Patchwork [v10,3/5] KVM: PPC: Add support for ePAPR idle hcall in host kernel

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Submitter Stuart Yoder
Date March 15, 2012, 8:52 p.m.
Message ID <1331844737-30869-4-git-send-email-stuart.yoder@freescale.com>
Download mbox | patch
Permalink /patch/147072/
State New
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Comments

Stuart Yoder - March 15, 2012, 8:52 p.m.
From: Liu Yu-B13201 <Yu.Liu@freescale.com>

And add a new flag definition in kvm_ppc_pvinfo to indicate
whether the host supports the EV_IDLE hcall.

Signed-off-by: Liu Yu <yu.liu@freescale.com>
[stuart.yoder@freescale.com: cleanup,fixes for conditions allowing idle]
Signed-off-by: Stuart Yoder <stuart.yoder@freescale.com>
---
-v10:
   -ePAPR definitions now addressed in separate patch
   -move clearing of KVM_REQ_UNHALT after kvm_vcpu_block() call 

 arch/powerpc/include/asm/Kbuild |    1 +
 arch/powerpc/kvm/powerpc.c      |   20 +++++++++++++++++---
 include/linux/kvm.h             |    2 ++
 3 files changed, 20 insertions(+), 3 deletions(-)
Alexander Graf - May 8, 2012, 10:40 a.m.
On 15.03.2012, at 21:52, Stuart Yoder wrote:

> From: Liu Yu-B13201 <Yu.Liu@freescale.com>
> 
> And add a new flag definition in kvm_ppc_pvinfo to indicate
> whether the host supports the EV_IDLE hcall.
> 
> Signed-off-by: Liu Yu <yu.liu@freescale.com>
> [stuart.yoder@freescale.com: cleanup,fixes for conditions allowing idle]
> Signed-off-by: Stuart Yoder <stuart.yoder@freescale.com>
> ---
> -v10:
>   -ePAPR definitions now addressed in separate patch
>   -move clearing of KVM_REQ_UNHALT after kvm_vcpu_block() call 
> 
> arch/powerpc/include/asm/Kbuild |    1 +
> arch/powerpc/kvm/powerpc.c      |   20 +++++++++++++++++---
> include/linux/kvm.h             |    2 ++
> 3 files changed, 20 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/Kbuild b/arch/powerpc/include/asm/Kbuild
> index 7e313f1..13d6b7b 100644
> --- a/arch/powerpc/include/asm/Kbuild
> +++ b/arch/powerpc/include/asm/Kbuild
> @@ -34,5 +34,6 @@ header-y += termios.h
> header-y += types.h
> header-y += ucontext.h
> header-y += unistd.h
> +header-y += epapr_hcalls.h
> 
> generic-y += rwsem.h
> diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
> index d738626..7c4e5cc 100644
> --- a/arch/powerpc/kvm/powerpc.c
> +++ b/arch/powerpc/kvm/powerpc.c
> @@ -38,8 +38,7 @@
> 
> int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
> {
> -	return !(v->arch.shared->msr & MSR_WE) ||
> -	       !!(v->arch.pending_exceptions) ||
> +	return !!(v->arch.pending_exceptions) ||

Are you sure this doesn't break book3s or e500v2?

> 	       v->requests;
> }
> 
> @@ -86,6 +85,11 @@ int kvmppc_kvm_pv(struct kvm_vcpu *vcpu)
> 
> 		/* Second return value is in r4 */
> 		break;
> +	case _EV_HCALL_TOKEN(EV_EPAPR_VENDOR_ID, EV_IDLE):
> +		r = 0;  /* success */
> +		kvm_vcpu_block(vcpu);
> +		clear_bit(KVM_REQ_UNHALT, &vcpu->requests);
> +		break;
> 	default:
> 		r = EV_UNIMPLEMENTED;
> 		break;
> @@ -732,9 +736,16 @@ int kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf)
> 
> static int kvm_vm_ioctl_get_pvinfo(struct kvm_ppc_pvinfo *pvinfo)
> {
> +	u32 inst_nop = 0x60000000;
> +#ifdef CONFIG_KVM_BOOKE_HV
> +	u32 inst_sc1 = 0x44000022;
> +	pvinfo->hcall[0] = inst_sc1;
> +	pvinfo->hcall[1] = inst_nop;
> +	pvinfo->hcall[2] = inst_nop;
> +	pvinfo->hcall[3] = inst_nop;
> +#else

This hunk is unrelated to the rest of the patch. Please factor it out into its own patch :).

> 	u32 inst_lis = 0x3c000000;
> 	u32 inst_ori = 0x60000000;
> -	u32 inst_nop = 0x60000000;
> 	u32 inst_sc = 0x44000002;
> 	u32 inst_imm_mask = 0xffff;
> 
> @@ -751,6 +762,9 @@ static int kvm_vm_ioctl_get_pvinfo(struct kvm_ppc_pvinfo *pvinfo)
> 	pvinfo->hcall[1] = inst_ori | (KVM_SC_MAGIC_R0 & inst_imm_mask);
> 	pvinfo->hcall[2] = inst_sc;
> 	pvinfo->hcall[3] = inst_nop;
> +#endif
> +
> +	pvinfo->flags = KVM_PPC_PVINFO_FLAGS_EV_IDLE;
> 
> 	return 0;
> }
> diff --git a/include/linux/kvm.h b/include/linux/kvm.h
> index 7a9dd4b..640ec5a 100644
> --- a/include/linux/kvm.h
> +++ b/include/linux/kvm.h
> @@ -449,6 +449,8 @@ struct kvm_ppc_pvinfo {
> 	__u8  pad[108];
> };
> 
> +#define KVM_PPC_PVINFO_FLAGS_EV_IDLE   (1<<0)

This needs an update to the documentation in Documentation/virtual/kvm/api.txt. Please also update Documentation/virtual/kvm/ppc-pv.txt with the new hypercall.


Alex

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Scott Wood - May 16, 2012, 10:46 p.m.
On 05/08/2012 05:40 AM, Alexander Graf wrote:
> 
> On 15.03.2012, at 21:52, Stuart Yoder wrote:
> 
>> From: Liu Yu-B13201 <Yu.Liu@freescale.com>
>>
>> And add a new flag definition in kvm_ppc_pvinfo to indicate
>> whether the host supports the EV_IDLE hcall.
>>
>> Signed-off-by: Liu Yu <yu.liu@freescale.com>
>> [stuart.yoder@freescale.com: cleanup,fixes for conditions allowing idle]
>> Signed-off-by: Stuart Yoder <stuart.yoder@freescale.com>
>> ---
>> -v10:
>>   -ePAPR definitions now addressed in separate patch
>>   -move clearing of KVM_REQ_UNHALT after kvm_vcpu_block() call 
>>
>> arch/powerpc/include/asm/Kbuild |    1 +
>> arch/powerpc/kvm/powerpc.c      |   20 +++++++++++++++++---
>> include/linux/kvm.h             |    2 ++
>> 3 files changed, 20 insertions(+), 3 deletions(-)
>>
>> diff --git a/arch/powerpc/include/asm/Kbuild b/arch/powerpc/include/asm/Kbuild
>> index 7e313f1..13d6b7b 100644
>> --- a/arch/powerpc/include/asm/Kbuild
>> +++ b/arch/powerpc/include/asm/Kbuild
>> @@ -34,5 +34,6 @@ header-y += termios.h
>> header-y += types.h
>> header-y += ucontext.h
>> header-y += unistd.h
>> +header-y += epapr_hcalls.h
>>
>> generic-y += rwsem.h
>> diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
>> index d738626..7c4e5cc 100644
>> --- a/arch/powerpc/kvm/powerpc.c
>> +++ b/arch/powerpc/kvm/powerpc.c
>> @@ -38,8 +38,7 @@
>>
>> int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
>> {
>> -	return !(v->arch.shared->msr & MSR_WE) ||
>> -	       !!(v->arch.pending_exceptions) ||
>> +	return !!(v->arch.pending_exceptions) ||
> 
> Are you sure this doesn't break book3s or e500v2?

It's only used inside kvm_vcpu_block().  We only call kvm_vcpu_block()
if there's a request to go idle (MSR[WE], hcall, etc), and MSR[WE] can't
be cleared except via exception or userspace.  Exceptions are already
checked for in runnable(), and an exit to userspace would exit
kvm_vcpu_block().

-Scott

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Patch

diff --git a/arch/powerpc/include/asm/Kbuild b/arch/powerpc/include/asm/Kbuild
index 7e313f1..13d6b7b 100644
--- a/arch/powerpc/include/asm/Kbuild
+++ b/arch/powerpc/include/asm/Kbuild
@@ -34,5 +34,6 @@  header-y += termios.h
 header-y += types.h
 header-y += ucontext.h
 header-y += unistd.h
+header-y += epapr_hcalls.h
 
 generic-y += rwsem.h
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index d738626..7c4e5cc 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -38,8 +38,7 @@ 
 
 int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
 {
-	return !(v->arch.shared->msr & MSR_WE) ||
-	       !!(v->arch.pending_exceptions) ||
+	return !!(v->arch.pending_exceptions) ||
 	       v->requests;
 }
 
@@ -86,6 +85,11 @@  int kvmppc_kvm_pv(struct kvm_vcpu *vcpu)
 
 		/* Second return value is in r4 */
 		break;
+	case _EV_HCALL_TOKEN(EV_EPAPR_VENDOR_ID, EV_IDLE):
+		r = 0;  /* success */
+		kvm_vcpu_block(vcpu);
+		clear_bit(KVM_REQ_UNHALT, &vcpu->requests);
+		break;
 	default:
 		r = EV_UNIMPLEMENTED;
 		break;
@@ -732,9 +736,16 @@  int kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf)
 
 static int kvm_vm_ioctl_get_pvinfo(struct kvm_ppc_pvinfo *pvinfo)
 {
+	u32 inst_nop = 0x60000000;
+#ifdef CONFIG_KVM_BOOKE_HV
+	u32 inst_sc1 = 0x44000022;
+	pvinfo->hcall[0] = inst_sc1;
+	pvinfo->hcall[1] = inst_nop;
+	pvinfo->hcall[2] = inst_nop;
+	pvinfo->hcall[3] = inst_nop;
+#else
 	u32 inst_lis = 0x3c000000;
 	u32 inst_ori = 0x60000000;
-	u32 inst_nop = 0x60000000;
 	u32 inst_sc = 0x44000002;
 	u32 inst_imm_mask = 0xffff;
 
@@ -751,6 +762,9 @@  static int kvm_vm_ioctl_get_pvinfo(struct kvm_ppc_pvinfo *pvinfo)
 	pvinfo->hcall[1] = inst_ori | (KVM_SC_MAGIC_R0 & inst_imm_mask);
 	pvinfo->hcall[2] = inst_sc;
 	pvinfo->hcall[3] = inst_nop;
+#endif
+
+	pvinfo->flags = KVM_PPC_PVINFO_FLAGS_EV_IDLE;
 
 	return 0;
 }
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 7a9dd4b..640ec5a 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -449,6 +449,8 @@  struct kvm_ppc_pvinfo {
 	__u8  pad[108];
 };
 
+#define KVM_PPC_PVINFO_FLAGS_EV_IDLE   (1<<0)
+
 #define KVMIO 0xAE
 
 /* machine type bits, to be used as argument to KVM_CREATE_VM */