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[Qemu-devel] [PATCH v3 20/40] ivshmem: Leave INTx alone when using MSI-X
From: |
Markus Armbruster |
Subject: |
[Qemu-devel] [PATCH v3 20/40] ivshmem: Leave INTx alone when using MSI-X |
Date: |
Tue, 15 Mar 2016 19:34:35 +0100 |
The ivshmem device can either use MSI-X or legacy INTx for interrupts.
With MSI-X enabled, peer interrupt events trigger an MSI as they
should. But software can still raise INTx via interrupt status and
mask register in BAR 0. This is explicitly prohibited by PCI Local
Bus Specification Revision 3.0, section 6.8.3.3:
While enabled for MSI or MSI-X operation, a function is prohibited
from using its INTx# pin (if implemented) to request service (MSI,
MSI-X, and INTx# are mutually exclusive).
Fix the device model to leave INTx alone when using MSI-X.
Document that we claim to use INTx in config space even when we don't.
Unlike other devices, ivshmem does *not* use INTx when configured for
MSI-X and MSI-X isn't enabled by software.
Signed-off-by: Markus Armbruster <address@hidden>
Reviewed-by: Marc-André Lureau <address@hidden>
Reviewed-by: Paolo Bonzini <address@hidden>
---
hw/misc/ivshmem.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
index abcb1c1..65e3a76 100644
--- a/hw/misc/ivshmem.c
+++ b/hw/misc/ivshmem.c
@@ -126,6 +126,11 @@ static void ivshmem_update_irq(IVShmemState *s)
PCIDevice *d = PCI_DEVICE(s);
uint32_t isr = s->intrstatus & s->intrmask;
+ /* No INTx with msi=on, whether the guest enabled MSI-X or not */
+ if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
+ return;
+ }
+
/* don't print ISR resets */
if (isr) {
IVSHMEM_DPRINTF("Set IRQ to %d (%04x %04x)\n",
@@ -873,6 +878,10 @@ static void pci_ivshmem_realize(PCIDevice *dev, Error
**errp)
pci_conf = dev->config;
pci_conf[PCI_COMMAND] = PCI_COMMAND_IO | PCI_COMMAND_MEMORY;
+ /*
+ * Note: we don't use INTx with IVSHMEM_MSI at all, so this is a
+ * bald-faced lie then. But it's a backwards compatible lie.
+ */
pci_config_set_interrupt_pin(pci_conf, 1);
memory_region_init_io(&s->ivshmem_mmio, OBJECT(s), &ivshmem_mmio_ops, s,
--
2.4.3
- [Qemu-devel] [PATCH v3 24/40] ivshmem: Plug leaks on unplug, fix peer disconnect, (continued)
- [Qemu-devel] [PATCH v3 24/40] ivshmem: Plug leaks on unplug, fix peer disconnect, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 19/40] ivshmem: Clean up MSI-X conditions, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 06/40] tests/libqos/pci-pc: Fix qpci_pc_iomap() to map BARs aligned, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 12/40] ivshmem: Compile debug prints unconditionally to prevent bit-rot, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 09/40] ivshmem-test: Improve test cases /ivshmem/server-*, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 03/40] ivshmem-server: Don't overload POSIX shmem and file name, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 13/40] ivshmem: Clean up after commit 9940c32, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 17/40] ivshmem: Failed realize() can leave migration blocker behind, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 20/40] ivshmem: Leave INTx alone when using MSI-X,
Markus Armbruster <=
- [Qemu-devel] [PATCH v3 25/40] ivshmem: Receive shared memory synchronously in realize(), Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 18/40] ivshmem: Clean up register callbacks, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 11/40] ivshmem: Add missing newlines to debug printfs, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 23/40] ivshmem: Disentangle ivshmem_read(), Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 22/40] ivshmem: Simplify rejection of invalid peer ID from server, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 35/40] ivshmem: Replace int role_val by OnOffAuto master, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 15/40] ivshmem: Don't destroy the chardev on version mismatch, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 21/40] ivshmem: Assert interrupts are set up once, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 33/40] ivshmem: Inline check_shm_size() into its only caller, Markus Armbruster, 2016/03/15