[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH v2 03/18] tcg: move qemu_tcg_configure to accel/tcg/tcg-all.c
From: |
Marc-André Lureau |
Subject: |
Re: [PATCH v2 03/18] tcg: move qemu_tcg_configure to accel/tcg/tcg-all.c |
Date: |
Tue, 10 Dec 2019 16:05:08 +0400 |
Hi
On Mon, Dec 9, 2019 at 7:07 PM Paolo Bonzini <address@hidden> wrote:
>
> Move everything related to mttcg_enabled in accel/tcg/tcg-all.c,
> which will make even more sense when "thread" becomes a QOM property.
>
> For now, initializing mttcg_enabled in the instance_init function
> prepares for the next patch, which will only invoke qemu_tcg_configure
> when the command line includes a -accel option.
>
> Signed-off-by: Paolo Bonzini <address@hidden>
> ---
> accel/tcg/tcg-all.c | 85
> +++++++++++++++++++++++++++++++++++++++++++++++++++++
> cpus.c | 72 ---------------------------------------------
> 2 files changed, 85 insertions(+), 72 deletions(-)
>
> diff --git a/accel/tcg/tcg-all.c b/accel/tcg/tcg-all.c
> index c59d5b0..78a0ab5 100644
> --- a/accel/tcg/tcg-all.c
> +++ b/accel/tcg/tcg-all.c
> @@ -30,6 +30,11 @@
> #include "cpu.h"
> #include "sysemu/cpus.h"
> #include "qemu/main-loop.h"
> +#include "tcg/tcg.h"
> +#include "include/qapi/error.h"
> +#include "include/qemu/error-report.h"
> +#include "include/hw/boards.h"
> +#include "qemu/option.h"
>
> unsigned long tcg_tb_size;
>
> @@ -58,6 +63,55 @@ static void tcg_handle_interrupt(CPUState *cpu, int mask)
> }
> }
>
> +/*
> + * We default to false if we know other options have been enabled
> + * which are currently incompatible with MTTCG. Otherwise when each
> + * guest (target) has been updated to support:
> + * - atomic instructions
> + * - memory ordering primitives (barriers)
> + * they can set the appropriate CONFIG flags in ${target}-softmmu.mak
> + *
> + * Once a guest architecture has been converted to the new primitives
> + * there are two remaining limitations to check.
> + *
> + * - The guest can't be oversized (e.g. 64 bit guest on 32 bit host)
> + * - The host must have a stronger memory order than the guest
> + *
> + * It may be possible in future to support strong guests on weak hosts
> + * but that will require tagging all load/stores in a guest with their
> + * implicit memory order requirements which would likely slow things
> + * down a lot.
> + */
> +
> +static bool check_tcg_memory_orders_compatible(void)
> +{
> +#if defined(TCG_GUEST_DEFAULT_MO) && defined(TCG_TARGET_DEFAULT_MO)
> + return (TCG_GUEST_DEFAULT_MO & ~TCG_TARGET_DEFAULT_MO) == 0;
> +#else
> + return false;
> +#endif
> +}
> +
> +static bool default_mttcg_enabled(void)
> +{
> + if (use_icount || TCG_OVERSIZED_GUEST) {
> + return false;
> + } else {
> +#ifdef TARGET_SUPPORTS_MTTCG
> + return check_tcg_memory_orders_compatible();
> +#else
> + return false;
> +#endif
> + }
> +}
> +
> +static void tcg_accel_instance_init(Object *obj)
> +{
> + TCGState *s = TCG_STATE(obj);
It breaks compilation:
accel/tcg/tcg-all.c:110:19: error: implicit declaration of function
‘TCG_STATE’ [-Werror=implicit-function-declaration]
110 | TCGState *s = TCG_STATE(obj);
> +
> + mttcg_enabled = default_mttcg_enabled();
> +}
> +
> static int tcg_init(MachineState *ms)
> {
> tcg_exec_init(tcg_tb_size * 1024 * 1024);
> @@ -65,6 +119,36 @@ static int tcg_init(MachineState *ms)
> return 0;
> }
>
> +void qemu_tcg_configure(QemuOpts *opts, Error **errp)
> +{
> + const char *t = qemu_opt_get(opts, "thread");
> + if (!t) {
> + return;
> + }
> + if (strcmp(t, "multi") == 0) {
> + if (TCG_OVERSIZED_GUEST) {
> + error_setg(errp, "No MTTCG when guest word size > hosts");
> + } else if (use_icount) {
> + error_setg(errp, "No MTTCG when icount is enabled");
> + } else {
> +#ifndef TARGET_SUPPORTS_MTTCG
> + warn_report("Guest not yet converted to MTTCG - "
> + "you may get unexpected results");
> +#endif
> + if (!check_tcg_memory_orders_compatible()) {
> + warn_report("Guest expects a stronger memory ordering "
> + "than the host provides");
> + error_printf("This may cause strange/hard to debug
> errors\n");
> + }
> + mttcg_enabled = true;
> + }
> + } else if (strcmp(t, "single") == 0) {
> + mttcg_enabled = false;
> + } else {
> + error_setg(errp, "Invalid 'thread' setting %s", t);
> + }
> +}
> +
> static void tcg_accel_class_init(ObjectClass *oc, void *data)
> {
> AccelClass *ac = ACCEL_CLASS(oc);
> @@ -78,6 +162,7 @@ static void tcg_accel_class_init(ObjectClass *oc, void
> *data)
> static const TypeInfo tcg_accel_type = {
> .name = TYPE_TCG_ACCEL,
> .parent = TYPE_ACCEL,
> + .instance_init = tcg_accel_instance_init,
> .class_init = tcg_accel_class_init,
> };
>
> diff --git a/cpus.c b/cpus.c
> index 63bda15..b472378 100644
> --- a/cpus.c
> +++ b/cpus.c
> @@ -166,78 +166,6 @@ typedef struct TimersState {
> static TimersState timers_state;
> bool mttcg_enabled;
>
> -/*
> - * We default to false if we know other options have been enabled
> - * which are currently incompatible with MTTCG. Otherwise when each
> - * guest (target) has been updated to support:
> - * - atomic instructions
> - * - memory ordering primitives (barriers)
> - * they can set the appropriate CONFIG flags in ${target}-softmmu.mak
> - *
> - * Once a guest architecture has been converted to the new primitives
> - * there are two remaining limitations to check.
> - *
> - * - The guest can't be oversized (e.g. 64 bit guest on 32 bit host)
> - * - The host must have a stronger memory order than the guest
> - *
> - * It may be possible in future to support strong guests on weak hosts
> - * but that will require tagging all load/stores in a guest with their
> - * implicit memory order requirements which would likely slow things
> - * down a lot.
> - */
> -
> -static bool check_tcg_memory_orders_compatible(void)
> -{
> -#if defined(TCG_GUEST_DEFAULT_MO) && defined(TCG_TARGET_DEFAULT_MO)
> - return (TCG_GUEST_DEFAULT_MO & ~TCG_TARGET_DEFAULT_MO) == 0;
> -#else
> - return false;
> -#endif
> -}
> -
> -static bool default_mttcg_enabled(void)
> -{
> - if (use_icount || TCG_OVERSIZED_GUEST) {
> - return false;
> - } else {
> -#ifdef TARGET_SUPPORTS_MTTCG
> - return check_tcg_memory_orders_compatible();
> -#else
> - return false;
> -#endif
> - }
> -}
> -
> -void qemu_tcg_configure(QemuOpts *opts, Error **errp)
> -{
> - const char *t = qemu_opt_get(opts, "thread");
> - if (t) {
> - if (strcmp(t, "multi") == 0) {
> - if (TCG_OVERSIZED_GUEST) {
> - error_setg(errp, "No MTTCG when guest word size > hosts");
> - } else if (use_icount) {
> - error_setg(errp, "No MTTCG when icount is enabled");
> - } else {
> -#ifndef TARGET_SUPPORTS_MTTCG
> - warn_report("Guest not yet converted to MTTCG - "
> - "you may get unexpected results");
> -#endif
> - if (!check_tcg_memory_orders_compatible()) {
> - warn_report("Guest expects a stronger memory ordering "
> - "than the host provides");
> - error_printf("This may cause strange/hard to debug
> errors\n");
> - }
> - mttcg_enabled = true;
> - }
> - } else if (strcmp(t, "single") == 0) {
> - mttcg_enabled = false;
> - } else {
> - error_setg(errp, "Invalid 'thread' setting %s", t);
> - }
> - } else {
> - mttcg_enabled = default_mttcg_enabled();
> - }
> -}
>
> /* The current number of executed instructions is based on what we
> * originally budgeted minus the current state of the decrementing
> --
> 1.8.3.1
>
>
>
--
Marc-André Lureau
- [PATCH v2 01/18] memory: do not look at current_machine->accel, (continued)
- [PATCH v2 01/18] memory: do not look at current_machine->accel, Paolo Bonzini, 2019/12/09
- [PATCH v2 02/18] vl: move icount configuration earlier, Paolo Bonzini, 2019/12/09
- [PATCH v2 04/18] vl: extract accelerator option processing to a separate function, Paolo Bonzini, 2019/12/09
- [PATCH v2 05/18] vl: merge -accel processing into configure_accelerators, Paolo Bonzini, 2019/12/09
- [PATCH v2 03/18] tcg: move qemu_tcg_configure to accel/tcg/tcg-all.c, Paolo Bonzini, 2019/12/09
- [PATCH v2 06/18] accel: compile accel/accel.c just once, Paolo Bonzini, 2019/12/09
- [PATCH v2 09/18] vl: warn for unavailable accelerators, clarify messages, Paolo Bonzini, 2019/12/09
- [PATCH v2 11/18] qom: add object_new_with_class, Paolo Bonzini, 2019/12/09
- [PATCH v2 08/18] vl: configure accelerators from -accel options, Paolo Bonzini, 2019/12/09
- [PATCH v2 12/18] accel: pass object to accel_init_machine, Paolo Bonzini, 2019/12/09
- [PATCH v2 07/18] vl: introduce object_parse_property_opt, Paolo Bonzini, 2019/12/09