From: David Vrabel Date: Wed, 11 Apr 2012 15:49:45 +0000 (+0100) Subject: x86: fix delta calculation in TSC deadline timer emulation X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=7d4928ae1f8490507deb59e2e430d96c974a70a2;p=xen.git 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 Acked-by: Jan Beulich Committed-by: Keir Fraser --- 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)