Request a PPI for each vCPU during probe which will be used by the host
to communicate a stall detected event on the vCPU. When the host raises
this interrupt from the virtual machine monitor, the guest is expected to
handle the interrupt and panic.
Signed-off-by: Sebastian Ene <sebastianene@google.com>
---
drivers/misc/vcpu_stall_detector.c | 31 ++++++++++++++++++++++++++++--
1 file changed, 29 insertions(+), 2 deletions(-)
diff --git a/drivers/misc/vcpu_stall_detector.c b/drivers/misc/vcpu_stall_detector.c
index e2015c87f03f..17808e71cc30 100644
--- a/drivers/misc/vcpu_stall_detector.c
+++ b/drivers/misc/vcpu_stall_detector.c
@@ -32,6 +32,7 @@
struct vcpu_stall_detect_config {
u32 clock_freq_hz;
u32 stall_timeout_sec;
+ int ppi_irq;
void __iomem *membase;
struct platform_device *dev;
@@ -77,6 +78,12 @@ vcpu_stall_detect_timer_fn(struct hrtimer *hrtimer)
return HRTIMER_RESTART;
}
+static irqreturn_t vcpu_stall_detector_irq(int irq, void *dev)
+{
+ panic("vCPU stall detector");
+ return IRQ_HANDLED;
+}
+
static int start_stall_detector_cpu(unsigned int cpu)
{
u32 ticks, ping_timeout_ms;
@@ -132,7 +139,7 @@ static int stop_stall_detector_cpu(unsigned int cpu)
static int vcpu_stall_detect_probe(struct platform_device *pdev)
{
- int ret;
+ int ret, irq;
struct resource *r;
void __iomem *membase;
u32 clock_freq_hz = VCPU_STALL_DEFAULT_CLOCK_HZ;
@@ -169,9 +176,22 @@ static int vcpu_stall_detect_probe(struct platform_device *pdev)
vcpu_stall_config = (struct vcpu_stall_detect_config) {
.membase = membase,
.clock_freq_hz = clock_freq_hz,
- .stall_timeout_sec = stall_timeout_sec
+ .stall_timeout_sec = stall_timeout_sec,
+ .ppi_irq = -1,
};
+ irq = platform_get_irq_optional(pdev, 0);
+ if (irq > 0 && irq_is_percpu_devid(irq)) {
+ ret = request_percpu_irq(irq,
+ vcpu_stall_detector_irq,
+ "vcpu_stall_detector",
+ vcpu_stall_detectors);
+ if (ret)
+ goto err;
+
+ vcpu_stall_config.ppi_irq = irq;
+ }
+
ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
"virt/vcpu_stall_detector:online",
start_stall_detector_cpu,
@@ -184,6 +204,9 @@ static int vcpu_stall_detect_probe(struct platform_device *pdev)
vcpu_stall_config.hp_online = ret;
return 0;
err:
+ if (vcpu_stall_config.ppi_irq > 0)
+ free_percpu_irq(vcpu_stall_config.ppi_irq,
+ vcpu_stall_detectors);
return ret;
}
@@ -193,6 +216,10 @@ static void vcpu_stall_detect_remove(struct platform_device *pdev)
cpuhp_remove_state(vcpu_stall_config.hp_online);
+ if (vcpu_stall_config.ppi_irq > 0)
+ free_percpu_irq(vcpu_stall_config.ppi_irq,
+ vcpu_stall_detectors);
+
for_each_possible_cpu(cpu)
stop_stall_detector_cpu(cpu);
}
--
2.45.2.505.gda0bf45e8d-googHi Sebastian,
kernel test robot noticed the following build errors:
[auto build test ERROR on robh/for-next]
[also build test ERROR on soc/for-next char-misc/char-misc-testing char-misc/char-misc-next char-misc/char-misc-linus linus/master v6.10-rc3 next-20240613]
[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#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Sebastian-Ene/dt-bindings-vcpu_stall_detector-Add-a-PPI-interrupt-to-the-virtual-device/20240611-190759
base: https://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git for-next
patch link: https://lore.kernel.org/r/20240611110136.2003137-4-sebastianene%40google.com
patch subject: [PATCH v2 2/2] misc: Register a PPI for the vcpu stall detection virtual device
config: s390-randconfig-r112-20240613 (https://download.01.org/0day-ci/archive/20240613/202406132132.FBKSWFav-lkp@intel.com/config)
compiler: clang version 15.0.7 (https://github.com/llvm/llvm-project 8dfdcc7b7bf66834a761bd8de445840ef68e4d1a)
reproduce: (https://download.01.org/0day-ci/archive/20240613/202406132132.FBKSWFav-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202406132132.FBKSWFav-lkp@intel.com/
All errors (new ones prefixed by >>):
In file included from drivers/misc/vcpu_stall_detector.c:8:
In file included from include/linux/io.h:14:
In file included from arch/s390/include/asm/io.h:93:
include/asm-generic/io.h:548:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __raw_readb(PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:561:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:37:59: note: expanded from macro '__le16_to_cpu'
#define __le16_to_cpu(x) __swab16((__force __u16)(__le16)(x))
^
include/uapi/linux/swab.h:102:54: note: expanded from macro '__swab16'
#define __swab16(x) (__u16)__builtin_bswap16((__u16)(x))
^
In file included from drivers/misc/vcpu_stall_detector.c:8:
In file included from include/linux/io.h:14:
In file included from arch/s390/include/asm/io.h:93:
include/asm-generic/io.h:574:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:35:59: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
^
include/uapi/linux/swab.h:115:54: note: expanded from macro '__swab32'
#define __swab32(x) (__u32)__builtin_bswap32((__u32)(x))
^
In file included from drivers/misc/vcpu_stall_detector.c:8:
In file included from include/linux/io.h:14:
In file included from arch/s390/include/asm/io.h:93:
include/asm-generic/io.h:585:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writeb(value, PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:595:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:605:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:693:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsb(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:701:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsw(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:709:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsl(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:718:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesb(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:727:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesw(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:736:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesl(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
>> drivers/misc/vcpu_stall_detector.c:184:17: error: call to undeclared function 'irq_is_percpu_devid'; ISO C99 and later do not support implicit function declarations [-Werror,-Wimplicit-function-declaration]
if (irq > 0 && irq_is_percpu_devid(irq)) {
^
12 warnings and 1 error generated.
vim +/irq_is_percpu_devid +184 drivers/misc/vcpu_stall_detector.c
139
140 static int vcpu_stall_detect_probe(struct platform_device *pdev)
141 {
142 int ret, irq;
143 struct resource *r;
144 void __iomem *membase;
145 u32 clock_freq_hz = VCPU_STALL_DEFAULT_CLOCK_HZ;
146 u32 stall_timeout_sec = VCPU_STALL_DEFAULT_TIMEOUT_SEC;
147 struct device_node *np = pdev->dev.of_node;
148
149 vcpu_stall_detectors = devm_alloc_percpu(&pdev->dev,
150 typeof(struct vcpu_stall_priv));
151 if (!vcpu_stall_detectors)
152 return -ENOMEM;
153
154 membase = devm_platform_get_and_ioremap_resource(pdev, 0, &r);
155 if (IS_ERR(membase)) {
156 dev_err(&pdev->dev, "Failed to get memory resource\n");
157 return PTR_ERR(membase);
158 }
159
160 if (!of_property_read_u32(np, "clock-frequency", &clock_freq_hz)) {
161 if (!(clock_freq_hz > 0 &&
162 clock_freq_hz < VCPU_STALL_MAX_CLOCK_HZ)) {
163 dev_warn(&pdev->dev, "clk out of range\n");
164 clock_freq_hz = VCPU_STALL_DEFAULT_CLOCK_HZ;
165 }
166 }
167
168 if (!of_property_read_u32(np, "timeout-sec", &stall_timeout_sec)) {
169 if (!(stall_timeout_sec > 0 &&
170 stall_timeout_sec < VCPU_STALL_MAX_TIMEOUT_SEC)) {
171 dev_warn(&pdev->dev, "stall timeout out of range\n");
172 stall_timeout_sec = VCPU_STALL_DEFAULT_TIMEOUT_SEC;
173 }
174 }
175
176 vcpu_stall_config = (struct vcpu_stall_detect_config) {
177 .membase = membase,
178 .clock_freq_hz = clock_freq_hz,
179 .stall_timeout_sec = stall_timeout_sec,
180 .ppi_irq = -1,
181 };
182
183 irq = platform_get_irq_optional(pdev, 0);
> 184 if (irq > 0 && irq_is_percpu_devid(irq)) {
185 ret = request_percpu_irq(irq,
186 vcpu_stall_detector_irq,
187 "vcpu_stall_detector",
188 vcpu_stall_detectors);
189 if (ret)
190 goto err;
191
192 vcpu_stall_config.ppi_irq = irq;
193 }
194
195 ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
196 "virt/vcpu_stall_detector:online",
197 start_stall_detector_cpu,
198 stop_stall_detector_cpu);
199 if (ret < 0) {
200 dev_err(&pdev->dev, "failed to install cpu hotplug");
201 goto err;
202 }
203
204 vcpu_stall_config.hp_online = ret;
205 return 0;
206 err:
207 if (vcpu_stall_config.ppi_irq > 0)
208 free_percpu_irq(vcpu_stall_config.ppi_irq,
209 vcpu_stall_detectors);
210 return ret;
211 }
212
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
© 2016 - 2026 Red Hat, Inc.