calls falling within the FF-A range. Each call is either: + * + * - Forwarded on unmodified to the SPMD at EL3 + * - Rejected as "unsupported" + * - Accompanied by a host stage-2 page-table check/update and reissued + * + * Consequently, any attempts by the host to make guest memory pages + * accessible to the secure world using FF-A will be detected either here + * (in the case that the memory is already owned by the guest) or during + * donation to the guest (in the case that the memory was previously shared + * with the secure world). + * + * To allow the rolling-back of page-table updates and FF-A calls in the + * event of failure, operations involving the RXTX buffers are locked for + * the duration and are therefore serialised. + */ + +#include <linux/arm-smccc.h> +#include <linux/arm_ffa.h> +#include <asm/kvm_pkvm.h> + +#include <nvhe/ffa.h> +#include <nvhe/mem_protect.h> +#include <nvhe/memory.h> +#include <nvhe/trap_handler.h> +#include <nvhe/spinlock.h> + +/* + * "ID value 0 must be returned at the Non-secure physical FF-A instance" + * We share this ID with the host. + */ +#define HOST_FFA_ID 0 + +/* + * A buffer to hold the maximum descriptor size we can see from the host, + * which is required when the SPMD returns a fragmented FFA_MEM_RETRIEVE_RESP + * when resolving the handle on the reclaim path. + */ +struct kvm_ffa_descriptor_buffer { + void *buf; + size_t len; +}; + +static struct kvm_ffa_descriptor_buffer ffa_desc_buf; + +struct kvm_ffa_buffers { + hyp_spinlock_t lock; + void *tx; + void *rx; +}; + +/* + * Note that we don't currently lock these buffers explicitly, instead + * relying on the locking of the host FFA buffers as we only have one + * client. + */ +static struct kvm_ffa_buffers hyp_buffers; +static struct kvm_ffa_buffers host_buffers; +static u32 hyp_ffa_version; +static bool has_version_negotiated; +static hyp_spinlock_t version_lock; + +static void ffa_to_smccc_error(struct arm_smccc_1_2_regs *res, u64 ffa_errno) +{ + *res = (struct arm_smccc_1_2_regs) { + .a0 = FFA_ERROR, + .a2 = ffa_errno, + }; +} + +static void ffa_to_smccc_res_prop(struct arm_smccc_1_2_regs *res, int ret, u64 prop) +{ + if (ret == FFA_RET_SUCCESS) { + *res = (struct arm_smccc_1_2_regs) { .a0 = FFA_SUCCESS, + .a2 = prop }; + } else { + ffa_to_smccc_error(res, ret); + } +} + +static void ffa_to_smccc_res(struct arm_smccc_1_2_regs *res, int ret) +{ + ffa_to_smccc_res_prop(res, ret, 0); +} + +static void ffa_set_retval(struct kvm_cpu_context *ctxt, + struct arm_smccc_1_2_regs *res) +{ + cpu_reg(ctxt, 0) = res->a0; + cpu_reg(ctxt, 1) = res->a1; + cpu_reg(ctxt, 2) = res->a2; + cpu_reg(ctxt, 3) = res->a3; + cpu_reg(ctxt, 4) = res->a4; + cpu_reg(ctxt, 5) = res->a5; + cpu_reg(ctxt, 6) = res->a6; + cpu_reg(ctxt, 7) = res->a7; + + /* + * DEN0028C 2.6: SMC32/HVC32 call from aarch64 must preserve x8-x30. + * + * In FF-A 1.2, we cannot rely on the function ID sent by the caller to + * detect 32-bit calls because the CPU cycle management interfaces (e.g. + * FFA_MSG_WAIT, FFA_RUN) are 32-bit only but can have 64-bit responses. + * + * FFA-1.3 introduces 64-bit variants of the CPU cycle management + * interfaces. Moreover, FF-A 1.3 clarifies that SMC32 direct requests + * complete with SMC32 direct responses which *should* allow us use the + * function ID sent by the caller to determine whether to return x8-x17. + * + * Note that we also cannot rely on function IDs in the response. + * + * Given the above, assume SMC64 and send back x0-x17 unconditionally + * as the passthrough code (__kvm_hyp_host_forward_smc) does the same. + */ + cpu_reg(ctxt, 8) = res->a8; + cpu_reg(ctxt, 9) = res->a9; + cpu_reg(ctxt, 10) = res->a10; + cpu_reg(ctxt, 11) = res->a11; + cpu_reg(ctxt, 12) = res->a12; + cpu_reg(ctxt, 13) = res->a13; + cpu_reg(ctxt, 14) = res->a14; + cpu_reg(ctxt, 15) = res->a15; + cpu_reg(ctxt, 16) = res->a16; + cpu_reg(ctxt, 17) = res->a17; +} + +static bool is_ffa_call(u64 func_id) +{ + return ARM_SMCCC_IS_FAST_CALL(func_id) && + ARM_SMCCC_OWNER_NUM(func_id) == ARM_SMCCC_OWNER_STANDARD && + ARM_SMCCC_FUNC_NUM(func_id) >= FFA_MIN_FUNC_NUM && + ARM_SMCCC_FUNC_NUM(func_id) <= FFA_MAX_FUNC_NUM; +} + +static int ffa_map_hyp_buffers(u64 ffa_page_count) +{ + struct arm_smccc_1_2_regs res; + + arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) { + .a0 = FFA_FN64_RXTX_MAP, + .a1 = hyp_virt_to_phys(hyp_buffers.tx), + .a2 = hyp_virt_to_phys(hyp_buffers.rx), + .a3 = ffa_page_count, + }, &res); + + return res.a0 == FFA_SUCCESS ? FFA_RET_SUCCESS : res.a2; +} + +static int ffa_unmap_hyp_buffers(void) +{ + struct arm_smccc_1_2_regs res; + + arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) { + .a0 = FFA_RXTX_UNMAP, + .a1 = HOST_FFA_ID, + }, &res); + + return res.a0 == FFA_SUCCESS ? FFA_RET_SUCCESS : res.a2; +} + +static void ffa_mem_frag_tx(struct arm_smccc_1_2_regs *res, u32 handle_lo, + u32 handle_hi, u32 fraglen, u32 endpoint_id) +{ + arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) { + .a0 = FFA_MEM_FRAG_TX, + .a1 = handle_lo, + .a2 = handle_hi, + .a3 = fraglen, + .a4 = endpoint_id, + }, res); +} + +static void ffa_mem_frag_rx(struct arm_smccc_1_2_regs *res, u32 handle_lo, + u32 handle_hi, u32 fragoff) +{ + arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) { + .a0 = FFA_MEM_FRAG_RX, + .a1 = handle_lo, + .a2 = handle_hi, + .a3 = fragoff, + .a4 = HOST_FFA_ID, + }, res); +} + +static void ffa_mem_xfer(struct arm_smccc_1_2_regs *res, u64 func_id, u32 len, + u32 fraglen) +{ + arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) { + .a0 = func_id, + .a1 = len, + .a2 = fraglen, + }, res); +} + +static void ffa_mem_reclaim(struct arm_smccc_1_2_regs *res, u32 handle_lo, + u32 handle_hi, u32 flags) +{ + arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) { + .a0 = FFA_MEM_RECLAIM, + .a1 = handle_lo, + .a2 = handle_hi, + .a3 = flags, + }, res); +} + +static void ffa_retrieve_req(struct arm_smccc_1_2_regs *res, u32 len) +{ + arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) { + .a0 = FFA_FN64_MEM_RETRIEVE_REQ, + .a1 = len, + .a2 = len, + }, res); +} + +static void ffa_rx_release(struct arm_smccc_1_2_regs *res) +{ + arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) { + .a0 = FFA_RX_RELEASE, + }, res); +} + +static void do_ffa_rxtx_map(struct arm_smccc_1_2_regs *res, + struct kvm_cpu_context *ctxt) +{ + DECLARE_REG(phys_addr_t, tx, ctxt, 1); + DECLARE_REG(phys_addr_t, rx, ctxt, 2); + DECLARE_REG(u32, npages, ctxt, 3); + int ret = 0; + void *rx_virt, *tx_virt; + + if (npages != (KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE) / FFA_PAGE_SIZE) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out; + } + + if (!PAGE_ALIGNED(tx) || !PAGE_ALIGNED(rx)) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out; + } + + hyp_spin_lock(&host_buffers.lock); + if (host_buffers.tx) { + ret = FFA_RET_DENIED; + goto out_unlock; + } + + /* + * Map our hypervisor buffers into the SPMD before mapping and + * pinning the host buffers in our own address space. + */ + ret = ffa_map_hyp_buffers(npages); + if (ret) + goto out_unlock; + + ret = __pkvm_host_share_hyp(hyp_phys_to_pfn(tx)); + if (ret) { + ret = FFA_RET_INVALID_PARAMETERS; + goto err_unmap; + } + + ret = __pkvm_host_share_hyp(hyp_phys_to_pfn(rx)); + if (ret) { + ret = FFA_RET_INVALID_PARAMETERS; + goto err_unshare_tx; + } + + tx_virt = hyp_phys_to_virt(tx); + ret = hyp_pin_shared_mem(tx_virt, tx_virt + 1); + if (ret) { + ret = FFA_RET_INVALID_PARAMETERS; + goto err_unshare_rx; + } + + rx_virt = hyp_phys_to_virt(rx); + ret = hyp_pin_shared_mem(rx_virt, rx_virt + 1); + if (ret) { + ret = FFA_RET_INVALID_PARAMETERS; + goto err_unpin_tx; + } + + host_buffers.tx = tx_virt; + host_buffers.rx = rx_virt; + +out_unlock: + hyp_spin_unlock(&host_buffers.lock); +out: + ffa_to_smccc_res(res, ret); + return; + +err_unpin_tx: + hyp_unpin_shared_mem(tx_virt, tx_virt + 1); +err_unshare_rx: + __pkvm_host_unshare_hyp(hyp_phys_to_pfn(rx)); +err_unshare_tx: + __pkvm_host_unshare_hyp(hyp_phys_to_pfn(tx)); +err_unmap: + ffa_unmap_hyp_buffers(); + goto out_unlock; +} + +static void do_ffa_rxtx_unmap(struct arm_smccc_1_2_regs *res, + struct kvm_cpu_context *ctxt) +{ + DECLARE_REG(u32, id, ctxt, 1); + int ret = 0; + + if (id != HOST_FFA_ID) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out; + } + + hyp_spin_lock(&host_buffers.lock); + if (!host_buffers.tx) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out_unlock; + } + + hyp_unpin_shared_mem(host_buffers.tx, host_buffers.tx + 1); + WARN_ON(__pkvm_host_unshare_hyp(hyp_virt_to_pfn(host_buffers.tx))); + host_buffers.tx = NULL; + + hyp_unpin_shared_mem(host_buffers.rx, host_buffers.rx + 1); + WARN_ON(__pkvm_host_unshare_hyp(hyp_virt_to_pfn(host_buffers.rx))); + host_buffers.rx = NULL; + + ffa_unmap_hyp_buffers(); + +out_unlock: + hyp_spin_unlock(&host_buffers.lock); +out: + ffa_to_smccc_res(res, ret); +} + +static u32 __ffa_host_share_ranges(struct ffa_mem_region_addr_range *ranges, + u32 nranges) +{ + u32 i; + + for (i = 0; i < nranges; ++i) { + struct ffa_mem_region_addr_range *range = &ranges[i]; + u64 sz = (u64)range->pg_cnt * FFA_PAGE_SIZE; + u64 pfn = hyp_phys_to_pfn(range->address); + + if (!PAGE_ALIGNED(sz)) + break; + + if (__pkvm_host_share_ffa(pfn, sz / PAGE_SIZE)) + break; + } + + return i; +} + +static u32 __ffa_host_unshare_ranges(struct ffa_mem_region_addr_range *ranges, + u32 nranges) +{ + u32 i; + + for (i = 0; i < nranges; ++i) { + struct ffa_mem_region_addr_range *range = &ranges[i]; + u64 sz = (u64)range->pg_cnt * FFA_PAGE_SIZE; + u64 pfn = hyp_phys_to_pfn(range->address); + + if (!PAGE_ALIGNED(sz)) + break; + + if (__pkvm_host_unshare_ffa(pfn, sz / PAGE_SIZE)) + break; + } + + return i; +} + +static int ffa_host_share_ranges(struct ffa_mem_region_addr_range *ranges, + u32 nranges) +{ + u32 nshared = __ffa_host_share_ranges(ranges, nranges); + int ret = 0; + + if (nshared != nranges) { + WARN_ON(__ffa_host_unshare_ranges(ranges, nshared) != nshared); + ret = FFA_RET_DENIED; + } + + return ret; +} + +static int ffa_host_unshare_ranges(struct ffa_mem_region_addr_range *ranges, + u32 nranges) +{ + u32 nunshared = __ffa_host_unshare_ranges(ranges, nranges); + int ret = 0; + + if (nunshared != nranges) { + WARN_ON(__ffa_host_share_ranges(ranges, nunshared) != nunshared); + ret = FFA_RET_DENIED; + } + + return ret; +} + +static void do_ffa_mem_frag_tx(struct arm_smccc_1_2_regs *res, + struct kvm_cpu_context *ctxt) +{ + DECLARE_REG(u32, handle_lo, ctxt, 1); + DECLARE_REG(u32, handle_hi, ctxt, 2); + DECLARE_REG(u32, fraglen, ctxt, 3); + DECLARE_REG(u32, endpoint_id, ctxt, 4); + struct ffa_mem_region_addr_range *buf; + int ret = FFA_RET_INVALID_PARAMETERS; + u32 nr_ranges; + + if (fraglen > KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE) + goto out; + + if (fraglen % sizeof(*buf)) + goto out; + + hyp_spin_lock(&host_buffers.lock); + if (!host_buffers.tx) + goto out_unlock; + + buf = hyp_buffers.tx; + memcpy(buf, host_buffers.tx, fraglen); + nr_ranges = fraglen / sizeof(*buf); + + ret = ffa_host_share_ranges(buf, nr_ranges); + if (ret) { + /* + * We're effectively aborting the transaction, so we need + * to restore the global state back to what it was prior to + * transmission of the first fragment. + */ + ffa_mem_reclaim(res, handle_lo, handle_hi, 0); + WARN_ON(res->a0 != FFA_SUCCESS); + goto out_unlock; + } + + ffa_mem_frag_tx(res, handle_lo, handle_hi, fraglen, endpoint_id); + if (res->a0 != FFA_SUCCESS && res->a0 != FFA_MEM_FRAG_RX) + WARN_ON(ffa_host_unshare_ranges(buf, nr_ranges)); + +out_unlock: + hyp_spin_unlock(&host_buffers.lock); +out: + if (ret) + ffa_to_smccc_res(res, ret); + + /* + * If for any reason this did not succeed, we're in trouble as we have + * now lost the content of the previous fragments and we can't rollback + * the host stage-2 changes. The pages previously marked as shared will + * remain stuck in that state forever, hence preventing the host from + * sharing/donating them again and may possibly lead to subsequent + * failures, but this will not compromise confidentiality. + */ + return; +} + +static void __do_ffa_mem_xfer(const u64 func_id, + struct arm_smccc_1_2_regs *res, + struct kvm_cpu_context *ctxt) +{ + DECLARE_REG(u32, len, ctxt, 1); + DECLARE_REG(u32, fraglen, ctxt, 2); + DECLARE_REG(u64, addr_mbz, ctxt, 3); + DECLARE_REG(u32, npages_mbz, ctxt, 4); + struct ffa_mem_region_attributes *ep_mem_access; + struct ffa_composite_mem_region *reg; + struct ffa_mem_region *buf; + u32 offset, nr_ranges, checked_offset; + int ret = 0; + + if (addr_mbz || npages_mbz || fraglen > len || + fraglen > KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out; + } + + if (fraglen < sizeof(struct ffa_mem_region) + + sizeof(struct ffa_mem_region_attributes)) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out; + } + + hyp_spin_lock(&host_buffers.lock); + if (!host_buffers.tx) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out_unlock; + } + + if (len > ffa_desc_buf.len) { + ret = FFA_RET_NO_MEMORY; + goto out_unlock; + } + + buf = hyp_buffers.tx; + memcpy(buf, host_buffers.tx, fraglen); + + ep_mem_access = (void *)buf + + ffa_mem_desc_offset(buf, 0, hyp_ffa_version); + offset = ep_mem_access->composite_off; + if (!offset || buf->ep_count != 1 || buf->sender_id != HOST_FFA_ID) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out_unlock; + } + + if (check_add_overflow(offset, sizeof(struct ffa_composite_mem_region), &checked_offset)) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out_unlock; + } + + if (fraglen < checked_offset) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out_unlock; + } + + reg = (void *)buf + offset; + nr_ranges = ((void *)buf + fraglen) - (void *)reg->constituents; + if (nr_ranges % sizeof(reg->constituents[0])) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out_unlock; + } + + nr_ranges /= sizeof(reg->constituents[0]); + ret = ffa_host_share_ranges(reg->constituents, nr_ranges); + if (ret) + goto out_unlock; + + ffa_mem_xfer(res, func_id, len, fraglen); + if (fraglen != len) { + if (res->a0 != FFA_MEM_FRAG_RX) + goto err_unshare; + + if (res->a3 != fraglen) + goto err_unshare; + } else if (res->a0 != FFA_SUCCESS) { + goto err_unshare; + } + +out_unlock: + hyp_spin_unlock(&host_buffers.lock); +out: + if (ret) + ffa_to_smccc_res(res, ret); + return; + +err_unshare: + WARN_ON(ffa_host_unshare_ranges(reg->constituents, nr_ranges)); + goto out_unlock; +} + +#define do_ffa_mem_xfer(fid, res, ctxt) \ + do { \ + BUILD_BUG_ON((fid) != FFA_FN64_MEM_SHARE && \ + (fid) != FFA_FN64_MEM_LEND); \ + __do_ffa_mem_xfer((fid), (res), (ctxt)); \ + } while (0); + +static void do_ffa_mem_reclaim(struct arm_smccc_1_2_regs *res, + struct kvm_cpu_context *ctxt) +{ + DECLARE_REG(u32, handle_lo, ctxt, 1); + DECLARE_REG(u32, handle_hi, ctxt, 2); + DECLARE_REG(u32, flags, ctxt, 3); + struct ffa_mem_region_attributes *ep_mem_access; + struct ffa_composite_mem_region *reg; + u32 offset, len, fraglen, fragoff; + struct ffa_mem_region *buf; + int ret = 0; + u64 handle; + + handle = PACK_HANDLE(handle_lo, handle_hi); + + hyp_spin_lock(&host_buffers.lock); + + buf = hyp_buffers.tx; + *buf = (struct ffa_mem_region) { + .sender_id = HOST_FFA_ID, + .handle = handle, + }; + + ffa_retrieve_req(res, sizeof(*buf)); + buf = hyp_buffers.rx; + if (res->a0 != FFA_MEM_RETRIEVE_RESP) + goto out_unlock; + + len = res->a1; + fraglen = res->a2; + + ep_mem_access = (void *)buf + + ffa_mem_desc_offset(buf, 0, hyp_ffa_version); + offset = ep_mem_access->composite_off; + /* + * We can trust the SPMD to get this right, but let's at least + * check that we end up with something that doesn't look _completely_ + * bogus. + */ + 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); + if (res->a0 != FFA_MEM_FRAG_TX) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out_unlock; + } + + fraglen = res->a3; + memcpy((void *)buf + fragoff, hyp_buffers.rx, fraglen); + ffa_rx_release(res); + } + + ffa_mem_reclaim(res, handle_lo, handle_hi, flags); + if (res->a0 != FFA_SUCCESS) + goto out_unlock; + + reg = (void *)buf + offset; + /* If the SPMD was happy, then we should be too. */ + WARN_ON(ffa_host_unshare_ranges(reg->constituents, + reg->addr_range_cnt)); +out_unlock: + hyp_spin_unlock(&host_buffers.lock); + + if (ret) + ffa_to_smccc_res(res, ret); +} + +/* + * Is a given FFA function supported, either by forwarding on directly + * or by handling at EL2? + */ +static bool ffa_call_supported(u64 func_id) +{ + switch (func_id) { + /* Unsupported memory management calls */ + case FFA_FN64_MEM_RETRIEVE_REQ: + case FFA_MEM_RETRIEVE_RESP: + case FFA_MEM_RELINQUISH: + case FFA_MEM_OP_PAUSE: + case FFA_MEM_OP_RESUME: + case FFA_MEM_FRAG_RX: + case FFA_FN64_MEM_DONATE: + /* Indirect message passing via RX/TX buffers */ + case FFA_MSG_SEND: + case FFA_MSG_POLL: + case FFA_MSG_WAIT: + /* 32-bit variants of 64-bit calls */ + case FFA_MSG_SEND_DIRECT_RESP: + case FFA_RXTX_MAP: + case FFA_MEM_DONATE: + case FFA_MEM_RETRIEVE_REQ: + /* Optional notification interfaces added in FF-A 1.1 */ + case FFA_NOTIFICATION_BITMAP_CREATE: + case FFA_NOTIFICATION_BITMAP_DESTROY: + case FFA_NOTIFICATION_BIND: + case FFA_NOTIFICATION_UNBIND: + case FFA_NOTIFICATION_SET: + case FFA_NOTIFICATION_GET: + case FFA_NOTIFICATION_INFO_GET: + /* Optional interfaces added in FF-A 1.2 */ + case FFA_MSG_SEND_DIRECT_REQ2: /* Optional per 7.5.1 */ + case FFA_MSG_SEND_DIRECT_RESP2: /* Optional per 7.5.1 */ + case FFA_CONSOLE_LOG: /* Optional per 13.1: not in Table 13.1 */ + case FFA_PARTITION_INFO_GET_REGS: /* Optional for virtual instances per 13.1 */ + return false; + } + + return true; +} + +static bool do_ffa_features(struct arm_smccc_1_2_regs *res, + struct kvm_cpu_context *ctxt) +{ + DECLARE_REG(u32, id, ctxt, 1); + u64 prop = 0; + int ret = 0; + + if (!ffa_call_supported(id)) { + ret = FFA_RET_NOT_SUPPORTED; + goto out_handled; + } + + switch (id) { + case FFA_MEM_SHARE: + case FFA_FN64_MEM_SHARE: + case FFA_MEM_LEND: + case FFA_FN64_MEM_LEND: + ret = FFA_RET_SUCCESS; + prop = 0; /* No support for dynamic buffers */ + goto out_handled; + default: + return false; + } + +out_handled: + ffa_to_smccc_res_prop(res, ret, prop); + return true; +} + +static int hyp_ffa_post_init(void) +{ + size_t min_rxtx_sz; + struct arm_smccc_1_2_regs res; + + arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs){ + .a0 = FFA_ID_GET, + }, &res); + if (res.a0 != FFA_SUCCESS) + return -EOPNOTSUPP; + + if (res.a2 != HOST_FFA_ID) + return -EINVAL; + + arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs){ + .a0 = FFA_FEATURES, + .a1 = FFA_FN64_RXTX_MAP, + }, &res); + if (res.a0 != FFA_SUCCESS) + return -EOPNOTSUPP; + + switch (res.a2 & FFA_FEAT_RXTX_MIN_SZ_MASK) { + case FFA_FEAT_RXTX_MIN_SZ_4K: + min_rxtx_sz = SZ_4K; + break; + case FFA_FEAT_RXTX_MIN_SZ_16K: + min_rxtx_sz = SZ_16K; + break; + case FFA_FEAT_RXTX_MIN_SZ_64K: + min_rxtx_sz = SZ_64K; + break; + default: + return -EINVAL; + } + + if (min_rxtx_sz > PAGE_SIZE) + return -EOPNOTSUPP; + + return 0; +} + +static void do_ffa_version(struct arm_smccc_1_2_regs *res, + struct kvm_cpu_context *ctxt) +{ + DECLARE_REG(u32, ffa_req_version, ctxt, 1); + + if (FFA_MAJOR_VERSION(ffa_req_version) != 1) { + res->a0 = FFA_RET_NOT_SUPPORTED; + return; + } + + hyp_spin_lock(&version_lock); + if (has_version_negotiated) { + if (FFA_MINOR_VERSION(ffa_req_version) < FFA_MINOR_VERSION(hyp_ffa_version)) + res->a0 = FFA_RET_NOT_SUPPORTED; + else + res->a0 = hyp_ffa_version; + goto unlock; + } + + /* + * If the client driver tries to downgrade the version, we need to ask + * first if TEE supports it. + */ + if (FFA_MINOR_VERSION(ffa_req_version) < FFA_MINOR_VERSION(hyp_ffa_version)) { + arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) { + .a0 = FFA_VERSION, + .a1 = ffa_req_version, + }, res); + if (res->a0 == FFA_RET_NOT_SUPPORTED) + goto unlock; + + hyp_ffa_version = ffa_req_version; + } + + if (hyp_ffa_post_init()) { + res->a0 = FFA_RET_NOT_SUPPORTED; + } else { + smp_store_release(&has_version_negotiated, true); + res->a0 = hyp_ffa_version; + } +unlock: + hyp_spin_unlock(&version_lock); +} + +static void do_ffa_part_get(struct arm_smccc_1_2_regs *res, + struct kvm_cpu_context *ctxt) +{ + DECLARE_REG(u32, uuid0, ctxt, 1); + DECLARE_REG(u32, uuid1, ctxt, 2); + DECLARE_REG(u32, uuid2, ctxt, 3); + DECLARE_REG(u32, uuid3, ctxt, 4); + DECLARE_REG(u32, flags, ctxt, 5); + u32 count, partition_sz, copy_sz; + + hyp_spin_lock(&host_buffers.lock); + if (!host_buffers.rx) { + ffa_to_smccc_res(res, FFA_RET_BUSY); + goto out_unlock; + } + + arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) { + .a0 = FFA_PARTITION_INFO_GET, + .a1 = uuid0, + .a2 = uuid1, + .a3 = uuid2, + .a4 = uuid3, + .a5 = flags, + }, res); + + if (res->a0 != FFA_SUCCESS) + goto out_unlock; + + count = res->a2; + if (!count) + goto out_unlock; + + if (hyp_ffa_version > FFA_VERSION_1_0) { + /* Get the number of partitions deployed in the system */ + if (flags & 0x1) + goto out_unlock; + + partition_sz = res->a3; + } else { + /* FFA_VERSION_1_0 lacks the size in the response */ + partition_sz = FFA_1_0_PARTITON_INFO_SZ; + } + + copy_sz = partition_sz * count; + if (copy_sz > KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE) { + ffa_to_smccc_res(res, FFA_RET_ABORTED); + goto out_unlock; + } + + memcpy(host_buffers.rx, hyp_buffers.rx, copy_sz); +out_unlock: + hyp_spin_unlock(&host_buffers.lock); +} + +bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt, u32 func_id) +{ + struct arm_smccc_1_2_regs res; + + /* + * There's no way we can tell what a non-standard SMC call might + * be up to. Ideally, we would terminate these here and return + * an error to the host, but sadly devices make use of custom + * firmware calls for things like power management, debugging, + * RNG access and crash reporting. + * + * Given that the architecture requires us to trust EL3 anyway, + * we forward unrecognised calls on under the assumption that + * the firmware doesn't expose a mechanism to access arbitrary + * non-secure memory. Short of a per-device table of SMCs, this + * is the best we can do. + */ + if (!is_ffa_call(func_id)) + return false; + + if (func_id != FFA_VERSION && + !smp_load_acquire(&has_version_negotiated)) { + ffa_to_smccc_error(&res, FFA_RET_INVALID_PARAMETERS); + goto out_handled; + } + + switch (func_id) { + case FFA_FEATURES: + if (!do_ffa_features(&res, host_ctxt)) + return false; + goto out_handled; + /* Memory management */ + case FFA_FN64_RXTX_MAP: + do_ffa_rxtx_map(&res, host_ctxt); + goto out_handled; + case FFA_RXTX_UNMAP: + do_ffa_rxtx_unmap(&res, host_ctxt); + goto out_handled; + case FFA_MEM_SHARE: + case FFA_FN64_MEM_SHARE: + 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; + case FFA_MEM_FRAG_TX: + do_ffa_mem_frag_tx(&res, host_ctxt); + goto out_handled; + case FFA_VERSION: + do_ffa_version(&res, host_ctxt); + goto out_handled; + case FFA_PARTITION_INFO_GET: + do_ffa_part_get(&res, host_ctxt); + goto out_handled; + } + + if (ffa_call_supported(func_id)) + return false; /* Pass through */ + + ffa_to_smccc_error(&res, FFA_RET_NOT_SUPPORTED); +out_handled: + ffa_set_retval(host_ctxt, &res); + return true; +} + +int hyp_ffa_init(void *pages) +{ + struct arm_smccc_1_2_regs res; + void *tx, *rx; + + if (kvm_host_psci_config.smccc_version < ARM_SMCCC_VERSION_1_2) + return 0; + + arm_smccc_1_2_smc(&(struct arm_smccc_1_2_regs) { + .a0 = FFA_VERSION, + .a1 = FFA_VERSION_1_2, + }, &res); + if (res.a0 == FFA_RET_NOT_SUPPORTED) + return 0; + + /* + * Firmware returns the maximum supported version of the FF-A + * implementation. Check that the returned version is + * backwards-compatible with the hyp according to the rules in DEN0077A + * v1.1 REL0 13.2.1. + * + * Of course, things are never simple when dealing with firmware. v1.1 + * broke ABI with v1.0 on several structures, which is itself + * incompatible with the aforementioned versioning scheme. The + * expectation is that v1.x implementations that do not support the v1.0 + * ABI return NOT_SUPPORTED rather than a version number, according to + * DEN0077A v1.1 REL0 18.6.4. + */ + if (FFA_MAJOR_VERSION(res.a0) != 1) + return -EOPNOTSUPP; + + if (FFA_MINOR_VERSION(res.a0) < FFA_MINOR_VERSION(FFA_VERSION_1_2)) + hyp_ffa_version = res.a0; + else + hyp_ffa_version = FFA_VERSION_1_2; + + tx = pages; + pages += KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE; + rx = pages; + pages += KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE; + + ffa_desc_buf = (struct kvm_ffa_descriptor_buffer) { + .buf = pages, + .len = PAGE_SIZE * + (hyp_ffa_proxy_pages() - (2 * KVM_FFA_MBOX_NR_PAGES)), + }; + + hyp_buffers = (struct kvm_ffa_buffers) { + .lock = __HYP_SPIN_LOCK_UNLOCKED, + .tx = tx, + .rx = rx, + }; + + host_buffers = (struct kvm_ffa_buffers) { + .lock = __HYP_SPIN_LOCK_UNLOCKED, + }; + + version_lock = __HYP_SPIN_LOCK_UNLOCKED; + return 0; +} |