On Sat, Nov 10, 2012 at 03:44:51PM +0000, Christoffer Dall wrote:
> User space defines the model to emulate to a guest and should therefore
> decide which addresses are used for both the virtual CPU interface
> directly mapped in the guest physical address space and for the emulated
> distributor interface, which is mapped in software by the in-kernel VGIC
> support.
>
> Signed-off-by: Christoffer Dall <c.dall@xxxxxxxxxxxxxxxxxxxxxx>
> ---
> arch/arm/include/asm/kvm_mmu.h | 2 +
> arch/arm/include/asm/kvm_vgic.h | 9 ++++++
> arch/arm/kvm/arm.c | 16 ++++++++++
> arch/arm/kvm/vgic.c | 61 +++++++++++++++++++++++++++++++++++++++
> 4 files changed, 87 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
> index 9bd0508..0800531 100644
> --- a/arch/arm/include/asm/kvm_mmu.h
> +++ b/arch/arm/include/asm/kvm_mmu.h
> @@ -26,6 +26,8 @@
> * To save a bit of memory and to avoid alignment issues we assume 39-bit IPA
> * for now, but remember that the level-1 table must be aligned to its size.
> */
> +#define KVM_PHYS_SHIFT (38)
Seems a bit small...
> +#define KVM_PHYS_MASK ((1ULL << KVM_PHYS_SHIFT) - 1)
> #define PTRS_PER_PGD2 512
> #define PGD2_ORDER get_order(PTRS_PER_PGD2 * sizeof(pgd_t))
>
> diff --git a/arch/arm/include/asm/kvm_vgic.h b/arch/arm/include/asm/kvm_vgic.h
> index b444ecf..9ca8d21 100644
> --- a/arch/arm/include/asm/kvm_vgic.h
> +++ b/arch/arm/include/asm/kvm_vgic.h
> @@ -20,6 +20,9 @@
> #define __ASM_ARM_KVM_VGIC_H
>
> struct vgic_dist {
> + /* Distributor and vcpu interface mapping in the guest */
> + phys_addr_t vgic_dist_base;
> + phys_addr_t vgic_cpu_base;
> };
>
> struct vgic_cpu {
> @@ -31,6 +34,7 @@ struct kvm_run;
> struct kvm_exit_mmio;
>
> #ifdef CONFIG_KVM_ARM_VGIC
> +int kvm_vgic_set_addr(struct kvm *kvm, unsigned long type, u64 addr);
> bool vgic_handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run,
> struct kvm_exit_mmio *mmio);
>
> @@ -40,6 +44,11 @@ static inline int kvm_vgic_hyp_init(void)
> return 0;
> }
>
> +static inline int kvm_vgic_set_addr(struct kvm *kvm, unsigned long type, u64 addr)
> +{
> + return 0;
> +}
> +
> static inline int kvm_vgic_init(struct kvm *kvm)
> {
> return 0;
> diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
> index 426828a..3ac1aab 100644
> --- a/arch/arm/kvm/arm.c
> +++ b/arch/arm/kvm/arm.c
> @@ -61,6 +61,8 @@ static atomic64_t kvm_vmid_gen = ATOMIC64_INIT(1);
> static u8 kvm_next_vmid;
> static DEFINE_SPINLOCK(kvm_vmid_lock);
>
> +static bool vgic_present;
> +
> static void kvm_arm_set_running_vcpu(struct kvm_vcpu *vcpu)
> {
> BUG_ON(preemptible());
> @@ -825,7 +827,19 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
> static int kvm_vm_ioctl_set_device_address(struct kvm *kvm,
> struct kvm_device_address *dev_addr)
> {
> - return -ENODEV;
> + unsigned long dev_id, type;
> +
> + dev_id = (dev_addr->id & KVM_DEVICE_ID_MASK) >> KVM_DEVICE_ID_SHIFT;
> + type = (dev_addr->id & KVM_DEVICE_TYPE_MASK) >> KVM_DEVICE_TYPE_SHIFT;
> +
> + switch (dev_id) {
> + case KVM_ARM_DEVICE_VGIC_V2:
> + if (!vgic_present)
> + return -ENXIO;
> + return kvm_vgic_set_addr(kvm, type, dev_addr->addr);
> + default:
> + return -ENODEV;
> + }
> }
>
> long kvm_arch_vm_ioctl(struct file *filp,
> diff --git a/arch/arm/kvm/vgic.c b/arch/arm/kvm/vgic.c
> index 26ada3b..f85b275 100644
> --- a/arch/arm/kvm/vgic.c
> +++ b/arch/arm/kvm/vgic.c
> @@ -22,6 +22,13 @@
> #include <linux/io.h>
> #include <asm/kvm_emulate.h>
>
> +#define VGIC_ADDR_UNDEF (-1)
> +#define IS_VGIC_ADDR_UNDEF(_x) ((_x) == (typeof(_x))VGIC_ADDR_UNDEF)
> +
> +#define VGIC_DIST_SIZE 0x1000
> +#define VGIC_CPU_SIZE 0x2000
These defines might be useful to userspace so that they don't request the
distributor and the cpu interface to be place too close together (been there,
done that :).
> +
> +
> #define ACCESS_READ_VALUE (1 << 0)
> #define ACCESS_READ_RAZ (0 << 0)
> #define ACCESS_READ_MASK(x) ((x) & (1 << 0))
> @@ -136,3 +143,57 @@ bool vgic_handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run, struct kvm_exi
> {
> return KVM_EXIT_MMIO;
> }
> +
> +static bool vgic_ioaddr_overlap(struct kvm *kvm)
> +{
> + phys_addr_t dist = kvm->arch.vgic.vgic_dist_base;
> + phys_addr_t cpu = kvm->arch.vgic.vgic_cpu_base;
> +
> + if (IS_VGIC_ADDR_UNDEF(dist) || IS_VGIC_ADDR_UNDEF(cpu))
> + return false;
> + if ((dist <= cpu && dist + VGIC_DIST_SIZE > cpu) ||
> + (cpu <= dist && cpu + VGIC_CPU_SIZE > dist))
> + return true;
> + return false;
Just return the predicate that you're testing.
> +}
> +
> +int kvm_vgic_set_addr(struct kvm *kvm, unsigned long type, u64 addr)
> +{
> + int r = 0;
> + struct vgic_dist *vgic = &kvm->arch.vgic;
> +
> + if (addr & ~KVM_PHYS_MASK)
> + return -E2BIG;
> +
> + if (addr & ~PAGE_MASK)
> + return -EINVAL;
> +
> + mutex_lock(&kvm->lock);
> + switch (type) {
> + case KVM_VGIC_V2_ADDR_TYPE_DIST:
> + if (!IS_VGIC_ADDR_UNDEF(vgic->vgic_dist_base))
> + return -EEXIST;
> + if (addr + VGIC_DIST_SIZE < addr)
> + return -EINVAL;
I think somebody else pointed out the missing mutex_unlocks on the failure
paths.
> + kvm->arch.vgic.vgic_dist_base = addr;
> + break;
> + case KVM_VGIC_V2_ADDR_TYPE_CPU:
> + if (!IS_VGIC_ADDR_UNDEF(vgic->vgic_cpu_base))
> + return -EEXIST;
> + if (addr + VGIC_CPU_SIZE < addr)
> + return -EINVAL;
> + kvm->arch.vgic.vgic_cpu_base = addr;
> + break;
> + default:
> + r = -ENODEV;
> + }
> +
> + if (vgic_ioaddr_overlap(kvm)) {
> + kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF;
> + kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF;
> + return -EINVAL;
Perhaps we could put all the address checking in one place, so that the wrapping
round zero checks and the overlap checks can be in the same function?
> + }
> +
> + mutex_unlock(&kvm->lock);
> + return r;
> +}
Will
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
