* [PATCH 0/3] virtio-pci: Checks for virtio device presence on the bus.
@ 2021-06-09 9:58 Andrew Melnychenko
2021-06-09 9:58 ` [PATCH 1/3] virtio-pci: Added check for virtio device presence in mm callbacks Andrew Melnychenko
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Andrew Melnychenko @ 2021-06-09 9:58 UTC (permalink / raw)
To: mst; +Cc: qemu-devel
At some point, after unplugging virtio-pci the virtio device may be unrealised,
but the memory regions may be present in flatview. So, it's a possible situation
when memory region's callbacks are called for "unplugged" device.
In patches were added checks for virtio device presence on virtio-bus.
Added checks in PCI config callbacks. Also changed return values in memory
regions read if virtio not present.
BZ link https://bugzilla.redhat.com/show_bug.cgi?id=1938042
The issue similar to https://bugzilla.redhat.com/show_bug.cgi?id=1743098
Backtrace:
at ../hw/virtio/virtio-pci.c:1271
proxy = 0x560b535f8bf0
vdev = 0x0
(mr=<optimized out>, addr=<optimized out>, value=<optimized out>, size=<optimized out>, shift=<optimized out>, mask=<optimized out>, attrs=...) at ../softmmu/memory.c:491
tmp = <optimized out>
(addr=addr@entry=22, value=value@entry=0x7fd743dfe518, size=size@entry=2, access_size_min=<optimized out>, access_size_max=<optimized out>, access_fn=0x560b513fc500 <memory_region_write_accessor>, mr=0x560b535f95d0, attrs=...) at ../softmmu/memory.c:552
access_mask = 65535
access_size = 2
i = <optimized out>
r = 0
(mr=mr@entry=0x560b535f95d0, addr=22, data=<optimized out>, op=<optimized out>, attrs=attrs@entry=...) at ../softmmu/memory.c:1501
size = 2
(fv=fv@entry=0x7fd6f005d3b0, addr=addr@entry=4246716438, attrs=..., ptr=ptr@entry=0x7fe69b2b0028, len=len@entry=2, addr1=<optimized out>, l=<optimized out>, mr=0x560b535f95d0)
at /usr/src/debug/qemu-kvm-5.2.0-11.module+el8.4.0+10268+62bcbbed.x86_64/include/qemu/host-utils.h:164
ram_ptr = <optimized out>
val = <optimized out>
result = 0
release_lock = true
buf = 0x7fe69b2b0028 ""
at ../softmmu/physmem.c:2799
l = 2
addr1 = 22
mr = <optimized out>
result = 0
_rcu_read_auto = 0x1
result = 0
fv = <optimized out>
attrs = {unspecified = 0, secure = 0, user = 0, requester_id = 0, byte_swap = 0, target_tlb_bit0 = 0, target_tlb_bit1 = 0, target_tlb_bit2 = 0}
run = <optimized out>
ret = <optimized out>
run_ret = 0
cpu = 0x560b522738d0
r = <optimized out>
__clframe = {__cancel_routine = <optimized out>, __cancel_arg = 0x0, __do_it = 1, __cancel_type = <optimized out>}
qemu_thread_args = 0x560b5229a6f0
start_routine = 0x560b513faeb0 <kvm_vcpu_thread_fn>
arg = 0x560b522738d0
r = <optimized out>
Andrew Melnychenko (3):
virtio-pci: Added check for virtio device presence in mm callbacks.
virtio-pci: Added check for virtio device in PCI config cbs.
virtio-pci: Changed return values for "notify", "device" and "isr"
read.
hw/virtio/virtio-pci.c | 27 +++++++++++++++++++++++++--
1 file changed, 25 insertions(+), 2 deletions(-)
--
2.31.1
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH 1/3] virtio-pci: Added check for virtio device presence in mm callbacks.
2021-06-09 9:58 [PATCH 0/3] virtio-pci: Checks for virtio device presence on the bus Andrew Melnychenko
@ 2021-06-09 9:58 ` Andrew Melnychenko
2021-06-09 9:58 ` [PATCH 2/3] virtio-pci: Added check for virtio device in PCI config cbs Andrew Melnychenko
2021-06-09 9:58 ` [PATCH 3/3] virtio-pci: Changed return values for "notify", "device" and "isr" read Andrew Melnychenko
2 siblings, 0 replies; 4+ messages in thread
From: Andrew Melnychenko @ 2021-06-09 9:58 UTC (permalink / raw)
To: mst; +Cc: qemu-devel
During unplug the virtio device is unplugged from virtio-bus on pci. In some cases,
requests to virtio-pci mm may acquire during/after unplug. Added check that virtio
device is on the bus, for "common" memory region.
Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
---
hw/virtio/virtio-pci.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index b321604d9b..05865b1fcb 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -1146,6 +1146,10 @@ static uint64_t virtio_pci_common_read(void *opaque, hwaddr addr,
uint32_t val = 0;
int i;
+ if (vdev == NULL) {
+ return UINT64_MAX;
+ }
+
switch (addr) {
case VIRTIO_PCI_COMMON_DFSELECT:
val = proxy->dfselect;
@@ -1229,6 +1233,10 @@ static void virtio_pci_common_write(void *opaque, hwaddr addr,
VirtIOPCIProxy *proxy = opaque;
VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
+ if (vdev == NULL) {
+ return;
+ }
+
switch (addr) {
case VIRTIO_PCI_COMMON_DFSELECT:
proxy->dfselect = val;
--
2.31.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH 2/3] virtio-pci: Added check for virtio device in PCI config cbs.
2021-06-09 9:58 [PATCH 0/3] virtio-pci: Checks for virtio device presence on the bus Andrew Melnychenko
2021-06-09 9:58 ` [PATCH 1/3] virtio-pci: Added check for virtio device presence in mm callbacks Andrew Melnychenko
@ 2021-06-09 9:58 ` Andrew Melnychenko
2021-06-09 9:58 ` [PATCH 3/3] virtio-pci: Changed return values for "notify", "device" and "isr" read Andrew Melnychenko
2 siblings, 0 replies; 4+ messages in thread
From: Andrew Melnychenko @ 2021-06-09 9:58 UTC (permalink / raw)
To: mst; +Cc: qemu-devel
Now, if virtio device is not present on virtio-bus - pci config callbacks
will not lead to possible crush. The read will return "-1" which should be
interpreted by a driver that pci device may be unplugged.
Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
---
hw/virtio/virtio-pci.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index 05865b1fcb..186b7bc0f6 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -423,6 +423,11 @@ static uint64_t virtio_pci_config_read(void *opaque, hwaddr addr,
VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
uint32_t config = VIRTIO_PCI_CONFIG_SIZE(&proxy->pci_dev);
uint64_t val = 0;
+
+ if (vdev == NULL) {
+ return UINT64_MAX;
+ }
+
if (addr < config) {
return virtio_ioport_read(proxy, addr);
}
@@ -454,6 +459,11 @@ static void virtio_pci_config_write(void *opaque, hwaddr addr,
VirtIOPCIProxy *proxy = opaque;
uint32_t config = VIRTIO_PCI_CONFIG_SIZE(&proxy->pci_dev);
VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
+
+ if (vdev == NULL) {
+ return;
+ }
+
if (addr < config) {
virtio_ioport_write(proxy, addr, val);
return;
--
2.31.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH 3/3] virtio-pci: Changed return values for "notify", "device" and "isr" read.
2021-06-09 9:58 [PATCH 0/3] virtio-pci: Checks for virtio device presence on the bus Andrew Melnychenko
2021-06-09 9:58 ` [PATCH 1/3] virtio-pci: Added check for virtio device presence in mm callbacks Andrew Melnychenko
2021-06-09 9:58 ` [PATCH 2/3] virtio-pci: Added check for virtio device in PCI config cbs Andrew Melnychenko
@ 2021-06-09 9:58 ` Andrew Melnychenko
2 siblings, 0 replies; 4+ messages in thread
From: Andrew Melnychenko @ 2021-06-09 9:58 UTC (permalink / raw)
To: mst; +Cc: qemu-devel
Added check for "notify" memory region. Now reads will return "-1" if a virtio
device is not present on a virtio bus.
Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
---
hw/virtio/virtio-pci.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index 186b7bc0f6..447f13beae 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -1348,6 +1348,11 @@ static void virtio_pci_common_write(void *opaque, hwaddr addr,
static uint64_t virtio_pci_notify_read(void *opaque, hwaddr addr,
unsigned size)
{
+ VirtIOPCIProxy *proxy = opaque;
+ if (virtio_bus_get_device(&proxy->bus) == NULL) {
+ return UINT64_MAX;
+ }
+
return 0;
}
@@ -1385,7 +1390,7 @@ static uint64_t virtio_pci_isr_read(void *opaque, hwaddr addr,
uint64_t val;
if (vdev == NULL) {
- return 0;
+ return UINT64_MAX;
}
val = qatomic_xchg(&vdev->isr, 0);
@@ -1406,7 +1411,7 @@ static uint64_t virtio_pci_device_read(void *opaque, hwaddr addr,
uint64_t val;
if (vdev == NULL) {
- return 0;
+ return UINT64_MAX;
}
switch (size) {
--
2.31.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-06-09 10:03 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2021-06-09 9:58 [PATCH 0/3] virtio-pci: Checks for virtio device presence on the bus Andrew Melnychenko
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2021-06-09 9:58 ` [PATCH 2/3] virtio-pci: Added check for virtio device in PCI config cbs Andrew Melnychenko
2021-06-09 9:58 ` [PATCH 3/3] virtio-pci: Changed return values for "notify", "device" and "isr" read Andrew Melnychenko
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