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Re: [Qemu-devel] [RFC qom-cpu v2 1/8] apic: remove apic_no from apic_ini
From: |
chenfan |
Subject: |
Re: [Qemu-devel] [RFC qom-cpu v2 1/8] apic: remove apic_no from apic_init_common() |
Date: |
Wed, 11 Sep 2013 13:37:03 +0800 |
On Tue, 2013-09-10 at 14:16 +0200, Andreas Färber wrote:
> Am 10.09.2013 14:09, schrieb Igor Mammedov:
> > On Tue, 10 Sep 2013 17:43:41 +0800
> > Chen Fan <address@hidden> wrote:
> >
> >> the 'apic_no' is increased by one when initialize/create a vCPU each time,
> >> which causes APICCommonState s->idx always is increased.
> >> but if we want to re-add a vCPU after removing a vCPU, we need to re-use
> >> the
> >> vacant s->idx which the corresponding vCPU had been removed.
> >> so we could use the unique cpu apic_id instead of the progressive s->idx.
> >>
> >> Signed-off-by: Chen Fan <address@hidden>
> >> ---
> >> hw/intc/apic_common.c | 4 +---
> >> target-i386/cpu.c | 1 +
> >> 2 files changed, 2 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/hw/intc/apic_common.c b/hw/intc/apic_common.c
> >> index a0beb10..5568621 100644
> >> --- a/hw/intc/apic_common.c
> >> +++ b/hw/intc/apic_common.c
> >> @@ -289,13 +289,11 @@ static int apic_init_common(ICCDevice *dev)
> >> APICCommonState *s = APIC_COMMON(dev);
> >> APICCommonClass *info;
> >> static DeviceState *vapic;
> >> - static int apic_no;
> >> static bool mmio_registered;
> >>
> >> - if (apic_no >= MAX_APICS) {
> >> + if (s->idx >= MAX_APICS) {
> >> return -1;
> >> }
> >> - s->idx = apic_no++;
> >>
> >> info = APIC_COMMON_GET_CLASS(s);
> >> info->init(s);
> >> diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> >> index 42c5de0..2b99683 100644
> >> --- a/target-i386/cpu.c
> >> +++ b/target-i386/cpu.c
> >> @@ -2322,6 +2322,7 @@ static void x86_cpu_apic_create(X86CPU *cpu, Error
> >> **errp)
> >> /* TODO: convert to link<> */
> >> apic = APIC_COMMON(env->apic_state);
> >> apic->cpu = cpu;
> >> + apic->idx = env->cpuid_apic_id;
> > earlier here we set:
> > qdev_prop_set_uint8(env->apic_state, "id", env->cpuid_apic_id);
> > so apic->idx = env->cpuid_apic_id is redundant.
> >
> > it would be better to search by apic->id and preferably replace O(MAX_APIC)
> > scans with
> > a faster approach since for TCG iqr delivery might be a hot path, dropping
> > MAX_APIC
> > altogether and using dynamic present APICs list.
>
> Independent of that, the recent removal of X86_CPU() cast from
> x86_env_get_cpu() should allow us to finally tackle the TODO above,
> moving apic_state field from CPUX86State to X86CPU.
>
I will send V3 patches later including modification pointed out above.
Thanks
> Andreas
>
> >
> >> }
> >>
> >> static void x86_cpu_apic_realize(X86CPU *cpu, Error **errp)
> >
>
>
- [Qemu-devel] [RFC qom-cpu v2 0/8] i386: add cpu hot remove support, Chen Fan, 2013/09/10
- [Qemu-devel] [RFC qom-cpu v2 4/8] qom cpu: rename variable 'cpu_added_notifier' to 'cpu_hotplug_notifier', Chen Fan, 2013/09/10
- [Qemu-devel] [RFC qom-cpu v2 2/8] x86: add x86_cpu_unrealizefn() for cpu apic remove, Chen Fan, 2013/09/10
- [Qemu-devel] [RFC qom-cpu v2 3/8] qmp: add 'cpu-del' command support, Chen Fan, 2013/09/10
- [Qemu-devel] [RFC qom-cpu v2 5/8] qom cpu: add UNPLUG cpu notifier support, Chen Fan, 2013/09/10
- [Qemu-devel] [RFC qom-cpu v2 6/8] i386: implement pc interface pc_hot_del_cpu(), Chen Fan, 2013/09/10
- [Qemu-devel] [RFC qom-cpu v2 7/8] piix4: implement function cpu_status_write() for vcpu ejection, Chen Fan, 2013/09/10
- [Qemu-devel] [RFC qom-cpu v2 8/8] cpus: release allocated vCPU objects, Chen Fan, 2013/09/10