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authorDavid Vrabel <david.vrabel@citrix.com>2012-04-11 16:49:45 +0100
committerDavid Vrabel <david.vrabel@citrix.com>2012-04-11 16:49:45 +0100
commit7d4928ae1f8490507deb59e2e430d96c974a70a2 (patch)
tree32bed570c62252f77fe6d21e6f6f501fb81fd4d6 /xen/arch/x86/hvm/vlapic.c
parent37136d68c45604a7d8e51513cbd00c2a99321716 (diff)
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x86: fix delta calculation in TSC deadline timer emulation
In the virtual LAPIC, correct the delta calculation when emulating the TSC deadline timer. Without this fix, XenServer (which is based on Xen 4.1) does not work when running as an HVM guest. dom0 fails to boot because its timer interrupts are very delayed (by several minutes in some cases). Signed-off-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Jan Beulich <jbeulich@suse.com> Committed-by: Keir Fraser <keir@xen.org>
Diffstat (limited to 'xen/arch/x86/hvm/vlapic.c')
-rw-r--r--xen/arch/x86/hvm/vlapic.c12
1 files changed, 4 insertions, 8 deletions
diff --git a/xen/arch/x86/hvm/vlapic.c b/xen/arch/x86/hvm/vlapic.c
index 8401756de9..abdb556314 100644
--- a/xen/arch/x86/hvm/vlapic.c
+++ b/xen/arch/x86/hvm/vlapic.c
@@ -898,7 +898,6 @@ uint64_t vlapic_tdt_msr_get(struct vlapic *vlapic)
void vlapic_tdt_msr_set(struct vlapic *vlapic, uint64_t value)
{
uint64_t guest_tsc;
- uint64_t guest_time;
struct vcpu *v = vlapic_vcpu(vlapic);
/* may need to exclude some other conditions like vlapic->hw.disabled */
@@ -910,12 +909,10 @@ void vlapic_tdt_msr_set(struct vlapic *vlapic, uint64_t value)
/* new_value = 0, >0 && <= now, > now */
guest_tsc = hvm_get_guest_tsc(v);
- guest_time = hvm_get_guest_time(v);
if ( value > guest_tsc )
{
- uint64_t delta = value - v->arch.hvm_vcpu.cache_tsc_offset;
- delta = gtsc_to_gtime(v->domain, delta);
- delta = max_t(s64, delta - guest_time, 0);
+ uint64_t delta = gtsc_to_gtime(v->domain, value - guest_tsc);
+ delta = max_t(s64, delta, 0);
HVM_DBG_LOG(DBG_LEVEL_VLAPIC_TIMER, "delta[0x%016"PRIx64"]", delta);
@@ -949,9 +946,8 @@ void vlapic_tdt_msr_set(struct vlapic *vlapic, uint64_t value)
HVM_DBG_LOG(DBG_LEVEL_VLAPIC_TIMER,
"tdt_msr[0x%016"PRIx64"],"
- " gtsc[0x%016"PRIx64"],"
- " gtime[0x%016"PRIx64"]",
- vlapic->hw.tdt_msr, guest_tsc, guest_time);
+ " gtsc[0x%016"PRIx64"]",
+ vlapic->hw.tdt_msr, guest_tsc);
}
static int __vlapic_accept_pic_intr(struct vcpu *v)