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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [XEN PATCH v11 03/14] xen/arm: ffa: send guest events to Secure Partitions
The FF-A specification defines framework messages sent as direct
requests when certain events occurs. For instance when a VM (guest) is
created or destroyed. Only SPs which have subscribed to these events
will receive them. An SP can subscribe to these messages in its
partition properties.
Adds a check that the SP supports the needed FF-A features
FFA_PARTITION_INFO_GET and FFA_RX_RELEASE.
The partition properties of each SP is retrieved with
FFA_PARTITION_INFO_GET which returns the information in our RX buffer.
Using FFA_PARTITION_INFO_GET changes the owner of the RX buffer to the
caller (us), so once we're done with the buffer it must be released
using FFA_RX_RELEASE before another call can be made.
Signed-off-by: Jens Wiklander <jens.wiklander@xxxxxxxxxx>
---
v10->v11:
- Addressing comments and fixing a few style issues
- Fixing how is_in_subscr_list() is used, it's supposed to take an
sp_id, not a vm_id.
---
xen/arch/arm/tee/ffa.c | 234 ++++++++++++++++++++++++++++++++++++++++-
1 file changed, 233 insertions(+), 1 deletion(-)
diff --git a/xen/arch/arm/tee/ffa.c b/xen/arch/arm/tee/ffa.c
index 072198a1326d..5af3e5eedc88 100644
--- a/xen/arch/arm/tee/ffa.c
+++ b/xen/arch/arm/tee/ffa.c
@@ -160,14 +160,33 @@
#define FFA_MSG_SEND 0x8400006EU
#define FFA_MSG_POLL 0x8400006AU
+/* Partition information descriptor */
+struct ffa_partition_info_1_1 {
+ uint16_t id;
+ uint16_t execution_context;
+ uint32_t partition_properties;
+ uint8_t uuid[16];
+};
+
struct ffa_ctx {
/* FF-A version used by the guest */
uint32_t guest_vers;
+ /*
+ * Number of SPs that we have sent a VM created signal to, used in
+ * ffa_domain_teardown() to know which SPs need to be signalled.
+ */
+ uint16_t create_signal_count;
};
/* Negotiated FF-A version to use with the SPMC */
static uint32_t __ro_after_init ffa_version;
+/* SPs subscribing to VM_CREATE and VM_DESTROYED events */
+static uint16_t *subscr_vm_created __read_mostly;
+static uint16_t subscr_vm_created_count __read_mostly;
+static uint16_t *subscr_vm_destroyed __read_mostly;
+static uint16_t subscr_vm_destroyed_count __read_mostly;
+
/*
* Our rx/tx buffers shared with the SPMC. FFA_RXTX_PAGE_COUNT is the
* number of pages used in each of these buffers.
@@ -251,6 +270,87 @@ static int32_t ffa_rxtx_map(paddr_t tx_addr, paddr_t
rx_addr,
return ffa_simple_call(FFA_RXTX_MAP_64, tx_addr, rx_addr, page_count, 0);
}
+static int32_t ffa_partition_info_get(uint32_t w1, uint32_t w2, uint32_t w3,
+ uint32_t w4, uint32_t w5,
+ uint32_t *count)
+{
+ const struct arm_smccc_1_2_regs arg = {
+ .a0 = FFA_PARTITION_INFO_GET,
+ .a1 = w1,
+ .a2 = w2,
+ .a3 = w3,
+ .a4 = w4,
+ .a5 = w5,
+ };
+ struct arm_smccc_1_2_regs resp;
+ uint32_t ret;
+
+ arm_smccc_1_2_smc(&arg, &resp);
+
+ ret = get_ffa_ret_code(&resp);
+ if ( !ret )
+ *count = resp.a2;
+
+ return ret;
+}
+
+static int32_t ffa_rx_release(void)
+{
+ return ffa_simple_call(FFA_RX_RELEASE, 0, 0, 0, 0);
+}
+
+static int32_t ffa_direct_req_send_vm(uint16_t sp_id, uint16_t vm_id,
+ uint8_t msg)
+{
+ uint32_t exp_resp = FFA_MSG_FLAG_FRAMEWORK;
+ unsigned int retry_count = 0;
+ int32_t res;
+
+ if ( msg == FFA_MSG_SEND_VM_CREATED )
+ exp_resp |= FFA_MSG_RESP_VM_CREATED;
+ else if ( msg == FFA_MSG_SEND_VM_DESTROYED )
+ exp_resp |= FFA_MSG_RESP_VM_DESTROYED;
+ else
+ return FFA_RET_INVALID_PARAMETERS;
+
+ do {
+ const struct arm_smccc_1_2_regs arg = {
+ .a0 = FFA_MSG_SEND_DIRECT_REQ_32,
+ .a1 = sp_id,
+ .a2 = FFA_MSG_FLAG_FRAMEWORK | msg,
+ .a5 = vm_id,
+ };
+ struct arm_smccc_1_2_regs resp;
+
+ arm_smccc_1_2_smc(&arg, &resp);
+ if ( resp.a0 != FFA_MSG_SEND_DIRECT_RESP_32 || resp.a2 != exp_resp )
+ {
+ /*
+ * This is an invalid response, likely due to some error in the
+ * implementation of the ABI.
+ */
+ return FFA_RET_INVALID_PARAMETERS;
+ }
+ res = resp.a3;
+ if ( ++retry_count > 10 )
+ {
+ /*
+ * TODO
+ * FFA_RET_INTERRUPTED means that the SPMC has a pending
+ * non-secure interrupt, we need a way of delivering that
+ * non-secure interrupt.
+ * FFA_RET_RETRY is the SP telling us that it's temporarily
+ * blocked from handling the direct request, we need a generic
+ * way to deal with this.
+ * For now in both cases, give up after a few retries.
+ */
+ return res;
+ }
+ } while ( res == FFA_RET_INTERRUPTED || res == FFA_RET_RETRY );
+
+ return res;
+}
+
static uint16_t get_vm_id(const struct domain *d)
{
/* +1 since 0 is reserved for the hypervisor in FF-A */
@@ -374,6 +474,8 @@ static bool ffa_handle_call(struct cpu_user_regs *regs)
static int ffa_domain_init(struct domain *d)
{
struct ffa_ctx *ctx;
+ unsigned int n;
+ int32_t res;
if ( !ffa_version )
return -ENODEV;
@@ -390,17 +492,68 @@ static int ffa_domain_init(struct domain *d)
d->arch.tee = ctx;
+ for ( n = 0; n < subscr_vm_created_count; n++ )
+ {
+ res = ffa_direct_req_send_vm(subscr_vm_created[n], get_vm_id(d),
+ FFA_MSG_SEND_VM_CREATED);
+ if ( res )
+ {
+ printk(XENLOG_ERR "ffa: Failed to report creation of vm_id %u to
%u: res %d\n",
+ get_vm_id(d), subscr_vm_created[n], res);
+ ctx->create_signal_count = n;
+ return -EIO;
+ }
+ }
+ ctx->create_signal_count = subscr_vm_created_count;
+
return 0;
}
+static bool is_in_subscr_list(const uint16_t *subscr, uint16_t start,
+ uint16_t end, uint16_t sp_id)
+{
+ unsigned int n;
+
+ for ( n = start; n < end; n++ )
+ {
+ if ( subscr[n] == sp_id )
+ return true;
+ }
+
+ return false;
+}
+
/* This function is supposed to undo what ffa_domain_init() has done */
static int ffa_domain_teardown(struct domain *d)
{
struct ffa_ctx *ctx = d->arch.tee;
+ unsigned int n;
+ int32_t res;
if ( !ctx )
return 0;
+
+ for ( n = 0; n < subscr_vm_destroyed_count; n++ )
+ {
+ /*
+ * Skip SPs subscribed to the VM created event that never was
+ * notified of the VM creation due to an error during
+ * ffa_domain_init().
+ */
+ if ( is_in_subscr_list(subscr_vm_created, ctx->create_signal_count,
+ subscr_vm_created_count,
+ subscr_vm_destroyed[n]) )
+ continue;
+
+ res = ffa_direct_req_send_vm(subscr_vm_destroyed[n], get_vm_id(d),
+ FFA_MSG_SEND_VM_DESTROYED);
+
+ if ( res )
+ printk(XENLOG_ERR "ffa: Failed to report destruction of vm_id %u
to %u: res %d\n",
+ get_vm_id(d), subscr_vm_destroyed[n], res);
+ }
+
XFREE(d->arch.tee);
return 0;
@@ -411,6 +564,81 @@ static int ffa_relinquish_resources(struct domain *d)
return 0;
}
+static void uninit_subscribers(void)
+{
+ subscr_vm_created_count = 0;
+ subscr_vm_destroyed_count = 0;
+ XFREE(subscr_vm_created);
+ XFREE(subscr_vm_destroyed);
+}
+
+static bool init_subscribers(struct ffa_partition_info_1_1 *fpi, uint16_t
count)
+{
+ uint16_t n;
+ uint16_t c_pos;
+ uint16_t d_pos;
+
+ subscr_vm_created_count = 0;
+ subscr_vm_destroyed_count = 0;
+ for ( n = 0; n < count; n++ )
+ {
+ if ( fpi[n].partition_properties & FFA_PART_PROP_NOTIF_CREATED )
+ subscr_vm_created_count++;
+ if ( fpi[n].partition_properties & FFA_PART_PROP_NOTIF_DESTROYED )
+ subscr_vm_destroyed_count++;
+ }
+
+ if ( subscr_vm_created_count )
+ subscr_vm_created = xzalloc_array(uint16_t, subscr_vm_created_count);
+ if ( subscr_vm_destroyed_count )
+ subscr_vm_destroyed = xzalloc_array(uint16_t,
+ subscr_vm_destroyed_count);
+ if ( (subscr_vm_created_count && !subscr_vm_created) ||
+ (subscr_vm_destroyed_count && !subscr_vm_destroyed) )
+ {
+ printk(XENLOG_ERR "ffa: Failed to allocate subscription lists\n");
+ uninit_subscribers();
+ return false;
+ }
+
+ for ( c_pos = 0, d_pos = 0, n = 0; n < count; n++ )
+ {
+ if ( fpi[n].partition_properties & FFA_PART_PROP_NOTIF_CREATED )
+ subscr_vm_created[c_pos++] = fpi[n].id;
+ if ( fpi[n].partition_properties & FFA_PART_PROP_NOTIF_DESTROYED )
+ subscr_vm_destroyed[d_pos++] = fpi[n].id;
+ }
+
+ return true;
+}
+
+static bool init_sps(void)
+{
+ bool ret = false;
+ uint32_t count;
+ int e;
+
+ e = ffa_partition_info_get(0, 0, 0, 0, 0, &count);
+ if ( e )
+ {
+ printk(XENLOG_ERR "ffa: Failed to get list of SPs: %d\n", e);
+ goto out;
+ }
+
+ if ( count >= UINT16_MAX )
+ {
+ printk(XENLOG_ERR "ffa: Impossible number of SPs: %u\n", count);
+ goto out;
+ }
+
+ ret = init_subscribers(ffa_rx, count);
+
+out:
+ ffa_rx_release();
+
+ return ret;
+}
+
static bool ffa_probe(void)
{
uint32_t vers;
@@ -462,7 +690,8 @@ static bool ffa_probe(void)
* TODO: Rework the code to allow domain to use a subset of the
* features supported.
*/
- if (
+ if ( !check_mandatory_feature(FFA_PARTITION_INFO_GET) ||
+ !check_mandatory_feature(FFA_RX_RELEASE) ||
!check_mandatory_feature(FFA_RXTX_MAP_64) ||
!check_mandatory_feature(FFA_RXTX_UNMAP) ||
!check_mandatory_feature(FFA_MSG_SEND_DIRECT_REQ_32) )
@@ -484,6 +713,9 @@ static bool ffa_probe(void)
}
ffa_version = vers;
+ if ( !init_sps() )
+ goto err_free_ffa_tx;
+
return true;
err_free_ffa_tx:
--
2.34.1
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