This patch tries to make sure the virtio interrupt handler for MMIO
won't be called after a reset and before virtio_device_ready(). We
can't use IRQF_NO_AUTOEN since we're using shared interrupt
(IRQF_SHARED). So this patch tracks the interrupt enabling status in a
new intr_soft_enabled variable and toggle it during in
vm_disable/enable_interrupts(). The MMIO interrupt handler will check
intr_soft_enabled before processing the actual interrupt.
Signed-off-by: Jason Wang <jasowang at redhat.com>
---
drivers/virtio/virtio_mmio.c | 37 ++++++++++++++++++++++++++++++++++++
1 file changed, 37 insertions(+)
diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c
index 56128b9c46eb..796f0c789b09 100644
--- a/drivers/virtio/virtio_mmio.c
+++ b/drivers/virtio/virtio_mmio.c
@@ -90,6 +90,7 @@ struct virtio_mmio_device {
/* a list of queues so we can dispatch IRQs */
spinlock_t lock;
struct list_head virtqueues;
+ bool intr_soft_enabled;
};
struct virtio_mmio_vq_info {
@@ -100,7 +101,37 @@ struct virtio_mmio_vq_info {
struct list_head node;
};
+/* disable irq handlers */
+void vm_disable_cbs(struct virtio_device *vdev)
+{
+ struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
+ int irq = platform_get_irq(vm_dev->pdev, 0);
+ /*
+ * The below synchronize() guarantees that any
+ * interrupt for this line arriving after
+ * synchronize_irq() has completed is guaranteed to see
+ * intx_soft_enabled == false.
+ */
+ WRITE_ONCE(vm_dev->intr_soft_enabled, false);
+ synchronize_irq(irq);
+}
+
+/* enable irq handlers */
+void vm_enable_cbs(struct virtio_device *vdev)
+{
+ struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
+ int irq = platform_get_irq(vm_dev->pdev, 0);
+
+ disable_irq(irq);
+ /*
+ * The above disable_irq() provides TSO ordering and
+ * as such promotes the below store to store-release.
+ */
+ WRITE_ONCE(vm_dev->intr_soft_enabled, true);
+ enable_irq(irq);
+ return;
+}
/* Configuration interface */
@@ -262,6 +293,8 @@ static void vm_reset(struct virtio_device *vdev)
/* 0 status means a reset. */
writel(0, vm_dev->base + VIRTIO_MMIO_STATUS);
+ /* Disable VQ/configuration callbacks. */
+ vm_disable_cbs(vdev);
}
@@ -288,6 +321,9 @@ static irqreturn_t vm_interrupt(int irq, void *opaque)
unsigned long flags;
irqreturn_t ret = IRQ_NONE;
+ if (!READ_ONCE(vm_dev->intr_soft_enabled))
+ return IRQ_NONE;
+
/* Read and acknowledge interrupts */
status = readl(vm_dev->base + VIRTIO_MMIO_INTERRUPT_STATUS);
writel(status, vm_dev->base + VIRTIO_MMIO_INTERRUPT_ACK);
@@ -529,6 +565,7 @@ static bool vm_get_shm_region(struct virtio_device *vdev,
}
static const struct virtio_config_ops virtio_mmio_config_ops = {
+ .enable_cbs = vm_enable_cbs,
.get = vm_get,
.set = vm_set,
.generation = vm_generation,
--
2.25.1
Hi Jason,
I love your patch! Perhaps something to improve:
[auto build test WARNING on linus/master]
[also build test WARNING on v5.16-rc2 next-20211125]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url:
https://github.com/0day-ci/linux/commits/Jason-Wang/virtio-mmio-harden-interrupt/20211125-143334
base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
5f53fa508db098c9d372423a6dac31c8a5679cdf
config: m68k-allyesconfig
(https://download.01.org/0day-ci/archive/20211125/202111251934.ybhaqyh7-lkp at
intel.com/config)
compiler: m68k-linux-gcc (GCC) 11.2.0
reproduce (this is a W=1 build):
wget
https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O
~/bin/make.cross
chmod +x ~/bin/make.cross
#
https://github.com/0day-ci/linux/commit/e19a8a1a95bd891090863b2d6828b8dc55d3633f
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review
Jason-Wang/virtio-mmio-harden-interrupt/20211125-143334
git checkout e19a8a1a95bd891090863b2d6828b8dc55d3633f
# save the config file to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross
ARCH=m68k
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp at intel.com>
All warnings (new ones prefixed by >>):
>> drivers/virtio/virtio_mmio.c:105:6: warning: no previous prototype for
'vm_disable_cbs' [-Wmissing-prototypes]
105 | void vm_disable_cbs(struct virtio_device *vdev)
| ^~~~~~~~~~~~~~>> drivers/virtio/virtio_mmio.c:121:6: warning: no previous prototype for
'vm_enable_cbs' [-Wmissing-prototypes]
121 | void vm_enable_cbs(struct virtio_device *vdev)
| ^~~~~~~~~~~~~
vim +/vm_disable_cbs +105 drivers/virtio/virtio_mmio.c
103
104 /* disable irq handlers */
> 105 void vm_disable_cbs(struct virtio_device *vdev)
106 {
107 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
108 int irq = platform_get_irq(vm_dev->pdev, 0);
109
110 /*
111 * The below synchronize() guarantees that any
112 * interrupt for this line arriving after
113 * synchronize_irq() has completed is guaranteed to see
114 * intx_soft_enabled == false.
115 */
116 WRITE_ONCE(vm_dev->intr_soft_enabled, false);
117 synchronize_irq(irq);
118 }
119
120 /* enable irq handlers */
> 121 void vm_enable_cbs(struct virtio_device *vdev)
122 {
123 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
124 int irq = platform_get_irq(vm_dev->pdev, 0);
125
126 disable_irq(irq);
127 /*
128 * The above disable_irq() provides TSO ordering and
129 * as such promotes the below store to store-release.
130 */
131 WRITE_ONCE(vm_dev->intr_soft_enabled, true);
132 enable_irq(irq);
133 return;
134 }
135
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all at lists.01.org
Hi Jason,
I love your patch! Perhaps something to improve:
[auto build test WARNING on linus/master]
[also build test WARNING on v5.16-rc2 next-20211125]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url:
https://github.com/0day-ci/linux/commits/Jason-Wang/virtio-mmio-harden-interrupt/20211125-143334
base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
5f53fa508db098c9d372423a6dac31c8a5679cdf
config: mips-buildonly-randconfig-r003-20211125
(https://download.01.org/0day-ci/archive/20211125/202111252001.Z5tli1Np-lkp at
intel.com/config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project
67a1c45def8a75061203461ab0060c75c864df1c)
reproduce (this is a W=1 build):
wget
https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O
~/bin/make.cross
chmod +x ~/bin/make.cross
# install mips cross compiling tool for clang build
# apt-get install binutils-mips-linux-gnu
#
https://github.com/0day-ci/linux/commit/e19a8a1a95bd891090863b2d6828b8dc55d3633f
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review
Jason-Wang/virtio-mmio-harden-interrupt/20211125-143334
git checkout e19a8a1a95bd891090863b2d6828b8dc55d3633f
# save the config file to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=mips
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp at intel.com>
All warnings (new ones prefixed by >>):
>> drivers/virtio/virtio_mmio.c:105:6: warning: no previous prototype for
function 'vm_disable_cbs' [-Wmissing-prototypes]
void vm_disable_cbs(struct virtio_device *vdev)
^
drivers/virtio/virtio_mmio.c:105:1: note: declare 'static' if the
function is not intended to be used outside of this translation unit
void vm_disable_cbs(struct virtio_device *vdev)
^
static >> drivers/virtio/virtio_mmio.c:121:6: warning: no previous prototype for
function 'vm_enable_cbs' [-Wmissing-prototypes]
void vm_enable_cbs(struct virtio_device *vdev)
^
drivers/virtio/virtio_mmio.c:121:1: note: declare 'static' if the
function is not intended to be used outside of this translation unit
void vm_enable_cbs(struct virtio_device *vdev)
^
static
2 warnings generated.
vim +/vm_disable_cbs +105 drivers/virtio/virtio_mmio.c
103
104 /* disable irq handlers */
> 105 void vm_disable_cbs(struct virtio_device *vdev)
106 {
107 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
108 int irq = platform_get_irq(vm_dev->pdev, 0);
109
110 /*
111 * The below synchronize() guarantees that any
112 * interrupt for this line arriving after
113 * synchronize_irq() has completed is guaranteed to see
114 * intx_soft_enabled == false.
115 */
116 WRITE_ONCE(vm_dev->intr_soft_enabled, false);
117 synchronize_irq(irq);
118 }
119
120 /* enable irq handlers */
> 121 void vm_enable_cbs(struct virtio_device *vdev)
122 {
123 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
124 int irq = platform_get_irq(vm_dev->pdev, 0);
125
126 disable_irq(irq);
127 /*
128 * The above disable_irq() provides TSO ordering and
129 * as such promotes the below store to store-release.
130 */
131 WRITE_ONCE(vm_dev->intr_soft_enabled, true);
132 enable_irq(irq);
133 return;
134 }
135
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all at lists.01.org