On 13/09/16 10:04, Vladimir Murzin wrote: > On 13/09/16 09:38, Christoffer Dall wrote: >> On Mon, Sep 12, 2016 at 03:49:21PM +0100, Vladimir Murzin wrote: >>> vgic-v3 driver uses architecture specific MPIDR_LEVEL_SHIFT macro to >>> encode the affinity in a form compatible with ICC_SGI* registers. >>> Unfortunately, that macro is missing on ARM, so let's add it. >>> >>> Cc: Russell King <rmk+kernel@xxxxxxxxxxxxxxx> >>> Signed-off-by: Vladimir Murzin <vladimir.murzin@xxxxxxx> >>> --- >>> arch/arm/include/asm/cputype.h | 1 + >>> 1 file changed, 1 insertion(+) >>> >>> diff --git a/arch/arm/include/asm/cputype.h b/arch/arm/include/asm/cputype.h >>> index 1ee94c7..e2d94c1 100644 >>> --- a/arch/arm/include/asm/cputype.h >>> +++ b/arch/arm/include/asm/cputype.h >>> @@ -55,6 +55,7 @@ >>> >>> #define MPIDR_LEVEL_BITS 8 >>> #define MPIDR_LEVEL_MASK ((1 << MPIDR_LEVEL_BITS) - 1) >>> +#define MPIDR_LEVEL_SHIFT(level) (MPIDR_LEVEL_BITS * level) >>> >> >> I'm not sure I follow the correctness of this completely. >> >> This is called from vgic_v3_dispatch_sgi, which takes a u64 value, which >> may have something in the Aff3 field, which we now shift left 24 bits, >> but that is not the Aff3 field of AArch32's MPIDR. >> >> What is the rationale for this making sense again? > > IIUC, in such case we construct mpidr which won't match in match_mpidr() > with the value we get from kvm_vcpu_get_mpidr_aff() and no SGI will be > sent to the guest. > > Since we get that u64 value from the guest, I'd think it is something > wrong is going on in the guest in case Aff3 is non-zero; however, we can > hide it by zeroing out SGI Aff3 bits in access_gic_sgi(). I don't think zeroing Aff3 is the right move, as the spec doesn't say that Aff3 should be ignored in a write to ICC_SGI1R. On the other hand, the spec says (in the context of the target list): "If a bit is 1 and the bit does not correspond to a valid target PE, the bit must be ignored by the Distributor". This makes me think that, unless ICC_SGI1R.IMR is set, we should simply ignore that SGI because there is no way we can actually deliver it. Could you cook a small patch that would go on top of this series? Thanks, M. -- Jazz is not dead. It just smells funny... _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
