On Thu, Dec 13, 2012 at 04:05:55AM +0800, Xiao Guangrong wrote: > On 12/12/2012 07:36 AM, Marcelo Tosatti wrote: > > On Mon, Dec 10, 2012 at 05:11:35PM +0800, Xiao Guangrong wrote: > >> Changelog: > >> There are some changes from Marcelo and Gleb's review, thank you all! > >> - access indirect_shadow_pages in the protection of mmu-lock > >> - fix the issue when unhandleable instruction access on large page > >> - add a new test case for large page > >> > >> The current reexecute_instruction can not well detect the failed instruction > >> emulation. It allows guest to retry all the instructions except it accesses > >> on error pfn. > >> > >> For example, these cases can not be detected: > >> - for tdp used > >> currently, it refused to retry all instructions. If nested npt is used, the > >> emulation may be caused by shadow page, it can be fixed by unshadow the > >> shadow page. > >> > >> - for shadow mmu > >> some cases are nested-write-protect, for example, if the page we want to > >> write is used as PDE but it chains to itself. Under this case, we should > >> stop the emulation and report the case to userspace. > >> > >> There are two test cases based on kvm-unit-test can trigger a infinite loop on > >> current code (ept = 0), after this patchset, it can report the error to Qemu. > >> > >> Subject: [PATCH] access test: test unhandleable instruction > >> > >> Test the instruction which can not be handled by kvm > >> > >> Signed-off-by: Xiao Guangrong <xiaoguangrong@xxxxxxxxxxxxxxxxxx> > > > > Please submit the test for inclusion. There should be some way to make > > it fail.. > > Yes. > > But it is not easy. If the test cases run normally, kvm will report a error to Qemu > then Qemu will exit the vcpu thread after dumping the vcpu state. > > We need to do something to let guest can be aware that the error report is triggered. > I guess we can add a option in Qemu, say '-notify-guest' and allow Qemu to inject #GP > to guest with a special ERROR_CODE if error is reported. > > > program a timer interrupt and #GP? > > Could you please explain the detail? Before the instruction which writes continuously to the pagetable, arm say lapic timer. #GP on the interrupt handler and test with failure. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
