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[Qemu-devel] [PULL 27/47] ivshmem: Always remove irqfd notifiers
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PULL 27/47] ivshmem: Always remove irqfd notifiers |
Date: |
Mon, 5 Feb 2018 20:28:41 +0100 |
From: Ladi Prosek <address@hidden>
As of commit 660c97eef6f8 ("ivshmem: use kvm irqfd for msi notifications"),
QEMU crashes with:
ivshmem: msix_set_vector_notifiers failed
msix_unset_vector_notifiers: Assertion `dev->msix_vector_use_notifier &&
dev->msix_vector_release_notifier' failed.
if MSI-X is repeatedly enabled and disabled on the ivshmem device, for example
by loading and unloading the Windows ivshmem driver. This is because
msix_unset_vector_notifiers() doesn't call any of the release notifier callbacks
since MSI-X is already disabled at that point (msix_enabled() returning false
is how this transition is detected in the first place). Thus
ivshmem_vector_mask()
doesn't run and when MSI-X is subsequently enabled again ivshmem_vector_unmask()
fails.
This is fixed by keeping track of unmasked vectors and making sure that
ivshmem_vector_mask() always runs on MSI-X disable.
Fixes: 660c97eef6f8 ("ivshmem: use kvm irqfd for msi notifications")
Signed-off-by: Ladi Prosek <address@hidden>
Reviewed-by: Markus Armbruster <address@hidden>
Message-Id: <address@hidden>
Signed-off-by: Paolo Bonzini <address@hidden>
---
hw/misc/ivshmem.c | 26 +++++++++++++++++++++++---
1 file changed, 23 insertions(+), 3 deletions(-)
diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
index 0b471d9..95e85e4 100644
--- a/hw/misc/ivshmem.c
+++ b/hw/misc/ivshmem.c
@@ -76,6 +76,7 @@ typedef struct Peer {
typedef struct MSIVector {
PCIDevice *pdev;
int virq;
+ bool unmasked;
} MSIVector;
typedef struct IVShmemState {
@@ -320,6 +321,7 @@ static int ivshmem_vector_unmask(PCIDevice *dev, unsigned
vector,
error_report("ivshmem: vector %d route does not exist", vector);
return -EINVAL;
}
+ assert(!v->unmasked);
ret = kvm_irqchip_update_msi_route(kvm_state, v->virq, msg, dev);
if (ret < 0) {
@@ -327,7 +329,13 @@ static int ivshmem_vector_unmask(PCIDevice *dev, unsigned
vector,
}
kvm_irqchip_commit_routes(kvm_state);
- return kvm_irqchip_add_irqfd_notifier_gsi(kvm_state, n, NULL, v->virq);
+ ret = kvm_irqchip_add_irqfd_notifier_gsi(kvm_state, n, NULL, v->virq);
+ if (ret < 0) {
+ return ret;
+ }
+ v->unmasked = true;
+
+ return 0;
}
static void ivshmem_vector_mask(PCIDevice *dev, unsigned vector)
@@ -342,11 +350,14 @@ static void ivshmem_vector_mask(PCIDevice *dev, unsigned
vector)
error_report("ivshmem: vector %d route does not exist", vector);
return;
}
+ assert(v->unmasked);
ret = kvm_irqchip_remove_irqfd_notifier_gsi(kvm_state, n, v->virq);
- if (ret != 0) {
+ if (ret < 0) {
error_report("remove_irqfd_notifier_gsi failed");
+ return;
}
+ v->unmasked = false;
}
static void ivshmem_vector_poll(PCIDevice *dev,
@@ -816,11 +827,20 @@ static void ivshmem_disable_irqfd(IVShmemState *s)
PCIDevice *pdev = PCI_DEVICE(s);
int i;
+ msix_unset_vector_notifiers(pdev);
+
for (i = 0; i < s->peers[s->vm_id].nb_eventfds; i++) {
+ /*
+ * MSI-X is already disabled here so msix_unset_vector_notifiers()
+ * didn't call our release notifier. Do it now to keep our masks and
+ * unmasks balanced.
+ */
+ if (s->msi_vectors[i].unmasked) {
+ ivshmem_vector_mask(pdev, i);
+ }
ivshmem_remove_kvm_msi_virq(s, i);
}
- msix_unset_vector_notifiers(pdev);
}
static void ivshmem_write_config(PCIDevice *pdev, uint32_t address,
--
1.8.3.1
- [Qemu-devel] [PULL 19/47] build-sys: add --enable-sanitizers, (continued)
- [Qemu-devel] [PULL 19/47] build-sys: add --enable-sanitizers, Paolo Bonzini, 2018/02/05
- [Qemu-devel] [PULL 21/47] vhost: add traces for memory listeners, Paolo Bonzini, 2018/02/05
- [Qemu-devel] [PULL 20/47] ucontext: annotate coroutine stack for ASAN, Paolo Bonzini, 2018/02/05
- [Qemu-devel] [PULL 17/47] sockets: fix parsing of ipv4/ipv6 opts in parse_socket_addr, Paolo Bonzini, 2018/02/05
- [Qemu-devel] [PULL 23/47] vfio: listener unregister before unset container, Paolo Bonzini, 2018/02/05
- [Qemu-devel] [PULL 22/47] arm: postpone device listener unregister, Paolo Bonzini, 2018/02/05
- [Qemu-devel] [PULL 25/47] chardev/char-socket: add POLLHUP handler, Paolo Bonzini, 2018/02/05
- [Qemu-devel] [PULL 24/47] memory: do explicit cleanup when remove listeners, Paolo Bonzini, 2018/02/05
- [Qemu-devel] [PULL 28/47] ivshmem: Improve MSI irqfd error handling, Paolo Bonzini, 2018/02/05
- [Qemu-devel] [PULL 29/47] ivshmem: Disable irqfd on device reset, Paolo Bonzini, 2018/02/05
- [Qemu-devel] [PULL 27/47] ivshmem: Always remove irqfd notifiers,
Paolo Bonzini <=
- [Qemu-devel] [PULL 32/47] cpus: dummy: unregister thread with RCU, exit loop on unplug, Paolo Bonzini, 2018/02/05
- [Qemu-devel] [PULL 30/47] cpus: hax: register/unregister thread with RCU, exit loop on unplug, Paolo Bonzini, 2018/02/05
- [Qemu-devel] [PULL 31/47] cpus: kvm: unregister thread with RCU, Paolo Bonzini, 2018/02/05
- [Qemu-devel] [PULL 26/47] ivshmem: Don't update non-existent MSI routes, Paolo Bonzini, 2018/02/05
- [Qemu-devel] [PULL 35/47] cpus: join thread when removing a vCPU, Paolo Bonzini, 2018/02/05
- [Qemu-devel] [PULL 34/47] cpus: hvf: unregister thread with RCU, Paolo Bonzini, 2018/02/05
- [Qemu-devel] [PULL 33/47] cpus: tcg: unregister thread with RCU, fix exiting of loop on unplug, Paolo Bonzini, 2018/02/05
- [Qemu-devel] [PULL 36/47] memfd: add error argument, instead of perror(), Paolo Bonzini, 2018/02/05
- [Qemu-devel] [PULL 38/47] memfd: add hugetlbsize argument, Paolo Bonzini, 2018/02/05
- [Qemu-devel] [PULL 37/47] memfd: add hugetlb support, Paolo Bonzini, 2018/02/05