From fa666c10f2f3e15685ff88abd3bc433ddce012d6 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Tue, 15 Jul 2014 21:46:02 +0200 Subject: [PATCH] Revert "kvmclock: Ensure time in migration never goes backward" This reverts commit a096b3a6732f846ec57dc28b47ee9435aa0609bf. This patch caused a hang that was fixed by commit 9b17868 (kvmclock: Ensure proper env->tsc value for kvmclock_current_nsec calculation, 2014-06-03), and we just had to revert that commit. Drop this one too. Cc: agraf@suse.de Cc: mtosatti@redhat.com Cc: qemu-stable@nongnu.org Signed-off-by: Paolo Bonzini --- hw/i386/kvm/clock.c | 48 --------------------------------------------- 1 file changed, 48 deletions(-) diff --git a/hw/i386/kvm/clock.c b/hw/i386/kvm/clock.c index feb5fc5109..07b9c0e581 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" @@ -35,47 +34,6 @@ 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) -{ - CPUState *cpu = first_cpu; - 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) @@ -87,15 +45,9 @@ 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);