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Re: [PATCH v2 for-8.0] hw/rtc/mc146818rtc: Make this rtc device target i
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From: |
Bernhard Beschow |
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Subject: |
Re: [PATCH v2 for-8.0] hw/rtc/mc146818rtc: Make this rtc device target independent |
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Date: |
Mon, 12 Dec 2022 00:48:13 +0000 |
Am 10. Dezember 2022 13:48:00 UTC schrieb Mark Cave-Ayland
<mark.cave-ayland@ilande.co.uk>:
>On 09/12/2022 11:15, Thomas Huth wrote:
>
>> The only reason for this code being target dependent is the apic-related
>> code in rtc_policy_slew_deliver_irq(). Since these apic functions are rather
>> simple, we can easily move them into a new, separate file (apic_irqcount.c)
>> which will always be compiled and linked if either APIC or the mc146818
>> device
>> are required. This way we can get rid of the #ifdef TARGET_I386 switches in
>> mc146818rtc.c and declare it in the softmmu_ss instead of specific_ss, so
>> that the code only gets compiled once for all targets.
>
>> Signed-off-by: Thomas Huth <thuth@redhat.com>
>
>Looks much better!
>
>> ---
>> v2: Move the apic functions into a separate file instead of using
>> an ugly function pointer
>>
>> include/hw/i386/apic.h | 1 +
>> include/hw/i386/apic_internal.h | 1 -
>> include/hw/rtc/mc146818rtc.h | 1 +
>> hw/intc/apic_common.c | 27 -----------------
>> hw/intc/apic_irqcount.c | 53 +++++++++++++++++++++++++++++++++
>> hw/rtc/mc146818rtc.c | 25 +++++-----------
>> hw/intc/meson.build | 6 +++-
>> hw/rtc/meson.build | 3 +-
>> 8 files changed, 68 insertions(+), 49 deletions(-)
>> create mode 100644 hw/intc/apic_irqcount.c
>>
>> diff --git a/include/hw/i386/apic.h b/include/hw/i386/apic.h
>> index da1d2fe155..96b9939425 100644
>> --- a/include/hw/i386/apic.h
>> +++ b/include/hw/i386/apic.h
>> @@ -9,6 +9,7 @@ int apic_accept_pic_intr(DeviceState *s);
>> void apic_deliver_pic_intr(DeviceState *s, int level);
>> void apic_deliver_nmi(DeviceState *d);
>> int apic_get_interrupt(DeviceState *s);
>> +void apic_report_irq_delivered(int delivered);
>> void apic_reset_irq_delivered(void);
>> int apic_get_irq_delivered(void);
>> void cpu_set_apic_base(DeviceState *s, uint64_t val);
>> diff --git a/include/hw/i386/apic_internal.h
>> b/include/hw/i386/apic_internal.h
>> index c175e7e718..e61ad04769 100644
>> --- a/include/hw/i386/apic_internal.h
>> +++ b/include/hw/i386/apic_internal.h
>> @@ -199,7 +199,6 @@ typedef struct VAPICState {
>> extern bool apic_report_tpr_access;
>> -void apic_report_irq_delivered(int delivered);
>> bool apic_next_timer(APICCommonState *s, int64_t current_time);
>> void apic_enable_tpr_access_reporting(DeviceState *d, bool enable);
>> void apic_enable_vapic(DeviceState *d, hwaddr paddr);
>> diff --git a/include/hw/rtc/mc146818rtc.h b/include/hw/rtc/mc146818rtc.h
>> index 1db0fcee92..45bcd6f040 100644
>> --- a/include/hw/rtc/mc146818rtc.h
>> +++ b/include/hw/rtc/mc146818rtc.h
>> @@ -55,5 +55,6 @@ ISADevice *mc146818_rtc_init(ISABus *bus, int base_year,
>> qemu_irq intercept_irq);
>> void rtc_set_memory(ISADevice *dev, int addr, int val);
>> int rtc_get_memory(ISADevice *dev, int addr);
>> +void qmp_rtc_reset_reinjection(Error **errp);
>> #endif /* HW_RTC_MC146818RTC_H */
>> diff --git a/hw/intc/apic_common.c b/hw/intc/apic_common.c
>> index 2a20982066..b0f85f9384 100644
>> --- a/hw/intc/apic_common.c
>> +++ b/hw/intc/apic_common.c
>> @@ -33,7 +33,6 @@
>> #include "hw/sysbus.h"
>> #include "migration/vmstate.h"
>> -static int apic_irq_delivered;
>> bool apic_report_tpr_access;
>> void cpu_set_apic_base(DeviceState *dev, uint64_t val)
>> @@ -122,32 +121,6 @@ void apic_handle_tpr_access_report(DeviceState *dev,
>> target_ulong ip,
>> vapic_report_tpr_access(s->vapic, CPU(s->cpu), ip, access);
>> }
>> -void apic_report_irq_delivered(int delivered)
>> -{
>> - apic_irq_delivered += delivered;
>> -
>> - trace_apic_report_irq_delivered(apic_irq_delivered);
>> -}
>> -
>> -void apic_reset_irq_delivered(void)
>> -{
>> - /* Copy this into a local variable to encourage gcc to emit a plain
>> - * register for a sys/sdt.h marker. For details on this workaround,
>> see:
>> - * https://sourceware.org/bugzilla/show_bug.cgi?id=13296
>> - */
>> - volatile int a_i_d = apic_irq_delivered;
>> - trace_apic_reset_irq_delivered(a_i_d);
>> -
>> - apic_irq_delivered = 0;
>> -}
>> -
>> -int apic_get_irq_delivered(void)
>> -{
>> - trace_apic_get_irq_delivered(apic_irq_delivered);
>> -
>> - return apic_irq_delivered;
>> -}
>> -
>
>Just a comment whilst reviewing this patch: apic_irq_delivered is also used by
>hw/i386/kvm/i8259.c which seems incorrect since it is a PIC rather than an
>APIC, but that's why it isn't immediately possible to move apic_irq_delivered
>into APICCommonState.
>
>I suspect what should happen is that PICCommonState should have its own KVM
>irq delivery count rather than relying on the APIC one, which might actually
>be the reason that this dependency between mc146818rtc and APIC exists in the
>first place. Any x86 people care to comment?
What's more is that the non-KVM APIC also deals with the IRQ delivery count
while the non-KVM PIC doesn't. This seems inconsistent to me.
Then there is the KVM PIT which offers various policies while the non-KVM PIT
doesn't.
Is this perhaps a KVM-specific workaround [1]? Can we confine the workaround to
KVM on x86 (while making the code itself target-agnostic)? Should the new files
be moved and renamed accordingly?
Best regards,
Bernhard
[1] https://bugzilla.redhat.com/show_bug.cgi?id=865315
>
>> void apic_deliver_nmi(DeviceState *dev)
>> {
>> APICCommonState *s = APIC_COMMON(dev);
>> diff --git a/hw/intc/apic_irqcount.c b/hw/intc/apic_irqcount.c
>> new file mode 100644
>> index 0000000000..0aadef1cb5
>> --- /dev/null
>> +++ b/hw/intc/apic_irqcount.c
>> @@ -0,0 +1,53 @@
>> +/*
>> + * APIC support - functions for counting the delivered IRQs.
>> + * (this code is in a separate file since it is used from the
>> + * mc146818rtc code on targets without APIC, too)
>> + *
>> + * Copyright (c) 2011 Jan Kiszka, Siemens AG
>> + *
>> + * This library is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU Lesser General Public
>> + * License as published by the Free Software Foundation; either
>> + * version 2.1 of the License, or (at your option) any later version.
>> + *
>> + * This library is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
>> + * Lesser General Public License for more details.
>> + *
>> + * You should have received a copy of the GNU Lesser General Public
>> + * License along with this library; if not, see
>> <http://www.gnu.org/licenses/>
>> + */
>> +
>> +#include "qemu/osdep.h"
>> +#include "hw/i386/apic.h"
>> +#include "trace.h"
>> +
>> +static int apic_irq_delivered;
>> +
>> +void apic_report_irq_delivered(int delivered)
>> +{
>> + apic_irq_delivered += delivered;
>> +
>> + trace_apic_report_irq_delivered(apic_irq_delivered);
>> +}
>> +
>> +void apic_reset_irq_delivered(void)
>> +{
>> + /*
>> + * Copy this into a local variable to encourage gcc to emit a plain
>> + * register for a sys/sdt.h marker. For details on this workaround,
>> see:
>> + * https://sourceware.org/bugzilla/show_bug.cgi?id=13296
>> + */
>> + volatile int a_i_d = apic_irq_delivered;
>> + trace_apic_reset_irq_delivered(a_i_d);
>> +
>> + apic_irq_delivered = 0;
>> +}
>> +
>> +int apic_get_irq_delivered(void)
>> +{
>> + trace_apic_get_irq_delivered(apic_irq_delivered);
>> +
>> + return apic_irq_delivered;
>> +}
>> diff --git a/hw/rtc/mc146818rtc.c b/hw/rtc/mc146818rtc.c
>> index 1ebb412479..afb1f385a3 100644
>> --- a/hw/rtc/mc146818rtc.c
>> +++ b/hw/rtc/mc146818rtc.c
>> @@ -43,11 +43,7 @@
>> #include "qapi/qapi-events-misc.h"
>> #include "qapi/visitor.h"
>> #include "hw/rtc/mc146818rtc_regs.h"
>> -
>> -#ifdef TARGET_I386
>> -#include "qapi/qapi-commands-misc-target.h"
>> #include "hw/i386/apic.h"
>> -#endif
>> //#define DEBUG_CMOS
>> //#define DEBUG_COALESCED
>> @@ -112,7 +108,6 @@ static void rtc_coalesced_timer_update(RTCState *s)
>> static QLIST_HEAD(, RTCState) rtc_devices =
>> QLIST_HEAD_INITIALIZER(rtc_devices);
>> -#ifdef TARGET_I386
>> void qmp_rtc_reset_reinjection(Error **errp)
>> {
>> RTCState *s;
>> @@ -145,13 +140,6 @@ static void rtc_coalesced_timer(void *opaque)
>> rtc_coalesced_timer_update(s);
>> }
>> -#else
>> -static bool rtc_policy_slew_deliver_irq(RTCState *s)
>> -{
>> - assert(0);
>> - return false;
>> -}
>> -#endif
>> static uint32_t rtc_periodic_clock_ticks(RTCState *s)
>> {
>> @@ -922,14 +910,15 @@ static void rtc_realizefn(DeviceState *dev, Error
>> **errp)
>> rtc_set_date_from_host(isadev);
>> switch (s->lost_tick_policy) {
>> -#ifdef TARGET_I386
>> - case LOST_TICK_POLICY_SLEW:
>> - s->coalesced_timer =
>> - timer_new_ns(rtc_clock, rtc_coalesced_timer, s);
>> - break;
>> -#endif
>> case LOST_TICK_POLICY_DISCARD:
>> break;
>> + case LOST_TICK_POLICY_SLEW:
>> + /* Slew tick policy is only available if the machine has an APIC */
>> + if (object_resolve_path_type("", "apic-common", NULL) != NULL) {
>
>Hmmm. These days we should be using TYPE_APIC_COMMON, however it seems that
>APICCommonState is defined in apic_internal.h rather than apic.h which seems
>wrong (it prevents you from passing an APICCommonState as an object link
>property as well as from using TYPE_APIC_COMMON).
>
>> + s->coalesced_timer = timer_new_ns(rtc_clock,
>> rtc_coalesced_timer, s);
>> + break;
>> + }
>> + /* fallthrough */
>> default:
>> error_setg(errp, "Invalid lost tick policy.");
>> return;
>> diff --git a/hw/intc/meson.build b/hw/intc/meson.build
>> index bcbf22ff51..036ad1936b 100644
>> --- a/hw/intc/meson.build
>> +++ b/hw/intc/meson.build
>> @@ -25,8 +25,12 @@ softmmu_ss.add(when: 'CONFIG_XILINX', if_true:
>> files('xilinx_intc.c'))
>> softmmu_ss.add(when: 'CONFIG_XLNX_ZYNQMP', if_true:
>> files('xlnx-zynqmp-ipi.c'))
>> softmmu_ss.add(when: 'CONFIG_XLNX_ZYNQMP_PMU', if_true:
>> files('xlnx-pmu-iomod-intc.c'))
>> -specific_ss.add(when: 'CONFIG_ALLWINNER_A10_PIC', if_true:
>> files('allwinner-a10-pic.c'))
>> +if config_all_devices.has_key('CONFIG_APIC') or
>> config_all_devices.has_key('CONFIG_MC146818RTC')
>> + softmmu_ss.add(files('apic_irqcount.c'))
>> +endif
>> specific_ss.add(when: 'CONFIG_APIC', if_true: files('apic.c',
>> 'apic_common.c'))
>> +
>> +specific_ss.add(when: 'CONFIG_ALLWINNER_A10_PIC', if_true:
>> files('allwinner-a10-pic.c'))
>> specific_ss.add(when: 'CONFIG_ARM_GIC', if_true:
>> files('arm_gicv3_cpuif_common.c'))
>> specific_ss.add(when: 'CONFIG_ARM_GICV3_TCG', if_true:
>> files('arm_gicv3_cpuif.c'))
>> specific_ss.add(when: 'CONFIG_ARM_GIC_KVM', if_true:
>> files('arm_gic_kvm.c'))
>> diff --git a/hw/rtc/meson.build b/hw/rtc/meson.build
>> index dc33973384..34a4d316fa 100644
>> --- a/hw/rtc/meson.build
>> +++ b/hw/rtc/meson.build
>> @@ -13,5 +13,4 @@ softmmu_ss.add(when: 'CONFIG_ASPEED_SOC', if_true:
>> files('aspeed_rtc.c'))
>> softmmu_ss.add(when: 'CONFIG_GOLDFISH_RTC', if_true:
>> files('goldfish_rtc.c'))
>> softmmu_ss.add(when: 'CONFIG_LS7A_RTC', if_true: files('ls7a_rtc.c'))
>> softmmu_ss.add(when: 'CONFIG_ALLWINNER_H3', if_true:
>> files('allwinner-rtc.c'))
>> -
>> -specific_ss.add(when: 'CONFIG_MC146818RTC', if_true: files('mc146818rtc.c'))
>> +softmmu_ss.add(when: 'CONFIG_MC146818RTC', if_true: files('mc146818rtc.c'))
>
>Fixing up the headers to allow TYPE_APIC_COMMON rather than hard-coding
>"apic-common" would be my preference, however there is a lot of legacy code
>here and the fear would be that once you pull on that string then more will
>keep unravelling... so if that isn't something you can easily get to work I'm
>inclined to give a:
>
>Reviewed-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
>
>regardless since it nudges things in the right direction until we can get some
>guidance from more knowledgeable x86 people.
>
>
>ATB,
>
>Mark.