| Message ID | 20230818180702.4621-1-jinpu.wang@ionos.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [PATCHv3] x86/sgx: Avoid softlockup from sgx_vepc_release | expand |
On Fri Aug 18, 2023 at 9:07 PM EEST, Jack Wang wrote: > 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@kernel.org> > Cc: Haitao Huang <haitao.huang@linux.intel.com> > Cc: stable@vger.kernel.org > Fixes: 540745ddbc70 ("x86/sgx: Introduce virtual EPC for use by KVM guests") > Reported-by: Yu Zhang <yu.zhang@ionos.com> > Tested-by: Yu Zhang <yu.zhang@ionos.com> > Acked-by: Haitao Huang <haitao.huang@linux.intel.com> > Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> > Signed-off-by: Jack Wang <jinpu.wang@ionos.com> > --- > 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 Just acknowledging that my reviewed-by still holds for this patch. BR, Jarkko
On Fri, 2023-08-18 at 20:07 +0200, Jack Wang wrote: > 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@kernel.org> > Cc: Haitao Huang <haitao.huang@linux.intel.com> > Cc: stable@vger.kernel.org > Fixes: 540745ddbc70 ("x86/sgx: Introduce virtual EPC for use by KVM guests") > Reported-by: Yu Zhang <yu.zhang@ionos.com> > Tested-by: Yu Zhang <yu.zhang@ionos.com> > Acked-by: Haitao Huang <haitao.huang@linux.intel.com> > Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> > Signed-off-by: Jack Wang <jinpu.wang@ionos.com> Reviewed-by: Kai Huang <kai.huang@intel.com>
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))
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@kernel.org> Cc: Haitao Huang <haitao.huang@linux.intel.com> Cc: stable@vger.kernel.org Fixes: 540745ddbc70 ("x86/sgx: Introduce virtual EPC for use by KVM guests") Reported-by: Yu Zhang <yu.zhang@ionos.com> Tested-by: Yu Zhang <yu.zhang@ionos.com> Acked-by: Haitao Huang <haitao.huang@linux.intel.com> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Jack Wang <jinpu.wang@ionos.com> --- 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(+)