// 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 <[email protected]>
*
* 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_res *res, u64 ffa_errno)
{
*res = (struct arm_smccc_res) {
.a0 = FFA_ERROR,
.a2 = ffa_errno,
};
}
static void ffa_to_smccc_res_prop(struct arm_smccc_res *res, int ret, u64 prop)
{
if (ret == FFA_RET_SUCCESS) {
*res = (struct arm_smccc_res) { .a0 = FFA_SUCCESS,
.a2 = prop };
} else {
ffa_to_smccc_error(res, ret);
}
}
static void ffa_to_smccc_res(struct arm_smccc_res *res, int ret)
{
ffa_to_smccc_res_prop(res, ret, 0);
}
static void ffa_set_retval(struct kvm_cpu_context *ctxt,
struct arm_smccc_res *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;
}
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_res res;
arm_smccc_1_1_smc(FFA_FN64_RXTX_MAP,
hyp_virt_to_phys(hyp_buffers.tx),
hyp_virt_to_phys(hyp_buffers.rx),
ffa_page_count,
0, 0, 0, 0,
&res);
return res.a0 == FFA_SUCCESS ? FFA_RET_SUCCESS : res.a2;
}
static int ffa_unmap_hyp_buffers(void)
{
struct arm_smccc_res res;
arm_smccc_1_1_smc(FFA_RXTX_UNMAP,
HOST_FFA_ID,
0, 0, 0, 0, 0, 0,
&res);
return res.a0 == FFA_SUCCESS ? FFA_RET_SUCCESS : res.a2;
}
static void ffa_mem_frag_tx(struct arm_smccc_res *res, u32 handle_lo,
u32 handle_hi, u32 fraglen, u32 endpoint_id)
{
arm_smccc_1_1_smc(FFA_MEM_FRAG_TX,
handle_lo, handle_hi, fraglen, endpoint_id,
0, 0, 0,
res);
}
static void ffa_mem_frag_rx(struct arm_smccc_res *res, u32 handle_lo,
u32 handle_hi, u32 fragoff)
{
arm_smccc_1_1_smc(FFA_MEM_FRAG_RX,
handle_lo, handle_hi, fragoff, HOST_FFA_ID,
0, 0, 0,
res);
}
static void ffa_mem_xfer(struct arm_smccc_res *res, u64 func_id, u32 len,
u32 fraglen)
{
arm_smccc_1_1_smc(func_id, len, fraglen,
0, 0, 0, 0, 0,
res);
}
static void ffa_mem_reclaim(struct arm_smccc_res *res, u32 handle_lo,
u32 handle_hi, u32 flags)
{
arm_smccc_1_1_smc(FFA_MEM_RECLAIM,
handle_lo, handle_hi, flags,
0, 0, 0, 0,
res);
}
static void ffa_retrieve_req(struct arm_smccc_res *res, u32 len)
{
arm_smccc_1_1_smc(FFA_FN64_MEM_RETRIEVE_REQ,
len, len,
0, 0, 0, 0, 0,
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)
{
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_res *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_res *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 __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);
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;
int ret = 0;
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;
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;
}
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 (fraglen < offset + sizeof(struct ffa_composite_mem_region)) {
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;
}
static void do_ffa_mem_reclaim(struct arm_smccc_res *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:
return false;
}
return true;
}
static bool do_ffa_features(struct arm_smccc_res *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_res res;
arm_smccc_1_1_smc(FFA_ID_GET, 0, 0, 0, 0, 0, 0, 0, &res);
if (res.a0 != FFA_SUCCESS)
return -EOPNOTSUPP;
if (res.a2 != HOST_FFA_ID)
return -EINVAL;
arm_smccc_1_1_smc(FFA_FEATURES, FFA_FN64_RXTX_MAP,
0, 0, 0, 0, 0, 0, &res);
if (res.a0 != FFA_SUCCESS)
return -EOPNOTSUPP;
switch (res.a2) {
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_res *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) {
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_1_smc(FFA_VERSION, ffa_req_version, 0,
0, 0, 0, 0, 0,
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 {
has_version_negotiated = true;
res->a0 = hyp_ffa_version;
}
unlock:
hyp_spin_unlock(&version_lock);
}
static void do_ffa_part_get(struct arm_smccc_res *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_1_smc(FFA_PARTITION_INFO_GET, uuid0, uuid1,
uuid2, uuid3, flags, 0, 0,
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_res 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 (!has_version_negotiated && func_id != FFA_VERSION) {
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_res res;
void *tx, *rx;
if (kvm_host_psci_config.smccc_version < ARM_SMCCC_VERSION_1_2)
return 0;
arm_smccc_1_1_smc(FFA_VERSION, FFA_VERSION_1_1, 0, 0, 0, 0, 0, 0, &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_1))
hyp_ffa_version = res.a0;
else
hyp_ffa_version = FFA_VERSION_1_1;
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;
}
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