On Thu, 2015-12-11 at 05:44:42 UTC, Paul Mackerras wrote: > Currently, if HV KVM is configured but PR KVM isn't, we don't include > a test to see whether we were interrupted in KVM guest context for the > set of interrupts which get delivered directly to the guest by hardware > if they occur in the guest. This includes things like program > interrupts. > > However, the recent bug where userspace could set the MSR for a VCPU > to have an illegal value in the TS field, and thus cause a TM Bad Thing > type of program interrupt on the hrfid that enters the guest, showed that > we can never be completely sure that these interrupts can never occur > in the guest entry/exit code. If one of these interrupts does happen > and we have HV KVM configured but not PR KVM, then we end up trying to > run the handler in the host with the MMU set to the guest MMU context, > which generally ends badly. > > Thus, for robustness it is better to have the test in every interrupt > vector, so that if some way is found to trigger some interrupt in the > guest entry/exit path, we can handle it without immediately crashing > the host. > > This means that the distinction between KVMTEST and KVMTEST_PR goes > away. Thus we delete KVMTEST_PR and associated macros and use KVMTEST > everywhere that we previously used either KVMTEST_PR or KVMTEST. It > also means that SOFTEN_TEST_HV_201 becomes the same as SOFTEN_TEST_PR, > so we deleted SOFTEN_TEST_HV_201 and use SOFTEN_TEST_PR instead. > > Signed-off-by: Paul Mackerras <paulus@xxxxxxxxx> Applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/31a40e2b052c0f2b80df7b56 cheers -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
