From: Marcelo Tosatti <mtosatti@redhat.com> To: Anthony Liguori <aliguori@us.ibm.com> Cc: Jan Kiszka <jan.kiszka@siemens.com>, Marcelo Tosatti <mtosatti@redhat.com>, qemu-devel@nongnu.org, kvm@vger.kernel.org Subject: [PATCH 1/4] kvm: i8254: Cache kernel clock offset in KVMPITState Date: Tue, 14 Aug 2012 20:59:46 -0300 [thread overview] Message-ID: <205df4d1a87cbb14a50655fb2c0a987467fb29d6.1344988789.git.mtosatti@redhat.com> (raw) In-Reply-To: <cover.1344988789.git.mtosatti@redhat.com> From: Jan Kiszka <jan.kiszka@siemens.com> To prepare the final fix for clock calibration issues with the in-kernel PIT, we want to cache the offset between vmclock and the clock used by the in-kernel PIT. So far, we only need to update it when the VM state changes between running and stopped because we only read the in-kernel PIT state while the VM is running. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> --- hw/kvm/i8254.c | 38 ++++++++++++++++++++++++-------------- 1 files changed, 24 insertions(+), 14 deletions(-) diff --git a/hw/kvm/i8254.c b/hw/kvm/i8254.c index c5d3711..c235d80 100644 --- a/hw/kvm/i8254.c +++ b/hw/kvm/i8254.c @@ -35,7 +35,8 @@ typedef struct KVMPITState { PITCommonState pit; LostTickPolicy lost_tick_policy; - bool state_valid; + bool vm_stopped; + int64_t kernel_clock_offset; } KVMPITState; static int64_t abs64(int64_t v) @@ -43,19 +44,11 @@ static int64_t abs64(int64_t v) return v < 0 ? -v : v; } -static void kvm_pit_get(PITCommonState *pit) +static void kvm_pit_update_clock_offset(KVMPITState *s) { - 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; - } + int i; /* * Measure the delta between CLOCK_MONOTONIC, the base used for @@ -72,6 +65,21 @@ static void kvm_pit_get(PITCommonState *pit) clock_offset = offset; } } + s->kernel_clock_offset = clock_offset; +} + +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; + int i, ret; + + /* No need to re-read the state if VM is stopped. */ + if (s->vm_stopped) { + return; + } if (kvm_has_pit_state2()) { ret = kvm_vm_ioctl(kvm_state, KVM_GET_PIT2, &kpit); @@ -106,7 +114,7 @@ static void kvm_pit_get(PITCommonState *pit) sc->mode = kchan->mode; sc->bcd = kchan->bcd; sc->gate = kchan->gate; - sc->count_load_time = kchan->count_load_time + clock_offset; + sc->count_load_time = kchan->count_load_time + s->kernel_clock_offset; } sc = &pit->channels[0]; @@ -211,10 +219,12 @@ static void kvm_pit_vm_state_change(void *opaque, int running, KVMPITState *s = opaque; if (running) { - s->state_valid = false; + kvm_pit_update_clock_offset(s); + s->vm_stopped = false; } else { + kvm_pit_update_clock_offset(s); kvm_pit_get(&s->pit); - s->state_valid = true; + s->vm_stopped = true; } } -- 1.7.6.4
WARNING: multiple messages have this Message-ID (diff)
From: Marcelo Tosatti <mtosatti@redhat.com> To: Anthony Liguori <aliguori@us.ibm.com> Cc: Jan Kiszka <jan.kiszka@siemens.com>, Marcelo Tosatti <mtosatti@redhat.com>, qemu-devel@nongnu.org, kvm@vger.kernel.org Subject: [Qemu-devel] [PATCH 1/4] kvm: i8254: Cache kernel clock offset in KVMPITState Date: Tue, 14 Aug 2012 20:59:46 -0300 [thread overview] Message-ID: <205df4d1a87cbb14a50655fb2c0a987467fb29d6.1344988789.git.mtosatti@redhat.com> (raw) In-Reply-To: <cover.1344988789.git.mtosatti@redhat.com> From: Jan Kiszka <jan.kiszka@siemens.com> To prepare the final fix for clock calibration issues with the in-kernel PIT, we want to cache the offset between vmclock and the clock used by the in-kernel PIT. So far, we only need to update it when the VM state changes between running and stopped because we only read the in-kernel PIT state while the VM is running. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> --- hw/kvm/i8254.c | 38 ++++++++++++++++++++++++-------------- 1 files changed, 24 insertions(+), 14 deletions(-) diff --git a/hw/kvm/i8254.c b/hw/kvm/i8254.c index c5d3711..c235d80 100644 --- a/hw/kvm/i8254.c +++ b/hw/kvm/i8254.c @@ -35,7 +35,8 @@ typedef struct KVMPITState { PITCommonState pit; LostTickPolicy lost_tick_policy; - bool state_valid; + bool vm_stopped; + int64_t kernel_clock_offset; } KVMPITState; static int64_t abs64(int64_t v) @@ -43,19 +44,11 @@ static int64_t abs64(int64_t v) return v < 0 ? -v : v; } -static void kvm_pit_get(PITCommonState *pit) +static void kvm_pit_update_clock_offset(KVMPITState *s) { - 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; - } + int i; /* * Measure the delta between CLOCK_MONOTONIC, the base used for @@ -72,6 +65,21 @@ static void kvm_pit_get(PITCommonState *pit) clock_offset = offset; } } + s->kernel_clock_offset = clock_offset; +} + +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; + int i, ret; + + /* No need to re-read the state if VM is stopped. */ + if (s->vm_stopped) { + return; + } if (kvm_has_pit_state2()) { ret = kvm_vm_ioctl(kvm_state, KVM_GET_PIT2, &kpit); @@ -106,7 +114,7 @@ static void kvm_pit_get(PITCommonState *pit) sc->mode = kchan->mode; sc->bcd = kchan->bcd; sc->gate = kchan->gate; - sc->count_load_time = kchan->count_load_time + clock_offset; + sc->count_load_time = kchan->count_load_time + s->kernel_clock_offset; } sc = &pit->channels[0]; @@ -211,10 +219,12 @@ static void kvm_pit_vm_state_change(void *opaque, int running, KVMPITState *s = opaque; if (running) { - s->state_valid = false; + kvm_pit_update_clock_offset(s); + s->vm_stopped = false; } else { + kvm_pit_update_clock_offset(s); kvm_pit_get(&s->pit); - s->state_valid = true; + s->vm_stopped = true; } } -- 1.7.6.4
next prev parent reply other threads:[~2012-08-14 23:59 UTC|newest] Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top 2012-08-14 23:59 [PATCH 0/4] [PULL] qemu-kvm.git uq/master queue Marcelo Tosatti 2012-08-14 23:59 ` [Qemu-devel] " Marcelo Tosatti 2012-08-14 23:59 ` Marcelo Tosatti [this message] 2012-08-14 23:59 ` [Qemu-devel] [PATCH 1/4] kvm: i8254: Cache kernel clock offset in KVMPITState Marcelo Tosatti 2012-08-14 23:59 ` [PATCH 2/4] kvm: i8254: Finish time conversion fix Marcelo Tosatti 2012-08-14 23:59 ` [Qemu-devel] " Marcelo Tosatti 2012-08-14 23:59 ` [PATCH 3/4] kvmvapic: Disable if there is insufficient memory Marcelo Tosatti 2012-08-14 23:59 ` [Qemu-devel] " Marcelo Tosatti 2012-08-14 23:59 ` [PATCH 4/4] update-linux-headers.sh: Pull in asm-generic/kvm_para.h Marcelo Tosatti 2012-08-14 23:59 ` [Qemu-devel] " Marcelo Tosatti 2012-08-15 7:46 ` [PATCH 0/4] [PULL] qemu-kvm.git uq/master queue Peter Maydell 2012-08-15 7:46 ` [Qemu-devel] " Peter Maydell 2012-08-15 18:10 ` Marcelo Tosatti 2012-08-15 18:10 ` [Qemu-devel] " Marcelo Tosatti 2012-08-15 19:48 ` Anthony Liguori 2012-08-15 19:48 ` [Qemu-devel] " Anthony Liguori
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