On Fri, Jan 23, 2015 at 04:35:02PM +0000, Andre Przywara wrote:
> From: Marc Zyngier <[email protected]>
>
> As of 3.14, KVM/arm supports the creation/configuration of the GIC through
> a more generic device API, which is now the preferred way to do so.
>
> Plumb the new API in, and allow the old code to be used as a fallback.
>
> [Andre: Rename some functions on the way to differentiate between
> creation and initialisation more clearly.]
>
> Signed-off-by: Marc Zyngier <[email protected]>
> Signed-off-by: Andre Przywara <[email protected]>
> ---
> tools/kvm/arm/gic.c | 60
> ++++++++++++++++++++++++++++----
> tools/kvm/arm/include/arm-common/gic.h | 2 +-
> tools/kvm/arm/kvm.c | 6 ++--
> 3 files changed, 57 insertions(+), 11 deletions(-)
>
> diff --git a/tools/kvm/arm/gic.c b/tools/kvm/arm/gic.c
> index 5d8cbe6..ce5f7fa 100644
> --- a/tools/kvm/arm/gic.c
> +++ b/tools/kvm/arm/gic.c
> @@ -7,7 +7,41 @@
> #include <linux/byteorder.h>
> #include <linux/kvm.h>
>
> -int gic__init_irqchip(struct kvm *kvm)
> +static int gic_fd = -1;
> +
> +static int gic__create_device(struct kvm *kvm)
> +{
> + int err;
> + u64 cpu_if_addr = ARM_GIC_CPUI_BASE;
> + u64 dist_addr = ARM_GIC_DIST_BASE;
> + struct kvm_create_device gic_device = {
> + .type = KVM_DEV_TYPE_ARM_VGIC_V2,
> + };
> + struct kvm_device_attr cpu_if_attr = {
> + .group = KVM_DEV_ARM_VGIC_GRP_ADDR,
> + .attr = KVM_VGIC_V2_ADDR_TYPE_CPU,
> + .addr = (u64)(unsigned long)&cpu_if_addr,
> + };
> + struct kvm_device_attr dist_attr = {
> + .group = KVM_DEV_ARM_VGIC_GRP_ADDR,
> + .attr = KVM_VGIC_V2_ADDR_TYPE_DIST,
> + .addr = (u64)(unsigned long)&dist_addr,
> + };
> +
> + err = ioctl(kvm->vm_fd, KVM_CREATE_DEVICE, &gic_device);
> + if (err)
> + return err;
> +
> + gic_fd = gic_device.fd;
> +
> + err = ioctl(gic_fd, KVM_SET_DEVICE_ATTR, &cpu_if_attr);
> + if (err)
> + return err;
> +
> + return ioctl(gic_fd, KVM_SET_DEVICE_ATTR, &dist_attr);
> +}
> +
> +static int gic__create_irqchip(struct kvm *kvm)
> {
> int err;
> struct kvm_arm_device_addr gic_addr[] = {
> @@ -23,12 +57,6 @@ int gic__init_irqchip(struct kvm *kvm)
> }
> };
>
> - if (kvm->nrcpus > GIC_MAX_CPUS) {
> - pr_warning("%d CPUS greater than maximum of %d -- truncating\n",
> - kvm->nrcpus, GIC_MAX_CPUS);
> - kvm->nrcpus = GIC_MAX_CPUS;
> - }
> -
> err = ioctl(kvm->vm_fd, KVM_CREATE_IRQCHIP);
> if (err)
> return err;
> @@ -41,6 +69,24 @@ int gic__init_irqchip(struct kvm *kvm)
> return err;
> }
>
> +int gic__create(struct kvm *kvm)
> +{
> + int err;
> +
> + if (kvm->nrcpus > GIC_MAX_CPUS) {
> + pr_warning("%d CPUS greater than maximum of %d -- truncating\n",
> + kvm->nrcpus, GIC_MAX_CPUS);
> + kvm->nrcpus = GIC_MAX_CPUS;
> + }
> +
> + /* Try the new way first, and fallback on legacy method otherwise */
> + err = gic__create_device(kvm);
> + if (err)
> + err = gic__create_irqchip(kvm);
This fallback doesn't look safe to me:
- gic_fd might remain initialised
- What does the kernel vgic driver do if you've already done
a successful KVM_CREATE_DEVICE and then try to use the legacy method?
Will
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