From: Jan Kiszka <address@hidden>
Only signal MSI/MSI-X events on rising edges. So far we re-triggered the
interrupt sources even if the guest did no consumed the pending one,
easily causing interrupt storms.
Issue was observable with Linux 4.16 e1000e driver when MSI-X was used.
Vector 2 was causing interrupt storms after the driver activated the
device.
Signed-off-by: Jan Kiszka <address@hidden>
---
Changes in v2:
- also update msi_causes_pending after EIAC changes (required because
there is no e1000e_update_interrupt_state after that
hw/net/e1000e_core.c | 11 +++++++++++
hw/net/e1000e_core.h | 2 ++
2 files changed, 13 insertions(+)
diff --git a/hw/net/e1000e_core.c b/hw/net/e1000e_core.c
index c93c4661ed..d6ddd59986 100644
--- a/hw/net/e1000e_core.c
+++ b/hw/net/e1000e_core.c
@@ -2027,6 +2027,7 @@ e1000e_msix_notify_one(E1000ECore *core, uint32_t cause,
uint32_t int_cfg)
}
core->mac[ICR] &= ~effective_eiac;
+ core->msi_causes_pending &= ~effective_eiac;
if (!(core->mac[CTRL_EXT] & E1000_CTRL_EXT_IAME)) {
core->mac[IMS] &= ~effective_eiac;
@@ -2123,6 +2124,13 @@ e1000e_send_msi(E1000ECore *core, bool msix)
{
uint32_t causes = core->mac[ICR] & core->mac[IMS] & ~E1000_ICR_ASSERTED;
+ core->msi_causes_pending &= causes;
+ causes ^= core->msi_causes_pending;
+ if (causes == 0) {
+ return;
+ }
+ core->msi_causes_pending |= causes;
+
if (msix) {
e1000e_msix_notify(core, causes);
} else {
@@ -2160,6 +2168,9 @@ e1000e_update_interrupt_state(E1000ECore *core)
core->mac[ICS] = core->mac[ICR];
interrupts_pending = (core->mac[IMS] & core->mac[ICR]) ? true : false;
+ if (!interrupts_pending) {
+ core->msi_causes_pending = 0;
+ }
trace_e1000e_irq_pending_interrupts(core->mac[ICR] & core->mac[IMS],
core->mac[ICR], core->mac[IMS]);
diff --git a/hw/net/e1000e_core.h b/hw/net/e1000e_core.h
index 7d8ff41890..63a15510cc 100644
--- a/hw/net/e1000e_core.h
+++ b/hw/net/e1000e_core.h
@@ -109,6 +109,8 @@ struct E1000Core {
NICState *owner_nic;
PCIDevice *owner;
void (*owner_start_recv)(PCIDevice *d);
+
+ uint32_t msi_causes_pending;
};
void