diff options
| author | Rusty Russell <rusty@rustcorp.com.au> | 2007-10-22 05:03:30 +0400 |
|---|---|---|
| committer | Rusty Russell <rusty@rustcorp.com.au> | 2007-10-23 09:49:52 +0400 |
| commit | cc6d4fbcef328acdc9fa7023e69f39f753f72fe1 (patch) | |
| tree | 860672e7da1a3516e36dd40f962552451ef0bcf2 /drivers/lguest/core.c | |
| parent | 4614a3a3b638dfd7a67d0237944f6a76331af61d (diff) | |
| download | linux-cc6d4fbcef328acdc9fa7023e69f39f753f72fe1.tar.xz | |
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/core.c')
| -rw-r--r-- | drivers/lguest/core.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/lguest/core.c b/drivers/lguest/core.c index 06869a2d3b40..02556bae9e9f 100644 --- a/drivers/lguest/core.c +++ b/drivers/lguest/core.c @@ -198,10 +198,10 @@ int run_guest(struct lguest *lg, unsigned long __user *user) { /* We stop running once the Guest is dead. */ while (!lg->dead) { - /* First we run any hypercalls the Guest wants done: either in - * the hypercall ring in "struct lguest_data", or directly by - * using int 31 (LGUEST_TRAP_ENTRY). */ - do_hypercalls(lg); + /* First we run any hypercalls the Guest wants done. */ + if (lg->hcall) + do_hypercalls(lg); + /* It's possible the Guest did a SEND_DMA hypercall to the * Launcher, in which case we return from the read() now. */ if (lg->dma_is_pending) { |