On Tue, Feb 11, 2014 at 09:41:32PM -0800, Victor Kamensky wrote:
> According to recent clarifications of mmio.data array meaning -
> the mmio.data array should hold bytes as they would appear in
> memory. Vgic is little endian device. And in case of BE image
> kernel side that emulates vgic, holds data in BE form. So we
> need to byteswap cpu<->le32 vgic registers when we read/write them
> from mmio.data[].
>
> Change has no effect in LE case because cpu already runs in le32.
>
> Signed-off-by: Victor Kamensky <victor.kamensky@xxxxxxxxxx>
> ---
> virt/kvm/arm/vgic.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
> index 685fc72..7e11458 100644
> --- a/virt/kvm/arm/vgic.c
> +++ b/virt/kvm/arm/vgic.c
> @@ -236,12 +236,12 @@ static void vgic_cpu_irq_clear(struct kvm_vcpu *vcpu, int irq)
>
> static u32 mmio_data_read(struct kvm_exit_mmio *mmio, u32 mask)
> {
> - return *((u32 *)mmio->data) & mask;
> + return le32_to_cpu(*((u32 *)mmio->data)) & mask;
> }
>
> static void mmio_data_write(struct kvm_exit_mmio *mmio, u32 mask, u32 value)
> {
> - *((u32 *)mmio->data) = value & mask;
> + *((u32 *)mmio->data) = cpu_to_le32(value) & mask;
> }
>
> /**
> --
> 1.8.1.4
>
I hate the fact that we have endianness handling code inside the vgic
emulation, I would strongly prefer that the interface to the vgic code
is a typed union, but, that being said, I haven't looked at how the
changes to the code would look to accomplish that. You didn't reply to
my same comment last time around, but did you ahve a look?
The code here, with the ABI specification does look correct, so assuming
that ABI specification gets merged:
Reviewed-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
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