Messages in this thread | | | Subject | Re: [kvmtool PATCH 21/17] kvmtool: arm: Add support for creating VM with PA size | From | Julien Grall <> | Date | Thu, 26 Apr 2018 15:08:55 +0100 |
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Hi Suzuki,
On 27/03/18 14:15, Suzuki K Poulose wrote: > Specify the physical size for the VM encoded in the vm type. > > Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> > --- > arm/include/arm-common/kvm-arch.h | 6 +++++- > arm/kvm.c | 21 +++++++++++++++++++++ > 2 files changed, 26 insertions(+), 1 deletion(-) > > diff --git a/arm/include/arm-common/kvm-arch.h b/arm/include/arm-common/kvm-arch.h > index ca7ab0f..64bc92a 100644 > --- a/arm/include/arm-common/kvm-arch.h > +++ b/arm/include/arm-common/kvm-arch.h > @@ -42,7 +42,11 @@ > > #define KVM_IRQ_OFFSET GIC_SPI_IRQ_BASE > > -#define KVM_VM_TYPE 0 > +extern unsigned long kvm_arm_type; > +extern void kvm__arch_init_hyp(struct kvm *kvm); > + > +#define KVM_VM_TYPE kvm_arm_type > +#define kvm__arch_init_hyp kvm__arch_init_hyp > > #define VIRTIO_DEFAULT_TRANS(kvm) \ > ((kvm)->cfg.arch.virtio_trans_pci ? VIRTIO_PCI : VIRTIO_MMIO) > diff --git a/arm/kvm.c b/arm/kvm.c > index 5701d41..a9a9140 100644 > --- a/arm/kvm.c > +++ b/arm/kvm.c > @@ -11,6 +11,8 @@ > #include <linux/kvm.h> > #include <linux/sizes.h> > > +unsigned long kvm_arm_type; > + > struct kvm_ext kvm_req_ext[] = { > { DEFINE_KVM_EXT(KVM_CAP_IRQCHIP) }, > { DEFINE_KVM_EXT(KVM_CAP_ONE_REG) }, > @@ -18,6 +20,25 @@ struct kvm_ext kvm_req_ext[] = { > { 0, 0 }, > }; > > +#ifndef KVM_ARM_GET_MAX_VM_PHYS_SHIFT > +#define KVM_ARM_GET_MAX_VM_PHYS_SHIFT _IO(KVMIO, 0x0a) > +#endif
Once the IOCTL is agreed, I think you would need to update include/linux/kvm.h.
> + > +void kvm__arch_init_hyp(struct kvm *kvm) > +{ > + unsigned max_ipa; > + > + max_ipa = ioctl(kvm->sys_fd, KVM_ARM_GET_MAX_VM_PHYS_SHIFT); > + if (max_ipa < 0) > + max_ipa = 40; > + if (!kvm->cfg.arch.phys_shift) > + kvm->cfg.arch.phys_shift = 40; > + if (kvm->cfg.arch.phys_shift > max_ipa) > + die("Requested PA size (%u) is not supported by the host (%ubits)\n", > + kvm->cfg.arch.phys_shift, max_ipa); > + kvm_arm_type = kvm->cfg.arch.phys_shift;
FWIW, older Linux will not accept a KVM type other than 0. So I think the best would be to bail out if KVM_ARM_GET_MAX_VM_PHYS_SHIFT does not exist.
For safety, you could even check that arch.phys_shift is always 40 when running under older Linux.
Cheers,
-- Julien Grall
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