Seems no issue now. Thanks all.
On 2019-07-02 at 09:52:39 +0800, Li Wang wrote: > On Tue, Jul 2, 2019 at 12:04 AM Ricardo Neri < > [email protected]> wrote: > > > On Mon, Jul 01, 2019 at 08:57:28PM +0800, Li Wang wrote: > > > On Mon, Jul 1, 2019 at 8:02 PM Paolo Bonzini <[email protected]> > > wrote: > > > > > > > On 01/07/19 09:50, Li Wang wrote: > > > > > Hello there, > > > > > > > > > > LTP/umip_basic_test get failed on KVM UMIP > > > > > system(kernel-v5.2-rc4.x86_64). The test is only trying to do > > > > > asm volatile("smsw %0\n" : "=m" (val)); > > > > > and expect to get SIGSEGV in this SMSW operation, but it exits with 0 > > > > > unexpectedly. > > > > > > > > In addition to what Thomas said, perhaps you are using a host that does > > > > *not* have UMIP, and configuring KVM to emulate it(*). In that case, > > it > > > > is not possible to intercept SMSW, and therefore it will incorrectly > > > > succeed. > > > > > > > > > > Right, I checked the host system, and confirmed that CPU doesn't support > > > UMIP. > > > > > > > > > > > Paolo > > > > > > > > (*) before the x86 people jump at me, this won't happen unless you > > > > explicitly pass an option to QEMU, such as "-cpu host,+umip". :) The > > > > incorrect emulation of SMSW when CR4.UMIP=1 is why. > > > > > > > Good to know this, is there any document for that declaration? It seems > > > neither LTP issue nor kernel bug here. But anyway we'd better do > > something > > > to avoid the error in the test. > > > > The test case already checks for umip in /proc/cpuinfo, right? And in > > long mode it always expects a SIGSEGV signal. If you did not add -cpu > > host,+umip, > > how come umip was present in /proc/cpuinfo? > > > > Yes, right. > > But the KVM guest is not customized in manual, I reserved that system for > automation test and did not aware of the '-cpu host,+umip,' parameter until > Paolo points it out. In the last email, I was hoping to find a way to > recognize this situation for the LTP test intelligently. > > Thank you all for a reply to this. > > -- > Regards, > Li Wang
