diff mbox

[1/2] KVM: X86: Implement PV IPI in linux guest

Message ID 1530265876-18136-2-git-send-email-wanpengli@tencent.com (mailing list archive)
State New, archived
Headers show

Commit Message

Wanpeng Li June 29, 2018, 9:51 a.m. UTC 
From: Wanpeng Li <wanpengli@tencent.com>

Implement PV IPIs in guest kernel.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
---
 arch/x86/include/uapi/asm/kvm_para.h |  1 +
 arch/x86/kernel/kvm.c                | 63 ++++++++++++++++++++++++++++++++++++
 2 files changed, 64 insertions(+)

Comments

Vitaly Kuznetsov June 29, 2018, 10:10 a.m. UTC | #1 
Wanpeng Li <kernellwp@gmail.com> writes:

> From: Wanpeng Li <wanpengli@tencent.com>
>
> Implement PV IPIs in guest kernel.
>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: Radim Krčmář <rkrcmar@redhat.com>
> Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
> Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
> ---
>  arch/x86/include/uapi/asm/kvm_para.h |  1 +
>  arch/x86/kernel/kvm.c                | 63 ++++++++++++++++++++++++++++++++++++
>  2 files changed, 64 insertions(+)
>
> diff --git a/arch/x86/include/uapi/asm/kvm_para.h b/arch/x86/include/uapi/asm/kvm_para.h
> index 0ede697..19980ec 100644
> --- a/arch/x86/include/uapi/asm/kvm_para.h
> +++ b/arch/x86/include/uapi/asm/kvm_para.h
> @@ -28,6 +28,7 @@
>  #define KVM_FEATURE_PV_UNHALT		7
>  #define KVM_FEATURE_PV_TLB_FLUSH	9
>  #define KVM_FEATURE_ASYNC_PF_VMEXIT	10
> +#define KVM_FEATURE_PV_SEND_IPI	11
>
>  #define KVM_HINTS_REALTIME      0
>
> diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
> index 5b2300b..b4f8dc3 100644
> --- a/arch/x86/kernel/kvm.c
> +++ b/arch/x86/kernel/kvm.c
> @@ -454,6 +454,57 @@ static void __init sev_map_percpu_data(void)
>  }
>
>  #ifdef CONFIG_SMP
> +
> +static void __send_ipi_mask(const struct cpumask *mask, int vector)
> +{
> +	unsigned long flags, ipi_bitmap = 0;
> +	int cpu;
> +
> +	local_irq_save(flags);
> +
> +	for_each_cpu(cpu, mask)
> +		__set_bit(per_cpu(x86_cpu_to_apicid, cpu), &ipi_bitmap);

We need a protection against per_cpu(x86_cpu_to_apicid, cpu) > here.

> +	kvm_hypercall2(KVM_HC_SEND_IPI, ipi_bitmap, vector);
> +
> +	local_irq_restore(flags);
> +}
> +
> +static void kvm_send_ipi_mask(const struct cpumask *mask, int vector)
> +{
> +	__send_ipi_mask(mask, vector);
> +}
> +
> +static void kvm_send_ipi_mask_allbutself(const struct cpumask *mask, int vector)
> +{
> +	unsigned int this_cpu = smp_processor_id();
> +	struct cpumask new_mask;
> +	const struct cpumask *local_mask;
> +
> +	cpumask_copy(&new_mask, mask);
> +	cpumask_clear_cpu(this_cpu, &new_mask);
> +	local_mask = &new_mask;
> +	__send_ipi_mask(local_mask, vector);
> +}
> +
> +static void kvm_send_ipi_allbutself(int vector)
> +{
> +	kvm_send_ipi_mask_allbutself(cpu_online_mask, vector);
> +}
> +
> +static void kvm_send_ipi_all(int vector)
> +{
> +	__send_ipi_mask(cpu_online_mask, vector);
> +}
> +
> +static void kvm_setup_pv_ipi(void)
> +{
> +	apic->send_IPI_mask = kvm_send_ipi_mask;
> +	apic->send_IPI_mask_allbutself = kvm_send_ipi_mask_allbutself;
> +	apic->send_IPI_allbutself = kvm_send_ipi_allbutself;
> +	apic->send_IPI_all = kvm_send_ipi_all;
> +	printk("KVM setup pv IPIs\n");
> +}
> +
>  static void __init kvm_smp_prepare_cpus(unsigned int max_cpus)
>  {
>  	native_smp_prepare_cpus(max_cpus);
> @@ -624,12 +675,24 @@ static uint32_t __init kvm_detect(void)
>  	return kvm_cpuid_base();
>  }
>
> +static void __init kvm_apic_init(void)
> +{
> +	if (kvm_para_has_feature(KVM_FEATURE_PV_SEND_IPI))
> +		kvm_setup_pv_ipi();
> +}
> +
> +static void __init kvm_init_platform(void)
> +{
> +	x86_platform.apic_post_init = kvm_apic_init;
> +}
> +
>  const __initconst struct hypervisor_x86 x86_hyper_kvm = {
>  	.name			= "KVM",
>  	.detect			= kvm_detect,
>  	.type			= X86_HYPER_KVM,
>  	.init.guest_late_init	= kvm_guest_init,
>  	.init.x2apic_available	= kvm_para_available,
> +	.init.init_platform 	= kvm_init_platform,
>  };
>
>  static __init int activate_jump_labels(void)
kernel test robot June 29, 2018, 11:22 a.m. UTC | #2 
Hi Wanpeng,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on kvm/linux-next]
[also build test ERROR on v4.18-rc2 next-20180629]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Wanpeng-Li/KVM-x86-Add-PV-IPIs-support/20180629-185314
base:   https://git.kernel.org/pub/scm/virt/kvm/kvm.git linux-next
config: x86_64-randconfig-x003-201825 (attached as .config)
compiler: gcc-7 (Debian 7.3.0-16) 7.3.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All errors (new ones prefixed by >>):

   arch/x86/kernel/kvm.c: In function 'kvm_apic_init':
>> arch/x86/kernel/kvm.c:681:3: error: implicit declaration of function 'kvm_setup_pv_ipi'; did you mean 'idt_setup_traps'? [-Werror=implicit-function-declaration]
      kvm_setup_pv_ipi();
      ^~~~~~~~~~~~~~~~
      idt_setup_traps
   cc1: some warnings being treated as errors

vim +681 arch/x86/kernel/kvm.c

   677	
   678	static void __init kvm_apic_init(void)
   679	{
   680		if (kvm_para_has_feature(KVM_FEATURE_PV_SEND_IPI))
 > 681			kvm_setup_pv_ipi();
   682	}
   683	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
kernel test robot June 29, 2018, 1:01 p.m. UTC | #3 
Hi Wanpeng,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on kvm/linux-next]
[also build test ERROR on v4.18-rc2 next-20180629]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Wanpeng-Li/KVM-x86-Add-PV-IPIs-support/20180629-185314
base:   https://git.kernel.org/pub/scm/virt/kvm/kvm.git linux-next
config: i386-randconfig-a0-201825 (attached as .config)
compiler: gcc-4.9 (Debian 4.9.4-2) 4.9.4
reproduce:
        # save the attached .config to linux build tree
        make ARCH=i386 

All errors (new ones prefixed by >>):

   arch/x86//kernel/kvm.c: In function 'kvm_apic_init':
>> arch/x86//kernel/kvm.c:681:3: error: implicit declaration of function 'kvm_setup_pv_ipi' [-Werror=implicit-function-declaration]
      kvm_setup_pv_ipi();
      ^
   cc1: some warnings being treated as errors

vim +/kvm_setup_pv_ipi +681 arch/x86//kernel/kvm.c

   677	
   678	static void __init kvm_apic_init(void)
   679	{
   680		if (kvm_para_has_feature(KVM_FEATURE_PV_SEND_IPI))
 > 681			kvm_setup_pv_ipi();
   682	}
   683	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
Wanpeng Li June 30, 2018, 10:04 a.m. UTC | #4 
On Fri, 29 Jun 2018 at 18:10, Vitaly Kuznetsov <vkuznets@redhat.com> wrote:
>
> Wanpeng Li <kernellwp@gmail.com> writes:
>
> > From: Wanpeng Li <wanpengli@tencent.com>
> >
> > Implement PV IPIs in guest kernel.
> >
> > Cc: Paolo Bonzini <pbonzini@redhat.com>
> > Cc: Radim Krčmář <rkrcmar@redhat.com>
> > Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
> > Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
> > ---
> >  arch/x86/include/uapi/asm/kvm_para.h |  1 +
> >  arch/x86/kernel/kvm.c                | 63 ++++++++++++++++++++++++++++++++++++
> >  2 files changed, 64 insertions(+)
> >
> > diff --git a/arch/x86/include/uapi/asm/kvm_para.h b/arch/x86/include/uapi/asm/kvm_para.h
> > index 0ede697..19980ec 100644
> > --- a/arch/x86/include/uapi/asm/kvm_para.h
> > +++ b/arch/x86/include/uapi/asm/kvm_para.h
> > @@ -28,6 +28,7 @@
> >  #define KVM_FEATURE_PV_UNHALT                7
> >  #define KVM_FEATURE_PV_TLB_FLUSH     9
> >  #define KVM_FEATURE_ASYNC_PF_VMEXIT  10
> > +#define KVM_FEATURE_PV_SEND_IPI      11
> >
> >  #define KVM_HINTS_REALTIME      0
> >
> > diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
> > index 5b2300b..b4f8dc3 100644
> > --- a/arch/x86/kernel/kvm.c
> > +++ b/arch/x86/kernel/kvm.c
> > @@ -454,6 +454,57 @@ static void __init sev_map_percpu_data(void)
> >  }
> >
> >  #ifdef CONFIG_SMP
> > +
> > +static void __send_ipi_mask(const struct cpumask *mask, int vector)
> > +{
> > +     unsigned long flags, ipi_bitmap = 0;
> > +     int cpu;
> > +
> > +     local_irq_save(flags);
> > +
> > +     for_each_cpu(cpu, mask)
> > +             __set_bit(per_cpu(x86_cpu_to_apicid, cpu), &ipi_bitmap);
>
> We need a protection against per_cpu(x86_cpu_to_apicid, cpu) > here.

Will do in v2.

Regards,
Wanpeng Li
diff mbox

Patch

diff --git a/arch/x86/include/uapi/asm/kvm_para.h b/arch/x86/include/uapi/asm/kvm_para.h
index 0ede697..19980ec 100644
--- a/arch/x86/include/uapi/asm/kvm_para.h
+++ b/arch/x86/include/uapi/asm/kvm_para.h
@@ -28,6 +28,7 @@ 
 #define KVM_FEATURE_PV_UNHALT		7
 #define KVM_FEATURE_PV_TLB_FLUSH	9
 #define KVM_FEATURE_ASYNC_PF_VMEXIT	10
+#define KVM_FEATURE_PV_SEND_IPI	11
 
 #define KVM_HINTS_REALTIME      0
 
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 5b2300b..b4f8dc3 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -454,6 +454,57 @@  static void __init sev_map_percpu_data(void)
 }
 
 #ifdef CONFIG_SMP
+
+static void __send_ipi_mask(const struct cpumask *mask, int vector)
+{
+	unsigned long flags, ipi_bitmap = 0;
+	int cpu;
+
+	local_irq_save(flags);
+
+	for_each_cpu(cpu, mask)
+		__set_bit(per_cpu(x86_cpu_to_apicid, cpu), &ipi_bitmap);
+	kvm_hypercall2(KVM_HC_SEND_IPI, ipi_bitmap, vector);
+
+	local_irq_restore(flags);
+}
+
+static void kvm_send_ipi_mask(const struct cpumask *mask, int vector)
+{
+	__send_ipi_mask(mask, vector);
+}
+
+static void kvm_send_ipi_mask_allbutself(const struct cpumask *mask, int vector)
+{
+	unsigned int this_cpu = smp_processor_id();
+	struct cpumask new_mask;
+	const struct cpumask *local_mask;
+
+	cpumask_copy(&new_mask, mask);
+	cpumask_clear_cpu(this_cpu, &new_mask);
+	local_mask = &new_mask;
+	__send_ipi_mask(local_mask, vector);
+}
+
+static void kvm_send_ipi_allbutself(int vector)
+{
+	kvm_send_ipi_mask_allbutself(cpu_online_mask, vector);
+}
+
+static void kvm_send_ipi_all(int vector)
+{
+	__send_ipi_mask(cpu_online_mask, vector);
+}
+
+static void kvm_setup_pv_ipi(void)
+{
+	apic->send_IPI_mask = kvm_send_ipi_mask;
+	apic->send_IPI_mask_allbutself = kvm_send_ipi_mask_allbutself;
+	apic->send_IPI_allbutself = kvm_send_ipi_allbutself;
+	apic->send_IPI_all = kvm_send_ipi_all;
+	printk("KVM setup pv IPIs\n");
+}
+
 static void __init kvm_smp_prepare_cpus(unsigned int max_cpus)
 {
 	native_smp_prepare_cpus(max_cpus);
@@ -624,12 +675,24 @@  static uint32_t __init kvm_detect(void)
 	return kvm_cpuid_base();
 }
 
+static void __init kvm_apic_init(void)
+{
+	if (kvm_para_has_feature(KVM_FEATURE_PV_SEND_IPI))
+		kvm_setup_pv_ipi();
+}
+
+static void __init kvm_init_platform(void)
+{
+	x86_platform.apic_post_init = kvm_apic_init;
+}
+
 const __initconst struct hypervisor_x86 x86_hyper_kvm = {
 	.name			= "KVM",
 	.detect			= kvm_detect,
 	.type			= X86_HYPER_KVM,
 	.init.guest_late_init	= kvm_guest_init,
 	.init.x2apic_available	= kvm_para_available,
+	.init.init_platform 	= kvm_init_platform,
 };
 
 static __init int activate_jump_labels(void)