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authorDavid Vrabel <david.vrabel@citrix.com>2012-04-11 19:41:14 +0100
committerDavid Vrabel <david.vrabel@citrix.com>2012-04-11 19:41:14 +0100
commitf0ffe0dfcb801b7602ae78a6cd76aa6f52b8707f (patch)
tree9a4a2187b300a3abf2e6f1287880b56cedb33bc8
parent26b9db9bd2221562146805f5b590752ff20ff15b (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> xen-unstable changeset: 25191:a95fc7decc83 xen-unstable date: Wed Apr 11 16:49:45 2012 +0100
-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 b4142875ef..3af41cc7c5 100644
--- a/xen/arch/x86/hvm/vlapic.c
+++ b/xen/arch/x86/hvm/vlapic.c
@@ -889,7 +889,6 @@ 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 */
@@ -901,12 +900,10 @@ 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);
@@ -940,9 +937,8 @@ 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)