| Message ID | c0ad457b3fe6bc7df266c66c2e7f4d7778e5dbae.1378796990.git.chen.fan.fnst@cn.fujitsu.com |
|---|---|
| State | New |
| Headers | show |
On Tue, 10 Sep 2013 17:43:41 +0800 Chen Fan <chen.fan.fnst@cn.fujitsu.com> 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 <chen.fan.fnst@cn.fujitsu.com> > --- > 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. > } > > static void x86_cpu_apic_realize(X86CPU *cpu, Error **errp)
Am 10.09.2013 14:09, schrieb Igor Mammedov: > On Tue, 10 Sep 2013 17:43:41 +0800 > Chen Fan <chen.fan.fnst@cn.fujitsu.com> 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 <chen.fan.fnst@cn.fujitsu.com> >> --- >> 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. Andreas > >> } >> >> static void x86_cpu_apic_realize(X86CPU *cpu, Error **errp) >
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 <chen.fan.fnst@cn.fujitsu.com> 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 <chen.fan.fnst@cn.fujitsu.com> > >> --- > >> 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) > > > >
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; } static void x86_cpu_apic_realize(X86CPU *cpu, Error **errp)
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 <chen.fan.fnst@cn.fujitsu.com> --- hw/intc/apic_common.c | 4 +--- target-i386/cpu.c | 1 + 2 files changed, 2 insertions(+), 3 deletions(-)