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Re: [Qemu-devel] [PATCH 07/10] serial: fixing vmstate for save/restore
From: |
Paolo Bonzini |
Subject: |
Re: [Qemu-devel] [PATCH 07/10] serial: fixing vmstate for save/restore |
Date: |
Wed, 10 Sep 2014 12:41:17 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.0 |
Il 09/09/2014 14:30, Paolo Bonzini ha scritto:
> From: Pavel Dovgalyuk <address@hidden>
>
> Some fields were added to VMState by this patch to preserve correct
> loading of the serial port controller state.
> Updating FCR value while loading was also modified to disable generating
> an interrupt by loadvm.
This is actually not entirely correct because...
> Signed-off-by: Pavel Dovgalyuk <address@hidden>
> Signed-off-by: Paolo Bonzini <address@hidden>
> ---
> hw/char/serial.c | 265
> +++++++++++++++++++++++++++++++++++++++++++++----------
> 1 file changed, 220 insertions(+), 45 deletions(-)
>
> diff --git a/hw/char/serial.c b/hw/char/serial.c
> index 764e184..2b04927 100644
> --- a/hw/char/serial.c
> +++ b/hw/char/serial.c
> @@ -272,6 +272,64 @@ static gboolean serial_xmit(GIOChannel *chan,
> GIOCondition cond, void *opaque)
> }
>
>
> +/* Setter for FCR.
> + is_load flag means, that value is set while loading VM state
> + and interrupt should not be invoked */
> +static void serial_write_fcr(void *opaque, uint32_t val, int is_load)
> +{
> + SerialState *s = opaque;
> + val = val & 0xFF;
> +
> + if (s->fcr == val) {
> + return;
> + }
> +
> + /* Did the enable/disable flag change? If so, make sure FIFOs get
> flushed */
> + if ((val ^ s->fcr) & UART_FCR_FE) {
> + val |= UART_FCR_XFR | UART_FCR_RFR;
> + }
... if the value of the FE bit changes, this will nullify the change you
made to send/restore FIFOs. The handling of RFR/XFR must remain in
serial_ioport_write, and serial_write_fcr must receive the final value
(masked by 0xc9). I can fix this up.
Paolo
> + /* FIFO clear */
> +
> + if (val & UART_FCR_RFR) {
> + timer_del(s->fifo_timeout_timer);
> + s->timeout_ipending = 0;
> + fifo8_reset(&s->recv_fifo);
> + }
> +
> + if (val & UART_FCR_XFR) {
> + fifo8_reset(&s->xmit_fifo);
> + }
> +
> + if (val & UART_FCR_FE) {
> + s->iir |= UART_IIR_FE;
> + /* Set recv_fifo trigger Level */
> + switch (val & 0xC0) {
> + case UART_FCR_ITL_1:
> + s->recv_fifo_itl = 1;
> + break;
> + case UART_FCR_ITL_2:
> + s->recv_fifo_itl = 4;
> + break;
> + case UART_FCR_ITL_3:
> + s->recv_fifo_itl = 8;
> + break;
> + case UART_FCR_ITL_4:
> + s->recv_fifo_itl = 14;
> + break;
> + }
> + } else {
> + s->iir &= ~UART_IIR_FE;
> + }
> +
> + /* Set fcr - or at least the bits in it that are supposed to "stick" */
> + s->fcr = val & 0xC9;
> +
> + if (!is_load) {
> + serial_update_irq(s);
> + }
> +}
> +
> static void serial_ioport_write(void *opaque, hwaddr addr, uint64_t val,
> unsigned size)
> {
> @@ -327,50 +385,7 @@ static void serial_ioport_write(void *opaque, hwaddr
> addr, uint64_t val,
> }
> break;
> case 2:
> - val = val & 0xFF;
> -
> - if (s->fcr == val)
> - break;
> -
> - /* Did the enable/disable flag change? If so, make sure FIFOs get
> flushed */
> - if ((val ^ s->fcr) & UART_FCR_FE)
> - val |= UART_FCR_XFR | UART_FCR_RFR;
> -
> - /* FIFO clear */
> -
> - if (val & UART_FCR_RFR) {
> - timer_del(s->fifo_timeout_timer);
> - s->timeout_ipending=0;
> - fifo8_reset(&s->recv_fifo);
> - }
> -
> - if (val & UART_FCR_XFR) {
> - fifo8_reset(&s->xmit_fifo);
> - }
> -
> - if (val & UART_FCR_FE) {
> - s->iir |= UART_IIR_FE;
> - /* Set recv_fifo trigger Level */
> - switch (val & 0xC0) {
> - case UART_FCR_ITL_1:
> - s->recv_fifo_itl = 1;
> - break;
> - case UART_FCR_ITL_2:
> - s->recv_fifo_itl = 4;
> - break;
> - case UART_FCR_ITL_3:
> - s->recv_fifo_itl = 8;
> - break;
> - case UART_FCR_ITL_4:
> - s->recv_fifo_itl = 14;
> - break;
> - }
> - } else
> - s->iir &= ~UART_IIR_FE;
> -
> - /* Set fcr - or at least the bits in it that are supposed to "stick"
> */
> - s->fcr = val & 0xC9;
> - serial_update_irq(s);
> + serial_write_fcr(s, val, 0);
> break;
> case 3:
> {
> @@ -590,6 +605,14 @@ static void serial_pre_save(void *opaque)
> s->fcr_vmstate = s->fcr;
> }
>
> +static int serial_pre_load(void *opaque)
> +{
> + SerialState *s = (SerialState *)opaque;
> + s->thr_ipending = -1;
> + s->poll_msl = -1;
> + return 0;
> +}
> +
> static int serial_post_load(void *opaque, int version_id)
> {
> SerialState *s = opaque;
> @@ -597,17 +620,139 @@ static int serial_post_load(void *opaque, int
> version_id)
> if (version_id < 3) {
> s->fcr_vmstate = 0;
> }
> + if (s->thr_ipending == -1) {
> + s->thr_ipending = ((s->iir & UART_IIR_ID) == UART_IIR_THRI);
> + }
> + s->last_break_enable = (s->lcr >> 6) & 1;
> /* Initialize fcr via setter to perform essential side-effects */
> - serial_ioport_write(s, 0x02, s->fcr_vmstate, 1);
> + serial_write_fcr(s, s->fcr_vmstate, 1);
> serial_update_parameters(s);
> return 0;
> }
>
> +static bool serial_thr_ipending_needed(void *opaque)
> +{
> + SerialState *s = opaque;
> + bool expected_value = ((s->iir & UART_IIR_ID) == UART_IIR_THRI);
> + return s->thr_ipending != expected_value;
> +}
> +
> +const VMStateDescription vmstate_serial_thr_ipending = {
> + .name = "serial/thr_ipending",
> + .version_id = 1,
> + .minimum_version_id = 1,
> + .fields = (VMStateField[]) {
> + VMSTATE_INT32(thr_ipending, SerialState),
> + VMSTATE_END_OF_LIST()
> + }
> +};
> +
> +static bool serial_tsr_needed(void *opaque)
> +{
> + SerialState *s = (SerialState *)opaque;
> + return s->tsr_retry != 0;
> +}
> +
> +const VMStateDescription vmstate_serial_tsr = {
> + .name = "serial/tsr",
> + .version_id = 1,
> + .minimum_version_id = 1,
> + .fields = (VMStateField[]) {
> + VMSTATE_INT32(tsr_retry, SerialState),
> + VMSTATE_UINT8(thr, SerialState),
> + VMSTATE_UINT8(tsr, SerialState),
> + VMSTATE_END_OF_LIST()
> + }
> +};
> +
> +static bool serial_recv_fifo_needed(void *opaque)
> +{
> + SerialState *s = (SerialState *)opaque;
> + return !fifo8_is_empty(&s->recv_fifo);
> +
> +}
> +
> +const VMStateDescription vmstate_serial_recv_fifo = {
> + .name = "serial/recv_fifo",
> + .version_id = 1,
> + .minimum_version_id = 1,
> + .fields = (VMStateField[]) {
> + VMSTATE_STRUCT(recv_fifo, SerialState, 1, vmstate_fifo8, Fifo8),
> + VMSTATE_END_OF_LIST()
> + }
> +};
> +
> +static bool serial_xmit_fifo_needed(void *opaque)
> +{
> + SerialState *s = (SerialState *)opaque;
> + return !fifo8_is_empty(&s->xmit_fifo);
> +}
> +
> +const VMStateDescription vmstate_serial_xmit_fifo = {
> + .name = "serial/xmit_fifo",
> + .version_id = 1,
> + .minimum_version_id = 1,
> + .fields = (VMStateField[]) {
> + VMSTATE_STRUCT(xmit_fifo, SerialState, 1, vmstate_fifo8, Fifo8),
> + VMSTATE_END_OF_LIST()
> + }
> +};
> +
> +static bool serial_fifo_timeout_timer_needed(void *opaque)
> +{
> + SerialState *s = (SerialState *)opaque;
> + return timer_pending(s->fifo_timeout_timer);
> +}
> +
> +const VMStateDescription vmstate_serial_fifo_timeout_timer = {
> + .name = "serial/fifo_timeout_timer",
> + .version_id = 1,
> + .minimum_version_id = 1,
> + .fields = (VMStateField[]) {
> + VMSTATE_TIMER(fifo_timeout_timer, SerialState),
> + VMSTATE_END_OF_LIST()
> + }
> +};
> +
> +static bool serial_timeout_ipending_needed(void *opaque)
> +{
> + SerialState *s = (SerialState *)opaque;
> + return s->timeout_ipending != 0;
> +}
> +
> +const VMStateDescription vmstate_serial_timeout_ipending = {
> + .name = "serial/timeout_ipending",
> + .version_id = 1,
> + .minimum_version_id = 1,
> + .fields = (VMStateField[]) {
> + VMSTATE_INT32(timeout_ipending, SerialState),
> + VMSTATE_END_OF_LIST()
> + }
> +};
> +
> +static bool serial_poll_needed(void *opaque)
> +{
> + SerialState *s = (SerialState *)opaque;
> + return s->poll_msl >= 0;
> +}
> +
> +const VMStateDescription vmstate_serial_poll = {
> + .name = "serial/poll",
> + .version_id = 1,
> + .minimum_version_id = 1,
> + .fields = (VMStateField[]) {
> + VMSTATE_INT32(poll_msl, SerialState),
> + VMSTATE_TIMER(modem_status_poll, SerialState),
> + VMSTATE_END_OF_LIST()
> + }
> +};
> +
> const VMStateDescription vmstate_serial = {
> .name = "serial",
> .version_id = 3,
> .minimum_version_id = 2,
> .pre_save = serial_pre_save,
> + .pre_load = serial_pre_load,
> .post_load = serial_post_load,
> .fields = (VMStateField[]) {
> VMSTATE_UINT16_V(divider, SerialState, 2),
> @@ -621,6 +766,32 @@ const VMStateDescription vmstate_serial = {
> VMSTATE_UINT8(scr, SerialState),
> VMSTATE_UINT8_V(fcr_vmstate, SerialState, 3),
> VMSTATE_END_OF_LIST()
> + },
> + .subsections = (VMStateSubsection[]) {
> + {
> + .vmsd = &vmstate_serial_thr_ipending,
> + .needed = &serial_thr_ipending_needed,
> + } , {
> + .vmsd = &vmstate_serial_tsr,
> + .needed = &serial_tsr_needed,
> + } , {
> + .vmsd = &vmstate_serial_recv_fifo,
> + .needed = &serial_recv_fifo_needed,
> + } , {
> + .vmsd = &vmstate_serial_xmit_fifo,
> + .needed = &serial_xmit_fifo_needed,
> + } , {
> + .vmsd = &vmstate_serial_fifo_timeout_timer,
> + .needed = &serial_fifo_timeout_timer_needed,
> + } , {
> + .vmsd = &vmstate_serial_timeout_ipending,
> + .needed = &serial_timeout_ipending_needed,
> + } , {
> + .vmsd = &vmstate_serial_poll,
> + .needed = &serial_poll_needed,
> + } , {
> + /* empty */
> + }
> }
> };
>
> @@ -642,6 +813,10 @@ static void serial_reset(void *opaque)
> s->char_transmit_time = (get_ticks_per_sec() / 9600) * 10;
> s->poll_msl = 0;
>
> + s->timeout_ipending = 0;
> + timer_del(s->fifo_timeout_timer);
> + timer_del(s->modem_status_poll);
> +
> fifo8_reset(&s->recv_fifo);
> fifo8_reset(&s->xmit_fifo);
>
>
- Re: [Qemu-devel] [PATCH 06/10] parallel: adding vmstate for save/restore, (continued)
[Qemu-devel] [PATCH 05/10] fdc: adding vmstate for save/restore, Paolo Bonzini, 2014/09/09
[Qemu-devel] [PATCH 07/10] serial: fixing vmstate for save/restore, Paolo Bonzini, 2014/09/09
Re: [Qemu-devel] [PATCH 07/10] serial: fixing vmstate for save/restore,
Paolo Bonzini <=
[Qemu-devel] [PATCH 08/10] pckbd: adding new fields to vmstate, Paolo Bonzini, 2014/09/09
[Qemu-devel] [PATCH 10/10] mc146818rtc: add missed field to vmstate, Paolo Bonzini, 2014/09/09
[Qemu-devel] [PATCH 09/10] piix: do not raise irq while loading vmstate, Paolo Bonzini, 2014/09/09