Hi Vladimir,
I think commit title is too vague, can you be more specific?
On Tue, Aug 16, 2016 at 11:46:54AM +0100, Vladimir Murzin wrote:
> We have couple of 64-bit register defined in GICv3 architecture, so
'a couple', 'registers' (plural)
> "unsigned long" kind of accessors wouldn't work for 32-bit. However,
'wouldn't work for 32-bit' is kind of generic as well. Perhaps you mean
that unsigned long accesses to these registers will only access a single
32-bit work of that register.
> these registers can't be access as 64-bit in a one go if we run 32-bit
'accessed', 's/in one go/with a single instruction/' ?
'a 32-bit host'
> host simply because KVM doesn't support multiple load/store on MMIO
by 'multiple load/store' you mean the 'load/store multiple' instructions
specifically, right? Not a sequence of multiple loads and stores. I
think you should be more specific here as well, for example, I think
ldrd and strd are problematic as well.
> space.
>
> It means that 32-bit guest access these registers in 32-bit chunks, so
'a 32-bit guest', 'accesses'
> the only thing we need to do is to ensure that extract_bytes() always
> takes 64-bit data.
>
> Since we are here fix couple of other width related issues by using
> ULL variants over UL.
>
> Signed-off-by: Vladimir Murzin <vladimir.murzin@xxxxxxx>
> ---
> virt/kvm/arm/vgic/vgic-mmio-v3.c | 6 +++---
> virt/kvm/arm/vgic/vgic-mmio.h | 2 +-
> 2 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
> index ff668e0..cc20b60 100644
> --- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
> +++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
> @@ -23,7 +23,7 @@
> #include "vgic-mmio.h"
>
> /* extract @num bytes at @offset bytes offset in data */
> -unsigned long extract_bytes(unsigned long data, unsigned int offset,
> +unsigned long extract_bytes(u64 data, unsigned int offset,
> unsigned int num)
> {
> return (data >> (offset * 8)) & GENMASK_ULL(num * 8 - 1, 0);
> @@ -179,7 +179,7 @@ static unsigned long vgic_mmio_read_v3r_typer(struct kvm_vcpu *vcpu,
> int target_vcpu_id = vcpu->vcpu_id;
> u64 value;
>
> - value = (mpidr & GENMASK(23, 0)) << 32;
> + value = (mpidr & GENMASK_ULL(23, 0)) << 32;
why does this make a difference when mpidr is an unsigned long?
> value |= ((target_vcpu_id & 0xffff) << 8);
> if (target_vcpu_id == atomic_read(&vcpu->kvm->online_vcpus) - 1)
> value |= GICR_TYPER_LAST;
> @@ -603,7 +603,7 @@ void vgic_v3_dispatch_sgi(struct kvm_vcpu *vcpu, u64 reg)
> bool broadcast;
>
> sgi = (reg & ICC_SGI1R_SGI_ID_MASK) >> ICC_SGI1R_SGI_ID_SHIFT;
> - broadcast = reg & BIT(ICC_SGI1R_IRQ_ROUTING_MODE_BIT);
> + broadcast = reg & BIT_ULL(ICC_SGI1R_IRQ_ROUTING_MODE_BIT);
> target_cpus = (reg & ICC_SGI1R_TARGET_LIST_MASK) >> ICC_SGI1R_TARGET_LIST_SHIFT;
> mpidr = SGI_AFFINITY_LEVEL(reg, 3);
> mpidr |= SGI_AFFINITY_LEVEL(reg, 2);
> diff --git a/virt/kvm/arm/vgic/vgic-mmio.h b/virt/kvm/arm/vgic/vgic-mmio.h
> index 0b3ecf9..80f92ce 100644
> --- a/virt/kvm/arm/vgic/vgic-mmio.h
> +++ b/virt/kvm/arm/vgic/vgic-mmio.h
> @@ -96,7 +96,7 @@ unsigned long vgic_data_mmio_bus_to_host(const void *val, unsigned int len);
> void vgic_data_host_to_mmio_bus(void *buf, unsigned int len,
> unsigned long data);
>
> -unsigned long extract_bytes(unsigned long data, unsigned int offset,
> +unsigned long extract_bytes(u64 data, unsigned int offset,
> unsigned int num);
>
> u64 update_64bit_reg(u64 reg, unsigned int offset, unsigned int len,
> --
> 1.7.9.5
>
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