ia64/xen-unstable

changeset 13475:b4df7de0cbf7

[IA64] Fix oops message from timer_interrupton VTI domain

This patch intends to fix the oops message from timer_interrupt on
VTI domain. This problem occurred when we test PV-on-HVM driver by
ltp-20061121. Typical message shown as follows.

ltp Now Running...( Exception mode )
dom=domVTI
1 times
Unable to find swap-space signature
Oops: timer tick before it's due (itc=ed98bb5849,itm=ed98bb5849)
Oops: timer tick before it's due (itc=f20bca8ca3,itm=f20bca8ca3)
Oops: timer tick before it's due (itc=f4ea4e2b32,itm=f4ea4e2b32)
mmap1(7392): unaligned access to 0x60000fffffffb634, ip=0x200000000004fad0
mmap1(7392): unaligned access to 0x60000fffffffb634, ip=0x200000000004fad0
ltp End

These oops messages are generated because timer_interrupt checks
the condition itc > itm. Currently Xen-hypervisor outputs following
values, max(current_itc,vtm->last_itc). Sometimes oops message
appeared if we use the value of vtm->last_itc as ia64_get_itc()
return value, because the vtm->last_itc is same as itm. To fix this
issue, it needs to add return value like +1.

But, ia64_get_itc() is handled at vmx_asm_mov_from_ar@optvfault.S
and it works same logic of now_itc()@vlsapic.c. And these routines
shared vtm->last_itc. So I fix this problem by adding +1 at caller
of update_last_itc.

Signed-off-by: Atsushi SAKAI <sakaia@jp.fujitsu.com>
author awilliam@xenbuild2.aw
date Wed Jan 24 12:28:05 2007 -0700 (2007-01-24)
parents b8de061f3dc6
children 730e24a1594a
files xen/arch/ia64/vmx/vlsapic.c
line diff
     1.1 --- a/xen/arch/ia64/vmx/vlsapic.c	Wed Jan 24 12:21:37 2007 -0700
     1.2 +++ b/xen/arch/ia64/vmx/vlsapic.c	Wed Jan 24 12:28:05 2007 -0700
     1.3 @@ -171,7 +171,12 @@ static void vtm_timer_fn(void *data)
     1.4      } else
     1.5          vtm->pending = 1;
     1.6  
     1.7 -    update_last_itc(vtm, VCPU(vcpu, itm));  // update vITC
     1.8 +    /*
     1.9 +     * "+ 1" is for fixing oops message at timer_interrupt() on VTI guest. 
    1.10 +     * If oops checking condition changed to timer_after_eq() on VTI guest,
    1.11 +     * this parameter should be erased.
    1.12 +     */
    1.13 +    update_last_itc(vtm, VCPU(vcpu, itm) + 1);  // update vITC
    1.14  }
    1.15  
    1.16  void vtm_init(VCPU *vcpu)