From cc6d4fbcef328acdc9fa7023e69f39f753f72fe1 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Mon, 22 Oct 2007 11:03:30 +1000 Subject: Introduce "hcall" pointer to indicate pending hypercall. Currently we look at the "trapnum" to see if the Guest wants a hypercall. But once the hypercall is done we have to reset trapnum to a bogus value, otherwise if we exit to userspace and return, we'd run the same hypercall twice (that was a nasty bug to find!). This has two main effects: 1) When Jes's patch changes the hypercall args to be a generic "struct hcall_args" we simply change the type of "lg->hcall". It's set by arch code, so if it has to copy args or something it can do so, and point "hcall" into lg->arch somewhere. 2) Async hypercalls only get run when an actual hypercall is pending. This simplfies the code a little and is a more logical semantic. Signed-off-by: Rusty Russell --- drivers/lguest/lg.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/lguest/lg.h') diff --git a/drivers/lguest/lg.h b/drivers/lguest/lg.h index 203d3100c3b4..662994b776cc 100644 --- a/drivers/lguest/lg.h +++ b/drivers/lguest/lg.h @@ -106,6 +106,9 @@ struct lguest u32 esp1; u8 ss1; + /* If a hypercall was asked for, this points to the arguments. */ + struct lguest_regs *hcall; + /* Do we need to stop what we're doing and return to userspace? */ int break_out; wait_queue_head_t break_wq; -- cgit v1.2.3