> Another day, another CPL patch... > > It turns out that the simple approach of getting CPL from SS.DPL > broke x86/taskswitch2.flat. To fix that, already "imagine" that the > CPL is CS.RPL, or 3 for VM86 tasks, while loading segment descriptors > during task switches. This removes the hack where task switches call > kvm_set_rflags to override the VM flag (patch 2). My understanding about this problem is that during task switch, the CPL might be inconsistent with SS.DPL. This breaks the assumption of previous patch (i.e. patch 4). To fix this problem, we have to rely on CS.RPL to figure out CPL. If so , my question: is there other special cases similar to task switch which can break patch 4? > > While at it, add a new privilege test during task switches that is > missing. > > Patch 4 is the same as before. > > Paolo Bonzini (4): > KVM: x86: use new CS.RPL as CPL during task switch > KVM: x86: drop set_rflags callback > KVM: x86: check CS.DPL against RPL during task switch > KVM: x86: get CPL from SS.DPL > > arch/x86/include/asm/kvm_emulate.h | 1 - > arch/x86/include/asm/kvm_host.h | 1 - > arch/x86/kvm/emulate.c | 63 ++++++++++++++++++++++---------------- > arch/x86/kvm/svm.c | 35 +++++++++------------ > arch/x86/kvm/vmx.c | 24 +++------------ > arch/x86/kvm/x86.c | 6 ---- > 6 files changed, 54 insertions(+), 76 deletions(-) -- 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
