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/*
* Copyright 2018 The Hafnium Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "hf/api.h"
#include "hf/arch/cpu.h"
#include "hf/arch/tee.h"
#include "hf/arch/timer.h"
#include "hf/check.h"
#include "hf/dlog.h"
#include "hf/ffa_internal.h"
#include "hf/ffa_memory.h"
#include "hf/mm.h"
#include "hf/plat/console.h"
#include "hf/spinlock.h"
#include "hf/static_assert.h"
#include "hf/std.h"
#include "hf/vm.h"
#include "vmapi/hf/call.h"
#include "vmapi/hf/ffa.h"
/*
* To eliminate the risk of deadlocks, we define a partial order for the
* acquisition of locks held concurrently by the same physical CPU. Our current
* ordering requirements are as follows:
*
* vm::lock -> vcpu::lock -> mm_stage1_lock -> dlog sl
*
* Locks of the same kind require the lock of lowest address to be locked first,
* see `sl_lock_both()`.
*/
static_assert(HF_MAILBOX_SIZE == PAGE_SIZE,
"Currently, a page is mapped for the send and receive buffers so "
"the maximum request is the size of a page.");
static_assert(MM_PPOOL_ENTRY_SIZE >= HF_MAILBOX_SIZE,
"The page pool entry size must be at least as big as the mailbox "
"size, so that memory region descriptors can be copied from the "
"mailbox for memory sharing.");
static struct mpool api_page_pool;
/**
* Initialises the API page pool by taking ownership of the contents of the
* given page pool.
*/
void api_init(struct mpool *ppool)
{
mpool_init_from(&api_page_pool, ppool);
}
/**
* Switches the physical CPU back to the corresponding vCPU of the primary VM.
*
* This triggers the scheduling logic to run. Run in the context of secondary VM
* to cause FFA_RUN to return and the primary VM to regain control of the CPU.
*/
static struct vcpu *api_switch_to_primary(struct vcpu *current,
struct ffa_value primary_ret,
enum vcpu_state secondary_state)
{
struct vm *primary = vm_find(HF_PRIMARY_VM_ID);
struct vcpu *next = vm_get_vcpu(primary, cpu_index(current->cpu));
/*
* If the secondary is blocked but has a timer running, sleep until the
* timer fires rather than indefinitely.
*/
switch (primary_ret.func) {
case HF_FFA_RUN_WAIT_FOR_INTERRUPT:
case FFA_MSG_WAIT_32: {
if (arch_timer_enabled_current()) {
uint64_t remaining_ns =
arch_timer_remaining_ns_current();
if (remaining_ns == 0) {
/*
* Timer is pending, so the current vCPU should
* be run again right away.
*/
primary_ret.func = FFA_INTERRUPT_32;
/*
* primary_ret.arg1 should already be set to the
* current VM ID and vCPU ID.
*/
primary_ret.arg2 = 0;
} else {
primary_ret.arg2 = remaining_ns;
}
} else {
primary_ret.arg2 = FFA_SLEEP_INDEFINITE;
}
break;
}
default:
/* Do nothing. */
break;
}
/* Set the return value for the primary VM's call to HF_VCPU_RUN. */
arch_regs_set_retval(&next->regs, primary_ret);
/* Mark the current vCPU as waiting. */
sl_lock(&current->lock);
current->state = secondary_state;
sl_unlock(&current->lock);
return next;
}
/**
* Returns to the primary VM and signals that the vCPU still has work to do so.
*/
struct vcpu *api_preempt(struct vcpu *current)
{
struct ffa_value ret = {
.func = FFA_INTERRUPT_32,
.arg1 = ffa_vm_vcpu(current->vm->id, vcpu_index(current)),
};
return api_switch_to_primary(current, ret, VCPU_STATE_READY);
}
/**
* Puts the current vCPU in wait for interrupt mode, and returns to the primary
* VM.
*/
struct vcpu *api_wait_for_interrupt(struct vcpu *current)
{
struct ffa_value ret = {
.func = HF_FFA_RUN_WAIT_FOR_INTERRUPT,
.arg1 = ffa_vm_vcpu(current->vm->id, vcpu_index(current)),
};
return api_switch_to_primary(current, ret,
VCPU_STATE_BLOCKED_INTERRUPT);
}
/**
* Puts the current vCPU in off mode, and returns to the primary VM.
*/
struct vcpu *api_vcpu_off(struct vcpu *current)
{
struct ffa_value ret = {
.func = HF_FFA_RUN_WAIT_FOR_INTERRUPT,
.arg1 = ffa_vm_vcpu(current->vm->id, vcpu_index(current)),
};
/*
* Disable the timer, so the scheduler doesn't get told to call back
* based on it.
*/
arch_timer_disable_current();
return api_switch_to_primary(current, ret, VCPU_STATE_OFF);
}
/**
* Returns to the primary VM to allow this CPU to be used for other tasks as the
* vCPU does not have work to do at this moment. The current vCPU is marked as
* ready to be scheduled again.
*/
void api_yield(struct vcpu *current, struct vcpu **next)
{
struct ffa_value primary_ret = {
.func = FFA_YIELD_32,
.arg1 = ffa_vm_vcpu(current->vm->id, vcpu_index(current)),
};
if (current->vm->id == HF_PRIMARY_VM_ID) {
/* NOOP on the primary as it makes the scheduling decisions. */
return;
}
*next = api_switch_to_primary(current, primary_ret, VCPU_STATE_READY);
}
/**
* Switches to the primary so that it can switch to the target, or kick it if it
* is already running on a different physical CPU.
*/
struct vcpu *api_wake_up(struct vcpu *current, struct vcpu *target_vcpu)
{
struct ffa_value ret = {
.func = HF_FFA_RUN_WAKE_UP,
.arg1 = ffa_vm_vcpu(target_vcpu->vm->id,
vcpu_index(target_vcpu)),
};
return api_switch_to_primary(current, ret, VCPU_STATE_READY);
}
/**
* Aborts the vCPU and triggers its VM to abort fully.
*/
struct vcpu *api_abort(struct vcpu *current)
{
struct ffa_value ret = ffa_error(FFA_ABORTED);
dlog_notice("Aborting VM %u vCPU %u\n", current->vm->id,
vcpu_index(current));
if (current->vm->id == HF_PRIMARY_VM_ID) {
/* TODO: what to do when the primary aborts? */
for (;;) {
/* Do nothing. */
}
}
atomic_store_explicit(&current->vm->aborting, true,
memory_order_relaxed);
/* TODO: free resources once all vCPUs abort. */
return api_switch_to_primary(current, ret, VCPU_STATE_ABORTED);
}
/**
* Returns the ID of the VM.
*/
struct ffa_value api_ffa_id_get(const struct vcpu *current)
{
return (struct ffa_value){.func = FFA_SUCCESS_32,
.arg2 = current->vm->id};
}
/**
* Returns the number of VMs configured to run.
*/
ffa_vm_count_t api_vm_get_count(void)
{
return vm_get_count();
}
/**
* Returns the number of vCPUs configured in the given VM, or 0 if there is no
* such VM or the caller is not the primary VM.
*/
ffa_vcpu_count_t api_vcpu_get_count(ffa_vm_id_t vm_id,
const struct vcpu *current)
{
struct vm *vm;
/* Only the primary VM needs to know about vCPUs for scheduling. */
if (current->vm->id != HF_PRIMARY_VM_ID) {
return 0;
}
vm = vm_find(vm_id);
if (vm == NULL) {
return 0;
}
return vm->vcpu_count;
}
/**
* This function is called by the architecture-specific context switching
* function to indicate that register state for the given vCPU has been saved
* and can therefore be used by other pCPUs.
*/
void api_regs_state_saved(struct vcpu *vcpu)
{
sl_lock(&vcpu->lock);
vcpu->regs_available = true;
sl_unlock(&vcpu->lock);
}
/**
* Retrieves the next waiter and removes it from the wait list if the VM's
* mailbox is in a writable state.
*/
static struct wait_entry *api_fetch_waiter(struct vm_locked locked_vm)
{
struct wait_entry *entry;
struct vm *vm = locked_vm.vm;
if (vm->mailbox.state != MAILBOX_STATE_EMPTY ||
vm->mailbox.recv == NULL || list_empty(&vm->mailbox.waiter_list)) {
/* The mailbox is not writable or there are no waiters. */
return NULL;
}
/* Remove waiter from the wait list. */
entry = CONTAINER_OF(vm->mailbox.waiter_list.next, struct wait_entry,
wait_links);
list_remove(&entry->wait_links);
return entry;
}
/**
* Assuming that the arguments have already been checked by the caller, injects
* a virtual interrupt of the given ID into the given target vCPU. This doesn't
* cause the vCPU to actually be run immediately; it will be taken when the vCPU
* is next run, which is up to the scheduler.
*
* Returns:
* - 0 on success if no further action is needed.
* - 1 if it was called by the primary VM and the primary VM now needs to wake
* up or kick the target vCPU.
*/
static int64_t internal_interrupt_inject(struct vcpu *target_vcpu,
uint32_t intid, struct vcpu *current,
struct vcpu **next)
{
uint32_t intid_index = intid / INTERRUPT_REGISTER_BITS;
uint32_t intid_mask = 1U << (intid % INTERRUPT_REGISTER_BITS);
int64_t ret = 0;
sl_lock(&target_vcpu->lock);
/*
* We only need to change state and (maybe) trigger a virtual IRQ if it
* is enabled and was not previously pending. Otherwise we can skip
* everything except setting the pending bit.
*
* If you change this logic make sure to update the need_vm_lock logic
* above to match.
*/
if (!(target_vcpu->interrupts.interrupt_enabled[intid_index] &
~target_vcpu->interrupts.interrupt_pending[intid_index] &
intid_mask)) {
goto out;
}
/* Increment the count. */
target_vcpu->interrupts.enabled_and_pending_count++;
/*
* Only need to update state if there was not already an
* interrupt enabled and pending.
*/
if (target_vcpu->interrupts.enabled_and_pending_count != 1) {
goto out;
}
if (current->vm->id == HF_PRIMARY_VM_ID) {
/*
* If the call came from the primary VM, let it know that it
* should run or kick the target vCPU.
*/
ret = 1;
} else if (current != target_vcpu && next != NULL) {
*next = api_wake_up(current, target_vcpu);
}
out:
/* Either way, make it pending. */
target_vcpu->interrupts.interrupt_pending[intid_index] |= intid_mask;
sl_unlock(&target_vcpu->lock);
return ret;
}
/**
* Constructs an FFA_MSG_SEND value to return from a successful FFA_MSG_POLL
* or FFA_MSG_WAIT call.
*/
static struct ffa_value ffa_msg_recv_return(const struct vm *receiver)
{
switch (receiver->mailbox.recv_func) {
case FFA_MSG_SEND_32:
return (struct ffa_value){
.func = FFA_MSG_SEND_32,
.arg1 = (receiver->mailbox.recv_sender << 16) |
receiver->id,
.arg3 = receiver->mailbox.recv_size};
default:
/* This should never be reached, but return an error in case. */
dlog_error("Tried to return an invalid message function %#x\n",
receiver->mailbox.recv_func);
return ffa_error(FFA_DENIED);
}
}
/**
* Prepares the vCPU to run by updating its state and fetching whether a return
* value needs to be forced onto the vCPU.
*/
static bool api_vcpu_prepare_run(const struct vcpu *current, struct vcpu *vcpu,
struct ffa_value *run_ret)
{
bool need_vm_lock;
bool ret;
/*
* Check that the registers are available so that the vCPU can be run.
*
* The VM lock is not needed in the common case so it must only be taken
* when it is going to be needed. This ensures there are no inter-vCPU
* dependencies in the common run case meaning the sensitive context
* switch performance is consistent.
*/
sl_lock(&vcpu->lock);
/* The VM needs to be locked to deliver mailbox messages. */
need_vm_lock = vcpu->state == VCPU_STATE_BLOCKED_MAILBOX;
if (need_vm_lock) {
sl_unlock(&vcpu->lock);
sl_lock(&vcpu->vm->lock);
sl_lock(&vcpu->lock);
}
/*
* If the vCPU is already running somewhere then we can't run it here
* simultaneously. While it is actually running then the state should be
* `VCPU_STATE_RUNNING` and `regs_available` should be false. Once it
* stops running but while Hafnium is in the process of switching back
* to the primary there will be a brief period while the state has been
* updated but `regs_available` is still false (until
* `api_regs_state_saved` is called). We can't start running it again
* until this has finished, so count this state as still running for the
* purposes of this check.
*/
if (vcpu->state == VCPU_STATE_RUNNING || !vcpu->regs_available) {
/*
* vCPU is running on another pCPU.
*
* It's okay not to return the sleep duration here because the
* other physical CPU that is currently running this vCPU will
* return the sleep duration if needed.
*/
*run_ret = ffa_error(FFA_BUSY);
ret = false;
goto out;
}
if (atomic_load_explicit(&vcpu->vm->aborting, memory_order_relaxed)) {
if (vcpu->state != VCPU_STATE_ABORTED) {
dlog_notice("Aborting VM %u vCPU %u\n", vcpu->vm->id,
vcpu_index(vcpu));
vcpu->state = VCPU_STATE_ABORTED;
}
ret = false;
goto out;
}
switch (vcpu->state) {
case VCPU_STATE_RUNNING:
case VCPU_STATE_OFF:
case VCPU_STATE_ABORTED:
ret = false;
goto out;
case VCPU_STATE_BLOCKED_MAILBOX:
/*
* A pending message allows the vCPU to run so the message can
* be delivered directly.
*/
if (vcpu->vm->mailbox.state == MAILBOX_STATE_RECEIVED) {
arch_regs_set_retval(&vcpu->regs,
ffa_msg_recv_return(vcpu->vm));
vcpu->vm->mailbox.state = MAILBOX_STATE_READ;
break;
}
/* Fall through. */
case VCPU_STATE_BLOCKED_INTERRUPT:
/* Allow virtual interrupts to be delivered. */
if (vcpu->interrupts.enabled_and_pending_count > 0) {
break;
}
if (arch_timer_enabled(&vcpu->regs)) {
uint64_t timer_remaining_ns =
arch_timer_remaining_ns(&vcpu->regs);
/*
* The timer expired so allow the interrupt to be
* delivered.
*/
if (timer_remaining_ns == 0) {
break;
}
/*
* The vCPU is not ready to run, return the appropriate
* code to the primary which called vcpu_run.
*/
run_ret->func =
vcpu->state == VCPU_STATE_BLOCKED_MAILBOX
? FFA_MSG_WAIT_32
: HF_FFA_RUN_WAIT_FOR_INTERRUPT;
run_ret->arg1 =
ffa_vm_vcpu(vcpu->vm->id, vcpu_index(vcpu));
run_ret->arg2 = timer_remaining_ns;
}
ret = false;
goto out;
case VCPU_STATE_READY:
break;
}
/* It has been decided that the vCPU should be run. */
vcpu->cpu = current->cpu;
vcpu->state = VCPU_STATE_RUNNING;
/*
* Mark the registers as unavailable now that we're about to reflect
* them onto the real registers. This will also prevent another physical
* CPU from trying to read these registers.
*/
vcpu->regs_available = false;
ret = true;
out:
sl_unlock(&vcpu->lock);
if (need_vm_lock) {
sl_unlock(&vcpu->vm->lock);
}
return ret;
}
struct ffa_value api_ffa_run(ffa_vm_id_t vm_id, ffa_vcpu_index_t vcpu_idx,
const struct vcpu *current, struct vcpu **next)
{
struct vm *vm;
struct vcpu *vcpu;
struct ffa_value ret = ffa_error(FFA_INVALID_PARAMETERS);
/* Only the primary VM can switch vCPUs. */
if (current->vm->id != HF_PRIMARY_VM_ID) {
ret.arg2 = FFA_DENIED;
goto out;
}
/* Only secondary VM vCPUs can be run. */
if (vm_id == HF_PRIMARY_VM_ID) {
goto out;
}
/* The requested VM must exist. */
vm = vm_find(vm_id);
if (vm == NULL) {
goto out;
}
/* The requested vCPU must exist. */
if (vcpu_idx >= vm->vcpu_count) {
goto out;
}
/* Update state if allowed. */
vcpu = vm_get_vcpu(vm, vcpu_idx);
if (!api_vcpu_prepare_run(current, vcpu, &ret)) {
goto out;
}
/*
* Inject timer interrupt if timer has expired. It's safe to access
* vcpu->regs here because api_vcpu_prepare_run already made sure that
* regs_available was true (and then set it to false) before returning
* true.
*/
if (arch_timer_pending(&vcpu->regs)) {
/* Make virtual timer interrupt pending. */
internal_interrupt_inject(vcpu, HF_VIRTUAL_TIMER_INTID, vcpu,
NULL);
/*
* Set the mask bit so the hardware interrupt doesn't fire
* again. Ideally we wouldn't do this because it affects what
* the secondary vCPU sees, but if we don't then we end up with
* a loop of the interrupt firing each time we try to return to
* the secondary vCPU.
*/
arch_timer_mask(&vcpu->regs);
}
/* Switch to the vCPU. */
*next = vcpu;
/*
* Set a placeholder return code to the scheduler. This will be
* overwritten when the switch back to the primary occurs.
*/
ret.func = FFA_INTERRUPT_32;
ret.arg1 = ffa_vm_vcpu(vm_id, vcpu_idx);
ret.arg2 = 0;
out:
return ret;
}
/**
* Check that the mode indicates memory that is valid, owned and exclusive.
*/
static bool api_mode_valid_owned_and_exclusive(uint32_t mode)
{
return (mode & (MM_MODE_D | MM_MODE_INVALID | MM_MODE_UNOWNED |
MM_MODE_SHARED)) == 0;
}
/**
* Determines the value to be returned by api_vm_configure and ffa_rx_release
* after they've succeeded. If a secondary VM is running and there are waiters,
* it also switches back to the primary VM for it to wake waiters up.
*/
static struct ffa_value api_waiter_result(struct vm_locked locked_vm,
struct vcpu *current,
struct vcpu **next)
{
struct vm *vm = locked_vm.vm;
if (list_empty(&vm->mailbox.waiter_list)) {
/* No waiters, nothing else to do. */
return (struct ffa_value){.func = FFA_SUCCESS_32};
}
if (vm->id == HF_PRIMARY_VM_ID) {
/* The caller is the primary VM. Tell it to wake up waiters. */
return (struct ffa_value){.func = FFA_RX_RELEASE_32};
}
/*
* Switch back to the primary VM, informing it that there are waiters
* that need to be notified.
*/
*next = api_switch_to_primary(
current, (struct ffa_value){.func = FFA_RX_RELEASE_32},
VCPU_STATE_READY);
return (struct ffa_value){.func = FFA_SUCCESS_32};
}
/**
* Configures the hypervisor's stage-1 view of the send and receive pages. The
* stage-1 page tables must be locked so memory cannot be taken by another core
* which could result in this transaction being unable to roll back in the case
* of an error.
*/
static bool api_vm_configure_stage1(struct vm_locked vm_locked,
paddr_t pa_send_begin, paddr_t pa_send_end,
paddr_t pa_recv_begin, paddr_t pa_recv_end,
struct mpool *local_page_pool)
{
bool ret;
struct mm_stage1_locked mm_stage1_locked = mm_lock_stage1();
/* Map the send page as read-only in the hypervisor address space. */
vm_locked.vm->mailbox.send =
mm_identity_map(mm_stage1_locked, pa_send_begin, pa_send_end,
MM_MODE_R, local_page_pool);
if (!vm_locked.vm->mailbox.send) {
/* TODO: partial defrag of failed range. */
/* Recover any memory consumed in failed mapping. */
mm_defrag(mm_stage1_locked, local_page_pool);
goto fail;
}
/*
* Map the receive page as writable in the hypervisor address space. On
* failure, unmap the send page before returning.
*/
vm_locked.vm->mailbox.recv =
mm_identity_map(mm_stage1_locked, pa_recv_begin, pa_recv_end,
MM_MODE_W, local_page_pool);
if (!vm_locked.vm->mailbox.recv) {
/* TODO: partial defrag of failed range. */
/* Recover any memory consumed in failed mapping. */
mm_defrag(mm_stage1_locked, local_page_pool);
goto fail_undo_send;
}
ret = true;
goto out;
/*
* The following mappings will not require more memory than is available
* in the local pool.
*/
fail_undo_send:
vm_locked.vm->mailbox.send = NULL;
CHECK(mm_unmap(mm_stage1_locked, pa_send_begin, pa_send_end,
local_page_pool));
fail:
ret = false;
out:
mm_unlock_stage1(&mm_stage1_locked);
return ret;
}
/**
* Configures the send and receive pages in the VM stage-2 and hypervisor
* stage-1 page tables. Locking of the page tables combined with a local memory
* pool ensures there will always be enough memory to recover from any errors
* that arise.
*/
static bool api_vm_configure_pages(struct vm_locked vm_locked,
paddr_t pa_send_begin, paddr_t pa_send_end,
uint32_t orig_send_mode,
paddr_t pa_recv_begin, paddr_t pa_recv_end,
uint32_t orig_recv_mode)
{
bool ret;
struct mpool local_page_pool;
/*
* Create a local pool so any freed memory can't be used by another
* thread. This is to ensure the original mapping can be restored if any
* stage of the process fails.
*/
mpool_init_with_fallback(&local_page_pool, &api_page_pool);
/* Take memory ownership away from the VM and mark as shared. */
if (!vm_identity_map(
vm_locked, pa_send_begin, pa_send_end,
MM_MODE_UNOWNED | MM_MODE_SHARED | MM_MODE_R | MM_MODE_W,
&local_page_pool, NULL)) {
goto fail;
}
if (!vm_identity_map(vm_locked, pa_recv_begin, pa_recv_end,
MM_MODE_UNOWNED | MM_MODE_SHARED | MM_MODE_R,
&local_page_pool, NULL)) {
/* TODO: partial defrag of failed range. */
/* Recover any memory consumed in failed mapping. */
mm_vm_defrag(&vm_locked.vm->ptable, &local_page_pool);
goto fail_undo_send;
}
if (!api_vm_configure_stage1(vm_locked, pa_send_begin, pa_send_end,
pa_recv_begin, pa_recv_end,
&local_page_pool)) {
goto fail_undo_send_and_recv;
}
ret = true;
goto out;
/*
* The following mappings will not require more memory than is available
* in the local pool.
*/
fail_undo_send_and_recv:
CHECK(vm_identity_map(vm_locked, pa_recv_begin, pa_recv_end,
orig_recv_mode, &local_page_pool, NULL));
fail_undo_send:
CHECK(vm_identity_map(vm_locked, pa_send_begin, pa_send_end,
orig_send_mode, &local_page_pool, NULL));
fail:
ret = false;
out:
mpool_fini(&local_page_pool);
return ret;
}
/**
* Configures the VM to send/receive data through the specified pages. The pages
* must not be shared.
*
* Returns:
* - FFA_ERROR FFA_INVALID_PARAMETERS if the given addresses are not properly
* aligned or are the same.
* - FFA_ERROR FFA_NO_MEMORY if the hypervisor was unable to map the buffers
* due to insuffient page table memory.
* - FFA_ERROR FFA_DENIED if the pages are already mapped or are not owned by
* the caller.
* - FFA_SUCCESS on success if no further action is needed.
* - FFA_RX_RELEASE if it was called by the primary VM and the primary VM now
* needs to wake up or kick waiters.
*/
struct ffa_value api_ffa_rxtx_map(ipaddr_t send, ipaddr_t recv,
uint32_t page_count, struct vcpu *current,
struct vcpu **next)
{
struct vm *vm = current->vm;
struct vm_locked vm_locked;
paddr_t pa_send_begin;
paddr_t pa_send_end;
paddr_t pa_recv_begin;
paddr_t pa_recv_end;
uint32_t orig_send_mode;
uint32_t orig_recv_mode;
struct ffa_value ret;
/* Hafnium only supports a fixed size of RX/TX buffers. */
if (page_count != HF_MAILBOX_SIZE / FFA_PAGE_SIZE) {
return ffa_error(FFA_INVALID_PARAMETERS);
}
/* Fail if addresses are not page-aligned. */
if (!is_aligned(ipa_addr(send), PAGE_SIZE) ||
!is_aligned(ipa_addr(recv), PAGE_SIZE)) {
return ffa_error(FFA_INVALID_PARAMETERS);
}
/* Convert to physical addresses. */
pa_send_begin = pa_from_ipa(send);
pa_send_end = pa_add(pa_send_begin, HF_MAILBOX_SIZE);
pa_recv_begin = pa_from_ipa(recv);
pa_recv_end = pa_add(pa_recv_begin, HF_MAILBOX_SIZE);
/* Fail if the same page is used for the send and receive pages. */
if (pa_addr(pa_send_begin) == pa_addr(pa_recv_begin)) {
return ffa_error(FFA_INVALID_PARAMETERS);
}
/*
* The hypervisor's memory map must be locked for the duration of this
* operation to ensure there will be sufficient memory to recover from
* any failures.
*
* TODO: the scope of the can be reduced but will require restructuring
* to keep a single unlock point.
*/
vm_locked = vm_lock(vm);
/* We only allow these to be setup once. */
if (vm->mailbox.send || vm->mailbox.recv) {
ret = ffa_error(FFA_DENIED);
goto exit;
}
/*
* Ensure the pages are valid, owned and exclusive to the VM and that
* the VM has the required access to the memory.
*/
if (!mm_vm_get_mode(&vm->ptable, send, ipa_add(send, PAGE_SIZE),
&orig_send_mode) ||
!api_mode_valid_owned_and_exclusive(orig_send_mode) ||
(orig_send_mode & MM_MODE_R) == 0 ||
(orig_send_mode & MM_MODE_W) == 0) {
ret = ffa_error(FFA_DENIED);
goto exit;
}
if (!mm_vm_get_mode(&vm->ptable, recv, ipa_add(recv, PAGE_SIZE),
&orig_recv_mode) ||
!api_mode_valid_owned_and_exclusive(orig_recv_mode) ||
(orig_recv_mode & MM_MODE_R) == 0) {
ret = ffa_error(FFA_DENIED);
goto exit;
}
if (!api_vm_configure_pages(vm_locked, pa_send_begin, pa_send_end,
orig_send_mode, pa_recv_begin, pa_recv_end,
orig_recv_mode)) {
ret = ffa_error(FFA_NO_MEMORY);
goto exit;
}
/* Tell caller about waiters, if any. */
ret = api_waiter_result(vm_locked, current, next);
exit:
vm_unlock(&vm_locked);
return ret;
}
/**
* Checks whether the given `to` VM's mailbox is currently busy, and optionally
* registers the `from` VM to be notified when it becomes available.
*/
static bool msg_receiver_busy(struct vm_locked to, struct vm *from, bool notify)
{
if (to.vm->mailbox.state != MAILBOX_STATE_EMPTY ||
to.vm->mailbox.recv == NULL) {
/*
* Fail if the receiver isn't currently ready to receive data,
* setting up for notification if requested.
*/
if (notify) {
struct wait_entry *entry =
vm_get_wait_entry(from, to.vm->id);
/* Append waiter only if it's not there yet. */
if (list_empty(&entry->wait_links)) {
list_append(&to.vm->mailbox.waiter_list,
&entry->wait_links);
}
}
return true;
}
return false;
}
/**
* Notifies the `to` VM about the message currently in its mailbox, possibly
* with the help of the primary VM.
*/
static struct ffa_value deliver_msg(struct vm_locked to, ffa_vm_id_t from_id,
struct vcpu *current, struct vcpu **next)
{
struct ffa_value ret = (struct ffa_value){.func = FFA_SUCCESS_32};
struct ffa_value primary_ret = {
.func = FFA_MSG_SEND_32,
.arg1 = ((uint32_t)from_id << 16) | to.vm->id,
};
/* Messages for the primary VM are delivered directly. */
if (to.vm->id == HF_PRIMARY_VM_ID) {
/*
* Only tell the primary VM the size and other details if the
* message is for it, to avoid leaking data about messages for
* other VMs.
*/
primary_ret = ffa_msg_recv_return(to.vm);
to.vm->mailbox.state = MAILBOX_STATE_READ;
*next = api_switch_to_primary(current, primary_ret,
VCPU_STATE_READY);
return ret;
}
to.vm->mailbox.state = MAILBOX_STATE_RECEIVED;
/* Messages for the TEE are sent on via the dispatcher. */
if (to.vm->id == HF_TEE_VM_ID) {
struct ffa_value call = ffa_msg_recv_return(to.vm);
ret = arch_tee_call(call);
/*
* After the call to the TEE completes it must have finished
* reading its RX buffer, so it is ready for another message.
*/
to.vm->mailbox.state = MAILBOX_STATE_EMPTY;
/*
* Don't return to the primary VM in this case, as the TEE is
* not (yet) scheduled via FF-A.
*/
return ret;
}
/* Return to the primary VM directly or with a switch. */
if (from_id != HF_PRIMARY_VM_ID) {
*next = api_switch_to_primary(current, primary_ret,
VCPU_STATE_READY);
}
return ret;
}
/**
* Copies data from the sender's send buffer to the recipient's receive buffer
* and notifies the recipient.
*
* If the recipient's receive buffer is busy, it can optionally register the
* caller to be notified when the recipient's receive buffer becomes available.
*/
struct ffa_value api_ffa_msg_send(ffa_vm_id_t sender_vm_id,
ffa_vm_id_t receiver_vm_id, uint32_t size,
uint32_t attributes, struct vcpu *current,
struct vcpu **next)
{
struct vm *from = current->vm;
struct vm *to;
struct vm_locked to_locked;
const void *from_msg;
struct ffa_value ret;
bool notify =
(attributes & FFA_MSG_SEND_NOTIFY_MASK) == FFA_MSG_SEND_NOTIFY;
/* Ensure sender VM ID corresponds to the current VM. */
if (sender_vm_id != from->id) {
return ffa_error(FFA_INVALID_PARAMETERS);
}
/* Disallow reflexive requests as this suggests an error in the VM. */
if (receiver_vm_id == from->id) {
return ffa_error(FFA_INVALID_PARAMETERS);
}
/* Limit the size of transfer. */
if (size > FFA_MSG_PAYLOAD_MAX) {
return ffa_error(FFA_INVALID_PARAMETERS);
}
/* Ensure the receiver VM exists. */
to = vm_find(receiver_vm_id);
if (to == NULL) {
return ffa_error(FFA_INVALID_PARAMETERS);
}
/*
* Check that the sender has configured its send buffer. If the tx
* mailbox at from_msg is configured (i.e. from_msg != NULL) then it can
* be safely accessed after releasing the lock since the tx mailbox
* address can only be configured once.
*/
sl_lock(&from->lock);
from_msg = from->mailbox.send;
sl_unlock(&from->lock);
if (from_msg == NULL) {
return ffa_error(FFA_INVALID_PARAMETERS);
}
to_locked = vm_lock(to);
if (msg_receiver_busy(to_locked, from, notify)) {
ret = ffa_error(FFA_BUSY);
goto out;
}
/* Copy data. */
memcpy_s(to->mailbox.recv, FFA_MSG_PAYLOAD_MAX, from_msg, size);
to->mailbox.recv_size = size;
to->mailbox.recv_sender = sender_vm_id;
to->mailbox.recv_func = FFA_MSG_SEND_32;
ret = deliver_msg(to_locked, sender_vm_id, current, next);
out:
vm_unlock(&to_locked);
return ret;
}
/**
* Checks whether the vCPU's attempt to block for a message has already been
* interrupted or whether it is allowed to block.
*/
bool api_ffa_msg_recv_block_interrupted(struct vcpu *current)
{
bool interrupted;
sl_lock(&current->lock);
/*
* Don't block if there are enabled and pending interrupts, to match
* behaviour of wait_for_interrupt.
*/
interrupted = (current->interrupts.enabled_and_pending_count > 0);
sl_unlock(&current->lock);
return interrupted;
}
/**
* Receives a message from the mailbox. If one isn't available, this function
* can optionally block the caller until one becomes available.
*
* No new messages can be received until the mailbox has been cleared.
*/
struct ffa_value api_ffa_msg_recv(bool block, struct vcpu *current,
struct vcpu **next)
{
struct vm *vm = current->vm;
struct ffa_value return_code;
/*
* The primary VM will receive messages as a status code from running
* vCPUs and must not call this function.
*/
if (vm->id == HF_PRIMARY_VM_ID) {
return ffa_error(FFA_NOT_SUPPORTED);
}
sl_lock(&vm->lock);
/* Return pending messages without blocking. */
if (vm->mailbox.state == MAILBOX_STATE_RECEIVED) {
vm->mailbox.state = MAILBOX_STATE_READ;
return_code = ffa_msg_recv_return(vm);
goto out;
}
/* No pending message so fail if not allowed to block. */
if (!block) {
return_code = ffa_error(FFA_RETRY);
goto out;
}
/*
* From this point onward this call can only be interrupted or a message
* received. If a message is received the return value will be set at
* that time to FFA_SUCCESS.
*/
return_code = ffa_error(FFA_INTERRUPTED);
if (api_ffa_msg_recv_block_interrupted(current)) {
goto out;
}
/* Switch back to primary VM to block. */
{
struct ffa_value run_return = {
.func = FFA_MSG_WAIT_32,
.arg1 = ffa_vm_vcpu(vm->id, vcpu_index(current)),
};
*next = api_switch_to_primary(current, run_return,
VCPU_STATE_BLOCKED_MAILBOX);
}
out:
sl_unlock(&vm->lock);
return return_code;
}
/**
* Retrieves the next VM whose mailbox became writable. For a VM to be notified
* by this function, the caller must have called api_mailbox_send before with
* the notify argument set to true, and this call must have failed because the
* mailbox was not available.
*
* It should be called repeatedly to retrieve a list of VMs.
*
* Returns -1 if no VM became writable, or the id of the VM whose mailbox
* became writable.
*/
int64_t api_mailbox_writable_get(const struct vcpu *current)
{
struct vm *vm = current->vm;
struct wait_entry *entry;
int64_t ret;
sl_lock(&vm->lock);
if (list_empty(&vm->mailbox.ready_list)) {
ret = -1;
goto exit;
}
entry = CONTAINER_OF(vm->mailbox.ready_list.next, struct wait_entry,
ready_links);
list_remove(&entry->ready_links);
ret = vm_id_for_wait_entry(vm, entry);
exit:
sl_unlock(&vm->lock);
return ret;
}
/**
* Retrieves the next VM waiting to be notified that the mailbox of the
* specified VM became writable. Only primary VMs are allowed to call this.
*
* Returns -1 on failure or if there are no waiters; the VM id of the next
* waiter otherwise.
*/
int64_t api_mailbox_waiter_get(ffa_vm_id_t vm_id, const struct vcpu *current)
{
struct vm *vm;
struct vm_locked locked;
struct wait_entry *entry;
struct vm *waiting_vm;
/* Only primary VMs are allowed to call this function. */
if (current->vm->id != HF_PRIMARY_VM_ID) {
return -1;
}
vm = vm_find(vm_id);
if (vm == NULL) {
return -1;
}
/* Check if there are outstanding notifications from given VM. */
locked = vm_lock(vm);
entry = api_fetch_waiter(locked);
vm_unlock(&locked);
if (entry == NULL) {
return -1;
}
/* Enqueue notification to waiting VM. */
waiting_vm = entry->waiting_vm;
sl_lock(&waiting_vm->lock);
if (list_empty(&entry->ready_links)) {
list_append(&waiting_vm->mailbox.ready_list,
&entry->ready_links);
}
sl_unlock(&waiting_vm->lock);
return waiting_vm->id;
}
/**
* Releases the caller's mailbox so that a new message can be received. The
* caller must have copied out all data they wish to preserve as new messages
* will overwrite the old and will arrive asynchronously.
*
* Returns:
* - FFA_ERROR FFA_DENIED on failure, if the mailbox hasn't been read.
* - FFA_SUCCESS on success if no further action is needed.
* - FFA_RX_RELEASE if it was called by the primary VM and the primary VM now
* needs to wake up or kick waiters. Waiters should be retrieved by calling
* hf_mailbox_waiter_get.
*/
struct ffa_value api_ffa_rx_release(struct vcpu *current, struct vcpu **next)
{
struct vm *vm = current->vm;
struct vm_locked locked;
struct ffa_value ret;
locked = vm_lock(vm);
switch (vm->mailbox.state) {
case MAILBOX_STATE_EMPTY:
case MAILBOX_STATE_RECEIVED:
ret = ffa_error(FFA_DENIED);
break;
case MAILBOX_STATE_READ:
ret = api_waiter_result(locked, current, next);
vm->mailbox.state = MAILBOX_STATE_EMPTY;
break;
}
vm_unlock(&locked);
return ret;
}
/**
* Enables or disables a given interrupt ID for the calling vCPU.
*
* Returns 0 on success, or -1 if the intid is invalid.
*/
int64_t api_interrupt_enable(uint32_t intid, bool enable, struct vcpu *current)
{
uint32_t intid_index = intid / INTERRUPT_REGISTER_BITS;
uint32_t intid_mask = 1U << (intid % INTERRUPT_REGISTER_BITS);
if (intid >= HF_NUM_INTIDS) {
return -1;
}
sl_lock(&current->lock);
if (enable) {
/*
* If it is pending and was not enabled before, increment the
* count.
*/
if (current->interrupts.interrupt_pending[intid_index] &
~current->interrupts.interrupt_enabled[intid_index] &
intid_mask) {
current->interrupts.enabled_and_pending_count++;
}
current->interrupts.interrupt_enabled[intid_index] |=
intid_mask;
} else {
/*
* If it is pending and was enabled before, decrement the count.
*/
if (current->interrupts.interrupt_pending[intid_index] &
current->interrupts.interrupt_enabled[intid_index] &
intid_mask) {
current->interrupts.enabled_and_pending_count--;
}
current->interrupts.interrupt_enabled[intid_index] &=
~intid_mask;
}
sl_unlock(&current->lock);
return 0;
}
/**
* Returns the ID of the next pending interrupt for the calling vCPU, and
* acknowledges it (i.e. marks it as no longer pending). Returns
* HF_INVALID_INTID if there are no pending interrupts.
*/
uint32_t api_interrupt_get(struct vcpu *current)
{
uint8_t i;
uint32_t first_interrupt = HF_INVALID_INTID;
/*
* Find the first enabled and pending interrupt ID, return it, and
* deactivate it.
*/
sl_lock(&current->lock);
for (i = 0; i < HF_NUM_INTIDS / INTERRUPT_REGISTER_BITS; ++i) {
uint32_t enabled_and_pending =
current->interrupts.interrupt_enabled[i] &
current->interrupts.interrupt_pending[i];
if (enabled_and_pending != 0) {
uint8_t bit_index = ctz(enabled_and_pending);
/*
* Mark it as no longer pending and decrement the count.
*/
current->interrupts.interrupt_pending[i] &=
~(1U << bit_index);
current->interrupts.enabled_and_pending_count--;
first_interrupt =
i * INTERRUPT_REGISTER_BITS + bit_index;
break;
}
}
sl_unlock(&current->lock);
return first_interrupt;
}
/**
* Returns whether the current vCPU is allowed to inject an interrupt into the
* given VM and vCPU.
*/
static inline bool is_injection_allowed(uint32_t target_vm_id,
struct vcpu *current)
{
uint32_t current_vm_id = current->vm->id;
/*
* The primary VM is allowed to inject interrupts into any VM. Secondary
* VMs are only allowed to inject interrupts into their own vCPUs.
*/
return current_vm_id == HF_PRIMARY_VM_ID ||
current_vm_id == target_vm_id;
}
/**
* Injects a virtual interrupt of the given ID into the given target vCPU.
* This doesn't cause the vCPU to actually be run immediately; it will be taken
* when the vCPU is next run, which is up to the scheduler.
*
* Returns:
* - -1 on failure because the target VM or vCPU doesn't exist, the interrupt
* ID is invalid, or the current VM is not allowed to inject interrupts to
* the target VM.
* - 0 on success if no further action is needed.
* - 1 if it was called by the primary VM and the primary VM now needs to wake
* up or kick the target vCPU.
*/
int64_t api_interrupt_inject(ffa_vm_id_t target_vm_id,
ffa_vcpu_index_t target_vcpu_idx, uint32_t intid,
struct vcpu *current, struct vcpu **next)
{
struct vcpu *target_vcpu;
struct vm *target_vm = vm_find(target_vm_id);
if (intid >= HF_NUM_INTIDS) {
return -1;
}
if (target_vm == NULL) {
return -1;
}
if (target_vcpu_idx >= target_vm->vcpu_count) {
/* The requested vCPU must exist. */
return -1;
}
if (!is_injection_allowed(target_vm_id, current)) {
return -1;
}
target_vcpu = vm_get_vcpu(target_vm, target_vcpu_idx);
dlog_info("Injecting IRQ %d for VM %d vCPU %d from VM %d vCPU %d\n",
intid, target_vm_id, target_vcpu_idx, current->vm->id,
current->cpu->id);
return internal_interrupt_inject(target_vcpu, intid, current, next);
}
/** Returns the version of the implemented FF-A specification. */
struct ffa_value api_ffa_version(uint32_t requested_version)
{
/*
* Ensure that both major and minor revision representation occupies at
* most 15 bits.
*/
static_assert(0x8000 > FFA_VERSION_MAJOR,
"Major revision representation takes more than 15 bits.");
static_assert(0x10000 > FFA_VERSION_MINOR,
"Minor revision representation takes more than 16 bits.");
if (requested_version & FFA_VERSION_RESERVED_BIT) {
/* Invalid encoding, return an error. */
return (struct ffa_value){.func = FFA_NOT_SUPPORTED};
}
return (struct ffa_value){
.func = (FFA_VERSION_MAJOR << FFA_VERSION_MAJOR_OFFSET) |
FFA_VERSION_MINOR};
}
int64_t api_debug_log(char c, struct vcpu *current)
{
bool flush;
struct vm *vm = current->vm;
struct vm_locked vm_locked = vm_lock(vm);
if (c == '\n' || c == '\0') {
flush = true;
} else {
vm->log_buffer[vm->log_buffer_length++] = c;
flush = (vm->log_buffer_length == sizeof(vm->log_buffer));
}
if (flush) {
dlog_flush_vm_buffer(vm->id, vm->log_buffer,
vm->log_buffer_length);
vm->log_buffer_length = 0;
}
vm_unlock(&vm_locked);
return 0;
}
/**
* Discovery function returning information about the implementation of optional
* FF-A interfaces.
*/
struct ffa_value api_ffa_features(uint32_t function_id)
{
switch (function_id) {
case FFA_ERROR_32:
case FFA_SUCCESS_32:
case FFA_INTERRUPT_32:
case FFA_VERSION_32:
case FFA_FEATURES_32:
case FFA_RX_RELEASE_32:
case FFA_RXTX_MAP_64:
case FFA_ID_GET_32:
case FFA_MSG_POLL_32:
case FFA_MSG_WAIT_32:
case FFA_YIELD_32:
case FFA_RUN_32:
case FFA_MSG_SEND_32:
case FFA_MEM_DONATE_32:
case FFA_MEM_LEND_32:
case FFA_MEM_SHARE_32:
case FFA_MEM_RETRIEVE_REQ_32:
case FFA_MEM_RETRIEVE_RESP_32:
case FFA_MEM_RELINQUISH_32:
case FFA_MEM_RECLAIM_32:
return (struct ffa_value){.func = FFA_SUCCESS_32};
default:
return ffa_error(FFA_NOT_SUPPORTED);
}
}
struct ffa_value api_ffa_mem_send(uint32_t share_func, uint32_t length,
uint32_t fragment_length, ipaddr_t address,
uint32_t page_count, struct vcpu *current)
{
struct vm *from = current->vm;
struct vm *to;
const void *from_msg;
struct ffa_memory_region *memory_region;
struct ffa_value ret;
if (ipa_addr(address) != 0 || page_count != 0) {
/*
* Hafnium only supports passing the descriptor in the TX
* mailbox.
*/
return ffa_error(FFA_INVALID_PARAMETERS);
}
if (fragment_length > length) {
dlog_verbose(
"Fragment length %d greater than total length %d.\n",
fragment_length, length);
return ffa_error(FFA_INVALID_PARAMETERS);
}
if (fragment_length < sizeof(struct ffa_memory_region) +
sizeof(struct ffa_memory_access)) {
dlog_verbose(
"Initial fragment length %d smaller than header size "
"%d.\n",
fragment_length,
sizeof(struct ffa_memory_region) +
sizeof(struct ffa_memory_access));
return ffa_error(FFA_INVALID_PARAMETERS);
}
/*
* Check that the sender has configured its send buffer. If the TX
* mailbox at from_msg is configured (i.e. from_msg != NULL) then it can
* be safely accessed after releasing the lock since the TX mailbox
* address can only be configured once.
*/
sl_lock(&from->lock);
from_msg = from->mailbox.send;
sl_unlock(&from->lock);
if (from_msg == NULL) {
return ffa_error(FFA_INVALID_PARAMETERS);
}
/*
* Copy the memory region descriptor to a fresh page from the memory
* pool. This prevents the sender from changing it underneath us, and
* also lets us keep it around in the share state table if needed.
*/
if (fragment_length > HF_MAILBOX_SIZE ||
fragment_length > MM_PPOOL_ENTRY_SIZE) {
return ffa_error(FFA_INVALID_PARAMETERS);
}
memory_region = (struct ffa_memory_region *)mpool_alloc(&api_page_pool);
if (memory_region == NULL) {
dlog_verbose("Failed to allocate memory region copy.\n");
return ffa_error(FFA_NO_MEMORY);
}
memcpy_s(memory_region, MM_PPOOL_ENTRY_SIZE, from_msg, fragment_length);
/* The sender must match the caller. */
if (memory_region->sender != from->id) {
dlog_verbose("Memory region sender doesn't match caller.\n");
ret = ffa_error(FFA_INVALID_PARAMETERS);
goto out;
}
if (memory_region->receiver_count != 1) {
/* Hafnium doesn't support multi-way memory sharing for now. */
dlog_verbose(
"Multi-way memory sharing not supported (got %d "
"endpoint memory access descriptors, expected 1).\n",
memory_region->receiver_count);
ret = ffa_error(FFA_INVALID_PARAMETERS);
goto out;
}
/*
* Ensure that the receiver VM exists and isn't the same as the sender.
*/
to = vm_find(memory_region->receivers[0].receiver_permissions.receiver);
if (to == NULL || to == from) {
dlog_verbose("Invalid receiver.\n");
ret = ffa_error(FFA_INVALID_PARAMETERS);
goto out;
}
if (to->id == HF_TEE_VM_ID) {
/*
* The 'to' VM lock is only needed in the case that it is the
* TEE VM.
*/
struct two_vm_locked vm_to_from_lock = vm_lock_both(to, from);
if (msg_receiver_busy(vm_to_from_lock.vm1, from, false)) {
ret = ffa_error(FFA_BUSY);
goto out_unlock;
}
ret = ffa_memory_tee_send(
vm_to_from_lock.vm2, vm_to_from_lock.vm1, memory_region,
length, fragment_length, share_func, &api_page_pool);
/*
* ffa_tee_memory_send takes ownership of the memory_region, so
* make sure we don't free it.
*/
memory_region = NULL;
out_unlock:
vm_unlock(&vm_to_from_lock.vm1);
vm_unlock(&vm_to_from_lock.vm2);
} else {
struct vm_locked from_locked = vm_lock(from);
ret = ffa_memory_send(from_locked, memory_region, length,
fragment_length, share_func,
&api_page_pool);
/*
* ffa_memory_send takes ownership of the memory_region, so
* make sure we don't free it.
*/
memory_region = NULL;
vm_unlock(&from_locked);
}
out:
if (memory_region != NULL) {
mpool_free(&api_page_pool, memory_region);
}
return ret;
}
struct ffa_value api_ffa_mem_retrieve_req(uint32_t length,
uint32_t fragment_length,
ipaddr_t address, uint32_t page_count,
struct vcpu *current)
{
struct vm *to = current->vm;
struct vm_locked to_locked;
const void *to_msg;
struct ffa_memory_region *retrieve_request;
uint32_t message_buffer_size;
struct ffa_value ret;
if (ipa_addr(address) != 0 || page_count != 0) {
/*
* Hafnium only supports passing the descriptor in the TX
* mailbox.
*/
return ffa_error(FFA_INVALID_PARAMETERS);
}
if (fragment_length != length) {
dlog_verbose("Fragmentation not yet supported.\n");
return ffa_error(FFA_INVALID_PARAMETERS);
}
retrieve_request =
(struct ffa_memory_region *)cpu_get_buffer(current->cpu);
message_buffer_size = cpu_get_buffer_size(current->cpu);
if (length > HF_MAILBOX_SIZE || length > message_buffer_size) {
dlog_verbose("Retrieve request too long.\n");
return ffa_error(FFA_INVALID_PARAMETERS);
}
to_locked = vm_lock(to);
to_msg = to->mailbox.send;
if (to_msg == NULL) {
dlog_verbose("TX buffer not setup.\n");
ret = ffa_error(FFA_INVALID_PARAMETERS);
goto out;
}
/*
* Copy the retrieve request descriptor to an internal buffer, so that
* the caller can't change it underneath us.
*/
memcpy_s(retrieve_request, message_buffer_size, to_msg, length);
if (msg_receiver_busy(to_locked, NULL, false)) {
/*
* Can't retrieve memory information if the mailbox is not
* available.
*/
dlog_verbose("RX buffer not ready.\n");
ret = ffa_error(FFA_BUSY);
goto out;
}
ret = ffa_memory_retrieve(to_locked, retrieve_request, length,
&api_page_pool);
out:
vm_unlock(&to_locked);
return ret;
}
struct ffa_value api_ffa_mem_relinquish(struct vcpu *current)
{
struct vm *from = current->vm;
struct vm_locked from_locked;
const void *from_msg;
struct ffa_mem_relinquish *relinquish_request;
uint32_t message_buffer_size;
struct ffa_value ret;
uint32_t length;
from_locked = vm_lock(from);
from_msg = from->mailbox.send;
if (from_msg == NULL) {
dlog_verbose("TX buffer not setup.\n");
ret = ffa_error(FFA_INVALID_PARAMETERS);
goto out;
}
/*
* Calculate length from relinquish descriptor before copying. We will
* check again later to make sure it hasn't changed.
*/
length = sizeof(struct ffa_mem_relinquish) +
((struct ffa_mem_relinquish *)from_msg)->endpoint_count *
sizeof(ffa_vm_id_t);
/*
* Copy the relinquish descriptor to an internal buffer, so that the
* caller can't change it underneath us.
*/
relinquish_request =
(struct ffa_mem_relinquish *)cpu_get_buffer(current->cpu);
message_buffer_size = cpu_get_buffer_size(current->cpu);
if (length > HF_MAILBOX_SIZE || length > message_buffer_size) {
dlog_verbose("Relinquish message too long.\n");
ret = ffa_error(FFA_INVALID_PARAMETERS);
goto out;
}
memcpy_s(relinquish_request, message_buffer_size, from_msg, length);
if (sizeof(struct ffa_mem_relinquish) +
relinquish_request->endpoint_count * sizeof(ffa_vm_id_t) !=
length) {
dlog_verbose(
"Endpoint count changed while copying to internal "
"buffer.\n");
ret = ffa_error(FFA_INVALID_PARAMETERS);
goto out;
}
ret = ffa_memory_relinquish(from_locked, relinquish_request,
&api_page_pool);
out:
vm_unlock(&from_locked);
return ret;
}
struct ffa_value api_ffa_mem_reclaim(ffa_memory_handle_t handle,
ffa_memory_region_flags_t flags,
struct vcpu *current)
{
struct vm *to = current->vm;
struct ffa_value ret;
if ((handle & FFA_MEMORY_HANDLE_ALLOCATOR_MASK) ==
FFA_MEMORY_HANDLE_ALLOCATOR_HYPERVISOR) {
struct vm_locked to_locked = vm_lock(to);
ret = ffa_memory_reclaim(to_locked, handle, flags,
&api_page_pool);
vm_unlock(&to_locked);
} else {
struct vm *from = vm_find(HF_TEE_VM_ID);
struct two_vm_locked vm_to_from_lock = vm_lock_both(to, from);
ret = ffa_memory_tee_reclaim(vm_to_from_lock.vm1,
vm_to_from_lock.vm2, handle, flags,
&api_page_pool);
vm_unlock(&vm_to_from_lock.vm1);
vm_unlock(&vm_to_from_lock.vm2);
}
return ret;
}
struct ffa_value api_ffa_mem_frag_rx(ffa_memory_handle_t handle,
uint32_t fragment_offset,
ffa_vm_id_t sender_vm_id,
struct vcpu *current)
{
struct vm *to = current->vm;
struct vm_locked to_locked;
struct ffa_value ret;
/* Sender ID MBZ at virtual instance. */
if (sender_vm_id != 0) {
return ffa_error(FFA_INVALID_PARAMETERS);
}
to_locked = vm_lock(to);
if (msg_receiver_busy(to_locked, NULL, false)) {
/*
* Can't retrieve memory information if the mailbox is not
* available.
*/
dlog_verbose("RX buffer not ready.\n");
ret = ffa_error(FFA_BUSY);
goto out;
}
ret = ffa_memory_retrieve_continue(to_locked, handle, fragment_offset,
&api_page_pool);
out:
vm_unlock(&to_locked);
return ret;
}
struct ffa_value api_ffa_mem_frag_tx(ffa_memory_handle_t handle,
uint32_t fragment_length,
ffa_vm_id_t sender_vm_id,
struct vcpu *current)
{
struct vm *from = current->vm;
const void *from_msg;
void *fragment_copy;
struct ffa_value ret;
/* Sender ID MBZ at virtual instance. */
if (sender_vm_id != 0) {
return ffa_error(FFA_INVALID_PARAMETERS);
}
/*
* Check that the sender has configured its send buffer. If the TX
* mailbox at from_msg is configured (i.e. from_msg != NULL) then it can
* be safely accessed after releasing the lock since the TX mailbox
* address can only be configured once.
*/
sl_lock(&from->lock);
from_msg = from->mailbox.send;
sl_unlock(&from->lock);
if (from_msg == NULL) {
return ffa_error(FFA_INVALID_PARAMETERS);
}
/*
* Copy the fragment to a fresh page from the memory pool. This prevents
* the sender from changing it underneath us, and also lets us keep it
* around in the share state table if needed.
*/
if (fragment_length > HF_MAILBOX_SIZE ||
fragment_length > MM_PPOOL_ENTRY_SIZE) {
dlog_verbose(
"Fragment length %d larger than mailbox size %d.\n",
fragment_length, HF_MAILBOX_SIZE);
return ffa_error(FFA_INVALID_PARAMETERS);
}
if (fragment_length < sizeof(struct ffa_memory_region_constituent) ||
fragment_length % sizeof(struct ffa_memory_region_constituent) !=
0) {
dlog_verbose("Invalid fragment length %d.\n", fragment_length);
return ffa_error(FFA_INVALID_PARAMETERS);
}
fragment_copy = mpool_alloc(&api_page_pool);
if (fragment_copy == NULL) {
dlog_verbose("Failed to allocate fragment copy.\n");
return ffa_error(FFA_NO_MEMORY);
}
memcpy_s(fragment_copy, MM_PPOOL_ENTRY_SIZE, from_msg, fragment_length);
/*
* Hafnium doesn't support fragmentation of memory retrieve requests
* (because it doesn't support caller-specified mappings, so a request
* will never be larger than a single page), so this must be part of a
* memory send (i.e. donate, lend or share) request.
*
* We can tell from the handle whether the memory transaction is for the
* TEE or not.
*/
if ((handle & FFA_MEMORY_HANDLE_ALLOCATOR_MASK) ==
FFA_MEMORY_HANDLE_ALLOCATOR_HYPERVISOR) {
struct vm_locked from_locked = vm_lock(from);
ret = ffa_memory_send_continue(from_locked, fragment_copy,
fragment_length, handle,
&api_page_pool);
/*
* `ffa_memory_send_continue` takes ownership of the
* fragment_copy, so we don't need to free it here.
*/
vm_unlock(&from_locked);
} else {
struct vm *to = vm_find(HF_TEE_VM_ID);
struct two_vm_locked vm_to_from_lock = vm_lock_both(to, from);
/*
* The TEE RX buffer state is checked in
* `ffa_memory_tee_send_continue` rather than here, as we need
* to return `FFA_MEM_FRAG_RX` with the current offset rather
* than FFA_ERROR FFA_BUSY in case it is busy.
*/
ret = ffa_memory_tee_send_continue(
vm_to_from_lock.vm2, vm_to_from_lock.vm1, fragment_copy,
fragment_length, handle, &api_page_pool);
/*
* `ffa_memory_tee_send_continue` takes ownership of the
* fragment_copy, so we don't need to free it here.
*/
vm_unlock(&vm_to_from_lock.vm1);
vm_unlock(&vm_to_from_lock.vm2);
}
return ret;
}