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authorRusty Russell <rusty@rustcorp.com.au>2007-10-22 11:03:30 +1000
committerRusty Russell <rusty@rustcorp.com.au>2007-10-23 15:49:52 +1000
commitcc6d4fbcef328acdc9fa7023e69f39f753f72fe1 (patch)
tree860672e7da1a3516e36dd40f962552451ef0bcf2 /drivers/lguest/lg.h
parent4614a3a3b638dfd7a67d0237944f6a76331af61d (diff)
downloadop-kernel-dev-cc6d4fbcef328acdc9fa7023e69f39f753f72fe1.zip
op-kernel-dev-cc6d4fbcef328acdc9fa7023e69f39f753f72fe1.tar.gz
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 <rusty@rustcorp.com.au>
Diffstat (limited to 'drivers/lguest/lg.h')
-rw-r--r--drivers/lguest/lg.h3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/lguest/lg.h b/drivers/lguest/lg.h
index 203d310..662994b 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;
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