Jan Beulich
2007-Jun-19 09:40 UTC
[Xen-devel] [PATCH, resubmit] x86/hvm: determine shared info format earlier
Latch guest shared info format when hypercall page is being set up rather
than during an arbitrarily selected hypercall.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Index: 2007-06-18/xen/arch/x86/hvm/hvm.c
==================================================================---
2007-06-18.orig/xen/arch/x86/hvm/hvm.c 2007-06-18 08:34:29.000000000 +0200
+++ 2007-06-18/xen/arch/x86/hvm/hvm.c 2007-06-18 10:22:58.000000000 +0200
@@ -836,6 +836,15 @@ void hvm_update_guest_cr3(struct vcpu *v
void hvm_hypercall_page_initialise(struct domain *d,
void *hypercall_page)
{
+#ifdef __x86_64__
+ /*
+ * Since this operation is one of the very first executed by PV drivers
+ * on initialisation or after save/restore, it is a sensible point at
+ * which to sample the execution mode of the guest and latch 32- or 64-
+ * bit format for shared state.
+ */
+ d->arch.has_32bit_shinfo = (hvm_guest_x86_mode(current) != 8);
+#endif
hvm_funcs.init_hypercall_page(d, hypercall_page);
}
@@ -1066,10 +1075,8 @@ long do_hvm_op(unsigned long op, XEN_GUE
case HVM_PARAM_CALLBACK_IRQ:
hvm_set_callback_via(d, a.value);
/*
- * Since this operation is one of the very first executed
- * by PV drivers on initialisation or after save/restore, it
- * is a sensible point at which to sample the execution mode of
- * the guest and latch 32- or 64-bit format for shared state.
+ * For compatibility with older PV drivers, also latch guest
+ * execution mode here.
*/
d->arch.has_32bit_shinfo = (hvm_guest_x86_mode(current) !=
8);
break;
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Keir Fraser
2007-Jun-19 09:45 UTC
Re: [Xen-devel] [PATCH, resubmit] x86/hvm: determine shared info format earlier
On 19/6/07 10:40, "Jan Beulich" <jbeulich@novell.com> wrote:> Latch guest shared info format when hypercall page is being set up rather > than during an arbitrarily selected hypercall. > > Signed-off-by: Jan Beulich <jbeulich@novell.com>I like having the latch at the current place because it will work with (yes, slightly broken) older PV drivers which do not re-init the hypercall page after save/restore, but which *do* re-init the callback-irq value. I''d be happy to have the latch in *both* places though -- would this appease you? -- Keir _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel