From 0614cb82ca27bdffb83864e693fc29e29182667b Mon Sep 17 00:00:00 2001 From: Jim Meyering Date: Thu, 10 May 2012 18:19:47 +0200 Subject: kvm/apic: correct short memset kvm_put_apic_state's attempt to clear *kapic before setting its bits cleared sizeof(void*) bytes (no more than 8) rather than the intended 1024 (KVM_APIC_REG_SIZE) bytes. Spotted by coverity. Signed-off-by: Jim Meyering Signed-off-by: Avi Kivity --- hw/kvm/apic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/hw/kvm/apic.c b/hw/kvm/apic.c index 8ba4079025..80e3e48333 100644 --- a/hw/kvm/apic.c +++ b/hw/kvm/apic.c @@ -30,7 +30,7 @@ void kvm_put_apic_state(DeviceState *d, struct kvm_lapic_state *kapic) APICCommonState *s = DO_UPCAST(APICCommonState, busdev.qdev, d); int i; - memset(kapic, 0, sizeof(kapic)); + memset(kapic, 0, sizeof(*kapic)); kvm_apic_set_reg(kapic, 0x2, s->id << 24); kvm_apic_set_reg(kapic, 0x8, s->tpr); kvm_apic_set_reg(kapic, 0xd, s->log_dest << 24); -- cgit v1.2.3 From 0cdd3d14447da1a04e778c219c77db8b96f9cf33 Mon Sep 17 00:00:00 2001 From: Jan Kiszka Date: Wed, 6 Jun 2012 16:28:42 +0200 Subject: kvm: i8254: Fix conversion of in-kernel to userspace state Due to a offset between the clock used to generate the in-kernel count_load_time (CLOCK_MONOTONIC) and the clock used for processing this in userspace (vm_clock), reading back the output of PIT channel 2 via port 0x61 was broken. One use cases that suffered from it was the CPU frequency calibration of SeaBIOS, which also affected IDE/AHCI timeouts. This fixes it by calibrating the offset between both clocks on kvm_pit_get and adjusting the kernel value before saving it in the userspace state. As the calibration only works while the vm_clock is running, we cache the in-kernel state across stopped phases. Signed-off-by: Jan Kiszka Signed-off-by: Avi Kivity --- hw/kvm/i8254.c | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 52 insertions(+), 5 deletions(-) diff --git a/hw/kvm/i8254.c b/hw/kvm/i8254.c index bb5fe07d1e..c5d3711a04 100644 --- a/hw/kvm/i8254.c +++ b/hw/kvm/i8254.c @@ -23,31 +23,63 @@ * THE SOFTWARE. */ #include "qemu-timer.h" +#include "sysemu.h" #include "hw/i8254.h" #include "hw/i8254_internal.h" #include "kvm.h" #define KVM_PIT_REINJECT_BIT 0 +#define CALIBRATION_ROUNDS 3 + typedef struct KVMPITState { PITCommonState pit; LostTickPolicy lost_tick_policy; + bool state_valid; } KVMPITState; -static void kvm_pit_get(PITCommonState *s) +static int64_t abs64(int64_t v) { + return v < 0 ? -v : v; +} + +static void kvm_pit_get(PITCommonState *pit) +{ + KVMPITState *s = DO_UPCAST(KVMPITState, pit, pit); struct kvm_pit_state2 kpit; struct kvm_pit_channel_state *kchan; struct PITChannelState *sc; + int64_t offset, clock_offset; + struct timespec ts; int i, ret; + if (s->state_valid) { + return; + } + + /* + * Measure the delta between CLOCK_MONOTONIC, the base used for + * kvm_pit_channel_state::count_load_time, and vm_clock. Take the + * minimum of several samples to filter out scheduling noise. + */ + clock_offset = INT64_MAX; + for (i = 0; i < CALIBRATION_ROUNDS; i++) { + offset = qemu_get_clock_ns(vm_clock); + clock_gettime(CLOCK_MONOTONIC, &ts); + offset -= ts.tv_nsec; + offset -= (int64_t)ts.tv_sec * 1000000000; + if (abs64(offset) < abs64(clock_offset)) { + clock_offset = offset; + } + } + if (kvm_has_pit_state2()) { ret = kvm_vm_ioctl(kvm_state, KVM_GET_PIT2, &kpit); if (ret < 0) { fprintf(stderr, "KVM_GET_PIT2 failed: %s\n", strerror(ret)); abort(); } - s->channels[0].irq_disabled = kpit.flags & KVM_PIT_FLAGS_HPET_LEGACY; + pit->channels[0].irq_disabled = kpit.flags & KVM_PIT_FLAGS_HPET_LEGACY; } else { /* * kvm_pit_state2 is superset of kvm_pit_state struct, @@ -61,7 +93,7 @@ static void kvm_pit_get(PITCommonState *s) } for (i = 0; i < 3; i++) { kchan = &kpit.channels[i]; - sc = &s->channels[i]; + sc = &pit->channels[i]; sc->count = kchan->count; sc->latched_count = kchan->latched_count; sc->count_latched = kchan->count_latched; @@ -74,10 +106,10 @@ static void kvm_pit_get(PITCommonState *s) sc->mode = kchan->mode; sc->bcd = kchan->bcd; sc->gate = kchan->gate; - sc->count_load_time = kchan->count_load_time; + sc->count_load_time = kchan->count_load_time + clock_offset; } - sc = &s->channels[0]; + sc = &pit->channels[0]; sc->next_transition_time = pit_get_next_transition_time(sc, sc->count_load_time); } @@ -173,6 +205,19 @@ static void kvm_pit_irq_control(void *opaque, int n, int enable) kvm_pit_put(pit); } +static void kvm_pit_vm_state_change(void *opaque, int running, + RunState state) +{ + KVMPITState *s = opaque; + + if (running) { + s->state_valid = false; + } else { + kvm_pit_get(&s->pit); + s->state_valid = true; + } +} + static int kvm_pit_initfn(PITCommonState *pit) { KVMPITState *s = DO_UPCAST(KVMPITState, pit, pit); @@ -215,6 +260,8 @@ static int kvm_pit_initfn(PITCommonState *pit) qdev_init_gpio_in(&pit->dev.qdev, kvm_pit_irq_control, 1); + qemu_add_vm_change_state_handler(kvm_pit_vm_state_change, s); + return 0; } -- cgit v1.2.3