On Fri, Sep 16, 2016 at 10:37 PM, Marc Zyngier <marc.zyngier@xxxxxxx> wrote: > On 16/09/16 17:57, Vijay Kilari wrote: >> On Fri, Sep 16, 2016 at 8:06 PM, Marc Zyngier <marc.zyngier@xxxxxxx> wrote: >>> On 16/09/16 13:20, vijay.kilari@xxxxxxxxx wrote: >>>> From: Vijaya Kumar K <Vijaya.Kumar@xxxxxxxxxx> >>>> >>>> VGICv3 CPU interface registers are accessed using >>>> KVM_DEV_ARM_VGIC_CPU_SYSREGS ioctl. These registers are accessed >>>> as 64-bit. The cpu MPIDR value is passed along with register id. >>>> is used to identify the cpu for registers access. >>>> >>>> The version of VGIC v3 specification is define here >>>> http://lists.infradead.org/pipermail/linux-arm-kernel/2016-July/445611.html >>>> >>>> Signed-off-by: Pavel Fedin <p.fedin@xxxxxxxxxxx> >>>> Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@xxxxxxxxxx> >>>> --- >>>> arch/arm64/include/uapi/asm/kvm.h | 3 + >>>> arch/arm64/kvm/Makefile | 1 + >>>> include/linux/irqchip/arm-gic-v3.h | 30 ++++ >>>> virt/kvm/arm/vgic/vgic-kvm-device.c | 27 ++++ >>>> virt/kvm/arm/vgic/vgic-mmio-v3.c | 18 +++ >>>> virt/kvm/arm/vgic/vgic-sys-reg-v3.c | 296 ++++++++++++++++++++++++++++++++++++ >>>> virt/kvm/arm/vgic/vgic.h | 10 ++ >>>> 7 files changed, 385 insertions(+) > > [...] > >>>> diff --git a/virt/kvm/arm/vgic/vgic-sys-reg-v3.c b/virt/kvm/arm/vgic/vgic-sys-reg-v3.c >>>> new file mode 100644 >>>> index 0000000..8e4f403 >>>> --- /dev/null >>>> +++ b/virt/kvm/arm/vgic/vgic-sys-reg-v3.c >>>> @@ -0,0 +1,296 @@ >>>> +#include <linux/irqchip/arm-gic-v3.h> >>>> +#include <linux/kvm.h> >>>> +#include <linux/kvm_host.h> >>>> +#include <kvm/iodev.h> >>>> +#include <kvm/arm_vgic.h> >>>> +#include <asm/kvm_emulate.h> >>>> +#include <asm/kvm_arm.h> >>>> +#include <asm/kvm_mmu.h> >>>> + >>>> +#include "vgic.h" >>>> +#include "vgic-mmio.h" >>>> +#include "sys_regs.h" >>>> + >>>> +static bool access_gic_ctlr(struct kvm_vcpu *vcpu, struct sys_reg_params *p, >>>> + const struct sys_reg_desc *r) >>>> +{ >>>> + struct vgic_vmcr vmcr; >>>> + u64 val; >>>> + u32 ich_vtr; >>>> + >>>> + vgic_get_vmcr(vcpu, &vmcr); >>>> + if (p->is_write) { >>>> + val = p->regval; >>>> + vmcr.ctlr &= ~(ICH_VMCR_CBPR_MASK | ICH_VMCR_EOIM_MASK); >>>> + vmcr.ctlr |= ((val & ICC_CTLR_EL1_CBPR_MASK) >> >>>> + ICC_CTLR_EL1_CBPR_SHIFT) << ICH_VMCR_CBPR_SHIFT; >>>> + vmcr.ctlr |= ((val & ICC_CTLR_EL1_EOImode_MASK) >> >>>> + ICC_CTLR_EL1_EOImode_SHIFT) << ICH_VMCR_EOIM_SHIFT; >>>> + vgic_set_vmcr(vcpu, &vmcr); >>> >>> You've ignored my comments again: "What if userspace writes something >>> that is incompatible with the current configuration? Wrong number of ID >>> bits, or number of priorities?" >> >> IMO, In case of incompatibility, >> If ID bits and PRI bits are less than HW supported, it is ok. > > Yes. But you also need to track of what the guest has programmed in > order to be able to migrate it back to its original configuration. You mean the vgic has to track/store the ID and PRI bits that guest has programmed and return the same when guest reads back instead of returning HW supported value for ICC_CTLR_EL1 reg access?. > >> If ID bits and PRI bits are greater than HW supported, then warn would be good >> enough. Please suggest the behaviour that you think it should be. > > No, it is an error, plain and simple. You cannot run in this condition. > [...] > > Thanks, > > M. > -- > Jazz is not dead. It just smells funny... _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
