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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH v2 6/6] xen/arm: ffa: Deliver VM-to-VM notifications locally
VM notification binding and pending tracking exist for non-secure
endpoints, but FFA_NOTIFICATION_SET still only forwards secure
destinations to the SPMC. Non-secure VMs therefore cannot receive
notifications from other VMs. Local NPI delivery also needs explicit
re-arm tracking so repeated raises are not lost while the interrupt is
already pending.
Add a local VM notification delivery path for non-secure destinations.
notification_set_vm() resolves the destination endpoint, verifies that
every requested bit is bound to the sender, sets the receiver's
vm_pending bitmap under notif_lock, and raises an NPI only when local
pending state is not already armed.
Track whether a local NPI is already armed with notif_irq_raised,
clear that state once both VM and hypervisor pending bitmaps are
drained, and keep notif_lock held across the VM notification injection
attempt. If no destination vCPU is online, leave the pending bits set
and keep notif_irq_raised clear so delivery can be retried later.
Also expose firmware notification availability so FFA_FEATURES only
advertises notification support when it is actually provided by the
firmware or by CONFIG_FFA_VM_TO_VM.
Functional impact: when CONFIG_FFA_VM_TO_VM is enabled, non-secure
FFA_NOTIFICATION_SET delivers VM-to-VM notifications locally and keeps
NPI delivery reliable across repeated raises.
Signed-off-by: Bertrand Marquis <bertrand.marquis@xxxxxxx>
---
Changes since v1:
- serialize notification_set_vm() state updates with the NPI attempt
- keep pending VM notifications set when local injection fails
---
xen/arch/arm/tee/ffa.c | 24 ++++++++--
xen/arch/arm/tee/ffa_notif.c | 82 ++++++++++++++++++++++++++++++++--
xen/arch/arm/tee/ffa_private.h | 17 ++++---
3 files changed, 107 insertions(+), 16 deletions(-)
diff --git a/xen/arch/arm/tee/ffa.c b/xen/arch/arm/tee/ffa.c
index 1fe33f26454a..7fe021049cba 100644
--- a/xen/arch/arm/tee/ffa.c
+++ b/xen/arch/arm/tee/ffa.c
@@ -39,8 +39,13 @@
* o FFA_MSG_SEND_DIRECT_REQ:
* - only supported from a VM to an SP
* o FFA_NOTIFICATION_*:
+ * - only supported when firmware notifications are enabled or VM-to-VM
+ * support is built in
* - only supports global notifications, that is, per vCPU notifications
- * are not supported
+ * are not supported and secure per-vCPU notification information is
+ * not forwarded
+ * - the source endpoint ID reported for a notification may no longer
+ * exist by the time the receiver consumes it
* - doesn't support signalling the secondary scheduler of pending
* notification for secure partitions
* - doesn't support notifications for Xen itself
@@ -245,6 +250,8 @@ static void handle_features(struct cpu_user_regs *regs)
uint32_t a1 = get_user_reg(regs, 1);
struct domain *d = current->domain;
struct ffa_ctx *ctx = d->arch.tee;
+ bool notif_supported = IS_ENABLED(CONFIG_FFA_VM_TO_VM) ||
+ ffa_notif_fw_enabled();
/*
* FFA_FEATURES defines w2 as input properties only for specific
@@ -343,10 +350,16 @@ static void handle_features(struct cpu_user_regs *regs)
break;
case FFA_FEATURE_NOTIF_PEND_INTR:
- ffa_set_regs_success(regs, GUEST_FFA_NOTIF_PEND_INTR_ID, 0);
+ if ( notif_supported )
+ ffa_set_regs_success(regs, GUEST_FFA_NOTIF_PEND_INTR_ID, 0);
+ else
+ ffa_set_regs_error(regs, FFA_RET_NOT_SUPPORTED);
break;
case FFA_FEATURE_SCHEDULE_RECV_INTR:
- ffa_set_regs_success(regs, GUEST_FFA_SCHEDULE_RECV_INTR_ID, 0);
+ if ( notif_supported )
+ ffa_set_regs_success(regs, GUEST_FFA_SCHEDULE_RECV_INTR_ID, 0);
+ else
+ ffa_set_regs_error(regs, FFA_RET_NOT_SUPPORTED);
break;
case FFA_PARTITION_INFO_GET_REGS:
if ( ACCESS_ONCE(ctx->guest_vers) >= FFA_VERSION_1_2 )
@@ -361,7 +374,10 @@ static void handle_features(struct cpu_user_regs *regs)
case FFA_NOTIFICATION_SET:
case FFA_NOTIFICATION_INFO_GET_32:
case FFA_NOTIFICATION_INFO_GET_64:
- ffa_set_regs_success(regs, 0, 0);
+ if ( notif_supported )
+ ffa_set_regs_success(regs, 0, 0);
+ else
+ ffa_set_regs_error(regs, FFA_RET_NOT_SUPPORTED);
break;
default:
ffa_set_regs_error(regs, FFA_RET_NOT_SUPPORTED);
diff --git a/xen/arch/arm/tee/ffa_notif.c b/xen/arch/arm/tee/ffa_notif.c
index a841c8f8d747..b29d948a7110 100644
--- a/xen/arch/arm/tee/ffa_notif.c
+++ b/xen/arch/arm/tee/ffa_notif.c
@@ -21,6 +21,11 @@ static bool __ro_after_init fw_notif_enabled;
static unsigned int __ro_after_init notif_sri_irq;
static DEFINE_SPINLOCK(notif_info_lock);
+bool ffa_notif_fw_enabled(void)
+{
+ return fw_notif_enabled;
+}
+
static bool inject_notif_pending(struct domain *d)
{
struct vcpu *v;
@@ -107,6 +112,55 @@ out_unlock:
return ret;
}
+/*
+ * Deliver a VM-to-VM notification. ctx->notif.notif_lock protects
+ * vm_bind/vm_pending so callers must not hold it already.
+ */
+static int32_t notification_set_vm(uint16_t dst_id, uint16_t src_id,
+ uint32_t flags, uint64_t bitmap)
+{
+ struct domain *dst_d;
+ struct ffa_ctx *dst_ctx;
+ unsigned int id;
+ int32_t ret;
+
+ if ( flags )
+ return FFA_RET_INVALID_PARAMETERS;
+
+ ret = ffa_endpoint_domain_lookup(dst_id, &dst_d, &dst_ctx);
+ if ( ret )
+ return ret;
+
+ ret = FFA_RET_OK;
+
+ spin_lock(&dst_ctx->notif.notif_lock);
+
+ for ( id = 0; id < FFA_NUM_VM_NOTIF; id++ )
+ {
+ if ( !(bitmap & BIT(id, ULL)) )
+ continue;
+
+ if ( dst_ctx->notif.vm_bind[id] != src_id )
+ {
+ ret = FFA_RET_DENIED;
+ goto out_unlock;
+ }
+ }
+
+ dst_ctx->notif.vm_pending |= bitmap;
+ if ( !dst_ctx->notif.notif_irq_raised &&
+ (dst_ctx->notif.vm_pending || dst_ctx->notif.hyp_pending) &&
+ inject_notif_pending(dst_d) )
+ dst_ctx->notif.notif_irq_raised = true;
+
+out_unlock:
+ spin_unlock(&dst_ctx->notif.notif_lock);
+
+ rcu_unlock_domain(dst_d);
+
+ return ret;
+}
+
int32_t ffa_handle_notification_bind(struct cpu_user_regs *regs)
{
struct domain *d = current->domain;
@@ -288,6 +342,8 @@ void ffa_handle_notification_get(struct cpu_user_regs *regs)
if ( IS_ENABLED(CONFIG_FFA_VM_TO_VM) )
{
+ bool pending;
+
spin_lock(&ctx->notif.notif_lock);
if ( (flags & FFA_NOTIF_FLAG_BITMAP_HYP) && ctx->notif.hyp_pending )
@@ -298,6 +354,18 @@ void ffa_handle_notification_get(struct cpu_user_regs
*regs)
ctx->notif.notif_irq_raised = false;
}
+ if ( (flags & FFA_NOTIF_FLAG_BITMAP_VM) && ctx->notif.vm_pending )
+ {
+ w4 = (uint32_t)(ctx->notif.vm_pending & GENMASK(31, 0));
+ w5 = (uint32_t)((ctx->notif.vm_pending >> 32) & GENMASK(31, 0));
+ ctx->notif.vm_pending = 0;
+ }
+
+ pending = (ctx->notif.hyp_pending != 0) ||
+ (ctx->notif.vm_pending != 0);
+ if ( !pending )
+ ctx->notif.notif_irq_raised = false;
+
spin_unlock(&ctx->notif.notif_lock);
}
@@ -323,9 +391,17 @@ int32_t ffa_handle_notification_set(struct cpu_user_regs
*regs)
if ( flags )
return FFA_RET_INVALID_PARAMETERS;
- if ( FFA_ID_IS_SECURE(dest_id) && fw_notif_enabled )
- return ffa_simple_call(FFA_NOTIFICATION_SET, src_dst, flags, bitmap_lo,
- bitmap_hi);
+ if ( FFA_ID_IS_SECURE(dest_id) )
+ {
+ if ( fw_notif_enabled )
+ return ffa_simple_call(FFA_NOTIFICATION_SET, src_dst, flags,
+ bitmap_lo, bitmap_hi);
+ }
+ else if ( IS_ENABLED(CONFIG_FFA_VM_TO_VM) )
+ {
+ return notification_set_vm(dest_id, caller_id, flags,
+ ((uint64_t)bitmap_hi << 32) | bitmap_lo);
+ }
return FFA_RET_NOT_SUPPORTED;
}
diff --git a/xen/arch/arm/tee/ffa_private.h b/xen/arch/arm/tee/ffa_private.h
index 78a0a9815d56..923a071a9d7c 100644
--- a/xen/arch/arm/tee/ffa_private.h
+++ b/xen/arch/arm/tee/ffa_private.h
@@ -340,20 +340,18 @@ struct ffa_ctx_notif {
uint64_t vm_pending;
/*
- * Source endpoint bound to each VM notification ID (0 means unbound).
+ * Tracks whether an NPI has been raised for local pending notifications.
+ * Protected by notif_lock.
*/
- uint16_t vm_bind[FFA_NUM_VM_NOTIF];
+ bool notif_irq_raised;
/*
- * Lock protecting the hypervisor-managed notification state.
+ * Source endpoint bound to each VM notification ID (0 means unbound).
*/
- spinlock_t notif_lock;
+ uint16_t vm_bind[FFA_NUM_VM_NOTIF];
- /*
- * Tracks whether a local notification pending interrupt was raised.
- * Protected by notif_lock.
- */
- bool notif_irq_raised;
+ /* Lock protecting local notification state. */
+ spinlock_t notif_lock;
/*
* Bitmap of pending hypervisor notifications (for HYP bitmap queries).
@@ -495,6 +493,7 @@ void ffa_notif_init(void);
void ffa_notif_init_interrupt(void);
int ffa_notif_domain_init(struct domain *d);
void ffa_notif_domain_destroy(struct domain *d);
+bool ffa_notif_fw_enabled(void);
int32_t ffa_handle_notification_bind(struct cpu_user_regs *regs);
int32_t ffa_handle_notification_unbind(struct cpu_user_regs *regs);
--
2.53.0
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