We hit softlocup with following call trace:
? asm_sysvec_apic_timer_interrupt+0x16/0x20
xa_erase+0x21/0xb0
? sgx_free_epc_page+0x20/0x50
sgx_vepc_release+0x75/0x220
__fput+0x89/0x250
task_work_run+0x59/0x90
do_exit+0x337/0x9a0
Similar like commit 8795359e35bc ("x86/sgx: Silence softlockup detection
when releasing large enclaves"). The test system has 64GB of enclave memory,
and all assigned to a single VM. Release vepc take longer time and triggers
the softlockup warning.
Add cond_resched() to give other tasks a chance to run and placate
the softlockup detector.
Cc: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
Cc: Haitao Huang <haitao.huang@xxxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 540745ddbc70 ("x86/sgx: Introduce virtual EPC for use by KVM guests")
Reported-by: Yu Zhang <yu.zhang@xxxxxxxxx>
Tested-by: Yu Zhang <yu.zhang@xxxxxxxxx>
Acked-by: Haitao Huang <haitao.huang@xxxxxxxxxxxxxxx>
Reviewed-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
Signed-off-by: Jack Wang <jinpu.wang@xxxxxxxxx>
---
v3:
* improve commit message as suggested.
* Add cond_resched() to the 3rd loop too.
arch/x86/kernel/cpu/sgx/virt.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/x86/kernel/cpu/sgx/virt.c b/arch/x86/kernel/cpu/sgx/virt.c
index c3e37eaec8ec..7aaa3652e31d 100644
--- a/arch/x86/kernel/cpu/sgx/virt.c
+++ b/arch/x86/kernel/cpu/sgx/virt.c
@@ -204,6 +204,7 @@ static int sgx_vepc_release(struct inode *inode, struct file *file)
continue;
xa_erase(&vepc->page_array, index);
+ cond_resched();
}
/*
@@ -222,6 +223,7 @@ static int sgx_vepc_release(struct inode *inode, struct file *file)
list_add_tail(&epc_page->list, &secs_pages);
xa_erase(&vepc->page_array, index);
+ cond_resched();
}
/*
@@ -243,6 +245,7 @@ static int sgx_vepc_release(struct inode *inode, struct file *file)
if (sgx_vepc_free_page(epc_page))
list_add_tail(&epc_page->list, &secs_pages);
+ cond_resched();
}
if (!list_empty(&secs_pages))
--
2.34.1
