>>> On 19.10.18 at 17:59, <andrew.coop...@citrix.com> wrote: > On 19/10/18 15:28, Wei Liu wrote: >> @@ -347,6 +352,7 @@ void subarch_percpu_traps_init(void) >> /* Common SYSCALL parameters. */ >> wrmsrl(MSR_STAR, XEN_MSR_STAR); >> wrmsrl(MSR_SYSCALL_MASK, XEN_SYSCALL_MASK); >> +#endif > > It would be a wise precaution to initialise these MSRs to 0 in the !PV > case, so we don't retain stale values.
If anything, EFER.SCE needs to be kept clear, as that's what controls whether SYSCALL would raise #GP(0). But without a PV domain around, nothing can access the host values of these MSRs in the first place, so instead we could simplify some context switching by never restoring host values, and only ever loading guest ones. Except that, of course, VMLOAD is an all-or-nothing insn, and we need to use to get TR loaded. Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
