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* [PATCH] virtio-mmio: harden interrupt
@ 2021-11-25  6:30 Jason Wang
  2021-11-25 11:25 ` kernel test robot
  2021-11-25 12:07 ` kernel test robot
  0 siblings, 2 replies; 4+ messages in thread
From: Jason Wang @ 2021-11-25  6:30 UTC (permalink / raw)
  To: mst, jasowang, virtualization, linux-kernel

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@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


^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] virtio-mmio: harden interrupt
  2021-11-25  6:30 [PATCH] virtio-mmio: harden interrupt Jason Wang
@ 2021-11-25 11:25 ` kernel test robot
  2021-11-25 12:07 ` kernel test robot
  1 sibling, 0 replies; 4+ messages in thread
From: kernel test robot @ 2021-11-25 11:25 UTC (permalink / raw)
  To: Jason Wang, mst, virtualization, linux-kernel; +Cc: kbuild-all

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@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@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@lists.01.org

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] virtio-mmio: harden interrupt
  2021-11-25  6:30 [PATCH] virtio-mmio: harden interrupt Jason Wang
  2021-11-25 11:25 ` kernel test robot
@ 2021-11-25 12:07 ` kernel test robot
  2021-11-26  4:40   ` Jason Wang
  1 sibling, 1 reply; 4+ messages in thread
From: kernel test robot @ 2021-11-25 12:07 UTC (permalink / raw)
  To: Jason Wang, mst, virtualization, linux-kernel; +Cc: llvm, kbuild-all

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@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@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@lists.01.org

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] virtio-mmio: harden interrupt
  2021-11-25 12:07 ` kernel test robot
@ 2021-11-26  4:40   ` Jason Wang
  0 siblings, 0 replies; 4+ messages in thread
From: Jason Wang @ 2021-11-26  4:40 UTC (permalink / raw)
  To: kernel test robot; +Cc: mst, virtualization, linux-kernel, llvm, kbuild-all

On Thu, Nov 25, 2021 at 8:08 PM kernel test robot <lkp@intel.com> wrote:
>
> 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]

Will fix this in V2.

Thanks

>
> 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@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@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@lists.01.org
>


^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2021-11-26  4:42 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-11-25  6:30 [PATCH] virtio-mmio: harden interrupt Jason Wang
2021-11-25 11:25 ` kernel test robot
2021-11-25 12:07 ` kernel test robot
2021-11-26  4:40   ` Jason Wang

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