From 62ac85ec7c8e41b0454bdec0e0a9c7d5adc39280 Mon Sep 17 00:00:00 2001 From: "Dr. David Alan Gilbert (git)" Date: Wed, 22 Oct 2014 09:46:34 +0200 Subject: [PATCH 3/6] Revert "kvmclock: Ensure time in migration never goes backward" Message-id: <1413971197-4624-3-git-send-email-dgilbert@redhat.com> Patchwork-id: 61788 O-Subject: [RHEL-7.1 qemu-kvm PATCH 2/5] Revert "kvmclock: Ensure time in migration never goes backward" Bugzilla: 1098602 1130428 RH-Acked-by: Marcelo Tosatti RH-Acked-by: Eduardo Habkost RH-Acked-by: Paolo Bonzini From: "Dr. David Alan Gilbert" This reverts commit 4b6035c2a739bc4c086abbb36f0883a1178a8f1c. The equivalent upstream revert is Paolo's fa666c10f2f3e15685ff Signed-off-by: Dr. David Alan Gilbert Signed-off-by: Miroslav Rezanina --- hw/i386/kvm/clock.c | 49 ------------------------------------------------- 1 file changed, 49 deletions(-) diff --git a/hw/i386/kvm/clock.c b/hw/i386/kvm/clock.c index 1f2a26e..6d6f3a7 100644 --- a/hw/i386/kvm/clock.c +++ b/hw/i386/kvm/clock.c @@ -14,7 +14,6 @@ */ #include "qemu-common.h" -#include "qemu/host-utils.h" #include "sysemu/sysemu.h" #include "sysemu/kvm.h" #include "hw/sysbus.h" @@ -29,48 +28,6 @@ typedef struct KVMClockState { bool clock_valid; } KVMClockState; -struct pvclock_vcpu_time_info { - uint32_t version; - uint32_t pad0; - uint64_t tsc_timestamp; - uint64_t system_time; - uint32_t tsc_to_system_mul; - int8_t tsc_shift; - uint8_t flags; - uint8_t pad[2]; -} __attribute__((__packed__)); /* 32 bytes */ - -static uint64_t kvmclock_current_nsec(KVMClockState *s) -{ - CPUArchState *acpu = first_cpu; - CPUState *cpu = ENV_GET_CPU(acpu); - CPUX86State *env = cpu->env_ptr; - hwaddr kvmclock_struct_pa = env->system_time_msr & ~1ULL; - uint64_t migration_tsc = env->tsc; - struct pvclock_vcpu_time_info time; - uint64_t delta; - uint64_t nsec_lo; - uint64_t nsec_hi; - uint64_t nsec; - - if (!(env->system_time_msr & 1ULL)) { - /* KVM clock not active */ - return 0; - } - - cpu_physical_memory_read(kvmclock_struct_pa, &time, sizeof(time)); - - delta = migration_tsc - time.tsc_timestamp; - if (time.tsc_shift < 0) { - delta >>= -time.tsc_shift; - } else { - delta <<= time.tsc_shift; - } - - mulu64(&nsec_lo, &nsec_hi, delta, time.tsc_to_system_mul); - nsec = (nsec_lo >> 32) | (nsec_hi << 32); - return nsec + time.system_time; -} static void kvmclock_vm_state_change(void *opaque, int running, RunState state) @@ -82,15 +39,9 @@ static void kvmclock_vm_state_change(void *opaque, int running, if (running) { struct kvm_clock_data data; - uint64_t time_at_migration = kvmclock_current_nsec(s); s->clock_valid = false; - /* We can't rely on the migrated clock value, just discard it */ - if (time_at_migration) { - s->clock = time_at_migration; - } - data.clock = s->clock; data.flags = 0; ret = kvm_vm_ioctl(kvm_state, KVM_SET_CLOCK, &data); -- 1.8.3.1