On Mon, May 19, 2025 at 11:47:32AM +0000, Reshetova, Elena wrote: > > On Mon, 2025-05-19 at 10:24 +0300, Elena Reshetova wrote: > > > Currently SGX does not have a global counter to count the > > > active users from userspace or hypervisor. Implement such a counter, > > > sgx_usage_count. It will be used by the driver when attempting > > > to call EUPDATESVN SGX instruction. > > > > > > Suggested-by: Sean Christopherson <sea...@google.com> > > > Signed-off-by: Elena Reshetova <elena.reshet...@intel.com> > > > --- > > > arch/x86/kernel/cpu/sgx/driver.c | 1 + > > > arch/x86/kernel/cpu/sgx/encl.c | 1 + > > > arch/x86/kernel/cpu/sgx/main.c | 14 ++++++++++++++ > > > arch/x86/kernel/cpu/sgx/sgx.h | 3 +++ > > > arch/x86/kernel/cpu/sgx/virt.c | 2 ++ > > > 5 files changed, 21 insertions(+) > > > > > > diff --git a/arch/x86/kernel/cpu/sgx/driver.c > > b/arch/x86/kernel/cpu/sgx/driver.c > > > index 7f8d1e11dbee..b5ffe104af4c 100644 > > > --- a/arch/x86/kernel/cpu/sgx/driver.c > > > +++ b/arch/x86/kernel/cpu/sgx/driver.c > > > @@ -19,6 +19,7 @@ static int sgx_open(struct inode *inode, struct file > > > *file) > > > struct sgx_encl *encl; > > > int ret; > > > > > > + sgx_inc_usage_count(); > > > > This should be done at the end of sgx_open() where the open cannot fail, > > since > > sgx_release() is not called if sgx_open() failed AFAICT. > > > Could you please elaborate a bit more on this? > In case sgx_inc_usage_count fails, we dont allocate resources yet, so what is > wrong?
It's fine to do (or even perhaps advicable) to do right at the get go, before doing anything else, because it is "keep alive counter". I.e., I think the call is at the right place. And now there is a proper rollback procedure, as my previous review comments have been adressed. > > Best Regards, > Elena. BR, Jarkko
