lguest: fix kvm-style hypercall handling on modern Intel Impact: fix guest crash ' If the host has VT support, then the guest doing a VMCALL will cause a General Protection Fault, not an Invalid Opcode fault. You won't notice this on AMD boxes, nor under kvm (these are my two normal testing environments). Signed-off-by: Rusty Russell Cc: lguest@ozlabs.org Cc: Matias Zabaljauregui --- drivers/lguest/x86/core.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/drivers/lguest/x86/core.c b/drivers/lguest/x86/core.c --- a/drivers/lguest/x86/core.c +++ b/drivers/lguest/x86/core.c @@ -345,15 +346,6 @@ static bool is_hypercall(struct lg_cpu * void lguest_arch_handle_trap(struct lg_cpu *cpu) { switch (cpu->regs->trapnum) { - case 13: /* We've intercepted a General Protection Fault. */ - /* Check if this was one of those annoying IN or OUT - * instructions which we need to emulate. If so, we just go - * back into the Guest after we've done it. */ - if (cpu->regs->errcode == 0) { - if (emulate_insn(cpu)) - return; - } - break; case 14: /* We've intercepted a Page Fault. */ /* The Guest accessed a virtual address that wasn't mapped. * This happens a lot: we don't actually set up most of the page @@ -398,6 +390,15 @@ void lguest_arch_handle_trap(struct lg_c * up the pointer now to indicate a hypercall is pending. */ cpu->hcall = (struct hcall_args *)cpu->regs; return; + case 13: /* We've intercepted a General Protection Fault. */ + /* Check if this was one of those annoying IN or OUT + * instructions which we need to emulate. If so, we just go + * back into the Guest after we've done it. */ + if (cpu->regs->errcode == 0) { + if (emulate_insn(cpu)) + return; + } + /* It can also be a hypercall: if cpu has VT support. */ case 6: /* kvm hypercalls trigger an invalid opcode fault (6). * We need to check if ring == GUEST_PL and