After ACRN hypervisor captures the io_request(mmio, IO, PCI access) from
guest OS, it will send the IRQ interrupt to SOS system.
The HYPERVISOR_CALLBACK_VECTOR ISR handler will be executed and it
needs to call the driver-specific ISR handler to dispatch emulated
io_request.
After the emulation of ioreq request is finished, the ACRN hypervisor
is notified and then can resume the execution of guest OS.
Co-developed-by: Jason Chen CJ <jason.cj.chen@xxxxxxxxx>
Signed-off-by: Jason Chen CJ <jason.cj.chen@xxxxxxxxx>
Co-developed-by: Mingqiang Chi <mingqiang.chi@xxxxxxxxx>
Signed-off-by: Mingqiang Chi <mingqiang.chi@xxxxxxxxx>
Co-developed-by: Liu Shuo <shuo.a.liu@xxxxxxxxx>
Signed-off-by: Liu Shuo <shuo.a.liu@xxxxxxxxx>
Signed-off-by: Zhao Yakui <yakui.zhao@xxxxxxxxx>
---
drivers/staging/acrn/acrn_dev.c | 41 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 41 insertions(+)
diff --git a/drivers/staging/acrn/acrn_dev.c b/drivers/staging/acrn/acrn_dev.c
index 28258fb..93f45e3 100644
--- a/drivers/staging/acrn/acrn_dev.c
+++ b/drivers/staging/acrn/acrn_dev.c
@@ -18,6 +18,7 @@
#include <linux/kdev_t.h>
#include <linux/kernel.h>
#include <linux/init.h>
+#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/mm.h>
#include <linux/module.h>
@@ -41,6 +42,7 @@ static int acrn_hsm_inited;
static int major;
static struct class *acrn_class;
static struct device *acrn_device;
+static struct tasklet_struct acrn_io_req_tasklet;
static
int acrn_dev_open(struct inode *inodep, struct file *filep)
@@ -416,6 +418,16 @@ long acrn_dev_ioctl(struct file *filep,
break;
}
case IC_CLEAR_VM_IOREQ: {
+ /*
+ * we need to flush the current pending ioreq dispatch
+ * tasklet and finish it before clearing all ioreq of this VM.
+ * With tasklet_kill, there still be a very rare race which
+ * might lost one ioreq tasklet for other VMs. So arm one after
+ * the clearing. It's harmless.
+ */
+ tasklet_schedule(&acrn_io_req_tasklet);
+ tasklet_kill(&acrn_io_req_tasklet);
+ tasklet_schedule(&acrn_io_req_tasklet);
acrn_ioreq_clear_request(vm);
break;
}
@@ -449,6 +461,28 @@ static int acrn_dev_release(struct inode *inodep, struct file *filep)
return 0;
}
+static void io_req_tasklet(unsigned long data)
+{
+ struct acrn_vm *vm;
+ /* This is already in tasklet. Use read_lock for list_lock */
+
+ read_lock(&acrn_vm_list_lock);
+ list_for_each_entry(vm, &acrn_vm_list, list) {
+ if (!vm || !vm->req_buf)
+ break;
+
+ get_vm(vm);
+ acrn_ioreq_distribute_request(vm);
+ put_vm(vm);
+ }
+ read_unlock(&acrn_vm_list_lock);
+}
+
+static void acrn_intr_handler(void)
+{
+ tasklet_schedule(&acrn_io_req_tasklet);
+}
+
static const struct file_operations fops = {
.open = acrn_dev_open,
.release = acrn_dev_release,
@@ -462,6 +496,7 @@ static const struct file_operations fops = {
static int __init acrn_init(void)
{
+ unsigned long flag;
struct api_version *api_version;
acrn_hsm_inited = 0;
if (x86_hyper_type != X86_HYPER_ACRN)
@@ -518,6 +553,10 @@ static int __init acrn_init(void)
return PTR_ERR(acrn_device);
}
+ tasklet_init(&acrn_io_req_tasklet, io_req_tasklet, 0);
+ local_irq_save(flag);
+ acrn_setup_intr_irq(acrn_intr_handler);
+ local_irq_restore(flag);
acrn_ioreq_driver_init();
pr_info("acrn: ACRN Hypervisor service module initialized\n");
acrn_hsm_inited = 1;
@@ -529,6 +568,8 @@ static void __exit acrn_exit(void)
if (!acrn_hsm_inited)
return;
+ tasklet_kill(&acrn_io_req_tasklet);
+ acrn_remove_intr_irq();
device_destroy(acrn_class, MKDEV(major, 0));
class_unregister(acrn_class);
class_destroy(acrn_class);
--
2.7.4
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