From 564346224daaa8f7222d7a92cdbb7bafde59ae6e Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Tue, 26 May 2009 20:54:41 +0930 Subject: [PATCH 1/1] lguest: fix on Intel when KVM loaded (unhandled trap 13) When KVM is loaded, and hence VT set up, the vmcall instruction in an lguest guest causes a #GP, not #UD. Signed-off-by: Rusty Russell Signed-off-by: Linus Torvalds --- drivers/lguest/x86/core.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/drivers/lguest/x86/core.c b/drivers/lguest/x86/core.c index 1a83910f674f..eaf722fe309a 100644 --- a/drivers/lguest/x86/core.c +++ b/drivers/lguest/x86/core.c @@ -358,6 +358,16 @@ void lguest_arch_handle_trap(struct lg_cpu *cpu) if (emulate_insn(cpu)) return; } + /* If KVM is active, the vmcall instruction triggers a + * General Protection Fault. Normally it triggers an + * invalid opcode fault (6): */ + case 6: + /* We need to check if ring == GUEST_PL and + * faulting instruction == vmcall. */ + if (is_hypercall(cpu)) { + rewrite_hypercall(cpu); + return; + } break; case 14: /* We've intercepted a Page Fault. */ /* The Guest accessed a virtual address that wasn't mapped. @@ -403,15 +413,6 @@ void lguest_arch_handle_trap(struct lg_cpu *cpu) * up the pointer now to indicate a hypercall is pending. */ cpu->hcall = (struct hcall_args *)cpu->regs; return; - case 6: - /* kvm hypercalls trigger an invalid opcode fault (6). - * We need to check if ring == GUEST_PL and - * faulting instruction == vmcall. */ - if (is_hypercall(cpu)) { - rewrite_hypercall(cpu); - return; - } - break; } /* We didn't handle the trap, so it needs to go to the Guest. */ -- 2.34.1