diff mbox series

[v4,30/32] KVM: PPC: Book3S HV: Allow HV module to load without hypervisor mode

Message ID 1538654169-15602-31-git-send-email-paulus@ozlabs.org (mailing list archive)
State New, archived
Headers show
Series KVM: PPC: Book3S HV: Nested HV virtualization | expand

Commit Message

Paul Mackerras Oct. 4, 2018, 11:56 a.m. UTC
With this, the KVM-HV module can be loaded in a guest running under
KVM-HV, and if the hypervisor supports nested virtualization, this
guest can now act as a nested hypervisor and run nested guests.

This also adds some checks to inform userspace that HPT guests are not
supported by nested hypervisors, and to prevent userspace from
configuring a guest to use HPT mode.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
---
 arch/powerpc/kvm/book3s_hv.c | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

Comments

David Gibson Oct. 5, 2018, 3:05 a.m. UTC | #1
On Thu, Oct 04, 2018 at 09:56:07PM +1000, Paul Mackerras wrote:
> With this, the KVM-HV module can be loaded in a guest running under
> KVM-HV, and if the hypervisor supports nested virtualization, this
> guest can now act as a nested hypervisor and run nested guests.
> 
> This also adds some checks to inform userspace that HPT guests are not
> supported by nested hypervisors, and to prevent userspace from
> configuring a guest to use HPT mode.
> 
> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

> ---
>  arch/powerpc/kvm/book3s_hv.c | 20 ++++++++++++++++----
>  1 file changed, 16 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
> index 7561c99..7f89b22 100644
> --- a/arch/powerpc/kvm/book3s_hv.c
> +++ b/arch/powerpc/kvm/book3s_hv.c
> @@ -4214,6 +4214,10 @@ static int kvm_vm_ioctl_get_smmu_info_hv(struct kvm *kvm,
>  {
>  	struct kvm_ppc_one_seg_page_size *sps;
>  
> +	/* If we're a nested hypervisor, we only support radix guests */
> +	if (kvmhv_on_pseries())
> +		return -EINVAL;
> +
>  	/*
>  	 * POWER7, POWER8 and POWER9 all support 32 storage keys for data.
>  	 * POWER7 doesn't support keys for instruction accesses,
> @@ -4799,11 +4803,15 @@ static int kvmppc_core_emulate_mfspr_hv(struct kvm_vcpu *vcpu, int sprn,
>  
>  static int kvmppc_core_check_processor_compat_hv(void)
>  {
> -	if (!cpu_has_feature(CPU_FTR_HVMODE) ||
> -	    !cpu_has_feature(CPU_FTR_ARCH_206))
> -		return -EIO;
> +	if (cpu_has_feature(CPU_FTR_HVMODE) &&
> +	    cpu_has_feature(CPU_FTR_ARCH_206))
> +		return 0;
>  
> -	return 0;
> +	/* POWER9 in radix mode is capable of being a nested hypervisor. */
> +	if (cpu_has_feature(CPU_FTR_ARCH_300) && radix_enabled())
> +		return 0;
> +
> +	return -EIO;
>  }
>  
>  #ifdef CONFIG_KVM_XICS
> @@ -5121,6 +5129,10 @@ static int kvmhv_configure_mmu(struct kvm *kvm, struct kvm_ppc_mmuv3_cfg *cfg)
>  	if (radix && !radix_enabled())
>  		return -EINVAL;
>  
> +	/* If we're a nested hypervisor, we currently only support radix */
> +	if (kvmhv_on_pseries() && !radix)
> +		return -EINVAL;
> +
>  	mutex_lock(&kvm->lock);
>  	if (radix != kvm_is_radix(kvm)) {
>  		if (kvm->arch.mmu_ready) {
diff mbox series

Patch

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 7561c99..7f89b22 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -4214,6 +4214,10 @@  static int kvm_vm_ioctl_get_smmu_info_hv(struct kvm *kvm,
 {
 	struct kvm_ppc_one_seg_page_size *sps;
 
+	/* If we're a nested hypervisor, we only support radix guests */
+	if (kvmhv_on_pseries())
+		return -EINVAL;
+
 	/*
 	 * POWER7, POWER8 and POWER9 all support 32 storage keys for data.
 	 * POWER7 doesn't support keys for instruction accesses,
@@ -4799,11 +4803,15 @@  static int kvmppc_core_emulate_mfspr_hv(struct kvm_vcpu *vcpu, int sprn,
 
 static int kvmppc_core_check_processor_compat_hv(void)
 {
-	if (!cpu_has_feature(CPU_FTR_HVMODE) ||
-	    !cpu_has_feature(CPU_FTR_ARCH_206))
-		return -EIO;
+	if (cpu_has_feature(CPU_FTR_HVMODE) &&
+	    cpu_has_feature(CPU_FTR_ARCH_206))
+		return 0;
 
-	return 0;
+	/* POWER9 in radix mode is capable of being a nested hypervisor. */
+	if (cpu_has_feature(CPU_FTR_ARCH_300) && radix_enabled())
+		return 0;
+
+	return -EIO;
 }
 
 #ifdef CONFIG_KVM_XICS
@@ -5121,6 +5129,10 @@  static int kvmhv_configure_mmu(struct kvm *kvm, struct kvm_ppc_mmuv3_cfg *cfg)
 	if (radix && !radix_enabled())
 		return -EINVAL;
 
+	/* If we're a nested hypervisor, we currently only support radix */
+	if (kvmhv_on_pseries() && !radix)
+		return -EINVAL;
+
 	mutex_lock(&kvm->lock);
 	if (radix != kvm_is_radix(kvm)) {
 		if (kvm->arch.mmu_ready) {