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e1000e: Prevent MSI/MSI-X storms

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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 <jan.kiszka@siemens.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
This commit is contained in:
Jan Kiszka 2018-04-05 19:41:47 +02:00 committed by Jason Wang
parent 9f2b67e1ca
commit 4712c158c5
2 changed files with 13 additions and 0 deletions
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11
hw/net/e1000e_core.c
View File

@ -2023,6 +2023,7 @@ e1000e_msix_notify_one(E1000ECore *core, uint32_t cause, uint32_t int_cfg)
effective_eiac = core->mac[EIAC] & cause;
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;
@ -2119,6 +2120,13 @@ 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 {
@ -2156,6 +2164,9 @@ 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]);

2
hw/net/e1000e_core.h
View File

@ -109,6 +109,8 @@ struct E1000Core {
NICState *owner_nic;
PCIDevice *owner;
void (*owner_start_recv)(PCIDevice *d);
uint32_t msi_causes_pending;
};
void